The fragrance facts, graded

Children and pregnancy / Measured in people or real products

Three in four children's cosmetics (295 of 398, 74.1%) on sale in a Brazilian city listed "parfum/fragrance" on the label, including 90% of children's shampoos and 79% of baby wet wipes.

Moderate evidence.

Source: Uber 2024, Jornal de Pediatria (Rio de Janeiro) Link to this fact

Children and pregnancy / Measured in people or real products

Childcare air had about three times more limonene than new California homes (33 vs 11 µg/m³), which the authors link to frequent cleaning.

Moderate evidence: Comparison with a different study (Offermann 2009); daytime vs 24-h sampling.

Source: Hoang 2016, Indoor Air Link to this fact

Children and pregnancy / Measured in people or real products

Pregnant women who used lotion had 111% higher butyl paraben, a preservative that weakly mimics estrogen.

Moderate evidence: Exposure marker only.

Source: Braun 2014, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Children and pregnancy / Measured in people or real products

In a US study, baby boys whose mothers had higher levels of several phthalates in their urine during pregnancy had a shorter distance between the anus and genitals, a sign of reduced male-hormone action during development in animal studies. A much larger (N=753), purpose-designed prospective follow-up by the same research group (TIDES, Swan 2015) confirmed this specifically for DEHP metabolites (a PVC plasticizer), with a significant, dose-responsive association at about half the original exposure level. It found no association for diethyl phthalate (DEP), the phthalate used in fragrance, nor for the other three phthalates (DBP, BBzP, DiBP) that had appeared linked in the original small study.

Moderate evidence.

Source: Swan 2005, Environmental Health Perspectives Link to this fact

Children and pregnancy / Review of other studies

Synthetic musks reach mothers and babies mainly through the skin (cosmetics and clothes washed in scented detergent), not through food.

Moderate evidence.

Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact

Children and pregnancy / Review of other studies

As of 2019, the evidence that lavender or tea tree oil causes breast growth in young children consisted only of case reports: 11 children described in detail in 4 papers, with no controlled study.

Moderate evidence: Systematic review of case reports; undercounts (one included paper reports ~20 more cases in clinic tallies).

Source: Hawkins 2020, Complementary Therapies in Medicine Industry-funded Link to this fact

Children and pregnancy / Animal study

In the only independent animal experiment on the question, female rats housed with a lavender-oil diffuser from weaning reached puberty about 4.6 days earlier than unexposed rats (33.8 vs 38.4 days), with luteinizing hormone about 35% higher and follicle-stimulating hormone about 45% higher and no difference in body weight.

Moderate evidence: Five rats per group, one species, one sex, a single dose that was never measured in the cage air; no human data. The paper's abstract mislabels which group was exposed how.

Source: Kim & Lim 2022, Journal of Korean Medical Science Link to this fact

Children and pregnancy / Animal study

The effect appeared through breathing the air rather than through skin contact, which matters because the main scientific defense of lavender products is that too little gets through the skin to do anything.

Moderate evidence: Rat study; the inhaled dose was not measured, and no one has measured what a real room diffuser puts into the air either.

Source: Kim & Lim 2022, Journal of Korean Medical Science Link to this fact

Children and pregnancy / Animal study

In the same industry study's one-generation rat screen, the highest linalool dose (800 mg/kg/day, high enough to make the mother rats visibly ill) produced more stillbirths, worse pup survival in the first four days and pups that stayed smaller throughout nursing; the authors call follow-up testing 'mandatory' before this can be dismissed.

Moderate evidence.

Source: Hareng 2024, Archives of Toxicology Industry-funded Link to this fact

Children and pregnancy / Measured in people or real products

In a Danish/multi-country test of 25 children's cosmetics and cosmetic-toys, all 7 hydro-alcoholic children's fragrance products (5 eau de toilette, 1 eau de parfum, 1 roll-on deodorant) contained the allergen geraniol, and a separate children's toy-cosmetic perfume-blending kit's lilac essence contained cinnamic alcohol at 3.7% — about 4.6x (the paper's abstract states "by a factor of 5") the IFRA guideline of 0.8%.

Moderate evidence.

Source: Pastor-Nieto 2021 (Rastogi 1999), Current Treatment Options in Allergy Link to this fact

Children and pregnancy / Animal study

When rats were fed the sunscreen ingredient 4-MBC from before conception through pregnancy and nursing, male offspring reached puberty later and had smaller prostates as adults; the lowest dose that did this was 7 mg/kg/day, and for the related compound 3-BC it was 0.24 mg/kg/day, the lowest dose tested.

Moderate evidence.

Source: Schlumpf 2004, Toxicology Link to this fact

Children and pregnancy / Animal study

Developmental exposure to 4-MBC changed the activity of estrogen-controlled genes in the adult offspring's uterus, prostate and hypothalamus, erased the normal male-female difference in hypothalamic progesterone-receptor mRNA, and changed how those tissues later responded to an estrogen challenge.

Moderate evidence.

Source: Schlumpf 2004, Toxicology Link to this fact

Children and pregnancy / Self-reported survey

In a Brazilian hospital survey, caregivers said two in three children aged 14 and under (182 of 276, median age 4) wore perfume.

Moderate evidence: One Curitiba tertiary-hospital clinic sample, 2015-16; 'perfume' undefined; no frequency, age or sex breakdown; count identical to children's shampoo (possible copy error).

Source: Melo 2020, Revista Paulista de Pediatria Link to this fact

Children and pregnancy / Self-reported survey

A quarter of Brazilian children in a hospital survey (71 of 276) already wore make-up, starting at a median age of 4, usually because the child asked for it (75% of users).

Moderate evidence: One hospital sample; caregiver report; frequency not asked.

Source: Melo 2020, Revista Paulista de Pediatria Link to this fact

Children and pregnancy / Measured in people or real products

In a Danish registry of 1,179 cosmetics marketed for children, more than half (634, 53.8%) listed perfume or a named fragrance allergen, and nearly half (550, 46.6%) named at least one of the 26 EU-listed fragrance allergens.

Moderate evidence.

Source: Botvid 2023, Contact Dermatitis Link to this fact

Children and pregnancy / Measured in people or real products

93% of children's facial-care products in a Danish registry (80 of 86, almost all lip balms) listed fragrance, averaging nearly two named fragrance allergens each.

Moderate evidence: Label data; n=86; registry sample.

Source: Botvid 2023, Contact Dermatitis Link to this fact

Children and pregnancy / Review of other studies

Balsam of Peru, a strong skin sensitizer that the fragrance industry's own standards body (IFRA) had recommended banning, was an ingredient of popular US diaper-rash ointments in the 1990s, applied under occlusion to inflamed infant skin.

Moderate evidence: One clinical commentary citing one 1990 case series (Fisher); current diaper-rash product formulations were not checked for this page.

Source: Scheinman 1999, Journal of the American Academy of Dermatology Link to this fact

Children and pregnancy / Measured in people or real products

In a US label survey of 533 personal care products marketed for babies and children, 48% (255/533) contained a fragrance-category allergen and 55% (294/533) contained at least one of eight screened contact allergens.

Moderate evidence.

Source: Bonchak 2018, Dermatitis Link to this fact

Children and pregnancy / Measured in people or real products

Cheaper baby and children's personal care products contain significantly more contact allergens than pricier ones: products with two or more screened allergens averaged $1.39 per ounce versus $4.35 per ounce for products with none.

Moderate evidence.

Source: Bonchak 2018, Dermatitis Link to this fact

Children and pregnancy / Measured in people or real products

Pregnant women who used perfume in a 48-hour window had 2.3 times higher urinary levels of MEP, the breakdown product of the fragrance solvent diethyl phthalate (DEP), than non-users, in a study of 186 low-income African American and Dominican pregnant women in New York City — independently replicating the same finding in a Boston fertility-clinic cohort (Braun 2014, 167% higher) and a postpartum cohort (Parlett 2013, 2.92x).

Moderate evidence: Exposure marker only, no health outcome; single cohort, cross-sectional; 95% CI 1.6-3.3 overlaps Braun 2014 and Parlett 2013.

Source: Just 2010, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Children and pregnancy / Measured in people or real products

More frequent perfume use tracked higher urinary MEP in pregnant women in a clear dose-response pattern.

Moderate evidence: N=128 subset; exposure marker only, no health outcome.

Source: Just 2010, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Children and pregnancy / Measured in people or real products

In an ordinary primary-school classroom, children were exposed to ultrafine-particle bursts reaching 140,000 particles per cubic centimeter during art activities, the highest classroom particle level measured among the wiki's school-exposure studies — with no health outcome measured.

Moderate evidence.

Source: Morawska 2009, Environmental Science & Technology Link to this fact

Children and pregnancy / Measured in people or real products

In a 1999 European lab test, all 7 children's hydro-alcoholic fragrance products (eau de toilette, eau de parfum, roll-on deodorant) contained the allergen geraniol, and a children's toy perfume-blending kit's "lilac essence" contained cinnamic alcohol at 3.7% — about 4.6x (the paper's abstract states "by a factor of 5") the industry's own 0.8% safety guideline.

Moderate evidence.

Source: Rastogi 1999, Contact Dermatitis Link to this fact

Children and pregnancy / Measured in people or real products

Everyday children's shampoos, shower gels, creams and lotions rarely contained fragrance-mix allergens — cinnamic alcohol, cinnamic aldehyde and isoeugenol were absent from every sample tested — while the notable allergen exposure was concentrated in perfume-type products and one toy.

Moderate evidence: N=5 shampoos/shower gels, n=4 creams/lotions; small sample.

Source: Rastogi 1999, Contact Dermatitis Link to this fact

Children and pregnancy / Measured in people or real products

In a small pilot study of 14 Washington DC childcare facilities, chloroform – a byproduct of the chlorine bleach used to clean – was found in every single air sample, at levels averaging 1.4-1.8 times higher than in a comparable California childcare study.

Moderate evidence: Small unfunded pilot (14 facilities), single-day snapshot, convenience sample; measured no fragrance chemicals at all.

Source: Quirós-Alcalá 2016, Environmental Research Link to this fact

Children and pregnancy / Measured in people or real products

Two no-lye hair relaxer kits marketed for children had the highest measured levels of chemicals banned in EU cosmetics or listed under California's Proposition 65 (DEHP, nonylphenol, o-phenylphenol, diethanolamine) of any products tested in this study.

Moderate evidence: N=3 relaxer kits (2 marketed for children); no health outcome measured in children who used these products.

Source: Helm 2018, Environmental Research Link to this fact

Children and pregnancy / Measured in people or real products

In a Czech birth cohort of 3,411 children (ELSPAC-CZ), each 1-SD increase in an 18-product household chemical exposure score measured at 6 months raised the odds of intermediate-onset transient wheeze (adjusted OR 1.27), early-onset persistent wheeze (adjusted OR 1.36) and intermediate-onset persistent wheeze (adjusted OR 1.23) through age 5, and those persistent wheeze phenotypes carried 5-8x higher odds of a doctor-diagnosed asthma by age 7 (pediatrician records, not self-report).

Moderate evidence.

Source: Mikeš 2019, Science of the Total Environment Link to this fact

Children and pregnancy / Self-reported survey

Mothers who use cleaning sprays during pregnancy have infants with higher odds of both a lower respiratory tract infection (29% higher, OR 1.29) and wheezing (37% higher, OR 1.37) in their first year of life, in a pooled analysis of four Spanish birth cohorts (n=2,292); prenatal solvent use also raised wheezing odds (30% higher) and prenatal air freshener use raised LRTI odds (29% higher).

Moderate evidence.

Source: Casas 2013, International Journal of Public Health Industry-funded Link to this fact

Children and pregnancy / Self-reported survey

In a random sample of Swedish teenagers aged 13-19, about 1 in 6 (15.6%) said they were bothered by strong odors such as perfume, cleaning agents or flower scents, most often affecting the nose.

Moderate evidence: Single-item self-report; general odor sensitivity, not fragranced-product-specific; one Swedish town.

Source: Andersson 2008, International Journal of Hygiene and Environmental Health Link to this fact

Children and pregnancy / Self-reported survey

Teenage girls reported chemical sensitivity about twice as often as boys (20.6% vs 9.9%), and being female, being sensitive to noise, or having probable anxiety each roughly doubled the odds of reporting it.

Moderate evidence: Logistic regression with low explanatory power (Nagelkerke R2=0.092); only modeled for the general-CS outcome.

Source: Andersson 2008, International Journal of Hygiene and Environmental Health Link to this fact

Children and pregnancy / Measured in people or real products

In a US EPA/CDC study of 33 breastfeeding women, phthalate breakdown products were detected in fewer than 10% of breast milk samples and were essentially absent from saliva, even though the same women had detectable phthalate metabolites in nearly all of their urine samples.

Moderate evidence.

Source: Hines 2009, Environmental Health Perspectives Link to this fact

Children and pregnancy / Measured in people or real products

In a large US study of 753 pregnant women and their newborns, higher first-trimester urinary levels of DEHP (a plasticizer found in PVC, food packaging and some medical devices, not primarily a fragrance ingredient) were associated with a shorter anogenital distance in baby boys, a sign of reduced male-hormone action during development, replicating an earlier smaller study at about half the exposure level.

Moderate evidence.

Source: Swan 2015, Human Reproduction Link to this fact

Children and pregnancy / Measured in people or real products

In the same large study (N=753), urinary levels of diethyl phthalate (DEP), the phthalate most strongly and consistently tied to perfume and fragranced personal-care product use, showed no association with anogenital distance in baby boys — the largest and best-controlled human test yet of this specific fragrance-phthalate reproductive claim, in the same boys where DEHP did show an effect.

Moderate evidence.

Source: Swan 2015, Human Reproduction Link to this fact

Children and pregnancy / Review of other studies

The developing fetal and infant brain is far more vulnerable to industrial-chemical injury than the adult brain: the placenta is not an effective barrier to most industrial chemicals, the blood-brain barrier is not fully formed until about 6 months after birth, and lipophilic persistent chemicals concentrate in breast milk at up to 100-fold the mother's bodyweight-adjusted exposure.

Moderate evidence.

Source: Grandjean & Landrigan 2006, Lancet Link to this fact

Children and pregnancy / Measured in people or real products

In 101 Swedish first-time mothers tested over seven years, women who used perfume once a week or more had significantly higher levels of the musk chemical galaxolide (HHCB) in their breast milk than women who used it less often.

Moderate evidence: Product-use data from a N=44 subset; cross-sectional association, not an intervention; adjusted for sampling year.

Source: Lignell 2008, Environmental Science & Technology Link to this fact

Children and pregnancy / Measured in people or real products

Mothers who used perfumed laundry detergent had significantly higher levels of the musk chemical tonalide (AHTN) in their breast milk than mothers who used unscented detergent.

Moderate evidence: Product-use data from a N=44 subset; cross-sectional association, not an intervention; adjusted for sampling year.

Source: Lignell 2008, Environmental Science & Technology Link to this fact

Children and pregnancy / Measured in people or real products

In a national Canadian survey of 98 baby care products, diaper cream — not fragrance — was the largest single modeled source of infant dermal DEP exposure, contributing about half of babies' modeled total.

Moderate evidence: Exposure model uses non-Canada-specific consumer-use-pattern data and a fixed 5% skin-absorption assumption for all phthalates; it is a modeled dose, not a measured biomarker.

Source: Koniecki 2011, Environmental Research Link to this fact

Fragrance is everywhere / Measured in people or real products

Perfume, air fresheners and dryer sheets carried the highest levels of fragrance chemicals and the phthalate DEP; the pooled perfume sample was 1.4% DEP by weight.

Moderate evidence.

Source: Dodson 2012, Environmental Health Perspectives Link to this fact

Fragrance is everywhere / Measured in people or real products

A lab analysis of 59 soaps, surface cleaners, laundry and dish-washing products from four European countries found the citrus-scent chemical limonene in 78% of them, linalool in 61% and citronellol in 47%; all three are fragrance chemicals linked to skin allergy.

Moderate evidence: Products c. 2000, EU only; parent terpenes measured, not the allergenic oxidized forms; Unilever co-author.

Source: Rastogi 2001, Contact Dermatitis Industry-funded Link to this fact

Fragrance is everywhere / Measured in people or real products

Women who had used perfume in the previous day had nearly 3 times as much of a phthalate breakdown product (from diethyl phthalate, a chemical used to carry fragrance) in their urine as women who hadn't.

Moderate evidence: Single spot urine, 337 mostly white educated women; replicated by Braun 2014.

Source: Parlett 2013, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Fragrance is everywhere / Measured in people or real products

The more personal care products a woman used, the higher her levels of diethyl phthalate; deodorant (2.8x), nail polish (2.1x) and hair spray (1.8x) users also had higher levels.

Moderate evidence: Cross-sectional association; one urine sample.

Source: Parlett 2013, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Fragrance is everywhere / Self-reported survey

99.1% of US adults said they are exposed to fragranced products at least once a week, from their own use, other people's, or both.

Moderate evidence: Self-reported exposure; weak dose proxy; adults 18-65.

Source: Steinemann 2016, Air Quality, Atmosphere & Health Link to this fact

Fragrance is everywhere / Review of other studies

In California's 1997 inventory, air fresheners were the single largest category of cleaning-product chemical emissions: 7.5 tonnes a day, just ahead of general-purpose cleaners.

Moderate evidence: 1997 sales-based inventory; later SoCAB inventory had air fresheners <2.5 t/d.

Source: Nazaroff & Weschler 2004, Atmospheric Environment Link to this fact

Fragrance is everywhere / Review of other studies

Of 83 chemicals the EPA had flagged as priorities for safety review (TSCA Work Plan), 65 (over 80%) were known to be in consumer products.

Moderate evidence: Not fragrance-specific.

Source: Goldsmith 2014, Food and Chemical Toxicology Link to this fact

Fragrance is everywhere / Self-reported survey

99.3% of UK adults are exposed to fragranced products every week, and 89% through other people's products that they did not choose.

Moderate evidence: Self-reported exposure.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Fragrance is everywhere / Measured in people or real products

The more personal care products a pregnant woman used in a day, the higher her urine levels of phthalates and parabens, rising step by step.

Moderate evidence: Association with self-reported use.

Source: Braun 2014, Journal of Exposure Science and Environmental Epidemiology Link to this fact

Fragrance is everywhere / Review of other studies

In US national biomonitoring, MEP, the breakdown product of the fragrance solvent DEP, was the most abundant phthalate in people's urine (average 181 ug/g creatinine).

Moderate evidence: NHANES data cited by a review; cite CDC primary; secondary citation of older NHANES data, cite the CDC report directly.

Source: Crinnion 2010, Alternative Medicine Review Link to this fact

Fragrance is everywhere / Measured in people or real products

In a test of 59 best-selling Korean household products, the citrus-scent chemical limonene was the chemical most often given off: it came from 44% of products, including bleach, dish soap, laundry detergent, disinfectant and even a liquid pesticide.

Moderate evidence: Heated headspace, library-match ID, presence not exposure.

Source: Kwon 2007, Journal of Hazardous Materials Link to this fact

Fragrance is everywhere / Review of other studies

In the Los Angeles air basin in 2005, consumer products such as hair spray, cleaners and perfumes were the second-largest human-made source of organic gases by weight (118.7 tonnes a day), behind only passenger cars, according to California's air regulator.

Moderate evidence.

Source: Chen & Luo 2012, Atmospheric Environment Link to this fact

Fragrance is everywhere / Review of other studies

Even after accounting for how readily each chemical forms smog, consumer products ranked third among all emission sources in the Los Angeles basin in 2005.

Moderate evidence.

Source: Chen & Luo 2012, Atmospheric Environment Link to this fact

Fragrance is everywhere / Review of other studies

Perfumes and colognes alone released about 2.5 tonnes of organic gases a day into Los Angeles air in 2005, not counting fragrance in cleaners, air fresheners or hair spray.

Moderate evidence: Inventory estimate for one CARB category.

Source: Chen & Luo 2012, Atmospheric Environment Link to this fact

Fragrance is everywhere / Measured in people or real products

In an EPA survey of 1,159 US household products from the late 1980s (mostly paints, automotive products, lubricants and cleaners), 81% contained at least one of 31 common solvents at more than 0.1% of the product's weight, often at tens of per cent.

Moderate evidence: Historical (1987 purchases), solvent-biased sample, not fragranced products; composition not air levels.

Source: Sack 1992, Atmospheric Environment. Part A. General Topics Link to this fact

Fragrance is everywhere / Measured in people or real products

Household products have been recognized as a major source of indoor chemical pollution since at least the 1980s; this EPA survey was one of the first to measure it.

Moderate evidence: Product content, not exposure.

Source: Sack 1992, Atmospheric Environment. Part A. General Topics Link to this fact

Fragrance is everywhere / Measured in people or real products

Unlike traffic chemicals, scent chemicals were just as high in northern as in southern Europe (median 11.4 vs 12.0 ug/m3), pointing to everyday product use across the continent.

Moderate evidence: Grouped terpenes, no significance tests.

Source: Geiss 2011, Atmospheric Environment Link to this fact

Fragrance is everywhere / Measured in people or real products

In a lab experiment, women still learned to react differently to two women's body odors when both wore the same perfume: perfume did not stop people telling individuals apart by smell.

Moderate evidence.

Source: Gaby & Dalton 2019, Perception Link to this fact

Fragrance is everywhere / Review of other studies

Musk ketone, a synthetic musk used mainly in cosmetics, was found in the body fat of every German tested in the 1990s and in breast milk at up to 240 µg per kg of milk fat.

Moderate evidence.

Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact

Fragrance is everywhere / Measured in people or real products

An older nitro musk (musk ketone), after European industry had moved away from nitro musks, was still in 85% of US mothers' milk in 2004.

Moderate evidence: N=39, Massachusetts only.

Source: Reiner 2007, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Animal study

The vapor from a single cologne contained at least twenty identifiable chemicals – limonene, linalool, linalyl acetate, alpha- and beta-pinene, terpinolene, citronellol, anethole, coumarin, diethyl phthalate among them – none of which appear on the label.

Moderate evidence: Qualitative GC/MS of one test atmosphere, recoveries unknown, isomers possibly unresolved; one unnamed product.

Source: Anderson & Anderson 1998, Archives of Environmental Health Link to this fact

Fragrance is everywhere / Review of other studies

Fragrance is not only in perfume: dermatologists list it in makeup, shampoo, sunscreen, toothpaste, mouthwash, wipes, dish soap, detergent, air fresheners, cleaners, plastics, rubber, glue, paint and waxes, and one Belgian survey found fragrance in 10% of topical medicines (66 different fragrance substances).

Moderate evidence: Qualitative list (de Groot 2020); the 10% is Nardelli 2009, Belgium.

Source: Rodriguez 2024, Cutis Link to this fact

Fragrance is everywhere / Self-reported survey

In a New Jersey university community, adults had used an average of about 14 personal care products in the previous day or two.

Moderate evidence: 593 highly educated, 86% female university-affiliated adults, 2019; not nationally representative.

Source: Barrett 2025, Journal of Exposure Science & Environmental Epidemiology Link to this fact

Fragrance is everywhere / Measured in people or real products

All five scented personal-care products tested, including a hand lotion and a roll-on deodorant, released terpene fragrance chemicals that react with ozone in indoor air.

Moderate evidence: 5 Swiss grocery-store products; lotion/roll-on emissions measured from a Kimwipe for 1 h, not skin.

Source: Wu 2024, Environmental Science & Technology Letters Link to this fact

Fragrance is everywhere / Measured in people or real products

All 31 UK shampoos, shower gels, conditioners, moisturizers and foundations with reported emission rates gave off fragrance terpenes (measured together as limonene); shampoos and shower gels released the most.

Moderate evidence.

Source: Yeoman 2020, Indoor Air Link to this fact

Fragrance is everywhere / Review of other studies

About 60% of the fragrance used in homes goes down the drain into rivers and lakes, and wastewater treatment removes little of it; polycyclic musks such as galaxolide turn up in rivers, lake air, mussels and human milk.

Moderate evidence.

Source: Khalid & Abdollahi 2021, Iranian Journal of Pharmaceutical Research Link to this fact

Fragrance is everywhere / Review of other studies

PTFE, the non-stick coating better known as Teflon, is used in foundations, mascara and lipsticks as a filler and slip agent, at up to 13% of leave-on products according to the industry-funded Cosmetic Ingredient Review.

Moderate evidence: Use level is a maximum reported by industry, not a typical level; industry-author review in a new non-indexed journal.

Source: Jomaa 2024, Journal of the Netherlands Society of Toxicology (JNST) Industry-funded Link to this fact

Fragrance is everywhere / Review of other studies

A 1991 US EPA survey of 31 fragrance products already found limonene, linalool, alpha-pinene, benzyl acetate, benzyl alcohol, camphor and acetone among the most common chemicals, the same compounds found in fragranced products tested in the 2010s.

Moderate evidence: Known only second-hand (Kendall 1995 list; Steinemann 2011 quotes its prevalences); the EPA report itself is not in our evidence base.

Source: DONTSPRAYCALIFORNIA 2008 (DOJ ADA docket) Link to this fact

Fragrance is everywhere / Measured in people or real products

Plug-in and hanging car air fresheners mainly release fragrance terpenes (limonene, pinene, dihydromyrcenol) and fruity-smelling esters, the same terpenes found across larger product surveys.

Moderate evidence.

Source: Pino-Delgado 2021; Steinemann 2011, Journal of Student Research Link to this fact

Fragrance is everywhere / Animal study

The sunscreen ingredient 4-MBC built up in the rats' body fat: at the lowest dose that produced effects, fat levels reached 449 ng/g, the same range already measured in roach and perch from Swiss lakes (44-166 ng/g lipid).

Moderate evidence: Rat adipose measured by GC-MS, n = 3-9; the fish comparison is to a cited 2004 Swiss survey, not measured here; no human tissue or breast-milk levels existed at the time.

