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.
Children and pregnancy / Measured in people or real products
About half of children's diaper-rash creams (13 of 28) and a third of children's sunscreens (10 of 29) listed fragrance.
Weak evidence.
Caveats
Small category counts; label count only. Sunscreen share is market-specific: 64.9% (87/134) of Danish children's sunscreens and sun sprays listed fragrance or a named allergen (Botvid 2023), so 'a third of sunscreens' should not be generalized beyond Brazil; diaper creams were not reported separately in Denmark.
Source: Uber 2024, Jornal de Pediatria (Rio de Janeiro) Link to this fact
Children and pregnancy / Measured in people or real products
In 130 Danish and Finnish mothers, phthalate breakdown products were reported in essentially every breast milk sample (95-100% for each of the six measured) — but an independent, more contamination-controlled US study (Hines 2009) found the analogous class of monoester phthalate metabolites in under 10% of milk samples from a separate cohort, and declined to report its own milk hydrolytic-monoester data (which would include MEP) as likely contamination-inflated.
Weak evidence.
Caveats
1997-2001 samples; composite home-collected milk; phosphoric acid was not added at collection 'due to logistics' (this page's own Methods/limitations), a known contamination risk for hydrolytic monoesters. Hines 2009 (EPA/CDC, tighter contamination controls) found the analogous metabolite class in <10% of milk samples and withheld its own milk hydrolytic-monoester data on contamination grounds. US EPA systematic review (Radke 2018) separately excluded this study's milk data as a critically deficient exposure matrix.
Source: Main 2006, Environmental Health Perspectives Link to this fact
Children and pregnancy / Measured in people or real products
Baby boys whose mothers' milk contained more dibutyl phthalate had slightly lower free testosterone at 3 months (about 15% lower per 10-fold rise). For diethyl phthalate, the fragrance phthalate, the link was with higher SHBG, and its free-testosterone trend was not significant. These are correlations in 96 boys, not proof of harm.
Weak evidence.
Caveats
MBP–free T r = −0.22 (p = 0.033); mEP–free T r = −0.19 (p = 0.07, NS). US EPA review excluded this study (breast milk critically deficient as an exposure matrix for short-chain phthalates) and rated infant-testosterone evidence indeterminate (Lin 2011: MEP r = −0.10). 46% of Danish mothers used breast pumps.
Source: Main 2006, Environmental Health Perspectives Link to this fact
Children and pregnancy / Measured in people or real products
In one early, small US study, boys in the highest phthalate group had about 4 to 10 times the odds (3.8-10.2) of a shorter-than-expected anogenital distance than the lowest group, depending on the phthalate. A larger (N=753) follow-up by the same group found much smaller effect sizes for the one phthalate class (DEHP) that replicated, and did not test comparable categorical odds ratios.
Weak evidence.
Caveats
Single small cohort with very wide CIs (MEP OR 3.8, 1.03-13.9); US EPA rated this cohort's AGD data (extended n=106) low confidence. The DEP (MEP) part did not replicate in three larger cohorts, including the same group's own N=753 TIDES follow-up (Swan 2015), which also found smaller continuous effect sizes for the metabolites that did replicate (DEHP: beta -1.12 to -1.43 in TIDES vs -3.50 to -5.13 in this cohort, per Swan 2015's Discussion), consistent with lower current-day exposure. Quote as one small study's result only; prefer the EPA review or Swan 2015 for general claims.
Source: Swan 2005, Environmental Health Perspectives Link to this fact
Children and pregnancy / Self-reported survey
In a US survey, parents reported that 7 in 10 children aged 12 and under (219 of 312) had used makeup or body products such as face paint, glitter, nail polish, or body spray, including more than half of children aged 3 or younger (48 of 84).
Weak evidence.
Caveats
207 self-selected parents recruited mostly online in NYC/Boston/Houston; not nationally representative; ~60% of raw responses excluded as spam/fraud. Partial external check: in a Brazilian clinic survey (Melo 2020) per-category color-cosmetic rates matched Medley's (lipstick 18.8% vs lip ≈21%, nail 22.4% vs ≈22%), but the 70% total is driven by body products (face paint, glitter, bath bombs) that Melo did not ask about, and Melo found make-up in only ≈3% of infants, so the under-3 figure reflects body products, not make-up.
