Every fact on this site, with its evidence grade, its caveats, and a link to the source.
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.
Fragrance is everywhere / Measured in people or real products
Even at musk levels roughly an order of magnitude below US, South Korean, and Danish cohorts, synthetic musk fragrance chemicals were still detected in 95% of blood, cord-blood, and breast-milk samples from 42 Shanghai mothers and their newborns.
Moderate evidence.
Caveats
Shanghai musk levels were roughly an order of magnitude lower than comparable US, South Korean or Danish cohorts, reflecting lower musk-containing product use in China in 2007; no product-use data were actually collected in this study to confirm the cause.
Source: Zhang 2015, International Journal of Hygiene and Environmental Health 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.
Caveats
Masking itself is still unmeasured (a review statement). For a primary count cite Xu 2017: 18/40 (45%) best-selling US 'fragrance-free' moisturizers listed a fragrance cross-reactor or botanical, which is identity-based, not masking.
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.
Caveats
Presence only; oxidized (allergenic) forms not measured in these products. Hagvall 2008 shows linalool in an essential oil (lavender) oxidizes in air at the same rate as synthetic linalool, so the natural source gives no protection; real-product hydroperoxide levels unknown.
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.
Caveats
Mouse LLNA (groups of 3-4 mice; one 45-week sample) from the primary Hagvall 2008, lab open-flask exposure; aged oil reached 'moderate', not 'strong', potency. Human support: 4/4 oxidized-linalool-allergic patients reacted to oxidized lavender oil (elicitation, n=4). Earlier evidence base figure '11% -> 4.4%' was a misreading.
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.
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.
Caveats
80/162 is a count of documented allergens (de Groot), not a risk comparison; the store claim is unquantified. Klaschka 2016 supports the mechanism (supplier SDSs: orange oil ~95% limonene, lavender ~40% linalool) but counted no 'fragrance-free'-labeled products, and in its EU sample 58/100 products did declare natural-origin allergens, so on EU labels the ingredient list often shows them.
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.
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.
Caveats
91%/35% is Rastogi 1996's own perfume-vs-other-cosmetics split, now confirmed by reading the primary directly (a review had dropped the perfume qualifier and stated 91% as if it covered 'natural cosmetics' generally; corrected 2026-09-27). Rastogi 1996 also found synthetic-only fragrance chemicals (hydroxycitronellal, alpha-hexylcinnamic aldehyde) in some 'natural' products, at concentrations that in one case (6.04% hydroxycitronellal) exceeded the level shown to sensitize 36% of volunteers in patch testing. 82/100 is Klaschka 2016's independent label analysis (10 products from each of 10 brands, not representative, declarations only). The oxidation half rests on Karlberg/Bråred Christensson primaries, not on these surveys. Single small studies (n=42 and n=100), not replicated across labs, so strength stays moderate per the grading rule.
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.
Caveats
Ingredient-label survey, one product class and snapshot; CAMP list is broad (plant extracts, multifunctional chemicals such as benzyl alcohol); flagged ingredients not itemized; not added scent or masking.
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.
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.
Caveats
Lab headspace (SIFT-MS) of 16 products from UK shops; 'limonene' is the sum of all monoterpenes; no statistical test; green products did have less synthetic-only solvents (t-butyl alcohol, 1,3-butanediol).
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.
Caveats
Ten named examples from 1999 labels, not a systematic survey; formulations have likely changed since. Masking is one manufacturer's admission and remains unquantified across products.
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.
Caveats
42 products, one country (Denmark), 1996 market snapshot; parent-compound GC-MS only, not label declarations; the 91% figure applies to the natural-ingredient PERFUME subset only, not natural cosmetics generally.
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.
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.
Caveats
No chemical analysis of the finished product is described; verification rests on declared ingredient lists checked against two lists (SCIL and the IFRA Transparency List), not analytical chemistry or clinical testing.
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.