Source: Schlumpf 2004, Toxicology Link to this fact

Fragrance is everywhere / Measured in people or real products

In winter Manhattan air the dominant terpene was limonene, the citrus scent chemical used in cleaners and personal care, while nearby forests gave off pine-type terpenes: scented products are a measurable source of city air pollution in New York.

Moderate evidence.

Source: Coggon 2021 Link to this fact

Fragrance is everywhere / Measured in people or real products

In New York City, everyday chemical products (paints, glues, cleaners, personal care) release about 50% more smog-forming vapor by weight than vehicles and other fossil fuels, and their tracers (D5-siloxane, ethanol) rise with population density across US and European cities.

Moderate evidence: NOAA FIVE-VCP inventory checked against tracer measurements; same group as McDonald 2018, so not an independent inventory method.

Source: Coggon 2021 Link to this fact

Fragrance is everywhere / Measured in people or real products

On New York's worst smog day of 2018, consumer and industrial chemical products added about 11 ppb of ozone to a 114 ppb regional peak (standard: 70 ppb), slightly more than vehicle and industry fuels (8 ppb).

Moderate evidence: Modeled attribution (WRF-Chem) for one heat-wave episode; the box model gives fossil fuels ~60% instead. Say 'comparable to vehicles'.

Source: Coggon 2021 Link to this fact

Fragrance is everywhere / Measured in people or real products

Scented product categories (personal care and cleaning) made about half of the ozone from consumer and industrial chemical products in New York, mostly through their alcohol and glycol solvents rather than the fragrance molecules.

Moderate evidence: Box-model budget, one city/episode; 'fragranced VCP' is a product category: fragrance compounds are ~6% of VCP ozone, oxygenates 24% and ethanol 15%.

Source: Coggon 2021 Link to this fact

Fragrance is everywhere / Measured in people or real products

About two in three children's sunscreens (87 of 134) and toothpastes (40 of 61) in a Danish registry listed fragrance or a named fragrance allergen.

Moderate evidence: Label data, registry sample; Brazilian children's sunscreens were 34.5% (Uber 2024), so rates are market-specific.

Source: Botvid 2023, Contact Dermatitis Link to this fact

Fragrance is everywhere / Measured in people or real products

The more densely populated a US city center is, the higher its outdoor air levels of personal-care and fragrance-product chemicals relative to traffic pollution — a pattern found consistently across four different cities.

Moderate evidence: Correlational (R2 0.48-0.82 depending on compound); does not by itself prove causation or rule out other density-linked sources.

Source: Gkatzelis 2021, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Measured in people or real products

In summer Manhattan, citrus/pine-scent chemicals from fragranced products reached an outdoor air level comparable to benzene, a chemical that mostly comes from vehicle exhaust, even though the two come from completely different sources.

Moderate evidence: One city, one season, one compound class (monoterpenes); not a claim about total organic mass, ozone or particle formation versus vehicles.

Source: Gkatzelis 2021, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Measured in people or real products

In a 2018 test of 18 hair products (hot oil, anti-frizz, leave-in conditioner, root stimulator, hair lotion, relaxer) commonly used by Black women, 45 of 66 targeted endocrine-disrupting and asthma-associated chemicals were detected, including every chemical class tested.

Moderate evidence: N=18 products, purchased 2008 based on a 2004-5 NYC usage survey; descriptive/exploratory, no statistical testing.

Source: Helm 2018, Environmental Research Link to this fact

Fragrance is everywhere / Measured in people or real products

In FDA's 2006 cosmetics survey, fragrance products carried the highest diethyl phthalate levels of any category tested (up to 3.9% by weight), and nail products carried the highest dibutyl phthalate levels (up to 6% by weight).

Moderate evidence: N=48 products, one purchasing round; category sizes as small as 1-9 products.

Source: Hubinger & Havery 2006, Journal of Cosmetic Science Link to this fact

Fragrance is everywhere / Measured in people or real products

A silicone ingredient in everyday deodorants, lotions and hair products (D5) shows up in city outdoor air on a clear morning schedule tracking when people shower and dress for work, peaking around 6-7 AM and fading over the following several hours.

Moderate evidence.

Source: Coggon 2018, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Measured in people or real products

During the morning rush hour in a US city, the mass of a personal-care-product ingredient (the silicone D5) entering outdoor air can exceed 30% of the mass of benzene entering the air from vehicle traffic, and the city-wide daily D5 emission total is in the same order of magnitude as the city's traffic-benzene emissions.

Moderate evidence.

Source: Coggon 2018, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Measured in people or real products

In a study of 427 people smelling real body-odor samples, individuals stayed identifiable by smell even when wearing a deodorant, but any deodorant (their own or an assigned one) still made people significantly worse at telling them apart than smelling the unfragranced body odor alone.

Moderate evidence.

Source: Allen, Havlíček & Roberts 2015, Frontiers in Psychology Link to this fact

Fragrance is everywhere / Measured in people or real products

People were better at telling two individuals apart when both wore their own habitual deodorant than when both wore an unfamiliar, experimenter-assigned deodorant, consistent with fragrance choice tracking a person's own body chemistry rather than being arbitrary.

Moderate evidence.

Source: Allen, Havlíček & Roberts 2015, Frontiers in Psychology Link to this fact

Fragrance is everywhere / Government agency

The cosmetics industry's own safety panel (CIR) reported PTFE (Teflon) in 365 US cosmetic products in 2018, at up to 13% in mascara, 12% in eye shadow, 2.4% in hair bleach, and 0.5-3% in face and fragrance powders.

Moderate evidence: Self-reported by the industry to FDA's voluntary registration program and to the industry's own trade association survey; not independently audited.

Source: CIR 2018 Industry-funded Link to this fact

Fragrance is everywhere / Measured in people or real products

Using a statistical method that does not assume the answer in advance, scientists confirmed that everyday chemical products, not traffic, were the dominant source (about 70-78%) of the measured organic-vapor emissions at the New York City site, contributing roughly three-quarters of it, versus about a quarter in the much less crowded city of Boulder, Colorado.

Moderate evidence.

Source: Gkatzelis 2021b, Environmental Science & Technology Link to this fact

Fragrance is everywhere / Measured in people or real products

Health Canada's modeled median dermal DEP exposure for Canadian women from cosmetic and personal-care product use (2.6 ug/kg bw/d) independently matches a Korean team's measured estimate (2.017 ug/kg bw/d) from a different country's products and a different exposure-assessment method.

Moderate evidence: Both are modeled/estimated exposures based on product content and use-pattern surveys, not biomarker-confirmed doses; this is a median, not a worst-case, comparison.

Source: Koniecki 2011, Environmental Research Link to this fact

Fragrance is everywhere / Measured in people or real products

As early as the mid-1990s, the musk fragrance chemicals galaxolide (HHCB) and tonalide (AHTN) were already detectable in the body fat and breast milk of every German person tested, 19 out of 19 samples.

Moderate evidence: Small sample (14 adipose + 5 milk, one German region, 1993/1995); no product-use data or health outcome measured.

Source: Rimkus & Wolf 1996, Chemosphere Link to this fact

Fragrance is everywhere / Measured in people or real products

A 2015 survey of 817 unique detergent products from 131 German households found limonene and linalool — the two fragrance chemicals most often linked to skin allergy when oxidized — named on 23.1% and 20.1% of product labels, more than any of the other 24 EU-declarable fragrance allergens.

Moderate evidence: Label-declaration frequency above the EU's 0.01% threshold, not a chemical measurement; Northern Germany, 2015, convenience sample, not representative.

Source: Wieck 2018, Regulatory Toxicology and Pharmacology Link to this fact

Fragrance is everywhere / Measured in people or real products

Tumble drying real household laundry released 256-342 milligrams of textile microfiber per kilogram of fabric dried, whether the dryer vented outdoors or condensed the moisture indoors, a similar order of magnitude to what washing machines release.

Moderate evidence: One UK lab, one detergent, one condenser model and one vented model, n=8 real loads per dryer type; measures plain cotton/polyester fiber, not fragrance or VOCs.

Source: Cummins 2023, PLOS ONE Industry-funded Link to this fact

Green, natural and unscented / Review of other studies

Products labeled unscented can still contain a fragrance added to mask other smells.

Moderate evidence.

Source: Kumar 2020, Journal of Cosmetic Dermatology Link to this fact

Green, natural and unscented / Measured in people or real products

In 14 of 17 'alternative' (mostly green-marketed) products that contained fragrance chemicals, the label never mentioned fragrance.

Moderate evidence: Mostly natural terpenes at low levels; single products from one retailer.

Source: Dodson 2012, Environmental Health Perspectives Link to this fact

Green, natural and unscented / Measured in people or real products

Products labeled 'green,' 'natural' or 'non-toxic' released hazardous chemicals too, with no significant difference from ordinary ones in a test of 25 best-sellers.

Moderate evidence: 11 vs 14 products; underpowered; list-membership counts; small sample (11 vs 14 products, p>0.30): a null result, not proof of equality.

Source: Steinemann 2011, Environmental Impact Assessment Review Link to this fact

Green, natural and unscented / Measured in people or real products

Baby products labeled green, organic or natural released no fewer chemicals than regular ones (398 vs 286 detections), and 20 of 21 in each group released at least one chemical classed as potentially hazardous.

Moderate evidence: Headspace counts, not concentrations; agrees with Lin 2020 and Steinemann 2011.

Source: Nematollahi 2018, Air Quality, Atmosphere & Health Link to this fact

Green, natural and unscented / Measured in people or real products

Natural baby products swapped one scent chemistry for another: linalool, a common fragrance allergen once it oxidizes, turned up in 16 of 21 green products vs 4 of 21 regular ones.

Moderate evidence.

Source: Nematollahi 2018, Air Quality, Atmosphere & Health Link to this fact

Green, natural and unscented / Animal study

'Natural' doesn't mean allergy-free: essential oils oxidize too; in mouse tests lavender oil exposed to air for 45 weeks became about 8 times more potent as a sensitizer (EC3 36% fresh, 4.4% aged), and oxidized alpha-terpinene from tea tree oil was the most potent of all.

Moderate evidence.

Source: Karlberg 2013, Contact Dermatitis Link to this fact

Green, natural and unscented / Self-reported survey

Three in four UK adults (75.0%) did not know that products called natural, green or organic can also release hazardous air pollutants, and more than half (53.5%) said they would stop using a product if they knew.

Moderate evidence: Awareness item; the emission claim itself rests on other studies.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Green, natural and unscented / Measured in people or real products

Plant-derived scent chemicals drove the particle bursts, so a 'natural' citrus or pine scent is not automatically cleaner to breathe.

Moderate evidence: No unscented comparison in this study.

Source: Rosales 2022, Science Advances Link to this fact

Green, natural and unscented / Measured in people or real products

Labels are not a guarantee: ethyl and butyl paraben actually rose after girls switched to paraben-free-labeled products, probably because some replacements contained them.

Moderate evidence: Replacement products were not tested; explanation inferred.

Source: Harley 2016, Environmental Health Perspectives Link to this fact

Green, natural and unscented / Journalism

A 2009 audit of 2,219 North American products making green claims found that more than 98% made at least one misleading or unsupported environmental claim.

Moderate evidence: TerraChoice gray literature; auditor sells eco-certification; audits substantiation not chemistry.

Source: Dahl 2010, Environmental Health Perspectives Link to this fact

Green, natural and unscented / Journalism

Green-claim auditors named 'all-natural' as a textbook example of a vague green claim and called household cleaning-product makers 'among the worst greenwash offenders'.

Moderate evidence: Opinion of TerraChoice staff; '3 of 397 cleaners' figure not text-verified.

Source: Dahl 2010, Environmental Health Perspectives Link to this fact

Green, natural and unscented / Measured in people or real products

In a test of 79 US feminine hygiene products, labels such as organic, natural or for sensitive skin did not predict lower levels of volatile chemicals.

Moderate evidence: Product content, not exposure; small subgroups.

Source: Lin 2020, Environment International Link to this fact

Green, natural and unscented / Journalism

Perfumers themselves say every perfume blends synthetic and natural materials: "As all perfumers, I create perfume formulas with both synthetic and natural perfumery raw materials" (a Charabot perfumer). A "natural" scent is rarely all natural.

Moderate evidence: One perfumer's essay; no proportions given; industry author.

Source: Ellena 2008, Chemistry & Biodiversity Industry-funded Link to this fact

Green, natural and unscented / Self-reported survey

'Natural' essential oils have not been shown safe for hormone-sensitive children: the only survey claiming so had about a 5% chance of detecting even a tripling of risk.

Moderate evidence: Power figure is evidence base arithmetic from the paper's group sizes and observed baseline; absence of proof of safety is not proof of harm.

Source: Hawkins 2021, International Journal of Pediatrics and Adolescent Medicine Industry-funded Link to this fact

Green, natural and unscented / Review of other studies

Many products sold as "fragrance free" in natural-product stores are free only of synthetic fragrance and still contain essential oils, which make up 80 of the 162 fragrance ingredients documented to cause skin allergy.

Moderate evidence.

Source: Rodriguez 2024, Cutis Link to this fact

Green, natural and unscented / Lab study (cells or chemistry)

'Natural' scent is not biologically inert: essential oils such as lavender and tea tree are chemical mixtures, and in lab tests they acted on estrogen and androgen receptors.

Moderate evidence: Shows biological activity, not harm at use levels.

Source: Henley 2007, New England Journal of Medicine Link to this fact

Green, natural and unscented / Review of other studies

Even a review that found little evidence of harm from lavender and tea tree oil in children warned that 'a lack of evidence of harm cannot be interpreted as evidence of safety' for essential oils in children's products.

Moderate evidence: Direct quote; the review's own conclusion is that the link is unsupported.

Source: Hawkins 2020, Complementary Therapies in Medicine Industry-funded Link to this fact

Green, natural and unscented / Lab study (cells or chemistry)

Natural does not mean hormonally inert: the hormone-active chemicals tested here are ordinary constituents of lavender and tea tree essential oils, not synthetic fragrance chemicals.

Moderate evidence: Cell assays only, at concentrations far above plausible human exposure; whole-animal guideline tests of the two main lavender constituents were negative.

Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact

Green, natural and unscented / Lab study (cells or chemistry)

Terpenes do not behave alike: alpha-terpineol and terpinen-4-ol were the most hormone-active of the eight essential-oil chemicals tested, while eucalyptol was inactive on both the estrogen and the androgen receptor.

Moderate evidence: Receptor assays only; eucalyptol is separately reported to inhibit the steroid-synthesis enzyme CYP17A1, which this study did not test.

Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact

Green, natural and unscented / Measured in people or real products

A fragrance-free body lotion still gave the highest VOC emissions measured in the study, mostly from a preservative (likely phenoxyethanol), and its plant oils reacted with ozone to form aldehydes such as nonanal and nonenal.

Moderate evidence: One lotion, 4 men, chamber; phenoxyethanol identity inferred from PTR-MS ions and the ingredient list.

Source: Wang 2024, Environmental Science & Technology Link to this fact

Green, natural and unscented / Lab study (cells or chemistry)

There is no known 'safe terpene'. Eucalyptol is inactive on hormone receptors but acts weakly on a hormone-making enzyme; alpha-terpineol is the most active on receptors and only middling on the enzyme; limonene is near-inert on receptors and a comparable enzyme inhibitor. The two rankings disagree in both directions.

Moderate evidence: Both rankings are in vitro and at concentrations far above real exposure. The point is that one screen does not clear a molecule, not that any of these molecules is proven harmful.

Source: Sharma 2024 + Ramsey 2019, Biomolecules Link to this fact

Green, natural and unscented / Review of other studies

Natural exfoliants such as salt, sugar, ground seeds or shells and cellulose beads can replace plastic microbeads.

Moderate evidence: Environmental substitution only; skin safety of the alternatives was not assessed.

Source: Han & Kim 2025, Cosmetics Link to this fact

Green, natural and unscented / Review of other studies

Essential oils oxidize in air into the same allergens as synthetic fragrance, and 'natural' cosmetics routinely carry fragrance allergens: 91% of 'natural' perfumes on the Danish market contained at least one target fragrance sensitizer (chemical analysis, 1996) — but only 35% of the other 'natural' cosmetics (shampoos, creams, lotions) in the same study did, at far lower concentrations — and 82 of 100 European natural-brand products checked in 2013-15 listed at least one allergen on the label.

Moderate evidence.

Source: Pastor-Nieto 2021 (Rastogi 1996; Klaschka 2016), Current Treatment Options in Allergy Link to this fact

Green, natural and unscented / Measured in people or real products

In a check of 100 'natural' personal-care products from 10 European natural-cosmetics brands, 82 listed at least one of the EU's labeled fragrance allergens (up to 11 in one product); limonene was on 71 labels and linalool on 70.

Moderate evidence: Label declarations only, no chemical analysis; 10 products from each of 10 anonymous brands, not representative; 2013-15, when the EU list had 26 allergens.

Source: Klaschka 2016, Environmental Sciences Europe Link to this fact

Green, natural and unscented / Measured in people or real products

'For sensitive skin' is not a promise of no fragrance allergens: all 15 natural products named 'sensitive', 'soothing' or 'soft' listed between 1 and 7 of the EU's labeled fragrance allergens.

Moderate evidence: N=15 products, labels only, European natural brands.

Source: Klaschka 2016, Environmental Sciences Europe Link to this fact

Green, natural and unscented / Measured in people or real products

In a 2016 survey of 174 best-selling US body moisturizers, 18 of the 40 labeled "fragrance free" (45%) still listed at least one ingredient that dermatologists' allergen database (ACDS CAMP) flags for fragrance-allergic patients.

Moderate evidence.

Source: Xu 2017, JAMA Dermatology Link to this fact

Green, natural and unscented / Measured in people or real products

Among the same best-selling US moisturizers, 15 of 18 labeled "hypoallergenic" (83%) and 95% of those labeled "dermatologist recommended" contained at least one common skin allergen; only 12% of all products contained none.

Moderate evidence: Listed allergens (NACDG series), not reactions; label data, 2016 formulations.

Source: Xu 2017, JAMA Dermatology Link to this fact

Green, natural and unscented / Measured in people or real products

All 16 UK day face moisturizers tested gave off fragrance terpenes (measured together as 'limonene'), and the 8 'green'-marketed ones released the same amount as the 8 regular ones (0.25 vs 0.26 µg per second per gram), as well as the same ethanol.

Moderate evidence.

Source: Yeoman 2022, Indoor Air Link to this fact

Green, natural and unscented / Review of other studies

In 1999 a dermatologist listed ten US "fragrance-free" skin products that named fragrance chemicals in their own ingredient lists, including a "fragrance-free" cleansing bar containing rose, rosewood, cedarwood and almond oils; one manufacturer admitted the benzaldehyde in its fragrance-free product was there to mask an unpleasant smell.

Moderate evidence.

Source: Scheinman 1999, Journal of the American Academy of Dermatology Link to this fact

Green, natural and unscented / Measured in people or real products

In a 1996 Danish GC-MS analysis, 91% (20 of 22) of perfumes marketed as based on natural ingredients contained 1 to 7 of 11 well-known fragrance sensitizers at concentrations up to 7.7%, including one perfume with 6.04% hydroxycitronellal — above the concentration shown to sensitize 36% of healthy volunteers in patch testing.

Moderate evidence.

Source: Rastogi 1996, Contact Dermatitis Link to this fact

Green, natural and unscented / Measured in people or real products

The same 1996 study found far fewer fragrance sensitizers in other 'natural' cosmetics (shampoos, creams, lotions, deodorants, massage oils): only 35% (7 of 20) contained 1-3 of the target substances, at concentrations (0.0003-0.082%) roughly 100x lower than the natural perfumes.

Moderate evidence: Small non-representative sample (n=20); shows fragrance-sensitizer exposure from 'natural' products is concentrated in perfume-type products, not uniform across the category.

Source: Rastogi 1996, Contact Dermatitis Link to this fact

Green, natural and unscented / Review of other studies

Essential oils are complex mixtures of hundreds of components whose composition varies by producer, plant origin, climate and extraction method, so a product labeled as containing 'lavender oil' or 'tea tree oil' does not guarantee a fixed chemical composition or a fixed level of biological activity.

Moderate evidence: Stated as general essential-oil chemistry background in this review; not measured for any specific consumer product here.

Source: Ramsey 2020 (YJBM), Yale Journal of Biology and Medicine Link to this fact

Green, natural and unscented / Self-reported survey

More than half of Germans (55.6%) wrongly believe products with natural fragrance ingredients are healthier than products with synthetic ones, and the false belief is highest (67-69%) among people who read ingredient labels or prefer fragrance-free products.

Moderate evidence: Belief survey, not a chemical measurement; the 'wrong' judgment is the author's own hazard-classification argument, not tested in this paper.

Source: Klaschka 2020a, Environmental Sciences Europe Link to this fact

Green, natural and unscented / Measured in people or real products

A headspace test of the fragranced and fragrance-free versions of the same detergent brand found 34 volatile chemicals in the fragranced version but only 7 in the fragrance-free version, and no fragrance terpenes (such as D-limonene or linalool) at all in the fragrance-free version.

Moderate evidence: Single product pair tested (one Australian brand); presence/absence only, not a full quantitative comparison.

Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact

Green, natural and unscented / Government agency

Allergy UK's Product Endorsement Scheme is run by Allergy Research Ltd, a private limited company that is a legally separate trading subsidiary of the charity British Allergy Foundation (which operates publicly as Allergy UK); ARL donates its profits to the charity.

Moderate evidence: Organizational/legal fact stated plainly on the page itself; not independently verified against Companies House or charity filings.

Source: Allergy UK 2026 Link to this fact

Green, natural and unscented / Government agency

On the page describing its Product Endorsement Scheme, Allergy UK publishes no fragrance-specific criteria: the word "fragrance" does not appear anywhere on the page, and the only stated assurance is that a product has been "scientifically tested by Allergy UK to confirm its claims," with no ingredient list, protocol, or threshold given.

Moderate evidence: Absence of published criteria on this page is not proof the underlying testing process lacks criteria internally; it is only what the public page discloses.

Source: Allergy UK 2026 Link to this fact

Green, natural and unscented / Government agency

EPA's Safer Choice fragrance-free certification is a documentary ingredient-list review, not a finished-product lab test: EPA checks that a product already meets the full Safer Choice Standard, then checks its ingredient list against the industry's own IFRA Transparency List of fragrance materials.

Moderate evidence.

Source: US EPA Safer Choice Link to this fact

Green, natural and unscented / Government agency

A product carrying the EPA Safer Choice 'fragrance-free' label can still have a smell, because ordinary functional ingredients such as surfactants and solvents can carry an odor without being classified as a fragrance material.

Moderate evidence: EPA states this directly; it is a definitional carve-out, not a measurement of any certified product's actual odor.

Source: US EPA Safer Choice Link to this fact

Green, natural and unscented / Government agency

Health Canada's cosmetic labeling guidance on 'unscented'/'fragrance-free' does not cover laundry detergent, fabric softener or dryer sheets; Canada's legal definition of 'cosmetic' (Food and Drugs Act s.2) covers products for the complexion, skin, hair or teeth, not fabric.

Moderate evidence.

Source: Health Canada 2026 Link to this fact

Health effects / Self-reported survey

In a national survey of 1,098 Australian adults, one in three (33%) said fragranced products such as air fresheners, cleaners and perfume gave them health problems, most often breathing trouble, migraines and skin reactions.

Moderate evidence: Self-report; same dataset as Steinemann 2018 AU asthmatics, 2018 AU MCS and 2019 AU arm (362/1,098 reconfirmed in the MCS paper's Table 1; not a replication).

Source: Steinemann 2017, Preventive Medicine Reports Link to this fact

Health effects / Self-reported survey

In national surveys of 4,435 adults in the US, Australia, the UK and Sweden, about 1 in 3 (32%) said fragranced products such as air fresheners, scented cleaners or other people's perfume cause them health problems.

Moderate evidence: Self-report; any symptom from any product counts; pooled re-analysis of previously published surveys; the US arm (34.7%) is the same dataset as four US papers.

Source: Steinemann 2019, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

About 1 in 8 adults (12.6%) in four countries said fragranced products trigger migraine headaches, and 7% said they trigger asthma attacks.

Moderate evidence: Self-report; no diagnosis check.

Source: Steinemann 2019, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

In a national US survey, about two in three adults with asthma (64.3%) said fragranced products made them ill, compared with about one in four (23.8%) of people without asthma.

Moderate evidence.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

27.9% of US adults with asthma said fragranced products had triggered asthma attacks.

Moderate evidence.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

In a random-based sample of 946 Danish adults, 42% said fragranced products gave them eye, nose or breathing symptoms in the past year (50% of women, 30% of men).

Moderate evidence: Self-attributed symptoms; sample enriched for allergy at baseline.

Source: Elberling 2005, Clinical and Experimental Allergy Link to this fact

Health effects / Self-reported survey

Among people with symptoms, 56% named other people's perfume, 32% air fresheners and 28% other people's freshly washed (fabric-softened) clothes as triggers.

Moderate evidence: Self-report.

Source: Elberling 2005, Clinical and Experimental Allergy Link to this fact

Health effects / Self-reported survey

About 1 in 7 Danish adults (14%) reported fragrance-triggered symptoms at least weekly, and 5% had changed where they shop, how they travel or how they work because of them.

Moderate evidence: Self-report.

Source: Elberling 2005, Clinical and Experimental Allergy Link to this fact

Health effects / Measured in people or real products

Standard allergy tests did not predict who reacted to fragrance; people with sensitive airways (including non-allergic asthma) were 2-4 times more likely to react, pointing to airway irritation rather than classic allergy.

Moderate evidence.

Source: Elberling 2005, Clinical and Experimental Allergy Link to this fact

Health effects / Self-reported survey

In a national survey of 1,100 Swedish adults, one in three (33.1%) said fragranced products gave them health problems, most often breathing difficulties (20.0%) and migraines (16.1%).

Moderate evidence.

Source: Steinemann 2018 (Sweden), Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

In a nationally representative survey of 1,136 US adults, 34.7% said fragranced products such as air fresheners, cleaners and perfume gave them health problems, most often breathing difficulties, eye/nose irritation or migraine.