Source: Medley 2023 Link to this fact
Children and pregnancy / Self-reported survey
Among US children who used makeup or body products, about 1 in 8 used them daily, about 1 in 5 wore them for 8 hours or more, and about 1 in 3 had swallowed some in the past year.
Weak evidence: Parent report for 217 child users; ingestion differed sharply by ethnicity (41% vs 11%), possibly a question-wording effect.
Source: Medley 2023 Link to this fact
Children and pregnancy / Self-reported survey
Most US children who use makeup also use products made for adults: only about a third (36%) used mostly children's products.
Weak evidence.
Caveats
Parent estimate of product share; small non-representative sample. Applies to makeup only: for cleansers, a Brazilian clinic survey (Melo 2020) found the majority used children's products (children's soap 56.5%, children's shampoo 65.9%; adult soap 37.3%, adult shampoo 27.2%, rising with age), so do not write 'most children use adult products' generally.
Source: Medley 2023 Link to this fact
Children and pregnancy / Self-reported survey
In a US survey, boys and girls who used makeup or body products used fragrance products (perfume, cologne, body spray) at the same rate, about 31%.
Weak evidence.
Caveats
Scent-purpose products only; cleansers excluded, so not a fragrance-exposure prevalence. Indirect support for sex parity: in Melo 2020 (Brazil, 182/276 perfume users, 126 girls) at least 56/150 boys (≥37%) used perfume, so perfume is not a girls-only product; but the Brazilian level (66% of all children) is 3x the US level (≈21%), so the ~31% figure must not be generalized.
Source: Medley 2023 Link to this fact
Children and pregnancy / Self-reported survey
The only population study of lavender and tea tree oils and hormone problems in children (556 US children) was too small to rule out a risk: regularly exposed children had 2.8 times the rate of endocrine diagnoses, with a 95% confidence interval from 0.35 to 22 times.
Weak evidence: Not statistically significant; parent-reported diagnoses; self-selected natural-product users; 9 events. Supports 'not ruled out', not 'causes'.
Source: Hawkins 2021, International Journal of Pediatrics and Adolescent Medicine Industry-funded Link to this fact
Children and pregnancy / Measured in people or real products
In 2007, US government (NIEHS) scientists described three boys aged 4–10 who developed breast tissue while using products containing lavender oil or lavender and tea tree oil (a homemade balm, hair gel and shampoo, soap and lotions); in each case it went away within months of stopping the products.
Weak evidence: 3 case reports, dechallenge only, no rechallenge, products not analyzed; causation contested (BASF guideline tests negative for linalool/linalyl acetate; Braunstein 2023 review).
Source: Henley 2007, New England Journal of Medicine Link to this fact
Children and pregnancy / Review of other studies
In the reported cases, children had been using lavender-scented products regularly (violet-water colognes, shampoos, soaps, baby bath, lotions) or sat beside a classroom diffuser, and breast growth went away after the products were stopped; early breast growth in children often goes away on its own, so this does not prove cause.
Weak evidence.
Caveats
Case reports with dechallenge only; no comparison group; at least one of the violet-water colognes declared and contained no essential oil by an industry analysis (Giroux & Orjubin 2020). Linklater 2015's own transient alpha-fetoprotein/prolactin elevation resolved on its own over the same 12 months, for an unrelated physiological reason (infant liver immaturity) the authors themselves cite — a concrete illustration, from inside this same case, that concurrent findings can normalize without being caused by the product change.
Source: Hawkins 2020, Complementary Therapies in Medicine Industry-funded Link to this fact
Children and pregnancy / Measured in people or real products
Four prepubertal children (three girls with early breast development and one boy with breast growth) whose doctors recorded continuous use of products they identified as containing lavender saw the breast tissue disappear within three to six months of stopping the product.
Weak evidence.
Caveats
Four uncontrolled case reports, dechallenge only, no product analysis by the authors, and no chemical measured in any child; both conditions can resolve spontaneously. An essential-oil industry analysis later reported the boy's violet-water cologne declared and contained no essential oil (DEP, alpha-isomethyl ionone, and azo dyes instead), and one girl's baby bath only 'very low' lavender oil (unquantified).
Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact
Children and pregnancy / Self-reported survey
At one Miami children's hospital, 16 of the 24 children seen over seven years for unexplained early breast growth had been using lavender-scented products; 14 of the 16 were Hispanic and the products were violet-water colognes of a kind often applied to babies.
Weak evidence.
Caveats
Clinic case tally with no unexposed comparison group and no use-prevalence denominator; a clinic aware of the lavender hypothesis will ask about lavender; one violet-water cologne from this clinic's case reports declared and contained no essential oil by an industry analysis. Diaz 2016 (2015, same hospital, corresponding author Alejandro Diaz also a co-author here) reported 3 boys with the same outcome in the years just before this tally's window; those 3 cases are almost certainly a subset of this 16/24 figure, not additional to it, so this figure and Diaz 2016 should never be added together.
Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact
Children and pregnancy / Measured in people or real products
One of the four children had never used a lavender product at all: she sat beside a classroom lavender oil diffuser that ran all day for a year, and her breast tissue regressed three months after the diffuser exposure stopped.
Weak evidence: Single case report, no air measurement was made in the classroom, and measured indoor terpene levels elsewhere are far below the concentrations that were active in the cell assays.
Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact
Children and pregnancy / Measured in people or real products
In the same 2018 NGO test, a children's shampoo had 24 unlabeled chemicals flagged for health hazards (17 on the fragrance-industry list), and a baby shampoo had 6.
Weak evidence: Counts, not amounts; single samples; not peer reviewed; not a risk ranking.
Source: BCPP 2018 Link to this fact
Children and pregnancy / Measured in people or real products
In a Danish–Finnish study (hormones measured in 96 of 130 baby boys), some phthalates in mothers' breast milk went with hormone changes at 3 months that point to weaker male-hormone action (higher SHBG; lower free testosterone for dibutyl phthalate only).
Weak evidence.
Caveats
Association; hormones in 96 boys; mEP (DEP) free-T link not significant (p = 0.07); 46% of Danish mothers used breast pumps; US EPA review excluded this study (milk critically deficient as exposure matrix) and rated infant testosterone indeterminate. Cite the primary, not the thesis, which inverted the direction.
Source: Main 2006 Link to this fact
Children and pregnancy / Self-reported survey
Children's lipstick, nail polish, and eyeshadow use was about the same in a Brazilian hospital survey and a US parent survey (roughly 19-22%, 22% and 11-13%), but perfume use was three times higher in Brazil (66% vs about 21%).
Weak evidence.
Caveats
Our cross-study arithmetic (Medley per-user rates re-based to all 312 children); different definitions ('perfume' vs 'fragrance products primarily for children'), ages (<=14 vs <=12) and sampling.
Source: Melo 2020, Revista Paulista de Pediatria Link to this fact
Children and pregnancy / Self-reported survey
Every one of 13 Washington DC childcare facilities that reported health data had at least one child with physician-diagnosed asthma, with a typical (median) facility rate of about 10%.
Weak evidence: Center-Director-reported, not chart-confirmed; no exposure-outcome link tested; n=13.
Source: Quirós-Alcalá 2016, Environmental Research Link to this fact
Children and pregnancy / Measured in people or real products
Three more boys (ages 9-11) developed breast tissue while using lavender-labeled products, a shampoo or an 'agua de violetas' cologne sprayed on by a parent since early childhood; in each case it resolved within about 4 months of stopping the product.
Weak evidence.
Caveats
Three uncontrolled case reports, dechallenge only, no rechallenge; same hospital and a shared corresponding author (Alejandro Diaz) as Ramsey 2019's later clinic tally, so this is not an independent replication of the case count.
Source: Diaz 2016, Journal of Pediatric Endocrinology and Metabolism Link to this fact
Children and pregnancy / Measured in people or real products
A 14-month-old girl in Melbourne, Australia developed breast tissue while being given five different lavender-scented infant products every day (wipes, shampoo, body wash, cream, and lotion); it went away after the products were stopped, and this case has no connection to the better-known United States case series.
Weak evidence.
Caveats
One case report (letter to the editor), dechallenge only, no rechallenge, no product testing; the exposure was identified only after the family saw a documentary about this exact link, not through routine clinical questioning.