Caveats
The 'cosmetic' definition and its exclusion of fabric-care products is confirmed directly from the source text; that laundry products instead fall under Canada's consumer chemical product safety rules (CCPSA) is background knowledge, not itself stated in either captured Health Canada page, so graded moderate rather than strong.
Source: Health Canada 2026 Link to this fact
Green, natural and unscented / Measured in people or real products
Laundry products labeled 'free and gentle' genuinely excluded fragrance (0% contained it across every product category), but still commonly contained preservative allergens (MI in 57.1% of free-and-gentle detergents) and surfactant allergens (decyl/lauryl glucoside in 28.6-33.3% of free-and-gentle detergents and stain removers).
Moderate evidence: N=7-13 per free-and-gentle subgroup depending on category; label survey only.
Green, natural and unscented / Measured in people or real products
In the same test house and wax warmer, an unscented wax melt produced no significant terpene release and no measurable nanoparticle formation, showing that the fragrance chemicals — not the melted wax itself — are what drives the particle-forming reaction.
Moderate evidence: A single unscented product tested as one control condition; supports the mechanism but is not itself a survey of unscented products generally.
Source: Patra et al. 2025, Environmental Science & Technology Letters Link to this fact
Green, natural and unscented / Review of other studies
Most 'natural' or herbal deodorant actives described in this review (essential oils such as tea tree and usnic acid, and dozens of herbal extracts) work the same way synthetic actives like triclosan and silver compounds do: by killing or inhibiting the skin bacteria that cause odor, not through some fundamentally gentler mechanism.
Moderate evidence: Based on antibacterial potency (MIC/MBC) data only; this review does not compare skin-irritation or sensitization rates between herbal actives and synthetic anti-microbial salts.
Source: Kanlayavattanakul & Lourith 2011, International Journal of Cosmetic Science Link to this fact
Green, natural and unscented / Measured in people or real products
The unscented 'plain' paraffin candle used as this study's own combustion reference produced the third-highest formaldehyde level of the six candles tested when lit (925 ppb), higher than two of the five scented candles.
Moderate evidence.
Caveats
Single lab, six products, no replication; wax type (paraffin vs. palm) did not track cleanly with formaldehyde output either, so this alone doesn't identify which factor (wax, wick, dye, or fragrance) actually controls it.
Source: Ahn et al. 2015, Journal of Hazardous Materials Link to this fact
Green, natural and unscented / Measured in people or real products
A series of six men's grooming products from one brand were marketed with the text 'Our products never contain artificial colors, synthetic fragrances' while labeled to contain Evernia furfuracea (tree moss) extract, a natural-source fragrance allergen.
Moderate evidence: Single-brand example (n=6 products from one line), not a systematic audit of 'natural' marketing claims.
Source: Bennike 2017/2018 Link to this fact
Green, natural and unscented / Measured in people or real products
Not all fragrance-based odor masking works the same way: Iso E Super, a common deodorant fragrance chemical that barely blocked the malodor receptors in lab dish tests, still reduced how strong a sulfur malodor smelled to people, but less effectively than beta-ionone, suggesting this masking runs mainly through the brain blending two smells together rather than through receptor blocking.
Moderate evidence: Central-processing explanation is the authors' inference from a negative in-vitro result, not directly tested; based on the same single-lab, single-cohort study.
Source: Fukutani et al. 2023, Current Biology Industry-funded Link to this fact
Green, natural and unscented / Measured in people or real products
Ethanol, linalool, and D-limonene, common fragrance and solvent terpenes found in both synthetic and "natural" scented products, were the single most-listed chemicals overall (about 27%, 16%, and 12% of products respectively) in a database of over 7,000 Korean household chemical products, ahead of synthetic fragrance aldehydes like hexyl cinnamaldehyde (about 8%).
Moderate evidence: Ingredient-list prevalence, not measured air or dermal exposure; does not distinguish products marketed as "natural"/"green" from conventional ones.