Moderate evidence.

Source: Steinemann 2016, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

In a national survey of 1,098 Australian adults, more than half of those with asthma or an asthma-like condition (55.6%) said fragranced products made them ill, against about a quarter (23.9%) of people without asthma.

Moderate evidence.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

About 1 in 4 Australian adults with asthma (24.0%) said a fragranced product had triggered an asthma attack; air fresheners were the most common trigger (14.1% of all asthmatics).

Moderate evidence: Self-report; consistent with US and Danish samples (~34-43% airway symptoms).

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Health effects / Review of other studies

Cleaning products were the suspected exposure in 236 of 1,915 (12%) confirmed work-related asthma cases across California, Massachusetts, Michigan and New Jersey (1993-1997); in California, janitors and cleaners had roughly double the confirmed-case rate of all other occupations combined (4.3 vs 2.3 per 100,000 workers).

Moderate evidence.

Source: Nazaroff & Weschler 2004, Atmospheric Environment Link to this fact

Health effects / Self-reported survey

In a US national survey, about 1 in 5 adults (20.4%) said air fresheners gave them health problems such as breathing difficulty, migraine or asthma attacks.

Moderate evidence: Restated from Steinemann 2016 survey; cite the primary; self-report.

Source: Steinemann 2017, Building and Environment Link to this fact

Health effects / Self-reported survey

In a nationally representative survey of 1,100 UK adults, 27.8% said fragranced products such as air fresheners, cleaners or perfume gave them health problems, including migraines (8.4%) and asthma attacks (6.8%).

Moderate evidence: Self-report, any symptom; same data as Steinemann 2019 UK arm.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Health effects / Review of other studies

In a small double-blind, randomized lab test (Ternesten-Hasséus 2002, the primary study behind this review's capsaicin-challenge claim), 12 people with multiple chemical sensitivity coughed significantly more than 12 matched healthy controls at every capsaicin dose tested (P<0.05 to P<0.005), a sign that their airway irritant nerves are oversensitive.

Moderate evidence.

Source: Molot 2023, Neuroscience and Biobehavioral Reviews Link to this fact

Health effects / Measured in people or real products

Estimated cancer risks were below one in a million for most feminine hygiene product types; washes (3.3 in a million) and sprays/powders (2.1 in a million) were just above that level under worst-case assumptions.

Moderate evidence: Modeled upper-bound scenario.

Source: Lin 2020, Environment International Link to this fact

Health effects / Lab study (cells or chemistry)

In lab studies, common flavor and fragrance chemicals act directly on TRPA1, the nerve receptor that senses irritants such as mustard oil: cinnamon's cinnamaldehyde and thyme's thymol switch it on, while camphor and eucalyptus oil block it.

Moderate evidence: Cell and animal pharmacology; the review's framing is therapeutic, not hazard.

Source: Mihara & Shibamoto 2015, Allergy, Asthma & Clinical Immunology Link to this fact

Health effects / Measured in people or real products

In a double-blind lab test where people could not smell it, perfume vapor piped to one eye caused more eye irritation than clean air in 10 of 42 people, including 2 healthy volunteers: perfume can irritate the eyes without being smelled.

Moderate evidence.

Source: Elberling 2006, Indoor Air Link to this fact

Health effects / Measured in people or real products

The eye irritation from perfume vapor was not an allergy: people patch-test allergic to the very same perfume were no more likely to react than those who were not.

Moderate evidence.

Source: Elberling 2006, Indoor Air Link to this fact

Health effects / Measured in people or real products

In a Toronto clinic for work-related breathing problems, about 1 in 10 referred workers had an irritable larynx (throat) syndrome rather than asthma; perfumes and cleaning agents, bleaches and air fresheners were among the named triggers.

Moderate evidence.

Source: Hoy 2010, Occupational Medicine Link to this fact

Health effects / Measured in people or real products

About 80% of workers with scent- and irritant-triggered irritable larynx syndrome were women, versus 24–52% of workers with occupational asthma at the same clinic.

Moderate evidence: N=30, one clinic; referral and care-seeking may differ by sex.

Source: Hoy 2010, Occupational Medicine Link to this fact

Health effects / Measured in people or real products

Scent-triggered throat and breathing reactions can mimic asthma but do not respond to asthma inhalers; almost two-thirds of these patients had been prescribed asthma medication anyway.

Moderate evidence.

Source: Hoy 2010, Occupational Medicine Link to this fact

Health effects / Measured in people or real products

An older, unblinded human study (Stewart 1970) reported eye, nose and throat irritation from PGME solvent vapor at 250 ppm in 23 subjects across five experimental runs, and odor tolerance developing within 25 minutes in 6 subjects at 100 ppm; a later double-blind study with objective eye measurements (Emmen 2003) found no objective eye effects at up to 150 ppm and only very slight subjective eye discomfort at 150 ppm, but did not test 250 ppm.

Moderate evidence.

Source: CIR 2008 (citing Stewart 1970), International Journal of Toxicology Industry-funded Link to this fact

Health effects / Animal study

Citronellol, a rose-scented fragrance ingredient present in about half of household products, crosses the blood-brain barrier: brain-to-blood ratios were 0.5-0.8 in fish, up to 0.6 in mice, and 0.77 in a laboratory barrier built from human brain cells.

Moderate evidence: BBB crossing is measured and dose-independent as a property, but the doses used were far above consumer exposure; routes were waterborne and oral, not inhalation or skin.

Source: Kim 2024, Journal of Hazardous Materials Link to this fact

Health effects / Animal study

At high doses in zebrafish and mice, citronellol pushed tryptophan metabolism toward 3-hydroxykynurenine, a neurotoxic metabolite, and produced brain inflammation, roughly double the oxidative stress, a five-fold rise in dying brain cells, a leaky blood-brain barrier and anxiety-like behavior.

Moderate evidence: Zebrafish 2-8 mg/L in water; mice 345-3450 mg/kg by gavage (top dose = an LD50); 10^5-10^6 times estimated human exposure; male mice only.

Source: Kim 2024, Journal of Hazardous Materials Link to this fact

Health effects / Animal study

Citronellol's effect on the brain reverses with dose: protective in a rat Parkinson's-disease model at 25 mg/kg oral (given as a month-long pretreatment before each day's toxin dose, not as treatment of existing damage), damaging at 345 mg/kg and above in a different paper, species and route.

Moderate evidence.

Source: Kim 2024, Journal of Hazardous Materials Link to this fact

Health effects / Review of other studies

Salicylate fragrance chemicals pass through skin and are converted in the body to salicylic acid, the compound aspirin becomes: for methyl salicylate (wintergreen), human studies found roughly 12-30% of an applied dose absorbed.

Moderate evidence.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

Health effects / Animal study

Mice breathing the vapor of five ordinary commercial colognes for one hour showed airway irritation and a 30-35% drop in mid-expiratory airflow, despite never having been exposed to any allergen or asthma trigger.

Moderate evidence.

Source: Anderson & Anderson 1998, Archives of Environmental Health Link to this fact

Health effects / Measured in people or real products

Over 20 years (1993–2012), California's work-related asthma surveillance confirmed 270 cases linked to perfume or air fresheners at work, 3.8% of all confirmed cases; perfume was the 9th most common workplace asthma exposure.

Moderate evidence: Surveillance count of physician-diagnosed, reported cases; misses >=2/3 of cases; no objective testing required; excludes fragranced cleaners.

Source: Weinberg 2017, Journal of Asthma Link to this fact

Health effects / Measured in people or real products

94% of workers with fragrance-related work asthma in California were women, mostly in offices, health care and schools, and most cases came from perfume worn by others.

Moderate evidence: Authors attribute the sex skew to occupation and exposure, not susceptibility; care-seeking bias possible.

Source: Weinberg 2017, Journal of Asthma Link to this fact

Health effects / Self-reported survey

Many people with chemical sensitivities delay or avoid medical care because clinics and hospitals are heavily scented; healthcare was named as one of the least accessible settings (31 of 60).

Moderate evidence: Qualitative, self-selected Canadian sample; frequency of care avoidance not quantified.

Source: Roy 2026 Link to this fact

Health effects / Review of other studies

People adapt to a steady odor, so a constant background scent stops being noticed while it is still in the air.

Moderate evidence: Adaptation reduces perceived odor, not exposure; well established in chemosensory science but cited here from a review.

Source: Dalton & Jaén 2010, Current Opinion in Allergy and Clinical Immunology Industry-funded Link to this fact

Health effects / Self-reported survey

In a nationally representative German survey, half of the people who get sick from fragranced products (51.1%) had been kept from going somewhere because of fragrance, and 43.8% had avoided public toilets with air fresheners or scented products.

Moderate evidence: Self-report; Germany 2019, n=219 fragrance-sensitive of 1,102; same data as Steinemann & Klaschka 2019.

Source: Klaschka 2020, Environmental Sciences Europe Link to this fact

Health effects / Review of other studies

Fragrance can cause skin allergy without touching your own products: from a partner's toiletries (consort dermatitis), from soap residue carried on the hands to the eyelids, and through the air, as in a small case series of a ride-share driver and four passengers whose airborne facial/eyelid dermatitis (all patch-test positive for fragrance mix I and/or balsam of Peru) was linked to car fragrance diffusers, with the driver's rash clearing when his diffuser was removed.

Moderate evidence.

Source: Rodriguez 2024, Cutis Link to this fact

Health effects / Lab study (cells or chemistry)

In lab tests on human cells, both lavender oil and tea tree oil switched on estrogen-receptor signaling (about half the maximum effect of the body's own estradiol) and blocked testosterone-type (androgen-receptor) signaling by 41–52%.

Moderate evidence.

Source: Henley 2007, New England Journal of Medicine Link to this fact

Health effects / Lab study (cells or chemistry)

Lavender oil and tea tree oil activated the human estrogen receptor in cell assays to about 17-18% of the response to estradiol, and blocked testosterone signaling more completely than flutamide, a prescription anti-androgen drug.

Moderate evidence.

Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact

Health effects / Review of other studies

If a young child has unexplained early breast development, it is reasonable to ask about lavender and tea tree products, including room diffusers, and try stopping them – which is what the study's authors recommend to doctors.

Moderate evidence: This is the authors' clinical recommendation, not a proven treatment; they explicitly state they are not recommending that anyone avoid these products generally.

Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact

Health effects / Self-reported survey

Of all personal care product types, perfumes and colognes had the highest hazard ratings in the Environmental Working Group's Skin Deep database, and adults aged 18–39 used the highest-rated ones (average 7.2 of 10, vs 5.9 for those 60 and over).

Moderate evidence: EWG hazard ratings from listed ingredients, not measured toxicity or exposure; 39% of perfumes used could not be rated.

Source: Barrett 2025, Journal of Exposure Science & Environmental Epidemiology Link to this fact

Health effects / Self-reported survey

Black women in a US university sample were twice as likely as White women to have recently used a hair product rated high-hazard by EWG (relative risk 1.99, 95% CI 1.37–2.89).

Moderate evidence.

Source: Barrett 2025, Journal of Exposure Science & Environmental Epidemiology Link to this fact

Health effects / Lab study (cells or chemistry)

Essential-oil terpenes can interfere with the enzymes that BUILD hormones, not just the receptors hormones act on — a route that the standard estrogen- and androgen-receptor safety screens are not designed to detect.

Moderate evidence: Mechanistic point only. The measured effects were weak (13–33%) and all at a single 10 µM with no dose–response.

Source: Sharma 2024, Biomolecules Link to this fact

Health effects / Lab study (cells or chemistry)

The antibacterial triclosan, once in about 45% of US soaps, reacts to UVB at an intensity matched to real midday sunlight by generating free radicals that damaged human skin cells (HaCaT keratinocytes) in the laboratory, dose-dependently and only when triclosan and radiation were combined.

Moderate evidence.

Source: Khalid & Abdollahi 2021, Iranian Journal of Pharmaceutical Research Link to this fact

Health effects / Review of other studies

A 2024 safety review by an industry toxicologist states there are no data on whether PTFE passes through the skin, how the body handles it, or whether it affects hormones, and that it does not biodegrade.

Moderate evidence.

Source: Jomaa 2024, Journal of the Netherlands Society of Toxicology (JNST) Industry-funded Link to this fact

Health effects / Lab study (cells or chemistry)

In a 2025 lab screen of 42 everyday perfumes, almost all contained compounds that damaged bacterial DNA, killed cells, blocked the hormone-making enzyme aromatase or acted on human estrogen or androgen receptors in test organisms, regardless of price or whether the perfume was marketed to men or women.

Moderate evidence.

Source: Morlock & Heil 2025, Journal of Chromatography A Link to this fact

Health effects / Animal study

Two fragrance musks, AETT and musk ambrette, damaged the nervous system of rats in industry-sponsored studies and were withdrawn; musk ambrette was also barred from skin products because it caused allergic reactions in sunlight.

Moderate evidence.

Source: Ford 1994 (RIFM) Industry-funded Link to this fact

Health effects / Measured in people or real products

Sunlight can turn some fragrance chemicals into skin allergens: the now-banned perfume ingredient 7-methoxycoumarin made 11 of 25 volunteers photoallergic, and in people already sensitized, 0.001% plus UVA light triggered a reaction.

Moderate evidence: Artificial UVA at 20 J/cm2 (~1 h summer sun) for the 0.001% figure; predictive photomaximization test; ingredient banned in EU cosmetics since 2000.

Source: SCCNFP 2000 Link to this fact

Health effects / Lab study (cells or chemistry)

Two sunscreen ingredients, oxybenzone (benzophenone-3) and homosalate, blocked the male hormone receptor in human cells, at roughly the potency of the pesticide metabolite p,p'-DDE.

Moderate evidence: MDA-kb2 reporter cells, IC50 4.98 and 5.57 uM against 0.1 nM DHT; cell assay only, no animal or human anti-androgen endpoint in this paper; data from the group's own Ma 2003.

Source: Schlumpf 2004, Toxicology Link to this fact

Health effects / Self-reported survey

In a national survey of 1,098 Australian adults, 6.5% said a doctor or health professional had told them they have multiple chemical sensitivities, and 18.9% said they are unusually sensitive to everyday chemicals.

Moderate evidence: Single self-reported 'ever told' item, online panel, adults 18-65; a South Australian population survey found 1% diagnosed; same dataset as the AU fragrance reports.

Source: Steinemann 2018, Preventive Medicine Reports Link to this fact

Health effects / Self-reported survey

Among Australians who said they had been diagnosed with multiple chemical sensitivities, 91.5% reported health problems from fragranced products such as air fresheners, scented cleaners and other people's perfume.

Moderate evidence: N = 71; self-report; partly built into the definition.

Source: Steinemann 2018, Preventive Medicine Reports Link to this fact

Health effects / Self-reported survey

In a 2016 US national survey, 86% of people who said a doctor had diagnosed them with multiple chemical sensitivity reported health problems from fragranced products, most often breathing problems (50%), migraines (47%) and eye/nose symptoms (47%).

Moderate evidence: Self-report; 'diagnosed' = told by any health professional; opt-in online panel; same dataset as Steinemann 2016.

Source: Steinemann 2018 (JOEM), Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Self-reported survey

In the same 2016 US survey, about 1 in 4 adults (25.9%) said they were unusually sensitive to everyday chemicals such as cleaning products, perfume and detergents, and 81% of them reported health problems from fragranced products.

Moderate evidence: Self-report; adults 18-65 in an opt-in online panel; earlier US telephone surveys gave 11-16%.

Source: Steinemann 2018 (JOEM), Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Measured in people or real products

Some people whose breathing problems are set off by scents do not have asthma or allergy: in a Swedish clinic study, 11 such patients had normal lung function, negative methacholine and allergy tests, and asthma medicines had given most of them little relief.

Moderate evidence: Clinic referrals selected for scent-triggered complaints; n=11; describes a phenotype, not its prevalence.

Source: Millqvist 1999, Allergy Link to this fact

Health effects / Measured in people or real products

In a small lab test where patients could not smell it, perfume released near their eyes caused more eye irritation than a saline dummy (1.1 vs 0.2 on a 0-3 scale); a later double-blind study found the same eye effect.

Moderate evidence: Single-blind, n=11, self-rated; corroborated double-blind by Elberling 2006 (8/21 patients vs 2/21 controls, P=0.07).

Source: Millqvist 1999, Allergy Link to this fact

Health effects / Review of other studies

A systematic review of workplace irritants found that people with pre-existing airway sensitivity (atopy plus non-specific bronchial hyper-responsiveness) can develop new-onset asthma from chronic, repeated exposure to an irritant at concentrations below the official occupational exposure limit.

Moderate evidence.

Source: Baur, Bakehe & Vellguth 2012, Journal of Occupational Medicine and Toxicology Link to this fact

Health effects / Measured in people or real products

In a small double-blind lab test, 12 people with multiple chemical sensitivity coughed significantly more than 12 healthy matched controls every time they inhaled capsaicin (the compound that makes chili peppers hot), and the difference grew larger at higher doses.

Moderate evidence: N=12 vs 12, single Gothenburg clinic, MCS diagnosed only by Cullen's clinical criteria (no independent biomarker), not independently replicated outside this research group.

Source: Ternesten-Hasséus 2002, Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Measured in people or real products

The extra coughing in multiple chemical sensitivity patients was not explained by asthma or classic allergy: patients tested negative on standard allergy skin-prick and methacholine airway-reactivity tests, and lung function (FEV1) did not change after capsaicin, pointing to an oversensitive airway nerve response rather than an allergic or asthmatic reaction.

Moderate evidence.

Source: Ternesten-Hasséus 2002, Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Measured in people or real products

In a nationally representative sample of 2,432 US women aged 20-49, women who douched frequently (2+ times/month) had 81% higher blood levels of 1,4-dichlorobenzene than women who never douched, with a dose-response trend across frequency categories (p=0.04).

Moderate evidence: Cross-sectional NHANES biomarker data; wide CI (2% to 221%); mothballs and toilet deodorizers are DCB's dominant known sources and could not be ruled out as confounders.

Source: Ding 2020, Journal of Women's Health Link to this fact

Health effects / Measured in people or real products

Using feminine powder in the past month was linked to 36% higher blood ethylbenzene in a nationally representative NHANES sample of reproductive-aged women.

Moderate evidence: Single VOC, modest effect size; alternative sources (e.g. talc packaging) not ruled out; no dose-response could be tested (frequency not collected).

Source: Ding 2020, Journal of Women's Health Link to this fact

Health effects / Measured in people or real products

Non-Hispanic Black women douched far more often than white women (39% vs 13% in the past month) and had significantly higher blood 1,4-dichlorobenzene, a possible contributor to racial differences in chemical exposure.

Moderate evidence: Association, not a demonstrated causal pathway; unadjusted racial comparison for the biomarker figure.

Source: Ding 2020, Journal of Women's Health Link to this fact

Health effects / Animal study

In a rat model of Parkinson's disease, oral citronellol (25 mg/kg/day) given as a month-long pretreatment before each day's dose of the neurotoxin rotenone reduced brain oxidative stress, inflammatory cytokines, glial activation and the loss of dopamine-producing neurons.

Moderate evidence.

Source: Jayaraj 2022, Heliyon Link to this fact

Health effects / Measured in people or real products

Cleaning products were the suspected exposure in 236 of 1,915 (12%) confirmed work-related asthma cases across California, Massachusetts, Michigan and New Jersey, 1993-1997; most were new-onset asthma (80%) and about a fifth were consistent with reactive airways dysfunction syndrome, an irritant-induced, non-allergic asthma type.

Moderate evidence.

Source: Rosenman 2003, Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Measured in people or real products

In California, janitors and cleaners had roughly double the confirmed work-related asthma rate of all other occupations combined (4.3 vs 2.3 per 100,000 workers).

Moderate evidence.

Source: Rosenman 2003, Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Self-reported survey

In a 1986 clinic and hospital survey of 60 asthma patients, 72% said perfume or cologne worsened their asthma, and two asthma patients who could not smell at all still reacted to perfume worn by others nearby.

Moderate evidence.

Source: Shim & Williams 1986, The American Journal of Medicine Link to this fact

Health effects / Self-reported survey

In a German cohort of 1,695 young adults (19-24) followed from childhood, frequent private use of household disinfectants (a composite of methods including hand-wash, machine, sponge and spray disinfection) was associated with close to a threefold increase in the odds of newly developing asthma, compared with people who didn't use disinfectants (OR 2.79, 95% CI 1.14-6.83).

Moderate evidence.

Source: Weinmann 2017, Occupational and Environmental Medicine Link to this fact

Health effects / Animal study

AETT, a musk fragrance once common in soaps, deodorants and cosmetics, caused progressive nerve-fiber demyelination and irreversible pigment build-up in the brains of rats fed the compound for 12-20 weeks; the fragrance industry voluntarily withdrew it from cosmetics in 1978 on the strength of its own data.

Moderate evidence: Small single-lab study (N=16 rats), one route (dietary), one dose pair (25/50 mg/kg/day); AETT was withdrawn from cosmetics in 1978 and is not a current fragrance ingredient.

Source: Spencer 1979, Science Industry-funded Link to this fact

Health effects / Measured in people or real products

The fragrance-linked phthalate DEP was found in 78% of the hair products tested, and cyclosiloxanes, parabens and DEP were found at the highest concentrations, including one anti-frizz product that was 38-46% cyclosiloxane by weight.

Moderate evidence: N=18 products; concentration in the product is not the same as absorbed dose or exposure.

Source: Helm 2018, Environmental Research Link to this fact

Health effects / Measured in people or real products

Nitrate radicals alone, generated from ozone and nitrogen dioxide with no terpene present at all, raised human eye-blink frequency 21% — comparable in size to the effect of isoprene ozonolysis products — suggesting that some of the eye-irritating power of 'scented product plus ozone' indoor chemistry may come from reactive radicals in general, not from limonene specifically.

Moderate evidence.

Source: Klenø & Wolkoff 2004 Link to this fact

Health effects / Review of other studies

Odor and fragrance exposure reliably distracts people and slows some cognitive tasks (reaction time, lexical decisions), independent of any toxic effect.

Moderate evidence: Effect sizes are small and inconsistent across tasks, and persistence beyond a single exposure session is not established.

Source: Wolkoff & Nielsen 2017, Environment International Link to this fact

Health effects / Animal study

Mice breathing the vapor of one commercial solid air freshener for one hour showed dose-dependent airway irritation and, at higher doses, a ~35% fall in mid-expiratory airflow — the same magnitude reported for colognes in the same lab's companion study.

Moderate evidence.

Source: Anderson & Anderson 1997, Archives of Environmental Health Link to this fact

Health effects / Measured in people or real products

Using the identical question and instrument in the same Swedish town, adults report being bothered by strong odors about twice as often as teenagers (33% vs 15.6%), and objectively confirmed sensory hyperreactivity is about seven times more common in adults (6.3% vs 0.9%), suggesting chemical sensitivity often develops with age rather than being present from childhood.

Moderate evidence.

Source: Andersson 2008, International Journal of Hygiene and Environmental Health Link to this fact

Health effects / Lab study (cells or chemistry)

Three fragrance and cosmetic chemicals used in bodycare products applied around the breast — benzyl salicylate, benzyl benzoate, and butylphenylmethylpropional (Lilial) — activated the human estrogen receptor and increased growth of estrogen-dependent breast cancer cells in a laboratory dish, an effect blocked by an anti-estrogen drug, suggesting the mechanism runs through the estrogen receptor.

Moderate evidence.

Source: Charles & Darbre 2009, Journal of Applied Toxicology Link to this fact

Health effects / Lab study (cells or chemistry)

These estrogen-receptor effects only appeared at concentrations tens of thousands to millions of times higher than the natural hormone estradiol needs to produce the same size effect — this is laboratory-dish evidence that these chemicals can act like a weak estrogen, not evidence that normal skin or cosmetic use delivers enough of them to the breast to do so.

Moderate evidence.

Source: Charles & Darbre 2009, Journal of Applied Toxicology Link to this fact

Health effects / Measured in people or real products

In lab tests, basophils (a type of blood immune cell) from people with perfume-related breathing symptoms released significantly more histamine when exposed to strong perfume than basophils from healthy volunteers, but only at the strongest concentration tested; both groups' basophils started releasing histamine at the same dose.

Moderate evidence.

Source: Elberling 2007, Clinical and Experimental Allergy Link to this fact

Health effects / Measured in people or real products

The excess basophil reactivity to perfume in symptomatic patients was not explained by allergy antibodies in the blood (a passive-serum-transfer test found no difference between groups) and did not track whether a patient also had a skin (contact) allergy, an inhalant allergy, or asthma.

Moderate evidence.

Source: Elberling 2007, Clinical and Experimental Allergy Link to this fact

Health effects / Lab study (cells or chemistry)

In a laboratory study, triclosan exposed to UVB at an intensity matched to real midday sunlight in a subtropical city generated damaging free radicals and killed human skin cells (HaCaT keratinocytes) in a dose-dependent way.

Moderate evidence.

Source: Dubey 2019, Ecotoxicology and Environmental Safety Link to this fact

Health effects / Lab study (cells or chemistry)

Triclosan and UVB/sunlight together caused significant DNA damage (comet assay, micronuclei, cyclobutane pyrimidine dimers) in human skin cells in the laboratory, while triclosan alone in the dark and UVB/sunlight alone caused none.

Moderate evidence: Single in-vitro cell-line study; genotoxicity not shown in whole skin or in vivo.

Source: Dubey 2019, Ecotoxicology and Environmental Safety Link to this fact

Health effects / Measured in people or real products

In a 2021 audit of 50 stores across 8 Boston neighborhoods, stores in lower-income Roxbury and Mission Hill were more than twice as likely to stock a hair product with a high (7-10) Environmental Working Group hazard score than stores in higher-income, predominantly White Beacon Hill (risk ratio 2.3 for both).

Moderate evidence.

Source: Chan 2023, Environmental Health Perspectives Link to this fact

Health effects / Measured in people or real products

Hair relaxers were found for sale only in the lower-income, more racially diverse Boston neighborhoods studied; none were cataloged in the two highest-income/highest-White or Asian-share neighborhoods (Beacon Hill, Chinatown).

