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.
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 / 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 / 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 / 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.
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Moderate evidence: Not peer reviewed; labs, detection limits, and concentrations not reported; hazard = database flag; IFRA list includes multifunctional solvents/preservatives.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.
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.
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 / 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.
Caveats
Estimated from use-concentration ranges compiled from industry websites and patents that the authors say 'differed by orders of magnitude'; the model assumes 100% of PFAS reaches wastewater and exactly one PFAS ingredient per product; total mass estimates span roughly two orders of magnitude (650-56,000 kg/year).
Source: Balan 2024, Environmental Science & Technology Link to this fact
Hidden ingredients / Measured in people or real products
In a French study of 543 healthcare workers who used disinfectants, 99 (18.2%) could not be classified by exposure status from self-report alone, and researchers had to review Material Safety Data Sheets with 3 experts to determine which products contained quaternary ammonium compounds.
Moderate evidence.
Caveats
This describes a French occupational healthcare-worker population in 2006-2007, not consumers; it does not measure how well consumers can identify QACs in household cleaning products from labels today.
Source: Gonzalez 2014, Clinical & Experimental Allergy Link to this fact
Hidden ingredients / Measured in people or real products
Besides PFOA, gamma-irradiated PTFE also released smaller amounts of related short-chain perfluorocarboxylic acids: about 46 ppb perfluorobutanoic acid (PFBA), 26 ppb perfluoropentanoic acid, 20 ppb perfluorohexanoic acid, and 15 ppb perfluoroheptanoic acid, and, when irradiated in an air-filled sealed bag, a wider range of these acids from 4 to 13 carbons.
Moderate evidence.
Caveats
Measured in laboratory-irradiated PTFE samples, not a finished product; short-chain PFAS are generally considered less bioaccumulative than PFOA but some (e.g. PFHxA) remain under regulatory scrutiny — this evidence base has not separately assessed their toxicology.
Source: Oshima et al. 2020, Scientific Reports Industry-funded Link to this fact
Hidden ingredients / Review of other studies
Body odor intensity has a genetic component: people carrying the ABCC11 gene variant linked to dry earwax (common in East Asian populations) had less body odor and lower levels of the odor-carrier protein apolipoprotein D than people without it, in the study this review cites.
Moderate evidence.
Caveats
Single cited primary study relayed by this review, not independently verified here; ABCC11's role in foot odor and isovaleric acid formation is separately noted but not from the same study.
Source: Kanlayavattanakul & Lourith 2011, International Journal of Cosmetic Science Link to this fact
Hidden ingredients / Animal study
GC-MS of the scented candle's emissions detected methylene chloride (2.71% of peak area, a carcinogen with two known toxic-metabolite pathways) and the phthalate DEHP (0.1%), neither of which would appear on a candle's fragrance or wax label.
Moderate evidence.
Caveats
Detected in headspace/combustion emissions, not necessarily added as ingredients; percentages are of total VOC peak area, not of candle mass, and the specific candle's ingredient list is not published.
Source: Mohamed et al. 2025, Frontiers in Public Health Link to this fact
Hidden ingredients / Measured in people or real products
FDA's 2010 follow-up testing of 84 consumer cosmetic products found the fragrance solvent diethyl phthalate (DEP) in all 11 fragrance products tested (up to 36,006 ug/g, about 3.6% by weight) and in 20 of 60 adult-use products overall, while dibutyl phthalate (DBP) was found only in nail products (11 of 24, up to 62,607 ug/g), even though phthalates carried in as part of 'fragrance' are not required to be named on the label.
Moderate evidence.
Caveats
Single FDA laboratory follow-up survey, 84 products bought in or near Washington DC or online before August 2010 (exact purchase date not stated); HPLC-UV product concentration, not absorbed dose.
Source: Hubinger 2010, Journal of Cosmetic Science Link to this fact
Hidden ingredients / Government agency
DEA and its condensates (cocamide DEA, lauramide DEA) are not banned from cosmetics, but US Cosmetic Ingredient Review guidance says they should not be combined with nitrite or other nitrosating agents in a formulation, because that reaction can form N-nitrosodiethanolamine (NDELA), an animal carcinogen that is not itself listed on any ingredient label.
Moderate evidence.
Caveats
This paper restates the regulatory rationale (citing 1983/1986 CIR positions) but does not itself measure NDELA formation in any tested product; the formation-measurement gap is still open in our evidence base.
Source: Kraeling 2004, Food and Chemical Toxicology Link to this fact
Hidden ingredients / Government agency
EPA lists moth repellents and air fresheners among household-product sources of organic-gas (VOC) indoor air pollution, and notes that paradichlorobenzene, a chemical carrying an 'avoid breathing vapors' warning on moth-repellent labels, is also the key active ingredient in many air fresheners.
Moderate evidence: EPA names the shared ingredient and the moth-repellent warning; it does not separately assess air-freshener-specific health risk.
Source: US EPA, "The Inside Story" Link to this fact
Hidden ingredients / Review of other studies
Danish product checks cited in a 2004 review found parabens in 77% of 215 cosmetics (0.01-0.87%) and 87% of skin creams, with ingredient labels wrong about parabens in about 10% of products.
Moderate evidence: Secondhand from Rastogi 1995 and 2000, and from 1990s Danish and Swedish products; not re-checked in this evidence base; current formulations differ.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Hidden ingredients / Other evidence
Under an FDA bulk-labeling rule the flavor industry relies on, a multi-ingredient flavor can carry one sentence ('All flavor ingredients contained in this product are approved for use in a regulation of the Food and Drug Administration') instead of a list of each ingredient, provided every flavor ingredient is approved in an FDA regulation; non-flavor ingredients and flavor ingredients outside such a regulation must be listed separately.