Source: Lee & Ji 2022, Ecotoxicology and Environmental Safety Link to this fact
Green, natural and unscented / Government agency
EPA's own advice for preventing unpleasant household odors is proper ventilation and basic household cleanliness, not air fresheners or fragranced products.
Moderate evidence: Stated in the context of moth-repellent/paradichlorobenzene odor, not a general product-safety recommendation.
Source: US EPA, "The Inside Story" Link to this fact
Green, natural and unscented / Government agency
Because the EU's expanded fragrance-allergen list includes most of the chemicals that make up common essential oils (lavender, citrus, rose, patchouli, and more), a product marketed as 'natural' or 'essential-oil-based' is not exempt from fragrance-allergen labeling and may in fact trigger more individual allergen declarations than a synthetic-fragrance product.
Moderate evidence.
Caveats
This is an inference from the regulation's own entry list (natural oils named by species as fragrance-allergen entries), not a product-testing study; see our existing natural-cosmetics label surveys for empirical confirmation of a related pattern.
Source: Regulation (EU) 2023/1545 Link to this fact
Green, natural and unscented / Measured in people or real products
A product labeled '100% PURE & NATURAL' (Citrus Magic) and a product labeled 'unscented' (Ozium Glycol-ized Air Sanitizer) both contained phthalates not listed on their labels, in NRDC's 2007 test of 14 air fresheners.
Moderate evidence: Only one all-natural product and one unscented product were tested; not a survey of 'natural'/'unscented' air fresheners generally.
Source: NRDC 2007, Clearing the Air 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.
Caveats
Self-report, unadjusted; asthma includes undefined 'asthma-like condition'; same dataset as Steinemann 2016; 34% of asthmatics also report diagnosed MCS and 42-53% of affected asthmatics are MCS-diagnosed, but asthmatics without MCS are still affected at 46-56% vs 20-22% of people with neither.
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.
Caveats
Self-report. Corroborated but not strengthened by an independent 1986 clinic/inpatient survey (Shim & Williams, n=60, unselected for fragrance sensitivity): 72% named perfume/cologne as worsening their asthma, well above this 27.9% attack-specific representative-survey rate, consistent with our clinic-ceiling-above-population-rate pattern.
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.
Caveats
Predictors measured 4-5 years before outcomes; association not causation. In clinic patients the reactive trait can be sensory rather than bronchial: Millqvist 1999's 11 perfume reactors were all methacholine-negative and 10/11 skin-prick negative, and Millqvist & Lowhagen 1996's 9 patients (an earlier, blinded, placebo-controlled challenge) were likewise all methacholine-negative yet still reacted significantly to unsmelled perfume with zero objective airway change. So 'sensitive airways' in this literature should not be read as bronchial hyper-reactivity when applied to clinic-referred sensory-hyperreactivity patients; Elberling's population-level BHR association may instead mark co-morbid asthma. A related but distinct 2007 study from the same Gentofte group (Elberling 2007, dermatology-clinic patients, not this population cohort) found a candidate non-IgE, non-neural mechanism in parallel: increased basophil histamine release to perfume, unrelated to atopy, contact allergy, or asthma status. 'Airway irritation' (a neural/sensory account) may not be the whole mechanistic story; BHR, sensory/capsaicin hyperreactivity, and basophil hyperreactivity have not been measured together in the same patients.
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.
Caveats
Self-report; same data as 2019 SE arm. A structurally different Swedish research program (Andersson 2008, CSS-SHR instrument) finds a similarly-sized ~33% figure in Skovde adults using a different question ("bothered by strong odors"), cited secondhand within Andersson 2008; that comparator is not yet a primary source in this evidence base, so it corroborates the general phenomenon without directly replicating this claim.
Source: Steinemann 2018 (Sweden), Air Quality, Atmosphere & Health Link to this fact
Information, not medical advice. See also: myths we won’t tell you.