Moderate evidence.

Source: Chan 2023, Environmental Health Perspectives Link to this fact

Health effects / Measured in people or real products

In the best-controlled human test available, propylene glycol methyl ether (PGME) solvent vapor at 150 ppm produced no measurable objective eye damage (redness, corneal swelling, tear-film stability, blinking rate) when tested double-blind against a matched-odor placebo in 12 volunteers.

Moderate evidence: Small study (n=12, all male), single 2.5 h exposure; does not test longer or repeated exposures, other populations, or higher occupational concentrations.

Source: Emmen et al. 2003, Toxicology Letters Industry-funded Link to this fact

Health effects / Measured in people or real products

A statistically significant 'nose irritation' rating from a scented solvent vapor disappeared once how strongly subjects could smell the vapor was accounted for statistically, showing that self-reported irritation from a scented product can really be a report of smell, not tissue injury.

Moderate evidence: One study, one chemical, one nasal-irritation question; the eye-irritation rating in the same study did not similarly vanish.

Source: Emmen et al. 2003, Toxicology Letters Industry-funded Link to this fact

Health effects / Measured in people or real products

In a 3-hour chamber test at realistic ozone and citrus-terpene (limonene) levels, people with mild asthma rated the air as less irritating to their eyes, nose and throat than healthy people did, but reported more chest tightness, headache and flu-like symptoms.

Moderate evidence.

Source: Fadeyi et al. 2015, Indoor Air Link to this fact

Health effects / Measured in people or real products

People with mild asthma performed a concentration task significantly less accurately than healthy people during a 3-hour ozone-limonene chamber exposure, despite working faster.

Moderate evidence: Single study, no unexposed control arm, so it is not established that the chemistry (rather than general chamber occupancy or task load) caused the accuracy difference.

Source: Fadeyi et al. 2015, Indoor Air Link to this fact

Health effects / Measured in people or real products

In the nasal-lavage arm of the same 130-woman chamber study, breathing a VOC-ozone mixture containing citrus and pine scent chemicals (limonene, alpha-pinene) caused no significant increase in nasal irritation symptoms or in objective inflammation markers (immune cells, IL-6, IL-8, protein) in nasal fluid.

Moderate evidence.

Source: Laumbach 2005, Journal of Occupational and Environmental Medicine Link to this fact

Health effects / Review of other studies

General reviews of the skin-penetration literature put the size ceiling for crossing intact skin's outer barrier (the Stratum Corneum) at around 100 nanometers; larger particles usually do not cross it.

Moderate evidence: Stated as a citation to a prior review (Revel et al. 2018), not new primary data from this paper; an order-of-magnitude rule, not a precise cutoff.

Source: Menichetti et al. 2025, Journal of Xenobiotics Link to this fact

Health effects / Lab study (cells or chemistry)

When the outer skin barrier (Stratum Corneum) is removed or already compromised, far more 100-500 nanometer plastic nanoparticles get through than when it is intact, pointing to skin condition, not just particle size, as the deciding factor.

Moderate evidence.

Source: Menichetti et al. 2025, Journal of Xenobiotics Link to this fact

Health effects / Measured in people or real products

In a small Swedish clinic study, people whose breathing symptoms were set off by scents reacted to a blinded perfume challenge with more symptoms than a saline placebo, even though a nasal clamp meant they could not smell either one, and their lung function, oxygen levels, heart rate and breathing rate never changed at all.

Moderate evidence: N=9, single clinic, self-rated symptoms, perfume-vs-saline contrast single-blind (not double-blind); no healthy control group.

Source: Millqvist & Löwhagen 1996, Allergy Link to this fact

Health effects / Measured in people or real products

Wearing a mask with an active-carbon filter, the kind designed to remove odors and organic vapors from the air, did not stop a scent-triggered breathing reaction to perfume: symptom scores with the carbon filter were no different from a dummy filter.

Moderate evidence.

Source: Millqvist & Löwhagen 1996, Allergy Link to this fact

Health effects / Measured in people or real products

In the clinical case series that first defined "irritable larynx syndrome," perfume was a named symptom trigger in about a quarter of patients (10 of 39), well behind reflux (72%) and other airborne irritants (51%).

Moderate evidence: Single specialist voice clinic, retrospective, uncontrolled, n=39; self-reported triggers, multiple allowed per patient; not an occupational or fragrance-specific population.

Source: Morrison 1999, Journal of Voice Link to this fact

Health effects / Measured in people or real products

About 85% of patients in the founding irritable larynx syndrome case series were judged to have gastroesophageal reflux contributing to their laryngeal symptoms, making reflux the single most common named trigger and etiologic factor, ahead of any airborne trigger including perfume.

Moderate evidence.

Source: Morrison 1999, Journal of Voice Link to this fact

Health effects / Measured in people or real products

In a small double-blind lab test, a drug that numbs sensory nerves (lidocaine) cut in half the number of coughs that chemically sensitive patients had after inhaling capsaicin, evidence that their airway sensitivity runs through nerve pathways rather than the kind of airway narrowing seen in asthma.

Moderate evidence.

Source: Millqvist 2000, Allergy Link to this fact

Health effects / Measured in people or real products

A blinded, controlled 30-minute lab exposure to two fragranced household aerosols caused no objective ocular redness or nasal congestion (acoustic rhinometry) change in mild or moderate asthmatics, and no drop in lung function (FEV1).

Moderate evidence.

Source: Opiekun 2003, Clinical and Experimental Allergy Industry-funded Link to this fact

Health effects / Measured in people or real products

Moderate asthmatics self-reported more nasal congestion after one of two fragranced aerosols, but objective nasal-airway measurement (acoustic rhinometry) on the same people at the same time found no change.

Moderate evidence.

Source: Opiekun 2003, Clinical and Experimental Allergy Industry-funded Link to this fact

Health effects / Review of other studies

Across 6 independent lab studies using a forced-choice 'which one is the real chemical?' test, people who report multiple chemical sensitivities were not better than other people at telling active chemical exposures apart from blank or sham ones.

Moderate evidence.

Source: Das-Munshi 2006, Journal of Allergy and Clinical Immunology Link to this fact

Health effects / Measured in people or real products

In one lab study of 180 people, simply telling them beforehand that an odor was an 'industrial solvent' (versus a 'relaxing natural extract' or a neutral label) made them report significantly more irritation and symptoms from the identical odorant, and the effect was strongest in people who normally rate odors as more reactive/irritating.

Moderate evidence: Reported via Das-Munshi's review, not read from the Dalton 1999 primary source directly; acquire Dalton 1999 (Health Psychol 18:579) to verify before treating as primary-grade.

Source: Das-Munshi 2006, citing Dalton 1999, Journal of Allergy and Clinical Immunology Link to this fact

Health effects / Self-reported survey

In a large random sample of Swedish adults (Vasterbotten, n=3,406), 12.2% said they get symptoms from odorous or pungent chemicals such as perfumes and cleaning agents in doses that don't bother most other people, but only 3.3% had actually been given a doctor's diagnosis of a chemical-intolerance condition.

Moderate evidence: Single region (Vasterbotten county), not national; diagnosis status is itself self-reported, not verified against medical records.

Source: Palmquist 2014, International Journal of Hygiene and Environmental Health Link to this fact

Health effects / Self-reported survey

People who report being intolerant to one environmental factor (chemicals, certain buildings, electromagnetic fields, or everyday sounds) are far more likely than chance to also report intolerance to another — for example, self-reported chemically intolerant Swedes were about six times more likely than average to also report building-related symptoms (observed 96 vs. 19.5 expected under chance).

Moderate evidence: Cross-sectional single-item design; cannot separate a shared physiological mechanism from a shared symptom-reporting/attribution style or shared exposure circumstances.

Source: Palmquist 2014, International Journal of Hygiene and Environmental Health Link to this fact

Health effects / Measured in people or real products

In a small case series, an Uber driver and four Uber passengers developed facial and eyelid airborne contact dermatitis linked to fragrance diffusers used inside the cars; all five patients had positive patch tests to fragrance mix I and/or balsam of Peru, and the driver's dermatitis improved after he removed his own diffuser.

Moderate evidence.

Source: Perper et al. 2017, Contact Dermatitis Link to this fact

Health effects / Measured in people or real products

In an unblinded human chamber study, 23 volunteers exposed to about 250 ppm propylene glycol monomethyl ether (PGME) vapor for 1-7 hours judged the odor objectionably unpleasant, and 20 of 23 developed eye irritation within about an hour, with some needing to leave early due to severe lacrimation; no subject at any tested concentration up to 2,050 ppm showed impaired vision, coordination, or reaction time.

Moderate evidence.

Source: Stewart 1970 (Arch Environ Health), Archives of Environmental Health: An International Journal Industry-funded Link to this fact

Health effects / Measured in people or real products

At 100 ppm PGME vapor, most of 6 subjects found the odor intolerable on first exposure, but odor tolerance developed within 25 minutes and all judged it mild; only 1-2 of the 6 reported mild or slight eye irritation over the following two hours, with no measurable effect on vision, coordination, or neurological tests.

Moderate evidence: Unblinded, n=6, no objective eye measurements; a double-blind study at the same concentration (Emmen 2003) found no eye effects at all, subjective or objective.

Source: Stewart 1970 (Arch Environ Health), Archives of Environmental Health: An International Journal Industry-funded Link to this fact

Health effects / Self-reported survey

In a nationally representative German survey, one in five adults (19.9%) report at least one health effect from fragranced products, and more than half of them (55.3%) report respiratory problems, not skin problems — the focus of most prior German fragrance research.

Moderate evidence: Self-report; no clinical confirmation; n=1,102, Germany 2019; same dataset as Klaschka 2020b.

Source: Klaschka 2020a, Environmental Sciences Europe Link to this fact

Health effects / Self-reported survey

People who already blame fragrances for their own symptoms do not use less of them: 98.6% of Germany's fragrance-sensitive survey respondents are still exposed to fragrances from their own weekly use, slightly above the general population's 96.9%.

Moderate evidence: Self-report; cannot rule out that affected people simply notice or report their own exposure more accurately rather than actually using more.

Source: Klaschka 2020a, Environmental Sciences Europe Link to this fact

Health effects / Self-reported survey

Among adults with a diagnosis of autism or autism spectrum disorder, 71.4% (US) and 51.2% (Australia) report health problems from the scent of laundry products coming from a dryer vent — the highest prevalence of any group measured (general population, asthmatics, autistic adults, migraineurs) in either country.

Moderate evidence.

Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact

Health effects / Self-reported survey

Among people who get migraines, 40.8% (US) and 29.1% (Australia) report health problems from the scent of laundry products coming from a dryer vent, with asthma attacks the most frequently reported effect in this group.

Moderate evidence.

Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact

Health effects / Review of other studies

Quaternary ammonium compounds such as benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) have been linked to occupational asthma, contact dermatitis and urticaria in healthcare workers, professional cleaners and hairdressers with heavy, repeated exposure to disinfectants, antiseptics and cosmetic preservatives.

Moderate evidence.

Source: Peyneau 2022, Frontiers in Toxicology Link to this fact

Hidden ingredients / Measured in people or real products

In a test of 6 best-selling US air fresheners and laundry products, researchers found 98 chemical detections (58 different chemicals) released into the air; none appeared on any product label, and only 1 (ethanol) appeared on a safety data sheet.

Moderate evidence: N=6 products, headspace only, semi-quantitative.

Source: Steinemann 2009, Environmental Impact Assessment Review Link to this fact

Hidden ingredients / Measured in people or real products

4 of the 6 products released at least one chemical the Clean Air Act classifies as a hazardous air pollutant (acetaldehyde, chloromethane or 1,4-dioxane), and none was listed.

Moderate evidence: Paper text says 5 of 6; tables support 4. Two of three HAPs come from the base formulation, not fragrance.

Source: Steinemann 2009, Environmental Impact Assessment Review Link to this fact

Hidden ingredients / Self-reported survey

68.6% of Australians were unaware that fragrance ingredients don't have to be fully listed on labels.

Moderate evidence: Awareness survey item.

Source: Steinemann 2017, Preventive Medicine Reports Link to this fact

Hidden ingredients / Self-reported survey

73.4% of Swedes didn't know fragrance ingredients don't have to be fully disclosed, and 70.9% didn't know that fragranced products sold as 'green' or 'organic' can also release potentially hazardous air pollutants.

Moderate evidence: Awareness items; the HAP premise itself rests on other studies.

Source: Steinemann 2018 (Sweden), Air Quality, Atmosphere & Health Link to this fact

Hidden ingredients / Measured in people or real products

When researchers tested 25 best-selling US laundry, cleaning, personal-care and air-freshener products, they found 133 different chemicals released into the air, but only 1 of them was listed on any product label.

Moderate evidence: Single headspace sample per product; VOC counts depend on detection threshold.

Source: Steinemann 2011, Environmental Impact Assessment Review Link to this fact

Hidden ingredients / Measured in people or real products

11 of 25 best-selling fragranced products (44%) released at least one chemical the EPA classes as a probable cancer-causing air pollutant, such as acetaldehyde or 1,4-dioxane, though the study couldn't tell whether these came from the fragrance or the rest of the formula.

Moderate evidence: Headspace, not exposure; mostly base-formula compounds.

Source: Steinemann 2011, Environmental Impact Assessment Review Link to this fact

Hidden ingredients / Self-reported survey

About two-thirds (64.6%) of US adults did not know fragrance ingredients don't have to be listed on the label, and more than half would prefer fragrance-free workplaces (53.2% vs 19.7% against) and health care (54.8% vs 22.4%).

Moderate evidence: Opinion survey.

Source: Steinemann 2016, Air Quality, Atmosphere & Health Link to this fact

Hidden ingredients / Measured in people or real products

Counting the word "parfum" undercounts scented children's products, because essential oils and individual fragrance chemicals are listed under other names.

Moderate evidence: Undercount size not measured for these products.

Source: Uber 2024, Jornal de Pediatria (Rio de Janeiro) Link to this fact

Hidden ingredients / Measured in people or real products

In a test of 42 fragranced baby products (shampoos, lotions, oils, sprays), 95% of the chemicals they released into the air were not listed on the label, safety data sheet or company website.

Moderate evidence: Headspace presence only; Australian products.

Source: Nematollahi 2018, Air Quality, Atmosphere & Health Link to this fact

Hidden ingredients / Measured in people or real products

The best-selling US laundry detergent's label and safety sheet disclosed almost none of what it released; only ethanol was listed.

Moderate evidence: Same detergent measured in 2009, 2011 and 2013 papers; count once.

Source: Steinemann 2013, Air Quality, Atmosphere & Health Link to this fact

Hidden ingredients / Review of other studies

One product's safety data sheet listed twelve ingredients, every one of them only as 'trade secret' at '1-100%'.

Moderate evidence: Single example cited by EPA authors.

Source: Goldsmith 2014, Food and Chemical Toxicology Link to this fact

Hidden ingredients / Review of other studies

In a German test of six air fresheners, more than 90% of the chemicals they released were not declared on the product.

Moderate evidence: Secondary citation of Uhde & Schulz 2015 (not in our evidence base); by number of substances (>75% by concentration).

Source: Steinemann 2017, Building and Environment Link to this fact

Hidden ingredients / Review of other studies

Fragrance turns up in products people don't think of as scented: household cleaners and detergents, tampons and panty liners, medicines, medical devices, toys and candles.

Moderate evidence: Qualitative list of exposure sources.

Source: Sukakul 2024, Acta Dermato-Venereologica Industry-funded Link to this fact

Hidden ingredients / Self-reported survey

When companies replace a chemical of concern, they often swap in one with far less safety data; one firm found a supplier's 'safer' substitute only looked safer because more of its ingredients were kept confidential.

Moderate evidence: Interview quotes and one anecdote.

Source: Scruggs 2011, Environmental Science & Policy Link to this fact

Hidden ingredients / Review of other studies

Testing cited by a 2010 review claimed the fragrance solvent DEP was found in all fragrances tested and in 71% of cosmetics, but the largest independent survey since (Koniecki 2011, n=252) found DEP in 70% of fragrances and 41% of cosmetics overall — lower than either earlier figure.

Moderate evidence.

Source: Crinnion 2010, Alternative Medicine Review Link to this fact

Hidden ingredients / Review of other studies

FDA's voluntary cosmetic registration listed benzyl alcohol in only 322 formulations in 1998 and 511 products in 2006, far below its real use in moisturizers, shampoos, baby products and deodorants, which the authors call widespread under-reporting.

Moderate evidence.

Source: Jacob & Barron 2007, Dermatitis Link to this fact

Hidden ingredients / Review of other studies

The glycol-ether solvent propylene glycol methyl ether (PGME), mostly used in industrial coatings and cleaners, is officially listed as a possible 'fragrance ingredient' in cosmetics, and a Swiss survey found it making up 30–50% of one perfume.

Moderate evidence: INCI function listing plus one Swiss product survey (Dentan 2000, cited secondhand); US registry shows only nail-product uses.

Source: CIR 2008, International Journal of Toxicology Industry-funded Link to this fact

Hidden ingredients / Review of other studies

The single word 'fragrance' on a label can stand for dozens to hundreds of chemicals. The fragrance industry's own inventory (RIFM) lists about 2,600 chemicals in current active use, plus roughly 3,500 discontinued materials it keeps only for internal read-across comparison.

Moderate evidence.

Source: Rádis-Baptista 2023, Journal of Xenobiotics Link to this fact

Hidden ingredients / Review of other studies

Several hundred different label names can signal fragrance (chemical names, over 50 essential oils by common or Latin name, and synonyms such as aroma, parfum, perfume and scent), so dermatologists say allergic patients are very unlikely to find fragrance-free products by reading labels alone.

Moderate evidence: Expert opinion.

Source: Rodriguez 2024, Cutis Link to this fact

Hidden ingredients / Review of other studies

A violet-water cologne that doctors reported as a lavender-oil exposure in a boy with breast growth declared no essential oil on its ingredient list, and an essential-oil industry group's lab analysis found none; it reported a synthetic fragrance allergen (alpha-isomethyl ionone), azo dyes and diethyl phthalate instead. Go by the ingredient list of the actual product, not its scent name.

Moderate evidence.

Source: Braunstein & Braunstein 2023, touchREVIEWS in Endocrinology Industry-funded Link to this fact

Hidden ingredients / Review of other studies

Nobody independently analyzed the products used by the children in the 2019 lavender breast-growth case reports: the only published analysis was by an essential-oil trade consortium, which covered two of the three products and reported no numbers; the researchers concede the products contain other, partly synthetic, substances whose composition may vary by where they were bought.

Moderate evidence.

Source: Ramsey et al. 2020 (JCEM reply), The Journal of Clinical Endocrinology & Metabolism Link to this fact

Hidden ingredients / Self-reported survey

About a third of the personal care products people actually used were not in EWG's Skin Deep database at all, including 39% of perfumes and nearly all intimate-care products, so their hazards could not be rated.

Moderate evidence: Database coverage as of July 2022; EWG has since added products.

Source: Barrett 2025, Journal of Exposure Science & Environmental Epidemiology Link to this fact

Hidden ingredients / Measured in people or real products

Once in the air, scent chemicals such as linalool, ionones and the woody musk OTNE ('Iso E Super') reacted with ozone to form dozens of new oxidized chemicals, including a hydroperoxide. None of these was in the product.

Moderate evidence: Compound identities are tentative (formula-level mass spectrometry); products unquantified; no hazard testing.

Source: Wu 2024, Environmental Science & Technology Letters Link to this fact

Hidden ingredients / Animal study

The regulatory endocrine dossier on linalool tested 99.7%-pure, freshly handled material — not the air-oxidized linalool that forms in an opened bottle and that accounts for almost all of linalool's known allergy risk. Nobody has tested whether oxidized linalool is hormonally active.

Moderate evidence: This is standard and correct practice for a REACH dossier; it is a limit on what the result covers, not a flaw in the study.

Source: Hareng 2024, Archives of Toxicology Industry-funded Link to this fact

Hidden ingredients / Review of other studies

Plastic particles are added to cosmetics on purpose for texture, a silky or powdery feel, opacity, shimmer and as carriers for other ingredients, not only as scrub beads; and the EU chemicals agency's definition does not count liquid, semi-solid or water-soluble polymers as microplastics.

Moderate evidence: Definition statement is the review's reading of ECHA; check against Regulation (EU) 2023/2055.

Source: Han & Kim 2025, Cosmetics Link to this fact

Hidden ingredients / Review of other studies

PFOA and GenX, both EU Substances of Very High Concern, may be used in making PTFE; a 2024 review says these impurities must be kept to a minimum but reports no measured levels in cosmetics, and the label says only 'PTFE'.

Moderate evidence.

Source: Jomaa 2024, Journal of the Netherlands Society of Toxicology (JNST) Industry-funded Link to this fact

Hidden ingredients / Measured in people or real products

In 2018, testing commissioned by Breast Cancer Prevention Partners of 25 personal care and 7 cleaning products found chemicals flagged for cancer, hormone disruption, respiratory or developmental hazards that were not on the label; 99 of the 124 were on the fragrance industry's own ingredient list.

Moderate evidence: Not peer reviewed; labs, detection limits and concentrations not reported; hazard = database flag; IFRA list includes multifunctional solvents/preservatives.

Source: BCPP 2018 Link to this fact

Hidden ingredients / Advocacy group testing

In a 2010 survey of more than 11,000 Canadian personal-care products with ingredient lists, 'fragrance' or 'parfum' was the most common ingredient of concern, listed on 56% of products and on about two-thirds of shampoos, soaps and deodorants.

Moderate evidence: Self-selected volunteers read labels; product entries not de-duplicated; 2010 formulations; label count is a lower bound on fragranced products.

Source: David Suzuki Foundation 2010 Link to this fact

Hidden ingredients / Measured in people or real products

Lab tests commissioned by US campaigners found 38 chemicals not listed on the label across 17 popular perfumes; 10 of them had no published safety data at all.

Moderate evidence: NGO report, not peer reviewed; relayed through a student thesis; cite the report itself.

Source: Sarantis et al. 2010 (Not So Sexy), via Gilton 2011 Link to this fact

Hidden ingredients / Lab study (cells or chemistry)

Eight of nine cosmetic UV filters tested were estrogenic in human breast-cancer cells, and six of nine increased uterine weight in immature rats; avobenzone (butyl methoxydibenzoylmethane) was the one inactive in every assay.

Moderate evidence.

Source: Schlumpf 2004, Toxicology Link to this fact

Hidden ingredients / Measured in people or real products

In one of the best-known reports linking 'lavender' products to breast growth in children, the boy's violet-water cologne declared no essential oil on its ingredient list; the essential-oil industry's own analysis found none, but reported a synthetic fragrance allergen (alpha-isomethyl ionone), azo dyes and diethyl phthalate, a fragrance solvent suspected of hormone disruption.

Moderate evidence: Industry-funded letter; GC-MS/LC-MS/MS results given as prose with no concentrations, detection limits, lab or sample provenance; not independently confirmed.

Source: Giroux & Orjubin 2020 (JCEM letter; Consortium Huiles Essentielles), The Journal of Clinical Endocrinology & Metabolism Industry-funded Link to this fact

Hidden ingredients / Review of other studies

The only chemical analysis ever published of the products named in the 2019 lavender breast-growth case reports was done by an essential-oil trade group, covered two of the three products and reported no numbers.

Moderate evidence: True of the published literature as read; the NIEHS reply to this letter (dgaa227) has not been read.

Source: Giroux & Orjubin 2020 (JCEM letter; Consortium Huiles Essentielles), The Journal of Clinical Endocrinology & Metabolism Industry-funded Link to this fact

Hidden ingredients / Measured in people or real products

In a Belgian test of 10 scented tampons, panty liners and pads, 8 of the 24 fragrance allergens that EU cosmetics must name were found; all 4 tampons and 1 liner held at least one above 10 µg/g, the level at which a cosmetic would have to list it, and none named any allergen on the pack.

Moderate evidence: 10 products from one country (2019); presence in product, not transfer to the body; mostly weak sensitizers at 0.001-0.01%.

Source: Desmedt 2020, Contact Dermatitis Link to this fact

Hidden ingredients / Measured in people or real products

The fragrance allergens found most in scented tampons were α-isomethyl ionone (in every tampon, 12.6-19.1 µg/g) and hexyl cinnamal, not the familiar citrus and lavender terpenes.

Moderate evidence: N=4 tampons, Belgian market; limonene/linalool may be under-read by a headspace method that sees parents only.

Source: Desmedt 2020, Contact Dermatitis Link to this fact

Hidden ingredients / Review of other studies

FDA's own 1998 registry data, reproduced in full by the industry's cosmetic safety panel, show benzyl alcohol's biggest single cosmetic use was hair dye (130 of 1,572 formulations), with smaller counts in baby shampoo (5 of 21), baby lotion (3 of 53), moisturizers (8 of 769) and body/hand skin care (16 of 796).

Moderate evidence: Voluntary registry counts (Jan 1998); concentration-of-use reporting to FDA had already stopped by 1992 per the same report, so these are presence counts, not amounts used.

Source: Nair 2001 (CIR Expert Panel), International Journal of Toxicology Industry-funded Link to this fact

Hidden ingredients / Measured in people or real products

A 2024 lab study of six cosmetics found that ingredient labels can misdescribe the PFAS actually present: one product's named ingredient (a silane) appeared to be a different molecular isomer than the standard, and another's named phosphate-ester ingredient did not disclose that it contained shorter fluorocarbon chain lengths than its name implies.

Moderate evidence: Small sample (6 products from one country, 2 with naming issues); does not establish how common INCI-naming errors are across the wider market.

Source: Namazkar 2024, Environmental Science: Processes & Impacts Link to this fact

Hidden ingredients / Measured in people or real products

Benzyl alcohol, a fragrance allergen dubbed the "covert fragrance," was found in 32 of 533 US baby and children's personal care products (6%) with no "fragrance," "perfume," or "parfum" wording anywhere on the label.

