Don’t take our word for it. Here’s every fact on this site, with its evidence grade, its caveats, and a link to the source, so you can check us.
We start you on the strong ones: findings that have been replicated or come from one large, well-controlled study. Moderate and weak facts are here too, labeled for what they are. Use “Link to this fact” to share a single card.
Children and pregnancy / Other evidence
The psychologists' standardized clinic tests in the same trial found no change in 3-year-olds' hyperactivity after the food color and benzoate drink (test scores stayed within about 0.04 standard deviations of baseline at every time point), so the effect was seen only by parents.
Moderate evidence.
Caveats
The authors suggest the clinic tests may be insensitive (test-retest reliability only 0.24 to 0.72), so a null clinic result does not prove there was no effect; it does mean the parent-rated result was not confirmed by an objective measure.
Source: Bateman 2004, Archives of Disease in Childhood Link to this fact
Children and pregnancy / Other evidence
In the same trial the parent-rated effect did not differ between children who were already hyperactive or allergic (atopic) and those who were not, which the authors read as evidence against an allergic (IgE) mechanism for additive effects on behavior.
Moderate evidence.
Caveats
Interaction tests with 30 to 87 children per cell may be underpowered; atopy was defined by skin-prick tests to six common allergens, not to the additives; this says nothing about fragrance allergy.
Source: Bateman 2004, Archives of Disease in Childhood Link to this fact
Children and pregnancy / Other evidence
In a US study of 8,889 children aged 4-10 and their mothers (NLSY), smoking during pregnancy went with more conduct, oppositional and ADHD-type behavior problems: about 0.27 to 0.29 standard deviations per pack a day when unrelated children were compared, falling only to about 0.17 to 0.21 after adjusting for mother's education, income, ability and delinquency.
Moderate evidence.
Caveats
Mother-reported smoking and mother-rated symptom scales, not diagnoses; this is the ordinary-cohort result that the same paper's sibling analysis then undercuts. Tobacco is not a fragrance ingredient.
Source: D'Onofrio 2008, Development and Psychopathology Link to this fact
Children and pregnancy / Other evidence
When children were compared with their own siblings who were exposed to different amounts of smoking in the womb, the link to conduct problems (about 0.06 for boys, none for girls) and oppositional-defiant problems (about -0.02) disappeared, which the authors read as family factors rather than prenatal smoke accounting for the earlier association.
Moderate evidence.
Caveats
One cohort (NLSY, mother-reported), sibling designs can miss a true effect when exposure is measured with error, and the authors say the result surprised them and needs replication. Not a fragrance exposure.
Source: D'Onofrio 2008, Development and Psychopathology Link to this fact
Children and pregnancy / Other evidence
For ADHD-type symptoms the sibling comparison cut the smoking association from about 0.27 to about 0.07 per pack a day (not statistically significant in the multilevel models), and smoking accounted for about 0.1% of within-family but 14% of between-family variance.
Moderate evidence.
Caveats
Abstract calls the remainder 'consistent with a causal effect', the text calls it non-significant and the structural model path is 0.09 (SE 0.04), so a small direct effect is not excluded; three-item maternal-report scale. Tobacco is not a fragrance ingredient.
Source: D'Onofrio 2008, Development and Psychopathology Link to this fact
Children and pregnancy / Other evidence
A 2009 review of genetically informed studies found that when brothers and sisters were compared within the same family, smoking in pregnancy no longer predicted children's conduct problems or poor school performance, suggesting the usual population-level link is largely carried by differences between families.
Moderate evidence.
Caveats
Narrative review of a few studies, not a meta-analysis; sibling designs can be biased by quitting patterns and exposure correlated across pregnancies; behavior and school outcomes only, not ADHD.
Source: Knopik 2009, Developmental Neuropsychology Link to this fact
Children and pregnancy / Other evidence
The same review reports that smoking in pregnancy keeps a direct, unconfounded association with lower birth weight in a children-of-twins analysis (D'Onofrio 2003), unlike behavioral outcomes, so the physical effect looks real.
Moderate evidence: Relays one primary study; the review does not pool estimates.
Source: Knopik 2009, Developmental Neuropsychology Link to this fact
Children and pregnancy / Other evidence
The review concludes established estimates of smoking-in-pregnancy effects on child outcomes are probably upwardly biased by uncontrolled inherited and family factors, yet the author says this should not lessen concern about smoking in pregnancy.
Moderate evidence: Author's reasoned opinion in a narrative review; no new data.
Source: Knopik 2009, Developmental Neuropsychology Link to this fact
Children and pregnancy / Other evidence
In that lead meta-analysis, the link to children's inattention and hyperactivity shrank only modestly after adjusting for income, parental education and IQ (inattention r .17 to .13; hyperactivity/impulsivity .15 to .09) and stayed statistically significant.