Source: Linklater & Hewitt 2015, Journal of Paediatrics and Child Health Link to this fact
Children and pregnancy / Review of other studies
Continuous nebulized albuterol (CNA), prepared from a benzalkonium-chloride-containing multidose 0.5% albuterol dropper bottle at standard pediatric dosing (10-20 mg/hour), would deliver an estimated 800-1600 micrograms of benzalkonium chloride over 4 hours — several-fold above the approximately 300-microgram cumulative dose shown to cause bronchospasm in adults with mild asthma.
Weak evidence.
Caveats
This is an arithmetic extrapolation from adult mild-asthma dosing studies to pediatric severe-asthma continuous nebulization, not a measured pediatric dose or outcome; no controlled trial has tested continuous nebulized albuterol with vs. without BAC in children.
Source: Prabhakaran 2017 Link to this fact
Children and pregnancy / Other evidence
In a retrospective cohort of 1,298 children with acute asthma treated with continuous nebulized albuterol (15 mg/hour) at Children's Hospital of Philadelphia, using a benzalkonium-chloride-containing dropper-bottle formulation, 31% required prolonged therapy (more than 24 hours) or had clinical deterioration.
Weak evidence.
Caveats
This retrospective cohort (Kenyon et al. 2014) had no benzalkonium-chloride-free comparison group, so the association with BAC is not established; the review's own authors call the causal link speculative ("tempting to speculate").
Source: Prabhakaran 2017 Link to this fact
Children and pregnancy / Self-reported survey
Household ammonia use was the only one of 10 individual cleaning agents (out of 30 agent-outcome comparisons) significantly associated with an outcome in this study: adolescents in homes where ammonia was ever used had lower odds of rhinitis, adjusted OR 0.60 (95% CI 0.44, 0.82), than those in homes that never used it.
Weak evidence.
Caveats
The study's own authors call this a likely chance finding given the number of associations tested and their limited statistical power to explore it further; not a basis for claiming ammonia protects against rhinitis.
Source: Bukalasa et al. 2019, Environment International Link to this fact
Children and pregnancy / Other evidence
Lilial's metabolites have been measured, at very low concentrations, in the urine of children and adolescents in Germany (geometric mean about 10.2 µg/L for p-tert-butylbenzoic acid, about 1.5 µg/L for lysmeral, and below quantification limits for lysmerylic acid and hydroxy-lysmerylic acid).
Weak evidence.
Caveats
This is a citation, within Jablonská 2023, of a separate human-biomonitoring survey (Murawski 2020, GerES V), not primary data generated by this paper; our evidence base does not yet hold that source directly.
Source: Jablonská 2023, Sci Rep 13:18536, Scientific Reports Link to this fact
Children and pregnancy / Review of other studies
US dermatology guidance recommends including aluminum in baseline allergy patch testing for children, given a high prevalence of aluminum allergy in children and early-life exposure to aluminum through childhood vaccines.
Weak evidence: A single-sentence guidance recommendation in a narrative review, not new pediatric data; the review does not report a pediatric aluminum-allergy prevalence figure itself.
Source: Musicante 2024, Cutis Industry-funded Link to this fact
Children and pregnancy / Government agency
In animal studies, a pregnant female's exposure to an endocrine-disrupting chemical can affect not only her offspring but her offspring's offspring, because developmental exposure can alter reproductive-cell programming that carries across generations.
Weak evidence: Evidence for these transgenerational effects comes from animal studies cited in the report; no multigenerational human dataset is cited for this specific claim.
Source: WHO/UNEP 2012 Link to this fact
Children and pregnancy / Other evidence
Prenatal exposure to phthalates in synthetic candle fragrance can promote permanent, irreversible changes to fetal immune-system development and contribute to childhood asthma and allergies.
Weak evidence: Secondhand citation of a general phthalate-immune mechanism paper, not a candle-specific exposure or outcome measurement; no dose given for candle-derived phthalate exposure.
Source: Singh 2023, Environmental Science & Technology Link to this fact
Children and pregnancy / Measured in people or real products
In a case-control study of adolescents aged 12-18 (62 with PCOS, 33 controls), urinary BPA levels were positively correlated with polycystic ovarian morphology seen on ultrasound.