Moderate evidence: Doesn't establish whether these products are marketed "fragrance-free"; measures label wording, not chemical content verification.

Source: Bonchak 2018, Dermatitis Link to this fact

Hidden ingredients / Measured in people or real products

Only 16% of the chemicals detected above the testing limit in these hair products were listed anywhere on the product label; fragrance ingredients were almost never named individually, appearing instead as the single word "fragrance".

Moderate evidence: Label concordance rose to 54% only for the highest-concentration chemicals (>1000 ug/g); 28 product/component labels checked.

Source: Helm 2018, Environmental Research Link to this fact

Hidden ingredients / Animal study

The air freshener's exact formulation is proprietary; GC/MS of its emissions identified toluene, limonene, alpha- and beta-pinene, terpinolene, sabinene and about a dozen other volatiles the consumer has no way to learn about from the label.

Moderate evidence: Qualitative GC/MS of one product, one test atmosphere, recoveries unknown; only peaks with 90%+ library-match certainty reported; brand unnamed.

Source: Anderson & Anderson 1997, Archives of Environmental Health Link to this fact

Hidden ingredients / Measured in people or real products

FDA's own testing of 48 consumer cosmetic products found the fragrance solvent diethyl phthalate (DEP) in all 5 fragrance products tested, at levels up to 38,663 parts per million (3.9% by weight), and in 27 of 48 products overall, though phthalate esters were named on the ingredient list of only some nail products, never on fragrance.

Moderate evidence: Single FDA laboratory, 48 products bought in the Washington DC area (~2003-05), method-validated HPLC-UV; concentration in the product, not absorbed dose.

Source: Hubinger & Havery 2006, Journal of Cosmetic Science Link to this fact

Hidden ingredients / Measured in people or real products

A common personal-care-product ingredient can appear on ingredient labels under several different chemical names (the silicone D5 may be listed as 'cyclopentasiloxane' or 'cyclomethicone'), which may not read as the same substance to a consumer trying to identify or avoid it.

Moderate evidence: Based on this study's own tested product labels and general INCI naming conventions for volatile methyl siloxanes, not a systematic label-disclosure survey.

Source: Coggon 2018, Environmental Science & Technology Link to this fact

Hidden ingredients / Measured in people or real products

Independent laboratory testing not funded by the essential-oil or fragrance industry chemically confirmed that one of these colognes genuinely contained lavender oil (linalool and linalyl acetate), the only time this has been done for an actual implicated product in this literature rather than a reference oil bought for a lab study.

Moderate evidence.

Source: Diaz 2016, Journal of Pediatric Endocrinology and Metabolism Link to this fact

Hidden ingredients / Other evidence

California state scientists estimate that the mass of PFAS in cosmetics is concentrated not in makeup but in shaving creams and gels, hair care products, facial cleansers, sun care products, and lotions and moisturizers, which together make up more than 90% of the total estimated PFAS mass in California cosmetics sold each year, while all makeup categories combined make up less than 3%.

Moderate evidence.

Source: Balan 2024, Environmental Science & Technology Link to this fact

Hidden ingredients / Measured in people or real products

Fragrance materials not known to occur in any natural essential oil were found in products marketed as natural: a 'natural' body lotion contained 0.082% alpha-amylcinnamic aldehyde, a concentration that would require the essential oil itself to be about 16% pure synthetic aldehyde if it came from any known essential oil at typical use levels — evidence the 'natural' formulation included added synthetic fragrance material.

Moderate evidence.

Source: Rastogi 1996, Contact Dermatitis Link to this fact

Hidden ingredients / Self-reported survey

Only about 1 in 4 Germans (27.5%) know that fragrance chemicals do not have to be fully disclosed on a product's label or safety data sheet.

Moderate evidence: Awareness item, not a measurement of actual disclosure; Germany 2019, n=1,102.

Source: Klaschka 2020a, Environmental Sciences Europe Link to this fact

Indoor air / Self-reported survey

19.4% of Australians reported health problems from being near someone wearing fragrance and 16.4% from air fresheners.

Moderate evidence: Self-report; no exposure measurement; counts 213/1,098 and 180/1,098 confirmed in Steinemann 2018 (MCS, AU) Table 2, same dataset.

Source: Steinemann 2017, Preventive Medicine Reports Link to this fact

Indoor air / Self-reported survey

About 1 in 6 adults (17%) in four countries said air fresheners or deodorizers make them unwell; of those, half reported breathing problems.

Moderate evidence: Self-report, no objective measure.

Source: Steinemann 2019, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Self-reported survey

41% of US adults with asthma reported health problems from air fresheners, and 36.7% said they can't use a public restroom that has one.

Moderate evidence: Self-report.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Self-reported survey

23.5% of Swedes reported health problems from being near someone wearing a fragranced product.

Moderate evidence: Self-report.

Source: Steinemann 2018 (Sweden), Air Quality, Atmosphere & Health Link to this fact

Indoor air / Self-reported survey

About 1 in 5 US adults (20.4%) reported health problems from air fresheners, and 23.6% from being near someone wearing a fragranced product.

Moderate evidence: Self-report; no exposure measurement.

Source: Steinemann 2016, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Self-reported survey

About 1 in 5 Australians with asthma (21.4%) said they can't or won't use public toilets that have air fresheners.

Moderate evidence: Self-report.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Measured in people or real products

Scented laundry products put fragrance chemicals into outdoor air: in two homes, limonene (a citrus scent chemical) came out of the dryer vent only when fragranced detergent or dryer sheets were used (up to 14.7 ug/m3), not in the no-product runs.

Moderate evidence.

Source: Steinemann 2013, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Measured in people or real products

In a room-sized test chamber, mopping with a pine-oil cleaner or spraying an orange-oil degreaser, with ozone at typical summer-smog levels, produced 130-280 µg/m³ of fine particles, versus 2-5 µg/m³ when the same products were used without ozone.

Moderate evidence.

Source: Singer 2006, Atmospheric Environment Link to this fact

Indoor air / Measured in people or real products

Scent chemicals in cleaners and air fresheners react with ozone that drifts in from outdoors to make formaldehyde: cleaning raised formaldehyde by 9-16 ppb for 4 hours, and a plug-in air freshener raised it by about 6 ppb for as long as it ran.

Moderate evidence.

Source: Singer 2006, Atmospheric Environment Link to this fact

Indoor air / Measured in people or real products

After 2-7 minutes of cleaning with a terpene cleaner, indoor air chemistry stayed altered for 10-12 hours because the scent chemicals soaked into walls and floors and came back out.

Moderate evidence.

Source: Singer 2006, Atmospheric Environment Link to this fact

Indoor air / Measured in people or real products

In a European study that measured the air 182 adults actually breathed over 48 hours, exposure to pine- and citrus-type scent chemicals from cleaning products and fragrances rose with the number of children at home (3-carene median 0.9 to 2.5 µg/m³); the authors attribute this to more cleaning.

Moderate evidence: Late-1990s, small subgroups, attribution to cleaning is the authors' inference; CEFIC-LRI co-funded.

Source: Edwards 2006, Atmospheric Environment Industry-funded Link to this fact

Indoor air / Self-reported survey

Air fresheners were the most common secondhand trigger: 15.5% of UK adults reported health problems from them, and 12.1% avoid or are reluctant to use public restrooms that have them.

Moderate evidence: Self-report.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Measured in people or real products

Keeping a gel air freshener in a car raised the fragrance chemical limonene in the air the driver breathed 3.6-4.7 times, to about 19-28 ug/m3, during real commutes (10 cars tested).

Moderate evidence: N=5 per group, non-randomized; mostly drivers' own products.

Source: Jo 2008, Chemosphere Link to this fact

Indoor air / Measured in people or real products

In lab tests, gel air fresheners released limonene at up to 1.5 mg per hour, far more than any other chemical measured.

Moderate evidence.

Source: Jo 2008, Chemosphere Link to this fact

Indoor air / Measured in people or real products

Indoors, vapors from these products run about 7 times higher than outdoors, and include fragrance chemicals such as limonene.

Moderate evidence: Box model checked against indoor measurements.

Source: McDonald 2018, Science Link to this fact

Indoor air / Measured in people or real products

Mopping a room with a terpene-based (pine- or citrus-type) cleaner caused bursts of tiny new particles, about 100 times the particle count of outdoor air, as the scent chemicals reacted with ozone.

Moderate evidence.

Source: Rosales 2022, Science Advances Link to this fact

Indoor air / Measured in people or real products

During mopping with a terpene cleaner, scent chemicals such as limonene and pinene peaked at 280-380 ppb in the room air.

Moderate evidence.

Source: Rosales 2022, Science Advances Link to this fact

Indoor air / Measured in people or real products

Homes painted, refurnished or re-floored in the previous 6 months had higher levels of indoor chemicals released into the air (including toluene and xylenes) than other homes.

Moderate evidence: Not a fragrance finding.

Source: Maisey 2013, Atmospheric Environment Link to this fact

Indoor air / Measured in people or real products

For the third of homes using p-dichlorobenzene products, the upper-bound cancer risk was about 3x the population average (~270 vs 90 in a million).

Moderate evidence: Upper-bound 1991 potencies, 7-10x above best estimates.

Source: Wallace 1991, Environmental Health Perspectives Link to this fact

Indoor air / Measured in people or real products

A limonene-scented foam cleaner released formaldehyde, an irritant and carcinogen, both directly and through reactions with ozone after use.

Moderate evidence.

Source: Rossignol 2013, Atmospheric Environment Link to this fact

Indoor air / Measured in people or real products

Scent was only part of what a scented cleaner released: its glycol-ether solvent reached about 1,100 ug/m3 in room air against 71 ug/m3 for limonene.

Moderate evidence.

Source: Rossignol 2013, Atmospheric Environment Link to this fact

Indoor air / Review of other studies

Average indoor formaldehyde in homes exceeded California's long-term health limit (9 µg/m³) in every European country the EU's own researchers assessed.

Moderate evidence: Secondary data; formaldehyde mainly from building materials, not shown to be from fragrance.

Source: Sarigiannis 2011, Environment International Link to this fact

Indoor air / Review of other studies

EU researchers attributed large swings in home limonene levels within the same city to whether people had used a fragrance, air freshener or cleaning product before the air was sampled.

Moderate evidence.

Source: Sarigiannis 2011, Environment International Link to this fact

Indoor air / Review of other studies

The standard week-long air tests used across Europe miss the short spikes of chemicals released after cleaning, which could change the risk picture for eye and airway irritation.

Moderate evidence: Authors' methodological caveat, not a measured result.

Source: Sarigiannis 2011, Environment International Link to this fact

Indoor air / Lab study (cells or chemistry)

In lab chamber tests set up to mimic a room, the citrus scent chemical limonene reacted with ozone in the air to form fine particles carrying reactive oxygen species.

Moderate evidence.

Source: Chen & Hopke 2010, Indoor Air Link to this fact

Indoor air / Lab study (cells or chemistry)

Limonene produced 2 to 11 times more of these reactive particles than alpha-pinene, the pine scent chemical.

Moderate evidence: Chamber comparison only.

Source: Chen & Hopke 2010, Indoor Air Link to this fact

Indoor air / Government agency

EPA notes that people using products can expose themselves and others to very high pollutant levels, and that elevated levels can persist in the air long after the activity ends.

Moderate evidence: About product use in general; the peak example given is paint stripping (up to 1,000x outdoor), not fragrance.

Source: US EPA 2026 Link to this fact

Indoor air / Measured in people or real products

In an office-sized test room with some ozone in the air, a single ordinary spray of perfume, body spray or hair spray, or a dab of hand lotion, set off a burst of new ultrafine particles within minutes, reaching 34,000–200,000 particles per cubic centimeter, more than in many city streets.

Moderate evidence: One chamber, 5 products, one use each; ozone held at 35–40 ppb (high end for indoors); masked volunteer; no toxicity measured.

Source: Wu 2024, Environmental Science & Technology Letters Link to this fact

Indoor air / Measured in people or real products

Almost everything in a perfume ends up in the air: one perfume released 964 mg of vapor per gram used, mostly alcohol but also about 32 mg per gram of terpene fragrance chemicals.

Moderate evidence: One perfume; emission factors are lower bounds (PTR-MS blind to some compounds).

Source: Wu 2024, Environmental Science & Technology Letters Link to this fact

Indoor air / Measured in people or real products

Skipping showers for one or two days raised skin-derived acetic acid emissions by 84% and 172%, and increased the products of ozone reacting with skin.

Moderate evidence: 4 men; bacterial origin of the acids is inferred, not measured; fragrance-free soap/shampoo used throughout.

Source: Wang 2024, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

Pure limonene only irritates human eyes at about 445 mg/m³, far above indoor levels. A limonene-ozone mixture reacted for just 10 minutes raises eye-blink rates at roughly 1,000-2,000x less limonene: Klenø & Wolkoff (2004, n=8, primary) found residual 0.42 mg/m³ limonene + 0.08 mg/m³ ozone raised blink frequency 42% (P<0.0001); Nøjgaard (2005, n=10, primary) found a lower dose, 0.23 mg/m³ limonene + 0.08 mg/m³ ozone, gave a smaller but still significant +17% (p=0.003).

Moderate evidence.

Source: Wolkoff 2013, International Journal of Hygiene and Environmental Health Link to this fact

Indoor air / Other evidence

In mouse tests, about three-fourths of the airway irritation from limonene reacting with ozone came from formaldehyde and residual limonene together (formaldehyde the dominant contributor, at roughly 17-22 percentage points; residual limonene a small but real contributor, under 5 percentage points), not from the particles.

Moderate evidence.

Source: Wolkoff 2013, International Journal of Hygiene and Environmental Health Link to this fact

Indoor air / Review of other studies

An indoor-air toxicologist recommends measuring limonene in offices because this common fragrance 'easily undergoes ozonolysis producing oxidation products that includes formaldehyde'.

Moderate evidence.

Source: Wolkoff 2013, International Journal of Hygiene and Environmental Health Link to this fact

Indoor air / Measured in people or real products

Indoor ozone reacts with the natural oils on our skin. In a test room with four people and 35 ppb ozone, this alone kept highly reactive hydroxyl (OH) radicals at about 7×10⁵ per cm³, similar to levels measured in empty rooms after cleaning with pine or citrus products.

Moderate evidence.

Source: Zannoni 2022, Science Link to this fact

Indoor air / Measured in people or real products

OH radicals attack almost every organic chemical in indoor air, not only the ~10% that ozone reacts with, and these reactions happen in the air closest to our bodies; the researchers note that many of the resulting products have never been tested for toxicity.

Moderate evidence: No toxicity or health endpoint measured; the 'untested' statement is the authors' assessment.

Source: Zannoni 2022, Science Link to this fact

Indoor air / Instrument measurement

The 'air quality index' on home air monitors is driven by particles; it did not move when only solvent-type products (nail polish remover, hair dye) were used, even though the VOC reading rose.

Moderate evidence: One unnamed device; its AQI does not follow the US EPA scale.

Source: Grigoryants 2025, Cureus Link to this fact

Indoor air / Journalism

In 2003 Southern California air regulators estimated that household and small-business products, including cleaners, cosmetics, perfume and room fresheners, released about 108 tons of smog-forming chemicals a day in the Los Angeles region, second only to vehicle tailpipes.

Moderate evidence: Agency inventory relayed by the LA Times; for measured/modeled figures use McDonald 2018 (LA) and Coggon 2021 (NYC 2018: VCPs comparable to vehicle fuels for ozone).

Source: DONTSPRAYCALIFORNIA 2008 (DOJ ADA docket) Link to this fact

Indoor air / Measured in people or real products

A new Little Tree car air freshener releases most of its limonene in the first few days: in a closed car the limonene signal halved roughly every day and was nearly gone within 4-5 days.

Moderate evidence: Relative peak areas only, no concentrations; one car and one scent; baseline not shown.

Source: Pino-Delgado 2021 (J Student Res), Journal of Student Research Link to this fact

Indoor air / Self-reported survey

Among Australians with diagnosed multiple chemical sensitivities, about three in four (77.5%) said a fragranced product had kept them from going somewhere, and about two in three (64.8%) can't or won't use public toilets with air fresheners.

Moderate evidence: N = 71 (95% CI roughly +/-10-12 points); self-report.

Source: Steinemann 2018, Preventive Medicine Reports Link to this fact

Indoor air / Measured in people or real products

When 40 ppb of ozone was added to a room holding a mix of 23 common indoor chemicals, including the citrus and pine scent chemicals limonene and alpha-pinene, formaldehyde tripled (13 to 40 µg/m³), ultrafine particles rose about 18-fold (2,500 to 46,000 per cm³) and particle mass reached 140 µg/m³.

Moderate evidence: Chamber with VOC load ~10x typical buildings; 23-compound office mixture, not a fragranced product; other alkenes also react.

Source: Fiedler 2005, Environmental Health Perspectives Link to this fact

Indoor air / Self-reported survey

Among US adults reporting diagnosed multiple chemical sensitivity, 59% said they could not use a public restroom with an air freshener and 70% had been kept from going somewhere by fragranced products.

Moderate evidence: Self-report; small subgroup (n=145) in one online panel.

Source: Steinemann 2018 (JOEM), Journal of Occupational and Environmental Medicine Link to this fact

Indoor air / Measured in people or real products

When moisturizer goes on the face, the wearer breathes a short burst of its vapors (alcohol, fragrance terpenes, benzyl alcohol) that room-air monitoring does not capture; at a mannequin's nose, alcohols and terpenes took about 30 minutes to fade and some solvents up to 2.5 hours.

Moderate evidence: Mannequin head, no people; unheated face (21 °C vs 32–34 °C skin) and a 5-ACH lab; the size of the burst is disputed (tabulated doses do not match the plotted traces).

Source: Yeoman 2022, Indoor Air Link to this fact

Indoor air / Measured in people or real products

With four people in a test room and indoor ozone at about 35 ppb, the chemical reactivity of the air roughly tripled once ozone was added (from about 8–11 to 25–35 per second). Almost all of the increase came from carbonyls made when ozone hit the natural oils on skin, and across the whole study ozone explained 85% of the variation.

Moderate evidence: One chamber (22.5 m³, 3.2 h⁻¹, mixing fans), one ozone level tested on/off; no health endpoint; fragrance-free products used throughout.

Source: Zannoni 2021, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

Wearing shorts and t-shirts instead of long clothes raised the skin-ozone products 6-MHO, 4-oxopentanal and geranyl acetone by 35–51%. Clothes that had been worn for a few hours took up ozone about as fast as bare skin, because skin oil moves into the fabric.

Moderate evidence: One group of 4 young adults, ~35 ppb ozone; chemistry only; 6-MHO values may be inflated by an inlet artifact.

Source: Zannoni 2021, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

A dried film of pine-oil cleaner or orange-oil degreaser, with its scent chemicals already evaporated away, still produced formaldehyde and a burst of new particles when later exposed to ozone.

Moderate evidence: Single glass-plate surface test per product in a lab chamber, not tested on real room surfaces (carpet, fabric, furniture).

Source: Destaillats 2006, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

Wiping a small kitchen table with a few grams of an ordinary spray cleaner put 270-2,300 ug/m3 of the solvent 2-butoxyethanol into the air of a room-sized test chamber for the next hour; four of five cleaners tested contained it.

Moderate evidence: 50 m3 empty chamber, use rate at the ~84th percentile of observed users; real furnished rooms sorb glycol ethers faster, lowering peaks.

Source: Singer 2006, Indoor Air, Indoor Air Link to this fact

Indoor air / Measured in people or real products

Cleaning with a pine-oil or citrus cleaner raised scent chemicals (limonene, terpinolene, alpha-terpineol) to about 1,000-6,000 ug/m3 for the first hour in a room-sized chamber, and some stayed elevated for many hours afterwards.

Moderate evidence: Empty chamber; one product per formulation; alpha-terpineol's persistence depends on surface water films and towels left in the room.

Source: Singer 2006, Indoor Air, Indoor Air Link to this fact

Indoor air / Measured in people or real products

A plug-in scented-oil air freshener evaporated 1.5 g of product a day and kept its scent chemicals at 30-160 ug/m3 in the room over three days; its two largest emissions were fragrance esters (bornyl and benzyl acetate, 280-410 ug/m3), not the ozone-reactive terpenes usually studied.

Moderate evidence: One plug-in product; a different air-freshener type (e.g. limonene-selected gels, Jo 2008) can be limonene-dominant instead.

Source: Singer 2006, Indoor Air, Indoor Air Link to this fact

Indoor air / Measured in people or real products

Leaving used paper towels in the room after cleaning increased the solvent and scent chemicals released by 35-100%.

Moderate evidence: Measured over 24 h in an empty chamber.

Source: Singer 2006, Indoor Air, Indoor Air Link to this fact

Indoor air / Measured in people or real products

Scented spray products — spray and plug-in air fresheners, dusting sprays — were among the specific product types most strongly associated with childhood wheeze and asthma risk in this Canadian birth cohort.

Moderate evidence.

Source: Parks et al. 2020, CMAJ (Canadian Medical Association Journal) Link to this fact

Indoor air / Measured in people or real products

When the same volunteers breathed through a mask into a separate room, so only their breath (not their skin) was in contact with the air, indoor ozone barely changed at all — showing the ozone-removing chemistry happens on skin and clothing, not from exhaling.

Moderate evidence: Based on a single experiment (Experiment 12) in the ICHEAR chamber; not replicated across groups.

Source: Bekö 2020, Indoor Air Link to this fact

Indoor air / Test-chamber measurement

A car air freshener's own terpenes (alpha-pinene, beta-pinene, p-cymene, limonene) react with in-vehicle ozone to form ultrafine particles and irritant gases (formaldehyde, acetaldehyde, acrolein) that never appear on the product's ingredient list, because they are made in the cabin air, not sold in the bottle.

Moderate evidence.

Source: Lamorena & Lee 2008 (J Hazard Mater), Journal of Hazardous Materials Link to this fact

Indoor air / Measured in people or real products

In a real working primary school, mopping a classroom with a limonene-containing detergent produced bursts of tens of thousands of tiny new particles per cubic centimeter within minutes, but only when ozone was present in the air; a plain water-only mop produced no such burst.

Moderate evidence.

Source: Morawska 2009, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

A limonene-cleaning event needs indoor ozone above roughly 5 parts per billion to trigger a detectable burst of new ultrafine particles; below that threshold, in this study's controlled trials, essentially no particle formation occurred.

Moderate evidence.

Source: Morawska 2009, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

Nearly all (93%) of the DC childcare facilities studied used chlorine bleach to sanitize surfaces, and chloroform (a bleach byproduct classified by IARC as possibly carcinogenic to humans, Group 2B) was detected in 100% of air samples; the authors attribute it mainly to bleach use.

Moderate evidence: Association, not a measured reaction; bleach usage self-reported, chloroform sources not otherwise investigated.

Source: Quirós-Alcalá 2016, Environmental Research Link to this fact

Indoor air / Measured in people or real products

Among 3,411 Czech households with an infant, the most commonly used chemical products were window cleaner (88%), deodorant (82%) and aerosol/hairspray products (74%) — not air fresheners, which were the second-least-used of 18 chemical product categories (26%).

Moderate evidence: Self-reported product use frequency, one Central European cohort; product prevalence does not equal exposure dose or emission rate.

Source: Mikeš 2019, Science of the Total Environment Link to this fact

Indoor air / Measured in people or real products

A 10-minute-old reacted mixture of limonene and ozone (residual 75 ppb limonene + 40 ppb ozone) raised human eye-blink frequency 42% relative to clean air, while the same men's eyes exposed separately to just limonene, or just ozone, at similar or higher levels, did not blink more.

Moderate evidence.

Source: Klenø & Wolkoff 2004 Link to this fact

Indoor air / Review of other studies

The four most common airborne fragrances in homes and offices — pinene, limonene, linalool and eugenol — are usually present at levels 2 to 3 times below the concentration needed to physically irritate the eyes and airways, but at or above the much lower level needed just to smell them.

Moderate evidence.

Source: Wolkoff & Nielsen 2017, Environment International Link to this fact

Indoor air / Measured in people or real products

In the two largest, most realistic human tests to date, breathing a fragrance-and-ozone reaction mixture (the kind formed when a citrus-scented product meets indoor ozone) produced no measurable increase in eye, nose or throat irritation, in either healthy people or asthmatics.

Moderate evidence.

Source: Wolkoff & Nielsen 2017, Environment International Link to this fact

Indoor air / Animal study

A Danish government toxicology lab derived a specific reference value for 4-oxopentanal (4-OPA), a common byproduct when ozone reacts with skin oils and fragrance terpenes indoors: 30 ppb (123 ug/m3), from mouse bronchoconstriction data with standard safety margins applied. Measured office and aircraft-cabin 4-OPA levels (2-10 ppb) sit below this value, though ventilation-filter and occupied-room measurements (up to 10-16 ppb) come closer.

Moderate evidence.

Source: Wolkoff et al. 2012/2013, Toxicology Letters Link to this fact

Indoor air / Animal study

Of five common ozone-terpene reaction products tested in mice (4-AMCH, dihydrocarvone, IPOH, 6-MHO and 4-OPA), the study's own conclusion was that four do not contribute substantially to airway irritation at indoor or ambient concentrations; only IPOH (sensory irritation) and 4-OPA (airflow limitation) were flagged as compounds of concern warranting precaution against excess formation.

Moderate evidence: Single animal study, one lab (NRCWE Copenhagen); precautionary conclusion, not evidence that current indoor exposure causes harm.

Source: Wolkoff et al. 2012/2013, Toxicology Letters Link to this fact

Indoor air / Measured in people or real products

In a study of 25 UK homes using real whole-air canister sampling (not a lab chamber), the scent chemicals D-limonene and alpha-pinene were the single most abundant VOC measured in 94% of homes, regardless of building age, size or occupancy.

Moderate evidence.