Moderate evidence: Adjustment sets mostly SES and IQ; no sibling or genetically informed designs, so parental ADHD is not ruled out as a third variable.
Source: Goodlad 2013, Clinical Psychology Review Link to this fact
Children and pregnancy / Other evidence
A 2013 meta-analysis of 8 small, mostly 1970s-80s randomized trials in children with ADHD found that removing artificial food colors was followed by a modest drop in ADHD symptom ratings (standardized difference 0.42, 95% CI 0.13 to 0.70) even when only probably blinded ratings, mostly teacher ratings, were counted.
Moderate evidence.
Caveats
Old, small trials (8-36 per arm), crossover data pooled as parallel groups, children often pre-selected as suspected responders; authors say the benefit may be limited to food-sensitive children; the 4 low/no-medication trials were not significant (0.32, -0.13 to 0.77); several authors have drug or supplement-industry ties.
Source: Sonuga-Barke 2013, American Journal of Psychiatry Link to this fact
Children and pregnancy / Other evidence
The same review found that restricted 'few foods' elimination diets, which looked very strong when judged by the rater closest to treatment (standardized difference 1.48), lost statistical significance (0.51, 95% CI -0.02 to 1.04) when only probably blinded ratings were used.
Moderate evidence: Only 5 trials had probably blinded ratings; heterogeneity high; the drop came from two open-label or parent-informed trials; not significant is not proof of no effect.
Source: Sonuga-Barke 2013, American Journal of Psychiatry Link to this fact
Children and pregnancy / Review of other studies
The review reports that sibling-discordant and assisted-conception studies suggest the link between smoking in pregnancy and child ADHD (pooled unadjusted odds ratio 2.36) is due at least in part to inherited or household confounding; it does not say smoking in pregnancy is safe.
Moderate evidence.
Caveats
Rests on a few studies by the authors' own group and others; the unrelated-mother group in the 2009 study had only 9 exposed children; association-level pooled estimate is unadjusted.
Source: Thapar 2013, Journal of Child Psychology and Psychiatry Link to this fact
Children and pregnancy / Other evidence
In 2,715 Barcelona schoolchildren aged 7-10 in 39 matched schools, those in high-traffic-pollution schools gained 9.9 fewer working-memory points over 12 months (95% CI -16 to -3.5) than children in low-pollution schools.
Moderate evidence: One observational cohort with school-level exposure (39 schools); residual social confounding not fully excluded; baseline gaps were not significant.
Source: Sunyer 2015 (BREATHE, Barcelona), PLOS Medicine Link to this fact
Children and pregnancy / Other evidence
Higher school NO2, elemental carbon and ultrafine particles each went with smaller 12-month gains in superior working memory (3-back numbers) and slower, more variable attention in Barcelona schoolchildren.
Moderate evidence: Results for working memory with word stimuli (2-back) were all non-significant; ultrafine particle exposure was the least reliable measure.
Source: Sunyer 2015 (BREATHE, Barcelona), PLOS Medicine Link to this fact
Children and pregnancy / Other evidence
When siblings were compared within families (one exposed to smoking in pregnancy, one not), the ADHD hazard ratio fell to 1.07 (95% CI 0.94-1.22), and the dose gradient disappeared (10+ cigarettes a day: 1.08, 0.77-1.51).
Moderate evidence.
Caveats
One national register cohort; the sibling design uses only pairs discordant for smoking and ADHD, and the upper CI limit (1.22) does not exclude a modest effect; sibling designs also amplify exposure misclassification.
Source: Obel 2016, Journal of Child Psychology and Psychiatry Link to this fact
Children and pregnancy / Other evidence
Full-sibling and maternal half-sibling comparisons gave similar results (HR 1.11 and 0.96), which the authors read as pointing to maternal genes or shared family environment, not the fetal environment, behind the population association.
Moderate evidence: Half-sibling group is small (75,026 children) with wide intervals; the design cannot separate genes from shared household environment.
Source: Obel 2016, Journal of Child Psychology and Psychiatry Link to this fact
Children and pregnancy / Other evidence
The same sibling model still found smoking in pregnancy linked to low birth weight (odds ratio 1.68, 95% CI 1.33-2.12, versus 2.60 in the whole cohort), which the authors use to show the design can detect a real prenatal effect.
Moderate evidence: A positive control supports the method but does not prove it is equally sensitive for a behavioral outcome like ADHD.
Source: Obel 2016, Journal of Child Psychology and Psychiatry Link to this fact
Children and pregnancy / Other evidence
A 2018 meta-analysis of 12 studies found children born very preterm or at very low birth weight were about 3 times as likely to have an ADHD diagnosis as term-born peers (OR 3.04, 95% CI 2.19-4.21).