Weak evidence: Single small study (Akgül 2019, cited within this review), not replicated in adolescents elsewhere in the review.
Children and pregnancy / Review of other studies
Studies of pregnant women's phthalate exposure and their children's later weight disagree in direction: one study linked higher maternal DEHP and DINP metabolites to a greater chance of excess infant weight gain, while another found children born to mothers with the highest DEHP exposure actually had slightly lower body fat at birth than those with the lowest exposure.
Weak evidence.
Caveats
Results vary by specific phthalate compound, child sex, and study design; the direction of effect (more fat vs. less fat) is inconsistent across the available prospective cohorts, so no reliable direction of effect can be claimed for maternal phthalate exposure and infant body composition.
Source: Dalamaga 2024, International Journal of Molecular Sciences Link to this fact
Children and pregnancy / Other evidence
In a small human study, petrolatum and paraffin oil applied to the forearms of 9 adults and 7 infants penetrated only into the stratum corneum (the skin's outer dead-cell layer) in both age groups, with petrolatum reaching deeper into that layer (up to about 30 micrometers) than paraffin oil (under 10 micrometers), but neither substance was detected passing into living skin layers or the bloodstream.
Weak evidence.
Caveats
Single small study (16 subjects total, both age groups pooled in the review's reporting) using a lab technique (confocal Raman spectroscopy) not independently replicated for infant skin in this review; industry-funded secondary source relaying the primary study, not independently re-analyzed here.
Source: Stamatas et al. 2008, via Petry et al. 2017, Toxicology Letters Industry-funded Link to this fact
Children and pregnancy / Other evidence
Standard adult default values for breathing rate and body weight used in cosmetic spray inhalation exposure calculations are not appropriate for children; breathing frequency and lung volume must be adapted for a child-specific assessment.
Weak evidence: The paper gives no child-specific parameter values, defaults or worked example; this is an acknowledgment that adult defaults don't apply, not a child exposure calculation.
Source: Steiling et al. 2025, Toxicology Letters Industry-funded Link to this fact
Children and pregnancy / Review of other studies
NRDC's 2007 report recommends avoiding air freshener use especially where children or pregnant women are present, based on general phthalate reproductive-toxicity evidence rather than any health study of these specific air freshener products or exposures.
Weak evidence: Precautionary recommendation; the report did not measure human exposure or health outcomes from air freshener use in children or pregnant women.
Source: NRDC 2007, Clearing the Air Link to this fact
Fragrance is everywhere / Review of other studies
A 2022 review of 37 studies found that phthalates, parabens, aldehydes, and aluminum salts are the contaminants most often reported in perfumes, colognes, and related scented products.
Weak evidence: Non-quantitative review with factual slips; cite primary studies for numbers.
Source: Kazemi 2022, Journal of Environmental Health Science and Engineering Link to this fact
Fragrance is everywhere / Measured in people or real products
Pine-scent chemicals were also common in Korean household products: alpha-pinene from 19% and beta-myrcene from 12%.
Weak evidence: Headspace presence only; high detection threshold.
Source: Kwon 2007, Journal of Hazardous Materials Link to this fact
Fragrance is everywhere / Hypothesis
Immigrant women in the US most often work as house cleaners and make up 71% of manicurists; an expert job-exposure tool rates both jobs as probably exposed to fragrance chemicals, and house cleaning also to cleaning-product ingredients such as alkylphenols and antimicrobials.
Weak evidence: Exposure ratings from job descriptions (WORC), not measurements.
Source: Knox 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Fragrance is everywhere / Measured in people or real products
The same perfume does not come off the skin the same way every day: in women not on the pill, a fixed dose of vanilla on the forearm was rated about 3 times stronger on cycle day 22 than during menstruation.
Weak evidence: 18 women (9 per group), 25 male raters, no hormone confirmation, no unperfumed control, no statistics printed, storage time unreported.
Source: Chróst 2021, Journal of Cosmetic Dermatology Link to this fact
Fragrance is everywhere / Measured in people or real products
In a mannequin-head test of 16 UK day face moisturizers, the authors report that one application (0.45 g) delivered on average about 16 times more limonene-type terpenes than 24 hours of typical UK home air, and, for the 7 products whose ethanol reached the nose, about 340 times more ethanol.