Source: Wang 2017, Environmental Science: Processes & Impacts Link to this fact

Indoor air / Measured in people or real products

The UK home with the heaviest, most frequent use of cleaning and fragranced products (9 different products, some used more than 10 times in a week, plus a scented candle) had a 5-day average D-limonene concentration of up to 1,439 ug/m3, around 80 times the study's median home and possibly the highest domestic value reported in the literature at the time.

Moderate evidence: Single home out of 25 driving the extreme; 5-day average, not a short-term peak, which the authors state was likely higher.

Source: Wang 2017, Environmental Science: Processes & Impacts Link to this fact

Indoor air / Measured in people or real products

A personal-care product containing the silicone D5 (such as a deodorant applied hours earlier) can raise D5 levels inside a car far above outdoor background, and this passenger-carried D5 vents out of the car and mixes with the vehicle's exhaust-associated emissions when the cabin fan runs.

Moderate evidence.

Source: Coggon 2018, Environmental Science & Technology Link to this fact

Indoor air / Measured in people or real products

In a study of 60 UK homes with real air sampling (not a lab chamber), the VOC found in the highest concentration indoors was n-butane, an aerosol-spray propellant, not a fragrance chemical; it reached a wintertime maximum of 4,630 ug/m3, and aerosol antiperspirant/deodorant was the single most universally used VOC-releasing product, used in all 60 homes.

Moderate evidence: One UK town's panel-recruited cohort (Ashford, Kent); Givaudan-funded (fieldwork), analysis independent at University of York.

Source: Heeley-Hill 2021, Environmental Science: Processes & Impacts Industry-funded Link to this fact

Indoor air / Measured in people or real products

Indoor VOC levels exceeded outdoor levels in the large majority of homes studied — 84% in summer and 100% in winter — confirming that for this cohort, indoor air, not outdoor air, was the dominant source of VOC exposure.

Moderate evidence: Outdoor samples were not individually paired with every indoor home/period; mean seasonal outdoor values used for comparison.

Source: Heeley-Hill 2021, Environmental Science: Processes & Impacts Industry-funded Link to this fact

Indoor air / Measured in people or real products

Even with daily diary records of exactly how often 60 households used 13 different types of scented and cleaning products over three days, how often people used these products did not predict how much VOC was in their home's air (R-squared less than 0.001 for total VOC; no individual VOC, including limonene, showed a significant relationship).

Moderate evidence: Frequency of use, not dose per use or product formulation, was recorded; a narrow, weak exception existed for limonene with insecticide/plug-in-air-freshener use specifically.

Source: Heeley-Hill 2021, Environmental Science: Processes & Impacts Industry-funded Link to this fact

Indoor air / Animal study

In a mouse study, when scientists physically separated the invisible ultrafine particles from the gas fumes made by citrus-scent limonene reacting with ozone, the airway-irritating effect disappeared entirely, showing it's the gas products, led by formaldehyde, that irritate, not the particles themselves.

Moderate evidence.

Source: Wolkoff et al. 2008, Toxicology Letters Link to this fact

Indoor air / Animal study

In the same mouse study, formaldehyde formed by the limonene-ozone reaction, together with the leftover limonene itself, accounted for roughly three-quarters of the airway-irritating effect measured; formaldehyde was the dominant contributor.

Moderate evidence.

Source: Wolkoff et al. 2008, Toxicology Letters Link to this fact

Indoor air / Measured in people or real products

Dryer-vent air carried far more of the citrus-scent chemical D-limonene when households used fragranced laundry detergent (2.35-118 ug/m3, mean 33.34) than when they used fragrance-free detergent (0.13-1.50 ug/m3 after switching; 0.24-0.26 ug/m3 in households that never used fragranced detergent).

Moderate evidence.

Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Measured in people or real products

Switching to fragrance-free laundry detergent also reduced D-limonene in the laundry room's own indoor air, not just at the dryer vent, by up to 72.7% (mean 45.8%) within one month.

Moderate evidence: 4 households, single background-air sample per round, no statistical testing.

Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact

Indoor air / Measured in people or real products

Every one of 25 fragranced laundry products tested (US and Australian detergents and dryer sheets) emitted a terpene fragrance chemical (such as limonene, alpha-pinene or eucalyptol), while none of 10 fragrance-free laundry products emitted any terpene at all.

Moderate evidence.

Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact

The industry / Self-reported survey

Even the companies selling products often don't know everything in them: all 20 'leader' consumer-product companies interviewed said ingredient or hazard information could be hard to get from suppliers, and 7 named suppliers' trade-secret claims as a major obstacle.

Moderate evidence: Interview study, 20 self-selected companies, 2009; no fragrance firms identified.

Source: Scruggs 2011, Environmental Science & Policy Link to this fact

The industry / Self-reported survey

Only 1 of 20 leading consumer-product companies could test its own products' chemistry in-house; most relied on suppliers' signed promises (18 of 20).

Moderate evidence: Counts are interview mentions.

Source: Scruggs 2011, Environmental Science & Policy Link to this fact

The industry / Lab study (cells or chemistry)

The fragrance industry's own data show its main explanation for how fragrance chemicals cause allergy doesn't cover most of them: 34 of 62 ingredients (55%) sensitize despite having no predicted protein-binding alert.

Moderate evidence.

Source: Lee 2024, Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

The non-animal tests now used to set fragrance safety levels are typically off by about 2 to 3 times when predicting how potent an ingredient is.

Moderate evidence.

Source: Lee 2024, Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

Those models underestimated allergy potency by more than fivefold for 18% of the 188 chemicals tested, and more than tenfold for 11%.

Moderate evidence.

Source: Natsch & Gerberick 2022, ALTEX Industry-funded Link to this fact

The industry / Animal study

Older synthetic musks (musk ambrette, AETT) caused nerve damage in animal studies and were later restricted.

Moderate evidence.

Source: Pinkas 2017, Environmental Research Link to this fact

The industry / Journalism

A perfumer writing in a chemistry journal said a natural ingredient such as rose oil is sometimes added in a "negligible quantity only to be able to say that you have rose oil in your formula", which "will please the marketing people" but does nothing for the scent.

Moderate evidence: Opinion; she advises against the practice and gives no frequency.

Source: Ellena 2008, Chemistry & Biodiversity Industry-funded Link to this fact

The industry / Animal study

Citronellol is treated as safe by default – GRAS at the US FDA, a 'non-toxic' biopesticide at the US EPA, and limited only by the fragrance industry's own voluntary IFRA standard – yet this government-funded study found it is brain-penetrant and calls for its content in consumer products to be regulated.

Moderate evidence: The call for regulation is the authors' conclusion from high-dose animal data; funded by the Korean Ministry of Environment, no industry money.

Source: Kim 2024, Journal of Hazardous Materials Link to this fact

The industry / Review of other studies

The industry's permitted levels for rose ketones (up to 0.07-0.8% depending on product type) overlap the concentrations at which already-sensitized volunteers reacted (0.05-0.1%), because the risk assessment is designed to prevent new allergies rather than to protect people who already have one.

Moderate evidence.

Source: Lalko 2007 (RIFM), Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Review of other studies

The fragrance industry's safety assessment of 17 salicylates counted exposure from 10 personal-care product types only. Household cleaners and detergents, which the same report lists as uses, and breathing fragrance in were not included.

Moderate evidence.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Review of other studies

The industry panel judged each salicylate's safety one chemical at a time, although the same report says all 17 are broken down in the body to the same substance, salicylic acid.

Moderate evidence.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Measured in people or real products

In a French fragrance-and-flavor factory, the company's own measurements found the butter-flavor chemical diacetyl (linked to 'popcorn lung' in US factory workers) in workers' breathing air at 0.05–9 ppm during short tasks; 29 of 31 samples were above the 15-minute limit of 0.1 ppm recommended by the EU's scientific committee on occupational limits.

Moderate evidence.

Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact

The industry / Measured in people or real products

The standard EU (REACH) screening tool for estimating workers' chemical exposure predicted lower levels than were actually measured in 61% of 431 measurements in a fragrance-and-flavor factory, sometimes by more than 100-fold.

Moderate evidence: One plant; evidence base count from the paper's S4 table (paper: 37% of tool predictions were above the measurement); short task samples.

Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact

The industry / Self-reported survey

More than a third of Germans (37.8%) think people who wear perfume are more hygiene-conscious; fragrance can mask a smell but does not clean.

Moderate evidence: Attitude item; the 'does not clean' half is the author's argument, not a measurement.

Source: Klaschka 2020, Environmental Sciences Europe Link to this fact

The industry / Animal study

This lavender study was funded by a university with no declared industry involvement, unlike much of the evidence used to argue these oils are safe for children, which comes from the essential-oil trade or from a manufacturer of lavender's main constituents.

Moderate evidence.

Source: Kim & Lim 2022, Journal of Korean Medical Science Link to this fact

The industry / Animal study

The industry's guideline testing cleared the two lavender molecules that were NOT the most active ones: in the study it was answering, alpha-terpineol and terpinen-4-ol were the strongest on both the estrogen and androgen receptors, and BASF tested neither.

Moderate evidence: Comparison across two papers (Hareng 2024 vs Ramsey 2019) using different assay systems; the point is the untested molecules, not a disagreement about the tested ones.

Source: Hareng 2024, Archives of Toxicology Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

The hormone safety testing on lavender and tea tree oil constituents is incomplete: no regulatory steroidogenesis assay (OECD Test Guideline 456) has been published for any of the eight internationally defined constituents of either oil — including the two that an industry laboratory reported as clear on hormone receptors.

Moderate evidence: An absence-of-evidence claim about the published record as of 2026-09; states a testing gap, not a harm. Say 'not tested', never 'found unsafe'.

Source: Sharma 2024, Biomolecules Link to this fact

The industry / Review of other studies

Fragrance safety is self-regulated: IFRA, which represents about 90% of fragrance suppliers, issues voluntary guidelines, and much of the safety research it relies on is done by the industry's own institute (RIFM) and is unpublished.

Moderate evidence: Secondary figures; the unpublished-studies point is better sourced from RIFM dossiers themselves.

Source: BCPP 2018 Link to this fact

The industry / Industry source

The industry's standard safety package for a fragrance ingredient in 1994 covered acute poisoning and skin effects (irritation, allergy, sun reactions); breathing it in was not tested, because the industry judged inhalation 'not a route of toxicological concern'.

Moderate evidence.

Source: Ford 1994 (RIFM) Industry-funded Link to this fact

The industry / Review of other studies

EPA's reviewers warned that replacing one phthalate with a close relative (DINP for DEHP, DIBP for DBP) should not be assumed to be safer.

Moderate evidence: Based on weaker data for the substitutes (fewer studies, lower exposures), not on evidence they are equally harmful.

Source: Radke 2018 (US EPA), Environment International Link to this fact

The industry / Measured in people or real products

The essential-oil industry's published defense of lavender oil in a child's breast-growth case rested on showing the child's cologne was synthetic fragrance containing a phthalate: that clears lavender oil, not the cologne.

Moderate evidence: Describes the letter's argument; one case, no dose, no biomarker; does not show the phthalate or anything else caused the breast growth.

Source: Giroux & Orjubin 2020 (JCEM letter; Consortium Huiles Essentielles), The Journal of Clinical Endocrinology & Metabolism Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

A 2026 lab test that adds simulated human liver metabolism to a DNA-damage (Ames mutagenicity) test found MORE mutagenic activity in skin creams and lotions than the conventional animal (rat) version of the same test — the opposite of metabolism detoxifying the product. Standard safety testing, including industry fragrance-material dossiers, defaults to the rat version.

Moderate evidence.

Source: Schmidtmann 2026, Analytical Chemistry Link to this fact

The industry / Review of other studies

The cosmetics industry's own safety panel found that 5% benzyl alcohol and 2% benzoic acid provoke a non-allergic skin reaction (redness, swelling, itching) in most people tested with no prior sensitization needed, yet concluded both are "safe" up to 5% in cosmetics because it judged typical exposure limited, not because the reaction is rare.

Moderate evidence.

Source: Nair 2001 (CIR Expert Panel), International Journal of Toxicology Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

The replacement tests are least accurate for the strongest allergens: they were wrong by about 6-fold for strong sensitizers and about 18-fold for the most extreme ones, almost always guessing them weaker than they are.

Moderate evidence: Geometric-mean fold error by LLNA potency class (Table 4); no human-outcome validation for this specific breakdown.

Source: Natsch 2015, Toxicological Sciences Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

When the same lab-dish tests that replace animal testing are checked against real human allergy-test panels instead of mouse data, they explain only about 32-45% of how strongly a chemical causes allergy in people, and the mouse test itself does barely better, explaining only 43%.

Moderate evidence: The strictly-human comparison dataset (n=62) is small and the author flags it as biased/non-representative; a larger human dataset might do better.

Source: Natsch 2023, ALTEX Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

Neither the animal test nor its lab-dish replacements are strong predictors of real human allergy thresholds; they are about equally weak, shown independently in 2015 and again in 2023.

Moderate evidence: Both comparisons reuse overlapping historical human patch-test literature (HRIPT/HMT), not independent new human data.

Source: Natsch 2023, ALTEX Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

Whether a chemical is irritating to cells in a dish, not just whether it reacts with proteins, drives a lot of the mouse allergy test's readout in ways that don't reflect real human allergy.

Moderate evidence: Statistical inference from regression coefficients across three chemical subsets, not a direct mechanistic experiment.

Source: Natsch 2023, ALTEX Industry-funded Link to this fact

The industry / Review of other studies

AETT was in fragrance use for 22 years before its neurotoxicity was documented, and cosmetic color additives are the only ingredient class the FDA actually regulates.

Moderate evidence: Regulatory-gap claim is accurate for the 1979 US framework described in the paper; verify current FDA cosmetic regulation status before using as a present-tense claim.

Source: Spencer 1979, Science Industry-funded Link to this fact

The industry / Animal study

The study's own authors, including two Research Institute for Fragrance Materials scientists, stated that the doses causing clear nerve damage in rats were 50 to 250 times their own estimate of maximum human fragrance exposure to musk ambrette, and that the lower-dose, longer-term study needed to assess real human risk was never done.

Moderate evidence: This is the study authors' own stated limitation, not an independent follow-up; no lifetime low-dose study has been conducted since (as far as this evidence base has found).

Source: Spencer 1984, Toxicology and Applied Pharmacology Industry-funded Link to this fact

The industry / Animal study

Musk ambrette is no longer used in fragrances; it was withdrawn from all skin-contact products in the 1980s, following both this neurotoxicity finding and separate reports of photoallergic skin reactions in real-world cologne use.

Moderate evidence.

Source: Spencer 1984; Ford 1994, Toxicology and Applied Pharmacology Industry-funded Link to this fact

The industry / Review of other studies

The 2020 update to the industry's fragrance safety-assessment methodology exists because an independent EU regulatory body (the SCCS), not the industry itself, found the original 2008 version's exposure assumptions and safety factors inadequately justified.

Moderate evidence: The SCCS opinions themselves are not yet ingested as primary sources in this evidence base; described via the industry paper's own account of the critique.

Source: Api 2020 (RIFM/IFRA), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Review of other studies

The fragrance industry's own most detailed exposure model to date estimates that about three-quarters of roughly 3,000 fragrance ingredients fall below a conservative safety threshold (TTC) for long-term systemic exposure, and 99% fall below it for inhalation — but by the same industry analysis, about a quarter of ingredients (777) are above their own systemic threshold and about half are above the skin-sensitization threshold (DST).

Moderate evidence.

Source: Lee 2024 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Review of other studies

As of 2024, the fragrance industry's aggregate exposure model finally covers household-care, air-care and oral-care products and the inhalation route for its full ~3,000-ingredient inventory — a scope earlier industry safety dossiers from 1994, 2003 and 2007 explicitly left out or dismissed by a single-ingredient calculation.

Moderate evidence.

Source: Lee 2024 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Review of other studies

The industry's own model finds fragrance exposure from household-care and air-care products is far lower than from cosmetics and personal-care products, and almost entirely by inhalation rather than skin contact (household 95th percentile 0.2 ug/kg/day, air care 5 ug/kg/day, versus cosmetics/personal care about 50 ug/kg/day, nearly all dermal).

Moderate evidence: Based on a 350-ingredient sample modeled from industry-supplied concentration and use-frequency survey data, not measured breathing-zone concentrations.

Source: Lee 2024 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Government agency

FDA's own 2006 testing concluded there was insufficient data to find a human health hazard from phthalate esters in cosmetics and took no regulatory action, even though the phthalates were already known to be common and concentrated in fragrance and nail products.

Moderate evidence: This is the regulator's own stated position at the time (2006), not a new toxicity finding; FDA said it would continue to monitor and could revisit if new hazard data emerged.

Source: Hubinger & Havery 2006, Journal of Cosmetic Science Link to this fact

The industry / Industry source

The fragrance industry's aggregate consumer exposure model did not include any estimate of inhaled fragrance exposure until 2017, when it added an inhalation route for air fresheners, scented candles and personal-care sprays only — 23 years after the industry's 1994 safety package dismissed inhalation testing.

Moderate evidence.

Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Industry source

Even after this 2017 update, the fragrance industry's own aggregate exposure model still explicitly excluded household cleaning and laundry products — the product category the industry's own 2003 safety-process paper says accounts for about 60% of fragrance volume — and named their inclusion as future work.

Moderate evidence.

Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Industry source

To build this exposure model, the fragrance industry combined three surveys that were never designed to work together — a 7-day product diary, a monthly recall survey, and a categorical daily-frequency questionnaire — by matching subjects only on age and gender and assuming they share the same habits for entirely unrelated products.

Moderate evidence.

Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Industry source

Some of the amount-per-use values feeding this industry exposure model come from very small studies — 10 Dutch adults for bar-soap-in-the-shower amounts, and a single non-distributional value for scented-candle amount per day — rather than large, representative samples.

Moderate evidence.

Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Lab study (cells or chemistry)

The fragrance industry's own 2007 safety review of benzyl salicylate assessed allergy, toxicity and cancer risk in detail but never tested it for hormone-like activity at all; the first test came two years later, from an independent lab with no fragrance-industry funding.

Moderate evidence.

Source: Charles & Darbre 2009, Journal of Applied Toxicology Link to this fact

The industry / Measured in people or real products

In RIFM's own comparison of 57 fragrance chemicals, the mouse test used to set fragrance skin-allergy safety limits agreed with real human sensitization thresholds within about 3-fold for 76% of the chemicals tested, but was off by up to nearly 800-fold for others, including hexyl and benzyl salicylate.

Moderate evidence.

Source: Api, Basketter & Lalko 2014, Cutaneous and Ocular Toxicology Industry-funded Link to this fact

The industry / Measured in people or real products

The older claim that PGME solvent vapor irritates the eyes and throat at 250 ppm comes from an unblinded 1970 study without objective eye measurements (20 of 23 subjects reported eye irritation at 250 ppm); a later double-blind study with objective eye tests found no effect at 100-150 ppm.

Moderate evidence.

Source: Emmen et al. 2003, Toxicology Letters Industry-funded Link to this fact

The industry / Government agency

California's 2022 law banning intentionally added PFAS in cosmetics (AB 2771), effective January 1, 2025, is expected by state toxicologists' own modeling to reduce PFAS reaching California wastewater treatment plants, particularly from shaving creams and gels, hair care products, and facial cleansers rather than from makeup.

Moderate evidence.

Source: Balan 2024, Environmental Science & Technology Link to this fact

The industry / Measured in people or real products

The study's own authors note that current diagnostic patch-test concentrations for oxidized linalool allergy are more than 500 times higher than the hydroperoxide levels they actually found in consumer products.

Moderate evidence: Industry-funded interpretation; does not itself prove patch tests over-diagnose, since already-sensitized skin can react to much lower doses than the diagnostic test threshold.

Source: Kern 2014, Analytical and Bioanalytical Chemistry Industry-funded Link to this fact

The industry / Other evidence

RIFM's founding scientific director personally authored the sole primary study behind the fragrance industry's 'quenching' safety exception; IFRA later codified it into a formal use-with-limonene rule (≥25% d-limonene) that required a higher proportion of the 'quenching' terpene than Opdyke's own 1976 test (~20% d-limonene) actually used.

Moderate evidence: The evidence base does not have IFRA's own documentation of why 25% (rather than the tested ~20%) was chosen, or of when/why the quenching exception was later withdrawn.

Source: Ford 1994 (RIFM), citing Opdyke 1976 Industry-funded Link to this fact

The industry / Measured in people or real products

Despite thousands of positive allergy-test reactions to oxidized limonene and linalool reported worldwide, the fragrance industry's own market-testing program concluded that where people are actually getting exposed to these allergens "remains elusive" — the industry itself has not identified the real-world consumer-product source of a widely documented skin allergy.

Moderate evidence.

Source: Natsch 2019, Food and Chemical Toxicology Industry-funded Link to this fact

The industry / Measured in people or real products

A musk fragrance chemical called ATTN (Versalide) disappeared entirely from human tissue in this 1996 study because industry had already stopped making it in 1980, after animal testing showed it damaged nerves – a real-world example of a musk being phased out after a toxicity finding.

Moderate evidence: Absence in 19 samples is consistent with, but does not by itself prove, the discontinued-production explanation the authors give; based on a small single-country sample.

Source: Rimkus & Wolf 1996, Chemosphere Link to this fact

The industry / Measured in people or real products

SC Johnson funded and co-authored a study that tested what was apparently its own newly developed fragranced air-sanitizer product in asthmatics and found no adverse ocular, nasal or lung effects.

Moderate evidence.

Source: Opiekun 2003, Clinical and Experimental Allergy Industry-funded Link to this fact

The industry / Animal study

When RIFM's own scientists restrict the comparison to fragrance chemicals without known problematic chemistry, the mouse test used to set fragrance safety limits correlates strongly with real human sensitization thresholds (R-squared = 0.78 for 35 chemicals).

Moderate evidence.

Source: Roberts & Api 2018, Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

The industry / Measured in people or real products

This foundational human PGME irritation study has a direct Dow Chemical link stronger than later PGME papers in the wiki: one author was a Dow Chemical employee and the test material was Dow-supplied ('Dowtherm 209'), yet the study documents substantial irritation at concentrations relevant to Dow's own radiator-coolant product rather than minimizing it.

Moderate evidence: A single industry-linked study reporting an adverse finding is still one study; the funding link is recorded for transparency, not as proof the finding is unbiased in general.

Source: Stewart 1970 (Arch Environ Health), Archives of Environmental Health: An International Journal Industry-funded Link to this fact

The industry / Animal study

A commercial testing laboratory's mouse-bioassay claims of consumer-product toxicity (the same ASTM E-981/FOB method the lab later applied to air fresheners and colognes) failed an independent, blinded EPA/ManTech replication attempt when applied to carpets; the largest toxicity-looking signals traced instead to stress from the restrained-exposure test procedure itself, present even in air-only control animals.

Moderate evidence.

Source: Tepper et al. 1995, American Industrial Hygiene Association Journal Link to this fact

The industry / Review of other studies

Modern (post-1980s) European fabric conditioners almost all use esterquats, a cationic surfactant class engineered with a hydrolyzable ester linkage to biodegrade faster than the older DHTDMAC/DSDMAC softeners it replaced; the industry's own account frames the switch as environmental (biodegradability), not human-health, driven.

Moderate evidence.

Source: HERA Project 2008 (A.I.S.E./CEFIC) Industry-funded Link to this fact

The industry / Measured in people or real products

Tumble dryer manufacturers give directly conflicting instructions on cleaning the lint filter: some tell consumers to rinse it under water, others recommend a dishwasher, others dry methods only, and one (John Lewis) explicitly says never use water, for environmental reasons.

Moderate evidence: One UK market snapshot (24 brands, January 2023), not checked against other countries or against what consumers actually do.

Source: Cummins 2023, PLOS ONE Industry-funded Link to this fact

The industry / Other evidence

The clinical safety testing (HRIPT, CIT or SIU) required to earn the NEA Seal is arranged and paid for by the manufacturer through a testing company of its own choosing; NEA states it "does not endorse or have a relationship with any clinical safety testing company" and instead reviews the submitted reports on paper through an independent physician panel.

Moderate evidence.

Source: NEA 2026 Link to this fact

Laws and loopholes / Measured in people or real products

More than 70% of the chemicals measured in childcare air had no health-based safety limit; several fragrance compounds were among 12 the authors flagged for further study.

Moderate evidence: Flags come from database/QSAR hazard scores, not measured effects.

Source: Hoang 2016, Indoor Air Link to this fact

Laws and loopholes / Review of other studies

No law in the US, the EU or Australia requires air-freshener makers to list all their ingredients; a label can simply say 'fragrance'.

Moderate evidence: Review's legal summary (2016); EU cosmetics allergen labeling does not cover air fresheners.

Source: Steinemann 2017, Building and Environment Link to this fact

Laws and loopholes / Measured in people or real products

US product rules written to limit smog (ozone) exempt several chemicals that still form fine particles, and fragrance ingredients do not have to be disclosed.

Moderate evidence: Regulatory analysis in the paper.

Source: McDonald 2018, Science Link to this fact

Laws and loopholes / Review of other studies

The EU bans more than 1,400 substances from cosmetics, while US rules restrict only a handful.

Moderate evidence: EU list includes never-used substances; US rules changing under MoCRA 2022; verify against a regulatory source.

Source: Alblooshi 2025, Frontiers in Toxicology Link to this fact

Laws and loopholes / Journalism

In a 2010 undercover test by the US Government Accountability Office, the Energy Star program certified 15 fake products, including a gas-powered alarm clock the size of a generator.

Moderate evidence: Energy efficiency label, not chemical safety; EPA/DOE promised reform.

Source: Dahl 2010, Environmental Health Perspectives Link to this fact

Laws and loopholes / Measured in people or real products

Trace benzene was found in 83% of 79 US feminine hygiene products and 1,4-dioxane in 50%, yet these products are regulated as medical devices with no federal ingredient-disclosure requirement.

Moderate evidence: Trace ng/g levels; 1,4-dioxane is a surfactant by-product.