Moderate evidence: Crude study-level pooling; no adjustment for parental ADHD or socioeconomic status; no sibling designs; high-income countries; preterm birth is not fragrance-related.
Children and pregnancy / Other evidence
In the same meta-analysis the ADHD odds were about 2 times higher for very preterm/VLBW (OR 2.25, 1.56-3.26) and about 4 times higher for extremely preterm/ELBW births (OR 4.05, 2.38-6.87).
Moderate evidence: Subgroup CIs overlap and no formal subgroup test is reported for diagnosis; unadjusted; not fragrance-related.
Children and pregnancy / Other evidence
In the US National Health Interview Survey, the share of children aged 4-17 whose parents said a doctor had ever diagnosed ADHD rose from 6.1% in 1997-1998 to 10.2% in 2015-2016, in every sex, race and ethnicity, income and region group.
Moderate evidence: Parent-reported lifetime diagnosis in a cross-sectional survey series (186,457 children); measures diagnosis, not symptoms, and not cause.
Children and pregnancy / Other evidence
The authors of the 20-year US ADHD diagnosis trend say the rise may be partly nonetiologic (physician education, changed diagnostic criteria, awareness, access to care, lower stigma) but did not measure how much each contributes.
Moderate evidence: Explanations are listed from the literature, untested in this survey; the paper also says the share due to etiologic factors is unknown.
Children and pregnancy / Other evidence
In 2015-2016, parent-reported ADHD diagnosis was 14.0% in US boys and 6.3% in girls, and 12.8% in non-Hispanic black, 12.0% in non-Hispanic white and 6.1% in Hispanic children; girls' rate about doubled since 1997-1998 (3.1% to 6.3%).
Moderate evidence: Weighted NHIS estimates of ever-diagnosis; differences reflect diagnosis and access as well as any true difference in the trait.
Children and pregnancy / Other evidence
A California state-agency review (OEHHA) found that 16 of 25 children's dye-challenge crossover trials reported some association between synthetic food dyes and worse behavior, and 13 of 25 were statistically significant.
Moderate evidence: Vote count, not a pooled estimate; 'association' includes effect sizes of 20% or more without significance; mostly small, older trials (19 of 25 before 1990); no certainty grading.
Children and pregnancy / Other evidence
In the 2022 US National Survey of Children's Health, 11.4% of children aged 3-17 (about 7.1 million) had ever been told by a provider they had ADHD and 10.5% (6.5 million) had current ADHD; this is parent report, not a clinical check.
Moderate evidence: Cross-sectional, 39.1% response rate, diagnoses unverified; weighting changed in 2022 so comparison with earlier years is limited.
Source: Danielson 2024 (NSCH 2022), Journal of Clinical Child & Adolescent Psychology Link to this fact
Children and pregnancy / Other evidence
The 2024 review's text describes black carbon in Forns 2016 as linked to ADHD symptoms, but the review's own table and the primary paper show null ADHD-symptom ratios (0.99 and 1.03); the school air-pollution signal was for general behavior difficulties.
Moderate evidence: Review's tabulated numbers are correct; only its narrative wording is wrong. Not fragrance-related.
Source: Ahmad 2024, Cureus Link to this fact
Children and pregnancy / Other evidence
The 2024 air-pollution ADHD review includes studies whose outcomes were attention-test scores, ASD severity or general externalizing behavior despite its stated rule to exclude non-ADHD outcomes, and treats several reports from the same Barcelona school cohort as independent.
Moderate evidence: Judged from the review's own tables; the pooled analyses use only some of these. Not fragrance-related.
Source: Ahmad 2024, Cureus Link to this fact
Children and pregnancy / Other evidence
In 6,790 US children aged 4-15 (NHANES 1999-2004), those living in a home where someone smoked indoors had about 1.6 times the odds of a parent-reported ADHD diagnosis (adjusted OR 1.58, 95% CI 1.17-2.15), an association from a cross-sectional survey.
Moderate evidence.
Caveats
Cross-sectional; exposure measured at survey, diagnosis is ever-lifetime parent report; no sibling or parental-ADHD control so familial confounding and reverse causation are open. Tobacco smoke is not a fragrance exposure.
Source: Bao 2026 (NHANES 1999-2004), Tobacco Induced Diseases Link to this fact
Children and pregnancy / Other evidence
The authors themselves warn that the smoking-ADHD association may partly reflect shared genes: ADHD is about 74-88% heritable and adults with ADHD are 2-3 times more likely to smoke, so parents with ADHD traits may smoke indoors and pass on ADHD risk.
Moderate evidence: Authors' reasoning, not tested in this study; sibling or genetically informed designs needed.