Weak evidence.
Caveats
Primary: Yeoman 2022 (Indoor Air 32:e12948), Table 6. The abstract's 'up to' is wrong: ×16 and ×339 are means over products with a nonzero dose (14/16, 7/16); maxima ×37 and ×804; over all 16 the medians are ×9 and ×0. Absolute doses are small (≤1.2 mg limonene; below UK PHE limits). The paper's own breathing-zone traces (Fig. 2, limonene ≤0.16 mg/m³) imply doses ~15–500× lower than its tables (evidence base arithmetic), so the ratios are unverified. No people; unheated head, lab at 5 ACH; 'limonene' = all monoterpenes.
Source: Yeoman 2022 via Rádis-Baptista 2023, Journal of Xenobiotics Link to this fact
Fragrance is everywhere / Review of other studies
An NGO analysis (Plastic Soup Foundation, 2022) reported that 87% of products from major European cosmetic brands contained microplastic ingredients.
Weak evidence: NGO figure, unreferenced in the review, definition not stated; major European brands only.
Fragrance is everywhere / Measured in people or real products
In the same 33 breastfeeding women, urinary MEP (the metabolite of DEP, the fragrance phthalate) was on average about 57 times higher in women who "often" used nail polish than in women who never did (2,874 vs. 50.5 micrograms per liter).
Weak evidence.
Caveats
Small pilot study (n=33); frequency-group sizes not reported; perfume/cologne use was not asked about, so fragrance products cannot be separated from nail polish as a source; the difference was significant only on untransformed means, and the authors themselves suggest nail-polish users may also use more perfume and other DEP-containing products.
Source: Hines 2009, Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Self-reported survey
Among Atlanta-area adults who reported chemical hypersensitivity, symptom onset was reported before age 20 in about a third of cases (32.4%), suggesting hypersensitivity is not exclusively an adult-onset condition.
Weak evidence.
Caveats
Retrospective self-report of childhood/adolescent onset in adults; no pediatric clinical verification; age-of-onset table has an internal mismatch with the running text for the older age brackets (see the page's Notes).
Source: Caress & Steinemann 2003 (EHP), Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Journalism
An EHP news report on a small Seattle-area study found that scented laundry detergent and dryer sheets sent volatile organic compounds, including several classified by EPA as hazardous air pollutants, out through home dryer vents into outdoor air.
Weak evidence: Secondary news coverage of one small two-home study with no replicates; numbers cross-checked and match the primary study (Steinemann 2013) exactly.
Source: Kessler 2011 (EHP Forum), Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Review of other studies
Deodorants alone are estimated to deliver roughly 1,000 metric tons of fragrance per year to the German population, based on standard daily-dose, dermal-retention, and perfume-content assumptions.
Weak evidence: A calculated estimate from published dose and market-size figures, not a measured total; depends on assumed 1% dermal retention and 3-5% perfume content.
Source: Klaschka 2012, International Journal of Hygiene and Environmental Health Link to this fact
Fragrance is everywhere / Measured in people or real products
In this study, fibers from ordinary household laundry outnumbered the deliberately added test-blanket fibers in outdoor snow samples at both homes — suggesting day-to-day laundry drying sheds more microfiber than a single garment alone.
Weak evidence.
Caveats
These 'other' fibers were identified only by visual shape and color under a microscope, not confirmed as textile fiber or identified chemically (no FTIR/Raman); their true source was not verified.
Source: Kapp & Miller 2020, PLOS ONE Industry-funded Link to this fact
Fragrance is everywhere / Review of other studies
Airborne nano- and microplastic concentrations measured in prior studies range from about 50 nanograms per cubic meter to 47 micrograms per cubic meter depending on location, illustrating how variable ambient exposure can be, though this paper does not connect that airborne range quantitatively to the topical doses it actually tested on skin.
Weak evidence.
Caveats
This figure is cited by Song et al. 2024 from earlier atmospheric-measurement studies (their refs 39-42), not measured by this paper itself, and the paper does not attempt to translate an airborne concentration into an equivalent skin dose.