Source: Lin 2020, Environment International Link to this fact

Laws and loopholes / Review of other studies

History shows removing the exposure works: as industrial turpentine use fell from 94.5% of US supply as a solvent in 1935 to 4.5% in 1975, turpentine skin allergy declined with it.

Moderate evidence: Ecological historical correlation.

Source: Karlberg & Lepoittevin 2021, Contact Dermatitis Link to this fact

Laws and loopholes / Review of other studies

Official limits for the same gas odorant differed about 280-fold in 2009: Germany allowed 50 ppm at work, a Dutch health agency derived 0.18 ppm, and the US had no limit.

Moderate evidence: Regulatory values as reported by the paper (2009); may have been revised since.

Source: Baur & Bittner 2009, American Journal of Industrial Medicine Link to this fact

Laws and loopholes / Review of other studies

In the US, "fragrance-free" means that no ingredient is used solely to give a smell. A fragrance chemical that also does another job, such as benzyl alcohol used as a preservative, can legally be in a "fragrance-free" product.

Moderate evidence: US definition as quoted by dermatologists in 2007; not a legal analysis; FDA has no binding definition of "fragrance-free".

Source: Jacob & Barron 2007, Dermatitis Link to this fact

Laws and loopholes / Review of other studies

After German industry stopped using musk xylene in 1993, its level in breast milk fell about 70% in four years, but the related musk ketone, which was not phased out, did not fall.

Moderate evidence: Cites a BgVV 2000 press release; single-country natural experiment.

Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact

Laws and loopholes / Self-reported survey

Nearly half (49%) of US families in a survey bought children's makeup from large online retailers, and US labeling law (the Fair Packaging and Labeling Act) requires ingredient lists on the package, not on the website.

Moderate evidence: Purchase share is survey self-report; legal point is the authors' reading of the FPLA as of 2022.

Source: Medley 2023 Link to this fact

Laws and loopholes / Review of other studies

Fewer than 20% of the roughly 3,000 high-production-volume (HPV) chemicals in the US have been tested for potential to cause developmental neurotoxicity.

Moderate evidence.

Source: Sealey 2016 (citing Landrigan 2010), Environment International Link to this fact

Laws and loopholes / Review of other studies

The researchers report that citronellol content varies up to 1000-fold within the same product category, which they attribute to the absence of regulation of fragrance content in household products.

Moderate evidence: Stated in the discussion citing industry/market sources; no product measurements in this paper.

Source: Kim 2024, Journal of Hazardous Materials Link to this fact

Laws and loopholes / Measured in people or real products

Workers with fragrance-related asthma were twice as likely as other work-asthma cases to still be exposed at work (50% vs 26%) and more often had workers' compensation claims denied (30% vs 21%), though ER visit and hospitalization rates were the same.

Moderate evidence: Interviewed cases only (~58% of fragrance cases); unadjusted.

Source: Weinberg 2017, Journal of Asthma Link to this fact

Laws and loopholes / Review of other studies

More than 40% of US occupational exposure limits are set to prevent eye, nose and throat irritation, and a systematic comparison of 18 agencies confirms that US, German and EU regulators set substantially different limits for the same chemicals — overall stringency ranges from Poland's geometric-mean level of 0.23 to US OSHA's 0.61 (a 2.67-fold spread), with the EU's own 'health-based' indicative limits sitting above Germany's stricter national MAK limits.

Moderate evidence.

Source: Dalton & Jaén 2010, Current Opinion in Allergy and Clinical Immunology Industry-funded Link to this fact

Laws and loopholes / Review of other studies

A fragrance-and-flavor company reported that about half of the chemicals it handles are classified hazardous, and that few of the more than 3,000 flavoring substances in use have workplace exposure limits.

Moderate evidence: Industry self-description, no inventory published; flavor materials at one company.

Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact

Laws and loopholes / Review of other studies

US product labels only have to say "fragrance", not which chemicals, and household products need not list ingredients at all; MoCRA (2022) requires companies to name on cosmetic labels the fragrance allergens FDA designates by regulation (proposed rule was due June 2024), which the authors expect to be many, but not all.

Moderate evidence: Check current MoCRA rule status before quoting; household products are outside MoCRA; statute §609(b) is a mandate; check final rule status.

Source: Rodriguez 2024, Cutis Link to this fact

Laws and loopholes / Measured in people or real products

The UK national air-pollution inventory counts zero emissions of limonene or the silicone D5 from shampoos, shower gels and skin products, although these were the two largest emissions measured from them.

Moderate evidence: The authors judge the missing mass small at national scale (~0.4 kt/yr vs 807 kt total UK VOC).

Source: Yeoman 2020, Indoor Air Link to this fact

Laws and loopholes / Review of other studies

Most national microbead bans cover only rinse-off products such as scrubs and cleansers; microplastics are still commonly used in leave-on products, especially color cosmetics like lipstick and eye makeup.

Moderate evidence: Narrative review; 8 of 14 listed jurisdictions explicitly rinse-off/exfoliant only; EU 2023/2055 is broader.

Source: Han & Kim 2025, Cosmetics Link to this fact

Laws and loopholes / Review of other studies

The EU bans or restricts more than 1,500 chemicals in personal care products and Canada about 800, while the US restricted 11.

Moderate evidence: Secondhand from a 2018 JAMA Intern Med commentary; EU count includes substances never used; US rules changed after MoCRA 2022.

Source: Khalid & Abdollahi 2021, Iranian Journal of Pharmaceutical Research Link to this fact

Laws and loopholes / Lab study (cells or chemistry)

A finished perfume is usually not toxicity-tested as a whole; its safety is assessed on paper from its secret ingredient list. When researchers tested 42 whole perfumes directly, they found hazards that ingredient-by-ingredient assessment is not designed to catch.

Moderate evidence: EU framework described by the authors; the hazards are in vitro and unidentified.

Source: Morlock & Heil 2025, Journal of Chromatography A Link to this fact

Laws and loopholes / Review of other studies

An advocacy group that pushes for fragrance disclosure itself says many brand owners are not told by their fragrance suppliers what their fragrances contain, so a disclosure law has to reach the fragrance supplier.

Moderate evidence: Asserted without evidence; interview evidence is Scruggs & Ortolano 2011.

Source: BCPP 2018 Link to this fact

Laws and loopholes / Review of other studies

A 2015 CMAJ editorial (Flegel & Martin, CMAJ 187:1187, DOI 10.1503/cmaj.151097) states hospital environments free from artificial scents 'should become a uniform policy, promoting the safety of patients, staff and visitors alike'; the US CDC's own workplace policy separately says fragrance 'is not appropriate for a professional work environment' (CDC wording still unverified against a primary CDC source).

Moderate evidence.

Source: ASEQ-EHAQ 2020 (quoting CMAJ 2015 and CDC) Link to this fact

Laws and loopholes / Review of other studies

People with chemical sensitivities asked the US Justice Department to consider fragrance as an access barrier during its 2008 ADA rulemaking.

Moderate evidence: Shows the issue was raised in the record; the attachment makes no legal argument and our evidence base has no record of DOJ's response.

Source: DONTSPRAYCALIFORNIA 2008 (DOJ ADA docket) Link to this fact

Laws and loopholes / Advocacy group testing

In a 2010 Canadian survey, volunteers found no ingredient list on 28% of toothpastes and mouthwashes and 14% of antiperspirants and deodorants; in Canada, personal-care products sold as 'drugs' need list only their active ingredients.

Moderate evidence: Some missing lists were discarded outer packaging; 2010 Canadian law.

Source: David Suzuki Foundation 2010 Link to this fact

Laws and loopholes / Government agency

In the US, fragrance sensitivity or multiple chemical sensitivity can count as a disability under the Americans with Disabilities Act, but not automatically: it is decided case by case, usually on whether breathing is substantially limited.

Moderate evidence: Authors' reading of statute in a 2009 business-conference paper; no case survey; the 2008 ADA Amendments postdate their cases.

Source: De Vader & Barker 2009 Link to this fact

Laws and loopholes / Government agency

In Hunt v. St. Peter School (1997), a scent-free classroom was treated as a reasonable accommodation, but a school-wide fragrance ban was ruled an undue hardship.

Moderate evidence: One district-court case as described by the authors; the opinion itself is not in our evidence base.

Source: De Vader & Barker 2009 Link to this fact

Laws and loopholes / Review of other studies

As of 2011, US law let makers write 'fragrance' instead of listing its ingredients as a trade secret, and the FDA pre-approved only color additives in cosmetics; the industry's own review panel had declared just 9 ingredients unsafe since 1976.

Moderate evidence: US situation in 2011; MoCRA (2022) later added limited changes; CIR count from its 2011 website.

Source: Gilton 2011 Link to this fact

Laws and loopholes / Animal study

The EU cosmetics committee's own estimate of how much 4-MBC enters the body of someone using it (0.23 mg/kg body weight) was only three times below the no-effect dose, and thirty times below the lowest harmful dose, in this rat developmental study.

Moderate evidence.

Source: Schlumpf 2004, Toxicology Link to this fact

Laws and loopholes / Measured in people or real products

Glycol solvents brought into consumer products as 'low-reactivity' replacements, and largely exempt from VOC limits, still make a large share of consumer-product ozone because so much is used.

Moderate evidence: Model result (oxygenates ~37% of VCP ozone in NYC); exemption statement is the authors' summary of US rules.

Source: Coggon 2021 Link to this fact

Laws and loopholes / Review of other studies

US law has never defined "fragrance-free"; the only definition is of fragrance itself ("used solely to impart an odor", 21 CFR 700.3(d)), so an ingredient that smells but is also claimed as a preservative or moisturizer can go into a "fragrance-free" product. FDA's own website said in 1999 that "fragrance-free" products, like "unscented" ones, may contain fragrance chemicals.

Moderate evidence.

Source: Scheinman 1999, Journal of the American Academy of Dermatology Link to this fact

Laws and loopholes / Review of other studies

A 2015 CMAJ editorial by two physicians argued that hospitals should adopt uniform scent-free policies, because patients — unlike employees — cannot request accommodation and can be involuntarily exposed to fragrance from staff, other patients or visitors.

Moderate evidence.

Source: Flegel & Martin 2015, CMAJ (Canadian Medical Association Journal) Link to this fact

Laws and loopholes / Review of other studies

As of 2015, no Canadian hospital accreditation standard required a scent-free policy, and it was not policy in all Canadian hospitals.

Moderate evidence: The editorial's own 2015 assessment; the policy landscape may have shifted since — see Roy 2026 for a later, focus-group-based assessment of implementation gaps.

Source: Flegel & Martin 2015, CMAJ (Canadian Medical Association Journal) Link to this fact

Laws and loopholes / Review of other studies

A leading pediatric environmental-health review states that fewer than 20% of the roughly 3,000 high-production-volume industrial chemicals in the US have been tested for potential to cause developmental neurotoxicity.

Moderate evidence: Landrigan 2010 traces this to Goldman 1998 (Environ Health Perspect), not read directly in this evidence base; concerns industrial chemicals in general, not fragrance specifically.

Source: Landrigan 2010, Current Opinion in Pediatrics Link to this fact

Laws and loopholes / Review of other studies

A 2006 Lancet review found that of roughly 3,000 US high-production-volume industrial chemicals, basic toxicity data were publicly unavailable for nearly half, and 80% had no information on developmental or pediatric toxicity at all.

Moderate evidence.

Source: Grandjean & Landrigan 2006, Lancet Link to this fact

Laws and loopholes / Government agency

The overall strictness of occupational exposure limits varies nearly threefold between the strictest and most lenient of 18 regulators studied, and the European Union's own limits, despite being described as purely health-based, are on average less strict than Germany's national limits.

Moderate evidence.

Source: Schenk et al. 2008, Regulatory Toxicology and Pharmacology Industry-funded Link to this fact

Laws and loopholes / Measured in people or real products

Even though EU law requires 26 specific fragrance allergens to be named individually above 0.01% concentration, 60% of the 1,447 scented detergents in this German household study listed only the generic term 'perfume', 'fragrance', or 'aroma' rather than naming any specific allergen, and only 46% named any of the 26 at all.

Moderate evidence.

Source: Wieck 2018, Regulatory Toxicology and Pharmacology Link to this fact

Laws and loopholes / Government agency

The UK continues to apply essentially the same EU cosmetic-claims rule after Brexit, unchanged in substance, as retained domestic law, with the UK's own legislation register confirming no outstanding legal effects have altered it.

Moderate evidence: Confirmed as of this single 2026-09-27 capture of legislation.gov.uk; the register could change at any later date and was not tracked over time here.

Source: Commission Regulation (EU) No 655/2013 Link to this fact

Laws and loopholes / Government agency

The European Commission's own guidance on cosmetic 'free from' claims (agreed with industry in 2017) says a 'free from perfume' claim should not be used if the product contains any ingredient that exerts a perfuming function, regardless of that ingredient's other functions — wording that would exclude a masking fragrance, not permit one.

Moderate evidence.

Source: EC Technical Document on Cosmetic Claims 2017 Industry-funded Link to this fact

Laws and loopholes / Government agency

EU guidance says a 'hypoallergenic' cosmetic claim requires the company to actively rule out known and suspected skin sensitizers through six named routes (including its own consumer-complaint records) and states plainly that the claim 'does not guarantee a complete absence of risk of an allergic reaction'.

Moderate evidence.

Source: EC Technical Document on Cosmetic Claims 2017 Industry-funded Link to this fact

Laws and loopholes / Government agency

Under the EPA's Safer Choice program, 'fragrance-free' and 'unscented' are not the same claim: 'unscented' still allows a masking chemical added to cover other ingredients' smell, while 'fragrance-free' specifically bars masking scents as well as added scent.

Moderate evidence.

Source: US EPA Safer Choice Link to this fact

Laws and loopholes / Government agency

As of this page's 2026-09-27 capture, FDA's own consumer guidance states it "does not have the same legal authority to require allergen labeling for cosmetics as for food," and does not mention MoCRA or any pending/final fragrance-allergen rule, more than three years after MoCRA required FDA to write one.

Moderate evidence.

Source: FDA 2026 (Fragrances in Cosmetics) Link to this fact

Skin allergy / Lab study (cells or chemistry)

In the fragrance industry's own reference set of 62 fragrance ingredients, 19 are rated moderate or strong skin sensitizers, meaning chemicals capable of causing allergy.

Moderate evidence: Industry (RIFM) weight-of-evidence categories; lab and animal data, not human exposure.

Source: Lee 2024, Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

In patch tests on 61 people, fresh limonene and linalool did not irritate skin, but after air exposure (oxidation) both did; oxidized limonene at 20% caused strong redness (average 7.3 of 9 vs near 0 fresh).

Moderate evidence: RIFM-funded; test concentrations far above product levels.

Source: Bråred Christensson 2009, Contact Dermatitis Industry-funded Link to this fact

Skin allergy / Review of other studies

In about half of oxidized limonene/linalool allergy cases, doctors could link the allergy to products the patient actually used.

Moderate evidence.

Source: Ogueta 2022, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

Allergy to these two scent chemicals rose significantly over the eight years studied (2013-2020).

Moderate evidence: Patch-test chamber system changed in 2018, which may affect the trend.

Source: Sukakul 2022, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

Women were affected about 1.5 to 2 times as often as men, and these patients were younger on average than people allergic to other fragrance ingredients.

Moderate evidence: Likely reflects product-use patterns; clinic population.

Source: Sukakul 2022, Contact Dermatitis Link to this fact

Skin allergy / Review of other studies

Benzyl alcohol, a fragrance allergen, is also a preservative in common prescription creams and injections, including steroid, antifungal (clotrimazole) and antibiotic (mupirocin) creams, so fragrance-allergic patients can meet it in their medicines.

Moderate evidence: Based on case reports; no prevalence of benzyl alcohol allergy given.

Source: Jacob & Barron 2007, Dermatitis Link to this fact

Skin allergy / Lab study (cells or chemistry)

Skin converts part of cinnamyl alcohol into cinnamal, the stronger allergen: on human skin samples, about 4% of applied cinnamyl alcohol became cinnamal within a day.

Moderate evidence: Excised human skin, neat material, occluded, 24 h (Smith 2000); single study.

Source: RIFM Expert Panel 2005, Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Allergy to one rose ketone tends to mean allergy to its relatives: all 3 volunteers sensitized to delta-damascone reacted to 0.1% cis-beta-damascone on cross-challenge.

Moderate evidence: N=3; from an unpublished RIFM report.

Source: Lalko 2007 (RIFM), Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Review of other studies

Benzyl salicylate, one of the most widely used fragrance chemicals (about 2,500 tonnes a year worldwide in 2007), caused skin allergy in the fragrance industry's own tests, and the industry's standards body IFRA restricts how much may be used.

Moderate evidence: Human maximization 3/50 positive at 20%; repeat-insult patch tests were negative (0/101 at 15%); LLNA EC3 1.5-2.9% in mice. Industry-funded review of largely unpublished reports.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Standard allergy screening misses a large share of fragrance allergy: in one UK clinic 42% of patients allergic to at least one of the 26 EU-labeled fragrance chemicals tested negative on the standard fragrance markers, and about 4 in 10 people who reacted to their own perfume or deodorant were negative on the screen.

Moderate evidence.

Source: Rodriguez 2024, Cutis Link to this fact

Skin allergy / Measured in people or real products

Some fragrance chemicals now banned from EU cosmetics sensitized almost every volunteer in the industry's own tests: diethyl maleate 25 of 25, dihydrocoumarin 25 of 25, alantroot oil 23 of 25.

Moderate evidence: Maximization test is deliberately exaggerated (irritant pre-treatment, occlusion, ~10x use level); substances are banned and mostly left perfumery before 2000.

Source: SCCNFP 2000 (RIFM data) Link to this fact

Skin allergy / Measured in people or real products

Essential oils are made largely of the same chemicals labeled as fragrance allergens: supplier data sheets give sweet-orange oil about 95% limonene, lavender oil about 40% linalool and palmarosa oil up to 84% geraniol.

Moderate evidence: Composition from supplier safety data sheets, which vary between suppliers (cypress oil limonene 5-7% vs 14%); not measured in finished products.

Source: Klaschka 2016, Environmental Sciences Europe Link to this fact

Skin allergy / Measured in people or real products

Half of best-selling US body moisturizers (87 of 174) list "fragrance" on the label, making it the most common potential skin allergen in them, ahead of parabens (75) and vitamin E/tocopherol (74).

Moderate evidence: Literal-word count, a lower bound for fragranced products; 2016 US online best-sellers.

Source: Xu 2017, JAMA Dermatology Link to this fact

Skin allergy / Animal study

Left open to air, lavender oil became about 8 times more potent as a skin sensitizer in mouse tests (EC3 36% fresh, 4.4% after 45 weeks).

Moderate evidence: Mouse LLNA, groups of 3-4 mice, one 45-week sample; aged oil reached 'moderate', not 'strong', potency; open-flask lab exposure.

Source: Hagvall 2008, Contact Dermatitis Industry-funded Link to this fact

Skin allergy / Measured in people or real products

After 10 weeks of air exposure, lavender oil contained about 3.3% linalyl acetate hydroperoxides and 0.5% linalool hydroperoxides, the kind of oxidation products behind the commonest fragrance allergies in European clinics.

Moderate evidence: Open-flask lab exposure (upper bound); retail bottles not measured.

Source: Hagvall 2008, Contact Dermatitis Industry-funded Link to this fact

Skin allergy / Measured in people or real products

The two commonest fragrance allergens on Danish children's cosmetics, limonene (22% of fragranced products) and linalool (18%), are not in the standard European patch test series; they become strong allergens when they oxidize in air.

Moderate evidence: Frequencies are label presence; oxidation not measured in these products (relayed from hydroperoxide literature); some clinics now add the hydroperoxides to their baseline.

Source: Botvid 2023, Contact Dermatitis Link to this fact

Skin allergy / Lab study (cells or chemistry)

Oxidized linalool and oxidized limonene, among the most common fragrance allergens found in European skin clinics, are not in the 312-chemical dataset these safety models were built on.

Moderate evidence: Clinic prevalence figures for oxidized terpenes come from a separate paper (Sukakul 2022), not this one.

Source: Natsch 2015, Toxicological Sciences Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Sensitivity to cinnamal varies enormously between allergic people: this study measured a 1000-fold range in the concentration needed to trigger a reaction.

Moderate evidence: Range measured in 9 patients only.

Source: Bruze et al. 2003, Journal of the American Academy of Dermatology Link to this fact

Skin allergy / Measured in people or real products

Whether a specific limonene-scented product is likely to trigger a reaction in an allergic person depends heavily on how oxidized/aged it is: an experimentally aged orange oil's allergenic hydroperoxide content rose nearly 6-fold (500 to 2900 ppm) after a year in storage, while some real aged fine fragrances tested by industry stayed below the reaction-triggering range.

Moderate evidence: The storage/aging data come from a separate cited experimental study, not this paper's own clinical subjects, and cover only one product type (orange oil).

Source: Bennike 2019, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

Only 15% of people with a borderline ('doubtful') patch-test reaction to limonene hydroperoxides went on to react when exposed repeatedly to a realistic dose, a rate no different from people with no allergy at all.

Moderate evidence: Small subgroup (13 people, 2 positive); underpowered to rule out that some fraction of doubtful reactors are truly allergic.

Source: Bennike 2019, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

In a survey of 187 US pediatric personal-care products, preservatives (57.8% of products) were a more common source of contact allergens than fragrance (29.4%), even though the products were being screened specifically for hypoallergenic/fragrance-related marketing claims.

Moderate evidence.

Source: Hamann 2015, Journal of Allergy and Clinical Immunology Link to this fact

Skin allergy / Measured in people or real products

A standard fragrance patch-test panel (Fragrance Mix I/II) misses about 1 in 5 cases of medication-caused fragrance allergy, because the reaction is to an individual essential oil or ingredient not covered by the mixes.

Moderate evidence.

Source: Nardelli 2009, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

For two common fragrance chemicals, trans-2-hexenal and methyl-2-nonanoate, the mouse test underestimated true human skin-sensitizing potency by 26- to 42-fold — the error direction that could make an industry safety limit too permissive rather than too strict.

Moderate evidence.

Source: Api, Basketter & Lalko 2014, Cutaneous and Ocular Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Women's fragrance contact allergy rates are roughly double men's.

Moderate evidence.

Source: Diepgen 2015 (EDEN), British Journal of Dermatology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

A Givaudan-funded study that chemically measured 39 real aged fragrance products found linalool hydroperoxide levels far below the dose shown to trigger a reaction in already-allergic patients, roughly 180 times lower on average.

Moderate evidence: Industry-funded (Givaudan), single study, not independently replicated; only two product categories tested (hydroalcoholic fine fragrance, antiperspirant/deodorant).

Source: Kern 2014, Analytical and Bioanalytical Chemistry Industry-funded Link to this fact

Skin allergy / Other evidence

The fragrance industry's original 1976 evidence for aldehyde 'quenching' (that a companion terpene or alcohol stops citral, cinnamic aldehyde or phenylacetaldehyde from causing skin sensitization) was a single, unreplicated human maximization test per mixture with no subject numbers reported, and the paper's own data are internally inconsistent: cinnamon bark oil sensitized despite being one of the paper's three 'protective natural oil' examples, and cinnamic aldehyde + eugenol sensitized at a 2.5:1 ratio where 1:1 had not.

Moderate evidence.

Source: Opdyke 1976 (RIFM), Food and Cosmetic Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

In a UK study that routinely patch tested 1,951 eczema patients with both the standard fragrance-allergy screen and all 26 individually EU-labeled fragrance chemicals, 42% of the patients allergic to at least one of those 26 chemicals would have been missed if only the standard screen had been used.

Moderate evidence.

Source: Mann 2014, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

The two fragrance mixes used in standard allergy testing (FM I and FM II) each miss roughly half of the people who are allergic to their own listed ingredients: only 58% of those reacting to an FM I ingredient, and only 52% of those reacting to an FM II ingredient, reacted to the mix itself.

Moderate evidence: Single UK clinic (n=1,951), not independently replicated at this exact figure.

Source: Mann 2014, Contact Dermatitis Link to this fact

Skin allergy / Measured in people or real products

A large fragrance-industry study tested 104 real consumer products, including creams, lotions and antiperspirants, for the allergenic chemicals that form when the scent chemicals limonene and linalool oxidize in air, and found almost none of them: 96% of products had no detectable hydroperoxide, and the one confirmed positive was hundreds of times below the dose known to trigger a reaction.

Moderate evidence: Industry-funded (IDEA consortium: Givaudan, Firmenich, IFF, IFRA), not independently replicated by a non-industry group.

Source: Natsch 2019, Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Even when scientists chemically tested the actual products that people with a confirmed allergy to oxidized limonene or linalool blamed for their skin reaction, none of the 28 products tested (11 from confirmed allergy patients) contained a detectable amount of the allergenic chemical.

Moderate evidence.

Source: Natsch 2019, Food and Chemical Toxicology Industry-funded Link to this fact

Skin allergy / Measured in people or real products

Concentrations of hydroxycitronellal found in some 'natural' perfumes (up to 6.04%) exceeded the concentration shown to sensitize 36% of healthy volunteers in repeated-insult patch testing (5%), and were also well above the fragrance industry's own 1996 recommended maximum (equivalent to about 1% in the finished product).

Moderate evidence.

Source: Rastogi 1996, Contact Dermatitis Link to this fact

Skin allergy / Review of other studies

Patch testing is the diagnostic gold standard for allergic contact dermatitis, including fragrance allergy, but access to it is uneven: in the US, African American and lower-income patients are referred for and receive patch testing less often than White and higher-income patients, and rural patients have reduced access and longer symptom duration.

Moderate evidence.

Source: Aristizabal-Torres 2025, JAAD Reviews Link to this fact

Skin allergy / Measured in people or real products

Among all detergent types studied, laundry (textile) detergents had both the highest share of products naming a fragrance allergen (50.0% of 270 products) and the highest average number of named allergens per product (1.7) — ahead of dish soap, glass cleaner, toilet cleaner, and dishwasher detergent.

Moderate evidence: Named-on-label only, not measured concentration or skin dose; German 2015 sample.