Source: Bao 2026 (NHANES 1999-2004), Tobacco Induced Diseases Link to this fact
Children and pregnancy / Other evidence
The ECHO authors state their prenatal-smoking results are 'not a genetically informed analysis' and are probably 'somewhat inflated by familial confounding'; mothers who smoked had less education, more psychiatric family history (55% vs 34% of all children recorded) and 65% vs 16% postnatal smoke exposure.
Moderate evidence: Authors' own caveat from a single large consortium analysis; family psychiatric history is a crude proxy with 34% missing.
Source: Marceau 2026 (ECHO), Development and Psychopathology Link to this fact
Children and pregnancy / Other evidence
In about 4,700 German adolescents followed from birth, higher long-term outdoor PM2.5 and a soot marker (PM2.5 absorbance) at home addresses went with modestly higher odds of a borderline or abnormal hyperactivity/inattention questionnaire score (about 11-14% per small exposure step, odds ratios 1.11-1.14); nitrogen dioxide showed no association.
Moderate evidence.
Caveats
Association only; symptom questionnaire, not ADHD diagnosis; sensitive to how borderline scores are grouped; no multiple-testing correction; authors request replication. Outdoor air pollution is not fragrance-related.
Source: Fuertes 2016, Environment International Industry-funded 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.
Caveats
Single pooled composite per category (Dodson 2012). The perfume DEP level is now independently supported by two other labs: FDA's Hubinger & Havery 2006 measured 0.55-3.9% DEP in individual fragrance products, and Health Canada's Koniecki 2011 (n=252, the largest of the three) measured DEP up to 2.6% in 70% of 30 fragrance products — three independent labs across two countries now bracket Dodson's 1.4% figure for perfume specifically. The air-freshener and dryer-sheet parts still rest on Dodson alone (Koniecki tested only cosmetic/personal-care products, no air fresheners or dryer sheets), so the combined claim stays moderate.
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 metric tons 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 metric tons a day), behind only passenger cars, according to California's air regulator.
Moderate evidence.
Caveats
Regulatory inventory, 2005 snapshot; includes non-fragranced products and solvents. Direction confirmed by measurement in a second city: NYC 2018 VCP VOC ~1.5x fossil fuels by mass, tracer-verified (Coggon 2021).
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.
Caveats
Model-based ozone reactivity; one episode. In NYC 2018, VCPs were modeled as comparable to fossil fuels for ozone (+11 vs +8 ppb at the downwind peak; box model 40:60) (Coggon 2021), so the 2005 LA ranking may understate them.
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 metric tons 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.
Caveats
46 women, 4 donors, custom low-dose perfume, conditioning as an indirect measure; no perfume x odor interaction tested. Now corroborated on the 'not abolished' floor claim by a much larger, direct primary test: Allen, Havlíček & Roberts 2015 (n=427, triangle test) found body-odor discrimination stayed above chance in all fragrance conditions (all p<0.001), though it fell significantly with fragrance and fell to chance for one specific subgroup (female donor odor + an unfamiliar assigned fragrance, 0.30-0.36 vs 0.33 chance) — so treat this as 'fragrance dampens but does not generally abolish discrimination', not as 'perfume has no effect'.
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.
Caveats
Secondary report of German surveys (391 Bavarian milk samples, mean 40 µg/kg fat, plus a smaller n=5 cohort at 11 µg/kg fat); 1990s data. Rimkus & Wolf 1996 (the primary source of that n=5 cohort) directly confirms musk ketone detection in all 19 of their own German fat/milk samples (1993/1995), but their own milk values (5-30 µg/kg fat, mean 11) are far below the oft-quoted 240 µg/kg maximum from the separate, larger Bavarian survey – do not imply 240 is a typical value.
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.
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.
Caveats
Lab headspace of products bought at one UK supermarket; SIFT-MS cannot separate monoterpenes, so 'limonene' is the sum of all of them; brands not named. Same lab's second, separate set of 16 UK day moisturizers (Yeoman 2022) also all emitted monoterpenes (0.08–0.41 µg/s/g), green and regular alike.
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.
Caveats
The 60% figure is from older industry/secondary sources (Bickers 2003, Bridges 2002). The human-milk sub-claim is now supported by three independent primary studies spanning three countries: Rimkus & Wolf 1996 (Germany, n=5, 1993/1995), Reiner 2007 (US, n=39, 2004), and Lignell 2008 (Sweden, n=101, 1996-2003); cite these primaries for milk levels, not this review.
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.
Caveats
7 products; presence only. Lamorena & Lee 2008 (KAIST chamber, GC-MS/FT-IR) independently confirms terpene-dominant emissions (α-pinene, β-pinene, p-cymene, limonene) from a car air freshener, but that product is an oil-based liquid type, not plug-in or hanging, so it corroborates the general 'car fresheners emit terpenes' pattern without directly extending evidence for the plug-in/hanging sub-types this claim specifies.
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.
Information, not medical advice. See also: myths we won’t tell you.