Source: Song et al. 2024, Journal of Hazardous Materials Link to this fact
Green, natural and unscented / Measured in people or real products
Scented tampons carried a median of 692 ng/g of fragrance terpenes against 2.9 ng/g in unscented ones.
Weak evidence: Only 2 scented vs 20 unscented tampons (p=0.04).
Source: Lin 2020, Environment International Link to this fact
Green, natural and unscented / Government agency
Under EU/UK law, a 'free from [substance]' cosmetic claim about a substance already banned for all EU cosmetics would appear to fall under the rule barring claims that dress up mere legal compliance as a special product benefit.
Weak evidence.
Caveats
This is our own reading of the regulation's general Criterion 1(3) applied to 'free from' wording, not a quotation naming that claim type, and no enforcement decision confirming this application was found.
Source: Commission Regulation (EU) No 655/2013 Link to this fact
Green, natural and unscented / Self-reported survey
'Fragrance-free'/'unscented' deodorant claims are not a reliable guarantee for fragrance-allergic people: in a cited patient survey, 4.7% of fragrance-contact-allergic patients who had used an unscented deodorant in the past 3 months got a rash from it.
Weak evidence: Figure is relayed from Lysdal and Johansen 2009, not Klaschka's own data; not in our evidence base as a primary yet.
Source: Klaschka 2012, International Journal of Hygiene and Environmental Health Link to this fact
Green, natural and unscented / Lab study (cells or chemistry)
A cold-atmospheric-plasma prototype device killed over 90% of two underarm-odor bacteria (Staphylococcus hominis 99.81%, Corynebacterium xerosis 90.99%) after 3 minutes of exposure in lab culture, and cut total electronic-nose sensor response to two major axillary-odor chemicals by about 51% (HMHA) and 34% (3M3SH) after 5 minutes, without applying antimicrobial chemicals or fragrance to skin.
Weak evidence.
Caveats
Antibacterial test used agar-cultured bacteria; deodorizing test used excised porcine skin dosed with pure synthetic odor compounds in methanol, not human sweat. Single lab, single prototype, no independent replication, no human skin testing.
Source: Bok et al. 2024, Scientific Reports Link to this fact
Green, natural and unscented / Other evidence
Candles made from renewable waxes (beeswax, soy, coconut, palm) scented with natural essential oils are generally safer and more sustainable than paraffin candles, but still carry an environmental cost through deforestation and habitat destruction from increased crop demand.
Weak evidence.
Caveats
No emissions or land-use quantification given; our own chamber data (Salthammer 2021, Andersen 2021) also show wax type has little effect on formaldehyde/PAH output compared to fragrance load, so a wax switch alone may not reduce indoor-air health risk even if it changes the environmental footprint.
Source: Singh 2023, Environmental Science & Technology Link to this fact
Green, natural and unscented / Other evidence
Study participants were given a free 'starter kit' of unscented cleaning products and 'alternative cleaning recipes' as part of a personalized action plan to reduce indoor VOC exposure, and researchers observed reduced use of scented products at follow-up visits.
Weak evidence.
Caveats
Product-use reduction was assessed by researcher observation during a scheduled visit, not by continuous monitoring, and patients knew they were being evaluated (compliance may be overstated).
Source: Rincón et al. 2024, Primary Health Care Research & Development Link to this fact
Health effects / Review of other studies
A 2022 review concluded that links between contaminants in perfumes and cancer, breathing problems, and hormone disruption are 'probable' but still need research to prove.
Weak evidence: Evidence mostly from phthalate/paraben studies not perfume exposure.
Source: Kazemi 2022, Journal of Environmental Health Science and Engineering Link to this fact
Health effects / Lab study (cells or chemistry)
In lab tests on cancer-derived nerve cell lines, three unnamed commercial fragrances changed cell shape and structure after 72 hours and cut the share of cells carrying oxytocin and vasopressin receptors in some lines but not others.
Weak evidence: Cell lines only; fragrances unidentified; no replication; only one cell line per sex.
Source: Sealey 2015, Environmental Research Link to this fact
Health effects / Hypothesis
Silent Spring Institute researchers name house cleaners and nurses as priority jobs for cutting exposure to fragrance, cleaning, and personal-care chemicals linked to breast cancer in lab and animal studies.
Weak evidence: No exposure or cancer data in these workers.