Source: Wieck 2018, Regulatory Toxicology and Pharmacology Link to this fact

Skin allergy / Review of other studies

Benzalkonium chloride was the sixth highest-reacting allergen in a large retrospective patch-testing cohort, and caused contact dermatitis in 7-18.6% of patients using BAC-containing topical medicine for chronic leg ulcers.

Moderate evidence: Figures are from BAC used as a medical/topical antiseptic preservative, not from laundry or fabric-softener exposure.

Source: Peyneau 2022, Frontiers in Toxicology Link to this fact

What you can do / Self-reported survey

About twice as many Australians would prefer fragrance-free workplaces (42.8%) as fragranced ones (22.2%), and over three times as many prefer unscented flights (57.7% vs 16.3%).

Moderate evidence.

Source: Steinemann 2017, Preventive Medicine Reports Link to this fact

What you can do / Self-reported survey

Most people would rather have fragrance-free spaces: 65% prefer fragrance-free airplanes, 61% hotels, 51% health care and 48% workplaces, against 16-22% who prefer them fragranced.

Moderate evidence: Preference survey, adults 18-65.

Source: Steinemann 2019, Air Quality, Atmosphere & Health Link to this fact

What you can do / Self-reported survey

People with asthma back fragrance-free spaces by wide margins: 66.2% vs 16.1% for fragrance-free workplaces and 72.1% vs 14.8% for fragrance-free health care.

Moderate evidence.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

What you can do / Measured in people or real products

Screening out products whose labels list 'fragrance' and a few other terms cut synthetic fragrance: 26 of 43 screened products had no detectable fragrance chemical, and high fragrance levels appeared 21 times in conventional samples vs 2 in screened ones.

Moderate evidence: Conventional composites vs single alternatives not directly comparable; did not remove parabens, phthalate substitutes.

Source: Dodson 2012, Environmental Health Perspectives Link to this fact

What you can do / Self-reported survey

Swedes overwhelmingly prefer scent-free spaces: 80.2% vs 6.0% for airplanes, 77.7% vs 9.8% for hotels, and 64.1% vs 14.0% for health care.

Moderate evidence.

Source: Steinemann 2018 (Sweden), Air Quality, Atmosphere & Health Link to this fact

What you can do / Measured in people or real products

Perfume was the strongest single predictor of diethyl phthalate exposure, so skipping perfume and fragranced personal care products is the most obvious way to lower it.

Moderate evidence: Association only; not tested as an intervention.

Source: Parlett 2013, Journal of Exposure Science and Environmental Epidemiology Link to this fact

What you can do / Measured in people or real products

Green, organic or natural labels on baby products did not mean fewer released chemicals, so choosing products labeled fragrance-free (without essential oils) is the more reliable way to avoid scent chemicals.

Moderate evidence.

Source: Nematollahi 2018, Air Quality, Atmosphere & Health Link to this fact

What you can do / Measured in people or real products

Researchers recommend lower-terpene (less citrus/pine-scented) cleaners, diluting them, ventilating during and for hours after cleaning, cleaning when fewer people are home, and never running ozone generators or ionizers with these products.

Moderate evidence: Author recommendations derived from chamber chemistry, not tested as interventions.

Source: Singer 2006, Atmospheric Environment Link to this fact

What you can do / Self-reported survey

More UK adults prefer fragrance-free over fragranced workplaces (44.7% vs 23.3%), health care (43.3% vs 26.7%) and airplanes (61.9% vs 18.4%).

Moderate evidence: Pluralities, not majorities, for workplace and health care; preference, not health benefit.

Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact

What you can do / Review of other studies

People with suspected fragrance dermatitis should ask for patch testing that includes oxidized limonene and linalool, because standard fragrance screens miss many cases.

Moderate evidence.

Source: Sukakul 2024, Acta Dermato-Venereologica Industry-funded Link to this fact

What you can do / Measured in people or real products

Taking the air freshener out of the car removes its main added chemical: without one, in-car limonene was about 5-6 ug/m3.

Moderate evidence: Small pilot; limonene only.

Source: Jo 2008, Chemosphere Link to this fact

What you can do / Measured in people or real products

People with unexplained dermatitis can ask for patch testing with oxidized limonene and linalool; standard screens can miss these allergies.

Moderate evidence.

Source: Bråred Christensson 2016, Contact Dermatitis Industry-funded Link to this fact

What you can do / Measured in people or real products

Using fewer scented personal care products is likely to lower phthalate and paraben levels, because levels tracked the number of products used.

Moderate evidence: Association; not tested as an intervention here (see HERMOSA).

Source: Braun 2014, Journal of Exposure Science and Environmental Epidemiology Link to this fact

What you can do / Measured in people or real products

When 100 teenage girls swapped their usual personal care products for ones labeled free of phthalates, parabens, triclosan and oxybenzone for just 3 days, levels of these chemicals in their urine fell by 27-45%.

Moderate evidence: No control arm, 100 Latina girls in one town, 3 days, summer.

Source: Harley 2016, Environmental Health Perspectives Link to this fact

What you can do / Measured in people or real products

The phthalate most linked to fragrance (diethyl phthalate) fell by 27% in 3 days when girls avoided products listing fragrance unless labeled phthalate-free.

Moderate evidence: Multi-product swap; fragrance effect not isolated; other DEP sources remain.

Source: Harley 2016, Environmental Health Perspectives Link to this fact

What you can do / Journalism

Treat vague words like 'natural', 'green', 'eco-friendly' or 'for sensitive skin' as marketing, not evidence: read the ingredient list for parfum/aroma, essential oils and named fragrance allergens. Even 'fragrance-free' can allow essential oils and multifunctional allergens such as benzyl alcohol.

Moderate evidence.

Source: Dahl 2010, Environmental Health Perspectives Link to this fact

What you can do / Measured in people or real products

EPA's TEAM investigator recommended source control at home: stop using air fresheners and moth crystals, and air out dry-cleaned clothes.

Moderate evidence: Recommendation derived from source apportionment, not a tested intervention.

Source: Wallace 1991, Environmental Health Perspectives Link to this fact

What you can do / Measured in people or real products

Choose unscented feminine hygiene products rather than relying on organic or natural labels, and avoid frequent vaginal douching and feminine powder use: scented tampons had far more terpenes in product testing, and a separate NHANES biomarker study found frequent douching (2+ times/month) linked to 81% higher blood 1,4-dichlorobenzene (dose-response, p=0.04) and feminine powder use linked to 36% higher blood ethylbenzene.

Moderate evidence.

Source: Lin 2020, Environment International Link to this fact

What you can do / Review of other studies

If you have unexplained eczema, ask for patch testing that includes oxidized limonene and linalool, now recommended for the European baseline series.

Moderate evidence.

Source: Ogueta 2022, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

Don't run ozone-generating air purifiers while using scented cleaners: the particle burst from a limonene cleaner only happened when ozone was present, including from a commercial ozone-generating purifier.

Moderate evidence: One product; ozone-free run had no particle-number increase.

Source: Rossignol 2013, Atmospheric Environment Link to this fact

What you can do / Measured in people or real products

If you have eczema, ask for patch testing that includes oxidized linalool and limonene: they are not in every standard test series, so the allergy can be missed.

Moderate evidence: The authors say more clinical-relevance data are needed before routine screening.

Source: Sukakul 2022, Contact Dermatitis Link to this fact

What you can do / Review of other studies

If you are allergic to fragrance, check the full ingredient list of "fragrance-free" products and prescribed creams for benzyl alcohol, and ask for patch testing with your own products if reactions continue.

Moderate evidence.

Source: Jacob & Barron 2007, Dermatitis Link to this fact

What you can do / Review of other studies

Occupational lung specialists treating irritable larynx syndrome recommend a 'low-scent' workplace policy or respiratory protection to limit exposure to triggers.

Moderate evidence: Clinical recommendation, not tested as an intervention.

Source: Hoy 2010, Occupational Medicine Link to this fact

What you can do / Review of other studies

Fragrance-free cosmetics and laundry products cut the main routes by which synthetic musks enter the body: skin contact and washed clothing.

Moderate evidence.

Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact

What you can do / Measured in people or real products

Musk levels in blood and milk seem to track current personal-care product use rather than lifetime storage: Hutter 2009 found that how often people used perfume and body lotion significantly predicted their blood levels of the polycyclic musks (galaxolide, tonalide) in 100 adults, so choosing fragrance-free personal care and laundry products during pregnancy and breastfeeding is a plausible way to lower a mother's musk levels and, in turn, transfer to the baby.

Moderate evidence.

Source: Reiner 2007, Environmental Science & Technology Link to this fact

What you can do / Review of other studies

If you have fragrance allergy, look for benzyl salicylate on the ingredient list (and hexyl salicylate, which cross-reacted with it in human tests); EU rules require named fragrance allergens to be declared above threshold.

Moderate evidence: Cross-reaction evidence: subjects induced with 30% hexyl salicylate reacted to 15% benzyl salicylate, in an industry report.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

What you can do / Animal study

Methyl salicylate (wintergreen oil) is a strong eye irritant in animal tests, causing irritation even at about 1%, and is toxic if swallowed; keep wintergreen oils and rubs away from children's eyes and mouths.

Moderate evidence: Rabbit eye tests (neat and 1.25% in alcohol); oral toxicity from acute rodent data and the well-known methyl salicylate poisoning literature outside this paper.

Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact

What you can do / Measured in people or real products

The California Department of Public Health recommends enforced fragrance-free workplace policies, no air fresheners or fragranced cleaners, and better ventilation instead of odor masking.

Moderate evidence: Recommendation from a public-health agency based on surveillance, not an intervention trial.

Source: Weinberg 2017, Journal of Asthma Link to this fact

What you can do / Review of other studies

Even the toxicologists who set these limits suggest stricter, setting-specific limits where people breathe through the mouth during exercise, such as sports halls, playgrounds and schoolyards.

Moderate evidence: A proposal, not a finding; no values are given.

Source: Kleinbeck & Wolkoff 2024, Archives of Toxicology Industry-funded Link to this fact

What you can do / Self-reported survey

A fragrance-free sign is not enough on its own: Canadians with chemical sensitivities described workplaces and hospitals with 'scent-free' policies where staff still wore scents and scented cleaners stayed in use.

Moderate evidence: Qualitative focus groups, n=60 self-selected MCS/IAQ-affected Canadians; advocacy-funded.

Source: Roy 2026 Link to this fact

What you can do / Self-reported survey

Fragrance-free policies need to cover cleaning and laundry products, not just perfume: of 60 people who react to fragranced products, 50 named cleaning products, 47 perfume and 41 laundry products as persistent triggers.

Moderate evidence: Self-selected Canadian sample (90% female); counts of participants naming a source, not exposure measurements.

Source: Roy 2026 Link to this fact

What you can do / Review of other studies

Smell scientists reviewing the evidence found that scenting workplaces to boost mood or productivity is not well supported, and noted that a chemically intolerant employee can react to a fragranced workplace.

Moderate evidence: Short narrative review; the positive-scent literature it weighs is small; no primary data.

Source: Dalton & Jaén 2010, Current Opinion in Allergy and Clinical Immunology Industry-funded Link to this fact

What you can do / Measured in people or real products

If you get recurring rashes, ask for patch testing: nickel and fragrance are the most common findings in the general population, and one fragrance test alone misses many fragrance allergies.

Moderate evidence.

Source: Alinaghi 2018, Contact Dermatitis Link to this fact

What you can do / Self-reported survey

Support for fragrance-free health care and workplaces is not limited to people with symptoms: in Germany roughly 70% of those who backed them reported no fragrance-related health effects themselves.

Moderate evidence: Our arithmetic from Table 5; preference, not outcome; German workplace support was only 33.2% (30.6% against, 35.3% unsure).

Source: Klaschka 2020, Environmental Sciences Europe Link to this fact

What you can do / Review of other studies

If you are allergic to fragrance, dermatologists advise avoiding all fragrance rather than only the chemicals you tested positive to, and choosing products from a checked database such as the ACDS CAMP list or SkinSAFE instead of trusting 'fragrance-free' claims.

Moderate evidence.

Source: Rodriguez 2024, Cutis Link to this fact

What you can do / Review of other studies

For fragrance-allergic people, dermatologists recommend removing diffusers, scented candles, room deodorizers, incense and wax melts, switching household cleaners, wipes and laundry products to fragrance-free, and bringing your own shampoo to the salon and your own oil to massages.

Moderate evidence: Expert advice; the salon point rests on a single exposure keeping skin flared up to ~4 weeks (clinical observation).

Source: Rodriguez 2024, Cutis Link to this fact

What you can do / Measured in people or real products

If a child develops unexplained breast tissue, tell the doctor about every product put on the skin, including homemade balms and essential-oil or 'natural' products; in one reported case the lavender balm came to light only after repeated questioning.

Moderate evidence: Practical advice from a case report; not evidence the oil was the cause.

Source: Henley 2007, New England Journal of Medicine Link to this fact

What you can do / Government agency

EPA's own first advice on indoor VOCs is to identify and remove the source, ventilate when products are used, and buy only what you will use soon, because even closed containers leak.

Moderate evidence: Generic VOC advice; EPA does not single out fragrance.

Source: US EPA 2026 Link to this fact

What you can do / Measured in people or real products

Ventilation and less ozone help: in the same test room, with lower ozone (25–30 ppb) and nearly 3× the air exchange, particle mass from perfume, hair spray and body spray fell by more than half.

Moderate evidence: One supplementary run; ozone and ventilation changed together, so their separate effects are unknown.

Source: Wu 2024, Environmental Science & Technology Letters Link to this fact

What you can do / Review of other studies

Check ingredient lists of leave-on products such as makeup, powders and glitter, not just scrubs, for plastic ingredients; ingredient-scanning apps such as Beat the Microbead flag them.

Moderate evidence: App described by the review; completeness of the app's polymer list not assessed.

Source: Han & Kim 2025, Cosmetics Link to this fact

What you can do / Self-reported survey

Fragrance-free health-care policies should cover cleaning and laundry products, not just staff perfume; Canadian advocates ask for exactly this, and people who react name cleaning products as their most common trigger (50 of 60).

Moderate evidence: Advocacy position plus a self-selected focus-group sample; no evidence yet that policies reduce exposure or symptoms.

Source: ASEQ-EHAQ 2020; Roy 2026 Link to this fact

What you can do / Government agency

Workplace accommodations for fragrance sensitivity do not have to be a building-wide ban: the US Labor Department's Job Accommodation Network lists scent-free meeting rooms, moving a worker away from air fresheners and vents, telework, air purifiers, signage and staff education.

Moderate evidence: List of options, not tested for effectiveness.

Source: De Vader & Barker 2009 Link to this fact

What you can do / Review of other studies

Pediatric dermatologists advise that products for children be mild, slightly acidic and fragrance-free.

Moderate evidence: Expert recommendation citing reviews (Kuller 2016, Fernandes 2011); the survey itself linked no product to any skin outcome.

Source: Melo 2020, Revista Paulista de Pediatria Link to this fact

What you can do / Measured in people or real products

Allergen-free moisturizers were no more expensive than others: the cheapest best-sellers with no common skin allergen were plain petroleum jelly and single-ingredient butters and oils, from about $0.28 an ounce.

Moderate evidence: 2016 prices; 'allergen-free' means no NACDG-series ingredient listed; natural oils vary in efficacy (olive oil may harm the barrier).

Source: Xu 2017, JAMA Dermatology Link to this fact

What you can do / Measured in people or real products

If you have fragrance allergy or eczema, don't rely on "fragrance free", "hypoallergenic" or "dermatologist recommended": in best-selling US moisturizers these claims often coexisted with listed skin allergens, so check the full ingredient list or a dermatologist-checked product list.

Moderate evidence: Advice follows from a label survey; not tested against reaction outcomes; two authors hold equity in a product-recommendation service.

Source: Xu 2017, JAMA Dermatology Link to this fact

What you can do / Animal study

Treat essential oils as perishable: keep bottles closed and don't keep old, long-opened oils for skin use, because their scent chemicals oxidize into skin allergens in air.

Moderate evidence: Mechanism shown in lab (open flasks); real-bottle oxidation rates and the benefit of these habits not tested.

Source: Hagvall 2008, Contact Dermatitis Industry-funded Link to this fact

What you can do / Measured in people or real products

Choose unscented tampons, liners and pads, and read "fresh" on the pack as "fragranced": the allergens inside will not be listed.

Moderate evidence: Allergens shown in scented products only; unscented products were bought but not reported; no evidence that switching reduces dermatitis.

Source: Desmedt 2020, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

How much formaldehyde and particle pollution formed was set mainly by how much ozone was available, not by how much product was used, so running an ozone-generating air purifier or ionizer alongside scented cleaning products or air fresheners adds directly to indoor formaldehyde and particles.

Moderate evidence: Conclusion drawn from controlled chamber chemistry (ozone as the limiting reagent in every run), not tested as a real-world intervention.

Source: Destaillats 2006, Environmental Science & Technology Link to this fact

What you can do / Measured in people or real products

Take used paper towels, sponges and mop water out of the room right after cleaning, ventilate during and after, and choose cleaners without 2-butoxyethanol (ethylene glycol monobutyl ether / butyl cellosolve on the label or SDS); avoid running ozone generators with terpene-scented products.

Moderate evidence: Author recommendations derived from chamber chemistry, not tested as interventions.

Source: Singer 2006, Indoor Air, Indoor Air Link to this fact

What you can do / Measured in people or real products

Being below a standard occupational exposure limit does not mean an irritant gas is safe for someone with asthma: chamber studies found severe asthma attacks from sulfur dioxide and sulfuric acid at concentrations at or below typical workplace limits for those substances.

Moderate evidence: Occupational limits are set for healthy workers by design; this is not itself an argument that the limits are wrong, only that they don't protect people with asthma.

Source: Johansson 2016, Critical Reviews in Toxicology Link to this fact

What you can do / Measured in people or real products

If you are diagnosed with oxidized-linalool contact allergy, avoiding products listing linalool or fragrance/parfum is worth doing even at low concentrations, since repeated use at product-realistic doses reproduced dermatitis in a clinical trial, and most participants who had already stopped using linalool-containing products reported their dermatitis improved.

Moderate evidence: Self-reported improvement on avoidance (4 of 5) is not blinded or controlled; the ROAT elicitation data (the stronger evidence) show reactions down to 0.3% oxidized linalool.

Source: Andersch Björkman 2014, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

Avoid frequent vaginal douching and feminine powder use as a modifiable source of blood VOC exposure, on top of existing medical advice against douching for infection risk.

Moderate evidence: Biomarker association from cross-sectional self-report data, not an intervention trial.

Source: Ding 2020, Journal of Women's Health Link to this fact

What you can do / Measured in people or real products

How often someone used body lotion and perfume was directly linked to how much of the synthetic musks galaxolide and tonalide were in their blood, giving direct human evidence that switching to musk-free lotions and perfumes could lower blood levels of these fragrance chemicals.

Moderate evidence: Cross-sectional frequency-of-use questionnaire, not an intervention; the link was not shown for musk ketone or musk xylene, only for the polycyclic musks.

Source: Hutter 2009, Science of the Total Environment Link to this fact

What you can do / Measured in people or real products

If you have a confirmed (not just borderline) positive patch test to limonene hydroperoxides, avoiding products with appreciable oxidized/aged limonene is well supported: realistic product-level doses reliably triggered a reaction in this group.

Moderate evidence: Applies to confirmed reactors; a borderline patch-test result is much weaker evidence of true allergy.

Source: Bennike 2019, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

If you have known fragrance allergy, ask your pharmacist or read the full leaflet (not just the outer box) for topical medicines, and request fragrance-free formulations for wound care, NSAID gels and antiseptics where alternatives exist; if a topical medicine causes a rash, ask for patch testing with the actual product and its individual ingredients, not just the standard fragrance mix.

Moderate evidence: Practical advice drawn from a single clinic's experience; a negative fragrance-mix patch test does not rule out fragrance allergy from a specific product.

Source: Nardelli 2009, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

In a study of 25 UK homes, easy-to-check building factors (home age, size, number of occupants, single- vs double-glazing) showed no measurable relationship to indoor scent-chemical levels; the homes with the highest levels were those whose occupants reported heavy cleaning/fragrance-product use.

Moderate evidence.

Source: Wang 2017, Environmental Science: Processes & Impacts Link to this fact

What you can do / Self-reported survey

During pregnancy, prefer pouring or wiping cleaning products rather than spraying them, and limit solvent and air-freshener use, since spray application was the exposure most consistently linked to infant respiratory symptoms across this and sibling cohort studies.

Moderate evidence.

Source: Casas 2013, International Journal of Public Health Industry-funded Link to this fact

What you can do / Self-reported survey

More than a third of people surveyed (37%) report avoiding at least one leave-on scented product (perfume, deodorant, skin cream) because it has caused them skin problems.

Moderate evidence.

Source: Diepgen 2015 (EDEN), British Journal of Dermatology Industry-funded Link to this fact

What you can do / Measured in people or real products

People with chronic, treatment-resistant hand eczema and a history of reacting to scented products can ask their dermatologist for patch testing beyond the standard fragrance mix, including citral, Lyral, hydroxycitronellal and oxidized limonene/linalool.

Moderate evidence: Based on one clinical population's reaction pattern (Heydorn 2003); a dermatologist should tailor markers to local product exposure.

Source: Heydorn 2003, Contact Dermatitis Industry-funded Link to this fact

What you can do / Measured in people or real products

Because galaxolide (HHCB) levels in milk tracked perfume use and tonalide (AHTN) levels tracked scented-laundry-detergent use specifically, choosing fragrance-free perfume and fragrance-free laundry detergent during pregnancy and breastfeeding are each independently plausible ways to lower the corresponding musk chemical passed to a nursing infant.

Moderate evidence.

Source: Lignell 2008, Environmental Science & Technology Link to this fact

What you can do / Measured in people or real products

For parents of infants, diaper cream is an under-recognized DEP source that deserves attention alongside fragranced products, not instead of them.

Moderate evidence: Based on a Canadian exposure model with non-Canada-specific use-pattern inputs, not measured infant biomarkers.

Source: Koniecki 2011, Environmental Research Link to this fact

What you can do / Measured in people or real products

A direct chemical test of real fragrance products found no build-up of the allergenic breakdown product (linalool hydroperoxide) even after 9 months of worst-case accelerated aging, so for fine fragrances and antiperspirants specifically, letting a bottle sit open for months to years did not measurably increase this particular hazard.

Moderate evidence.

Source: Kern 2014, Analytical and Bioanalytical Chemistry Industry-funded Link to this fact

What you can do / Measured in people or real products

Clinicians managing irritable larynx syndrome most often treat reflux (medication and lifestyle measures) and provide voice/relaxation therapy; formal psychotherapy and botulinum toxin injections are used less often, and botulinum toxin appeared less effective than in focal laryngeal dystonia.

Moderate evidence.

Source: Morrison 1999, Journal of Voice Link to this fact

What you can do / Self-reported survey

If you are allergic to a fragrance or preservative chemical, reading cosmetic ingredient labels is genuinely difficult, not just for you: in one clinical survey, 46% of patch-test-confirmed allergic patients found it difficult or extremely difficult, and this was significantly worse for people with less education.

Moderate evidence: Single-country (Danish), 3-clinic, self-rated VAS survey of 382 patients; not replicated elsewhere, so per our grading rule it stays below strong.

Source: Noiesen 2007, Contact Dermatitis Link to this fact

What you can do / Self-reported survey

People allergic to formaldehyde or methyldibromo glutaronitrile (MDBGN) have an especially hard time reading ingredient labels, likely due to long chemical names and formaldehyde's many synonyms and releasers; ask a dermatologist to write down or print the specific names and synonyms to watch for.

Moderate evidence: Single Danish survey; the mechanism (long/unfamiliar names) is the authors' plausible explanation, not directly tested.

Source: Noiesen 2007, Contact Dermatitis Link to this fact

What you can do / Self-reported survey

Many allergic patients who read ingredient labels still don't fully trust them: in one study only about half of patients affirmatively agreed that ingredient labels are accurate, so persistent reactions despite careful label reading are not necessarily a reading mistake.

Moderate evidence: Self-reported trust, not a test of actual label accuracy; the study does not adjudicate whether distrust reflects real label errors or post-hoc reasoning from continued reactions.

Source: Noiesen 2007, Contact Dermatitis Link to this fact

What you can do / Self-reported survey

Difficulty reading ingredient labels is a general problem across contact-allergic patients, not one limited to people with several different allergies, so simplifying label-reading advice would help broadly rather than only a small multi-allergic subgroup.

Moderate evidence: Single Danish survey (n=382); multiple-allergy status was defined only across the study's 7 target allergens.

Source: Noiesen 2007, Contact Dermatitis Link to this fact

What you can do / Measured in people or real products

A fading chemical smell is not a sign that exposure or irritation has stopped: PGME-exposed subjects lost the ability to smell the compound after about 3 hours at 250 ppm, while eye and nose irritation continued or worsened in those who stayed in the chamber.

Moderate evidence: Demonstrated only for PGME vapor at occupational-accident-level concentrations (hundreds of ppm), not for consumer-level scented product exposure.

Source: Stewart 1970 (Arch Environ Health), Archives of Environmental Health: An International Journal Industry-funded Link to this fact

What you can do / Measured in people or real products

Switching from a fragranced to a fragrance-free laundry detergent cut the fragrance chemical D-limonene coming out of the dryer vent by up to 99.7% (mean 79.1%) within one month, in real households, with no extra cost or apparent inconvenience.

Moderate evidence.

Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact

What you can do / Measured in people or real products

Emptying a dryer's lint filter dry (by hand, vacuum or brush) instead of rinsing it under a tap appears to substantially cut how much textile microfiber ends up in wastewater; a modeled comparison in one study found roughly 12.6 times more fiber reaching water when the filter was rinsed than when the fluff was thrown in household trash.

Moderate evidence.

Source: Cummins 2023, PLOS ONE Industry-funded Link to this fact