Moderate evidence.
Caveats
1995 description by FEMA's own authors, who add that FDA treated FEMA GRAS lists as reliable industry lists for this purpose. The 2024 CFR text of 21 CFR 101.22(g)(2) names only FDA regulations and says nothing about industry lists.
Source: Hallagan 1995, Regulatory Toxicology and Pharmacology Industry-funded Link to this fact
Hidden ingredients / Other evidence
The FEMA panel does not require toxicology tests on each flavor ingredient: for the 119 ring-structured terpene flavors it judged safety mainly from the metabolism and tests of a few parent compounds (such as menthol, carvone, camphor-type ketones) and from low estimated intake.
Moderate evidence.
Caveats
This is the industry panel's own method statement; the paper argues it is scientifically sound because related substances share metabolic pathways, and does not show case-by-case failure.
Source: Adams 1996, Food and Chemical Toxicology Industry-funded Link to this fact
Hidden ingredients / Other evidence
Several flavor chemicals in this review (menthol, carvone, camphor, borneol, terpineol, ionones, damascones and the musks muscone, and civettone) are also fragrance materials, but the FEMA review assesses them only as swallowed food ingredients; it gives non-oral data 'less weight' and has no inhalation or skin-allergy assessment.
Moderate evidence: The paper says some inhalation data may substitute when flavor exposure is far smaller than inhaled exposure; it does not claim any airborne or skin risk from these substances.
Source: Adams 1996, Food and Chemical Toxicology Industry-funded Link to this fact
Hidden ingredients / Other evidence
In 2008, about one in five (19.5%, 6,463 of 33,212) cosmetics and personal care products in the US FDA's voluntary registry contained a formaldehyde-releasing preservative, including 27.3% of rinse-off products and 16.9% of leave-on products.
Moderate evidence: The registry is voluntary, so it may not represent all US products; 2008 data, and the authors found no comparable European database.
Hidden ingredients / Other evidence
FEMA's 2009 list also affirmed sodium lauryl sulfate (FEMA 4437, 0.001 ppm), 2-phenoxyethanol (FEMA 4620, up to 8 ppm in baked goods) and camphor (FEMA 4513, up to 100 ppm in chewing gum) as flavoring substances, so a food 'flavor' can include chemicals better known from personal care products.
Moderate evidence: Industry's own use-level survey; food only; the usual and maximum levels are averages.
Source: Smith et al. 2009 (FEMA Expert Panel), GRAS Flavoring Substances 24, Food Technology 63(6), Food Technology Industry-funded Link to this fact
Hidden ingredients / Other evidence
A personal care product can be EWG Verified even if some of its ingredients do not score green on Skin Deep; EWG requires the overall product score to be green.
Moderate evidence: EWG's own FAQ; the scoring method is described elsewhere and was not reviewed here.
Source: EWG Verified FAQ, verified-portal.ewg.org, accessed 2026-10-16, EWG Verified portal web page Link to this fact
Hidden ingredients / Other evidence
Wet cleaning rests on water, but the detergents and spotting agents hold alcohol ethoxylates, glycol ethers, D-limonene, monoethanolamine, quaternary ammonia and trade secrets; many safety data sheets lacked ingredient data, some noted skin and eye irritation, and ethoxylated alcohols can carry 1,4-dioxane (county study pending).
Moderate evidence: From the county's review of a sample of safety data sheets, not testing of products or garments; the report still rated wet cleaning health-green.
Source: SCDHS 2018 Link to this fact
Hidden ingredients / Other evidence
Only 41% (62 of 150) of the "Clean" textured-hair products at this Target had a score in EWG's Skin Deep database, and none carried the EWG Verified mark, so most could not be looked up.
Moderate evidence: One store, scraped 2022 and matched to EWG in 2023; how products were matched is not described, and how scored and unscored products differ is unknown.
Source: Madrid Larrañaga 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Hidden ingredients / Other evidence
Limonene, linalool and Lyral are fragrance ingredients commonly found in personal care products, processed foods and beverages, and perfumes, and the society judges them relevant for many patch-tested patients.
Moderate evidence: Committee judgment based on cited reviews; no product-survey data in this paper.
Hidden ingredients / Other evidence
Almost 9 in 10 (88%, 57 of 65) top-rated Amazon sunscreens carried extra claims such as sensitive skin, preservative-free, natural or organic; the authors call these marketing claims, not performance standards.
Moderate evidence: Claims were recorded as printed; no ingredient lists were checked against them in this paper.
Hidden ingredients / Other evidence
A 2022 study found benzyl alcohol in 15.8% of 1,470 skin care products labeled clean, natural, organic or hypoallergenic.
Moderate evidence: Secondary citation; the figure is for those four label terms, not specifically 'fragrance-free'; product sampling frame not described here.
Source: Zheng et al. 2026, ACDS Allergen of the Year (Cutis), Cutis Link to this fact
Hidden ingredients / Review of other studies
A 2021 consensus essay names diethyl phthalate (DEP) and dibutyl phthalate among phthalates used in nail polish, lotions, fragrances and hair-styling products, and says studies show personal-care-product use tracks with urinary phthalate metabolites.
Moderate evidence: One sentence citing a single exposure study (Berger and colleagues); no concentrations given; fragrance is mentioned only in that list.
Source: Engel 2021, American Journal of Public Health Link to this fact
Information, not medical advice. See also: myths we won’t tell you.