Source: Knox 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Health effects / Review of other studies
Many everyday chemicals, including some released by scented and cleaning products, act on the same irritant-sensor nerves in the nose and airways (TRPA1 and TRPV1), one reason very different products can cause similar symptoms.
Weak evidence: Mechanism largely from lab/animal studies; dose relevance to homes untested.
Source: Molot 2023, Neuroscience and Biobehavioral Reviews Link to this fact
Health effects / Animal study
In animal and lab studies, common scent chemicals such as linalool, limonene, and eugenol act on brain signaling systems; what lifelong low-level exposure does in healthy people has never been studied.
Weak evidence: Mostly high-dose animal/in-vitro pharmacology; often protective effects in disease models.
Source: Pinkas 2017, Environmental Research Link to this fact
Health effects / Lab study (cells or chemistry)
In lab studies, inflammation lowers the threshold for this irritant receptor, a proposed reason scent reactions can be worse when airways are already inflamed.
Weak evidence: Mechanistic pathway only; not demonstrated in people exposed to products.
Source: Mihara & Shibamoto 2015, Allergy, Asthma & Clinical Immunology Link to this fact
Health effects / Measured in people or real products
Two German gas-works plumbers who repeatedly hand-poured the gas odorant tetrahydrothiophene in an unventilated room developed chronic rhinitis and lasting airway obstruction; neither had allergies on skin testing, and the accident insurer accepted both as occupational disease.
Weak evidence: Two case reports; exposure estimated, not measured; one worker smoked ~16 pack-years; industrial odorant, not fragrance.
Source: Baur & Bittner 2009, American Journal of Industrial Medicine Link to this fact
Health effects / Lab study (cells or chemistry)
Musk ketone does not damage DNA by itself, but in rat liver enzymes and human liver cells it made known carcinogens like benzo[a]pyrene more mutagenic.
Weak evidence: One laboratory's data (the review's senior author); human-cell LOEL 50 ng/ml is 12-70x above whole-milk levels.
Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact
Health effects / Animal study
In two of the five products the airflow reduction kept worsening after the exposure ended.
Weak evidence.
Caveats
Mice, n=3-12 per time course; no human counterpart; mechanism unknown. An independent replication attempt (Tepper et al. 1995, carpets, full text now in our evidence base) found no significant carpet-related toxicity overall via individual-animal statistics, but it never measured airflow limitation or post-exposure persistence of any respiratory endpoint, so it does not directly test this finding either way.
Source: Anderson & Anderson 1998, Archives of Environmental Health Link to this fact
Health effects / Review of other studies
Frequent private use of household disinfectants (a composite of methods including hand-wash, machine, sponge, and spray disinfection) was linked to close to a threefold increase in the odds of newly developing asthma in a single cross-sectional wave of young German adults (Weinmann 2017, OR 2.79, 95% CI 1.14-6.83); the evidence for household sprays alone driving that same result was already weak in that wave (OR 2.79, 95% CI 0.84-9.20), and a 10-year longitudinal follow-up of the same cohort (Pacheco Da Silva 2025) found no significant association between persistent spray-only use and current asthma or wheeze (point estimates at or below 1.0 for every outcome), with only a non-significant, attenuated OR of 1.68 (95% CI 0.48-5.88) for sustained use of multiple disinfectants/cleaning products together.
Weak evidence.
Caveats
Two analyses of the same German SOLAR cohort (Weinmann 2017's cross-sectional SOLAR II wave, and Pacheco Da Silva 2025's 10-year longitudinal follow-up adding SOLAR III with latent-class exposure profiles) now agree that spray-specific use is not significantly associated with adult asthma. The only positive signal across both papers is a composite 'persistent use of multiple DCPs' profile, which itself weakened from a significant OR 2.79 (single wave, simple frequency composite) to a non-significant OR 1.68 (10-year follow-up, latent-class model, wide CI 0.48-5.88). Both papers are single-cohort, self-reported-exposure studies from the same research group, so per the grading rule this stays below moderate. The follow-up nulls are underpowered (1,143 of the original 2,051; only ~8-12% in each persistent-use profile; CIs span roughly 0.5-6), so they weaken the claim without refuting it. Other cohorts not yet in our evidence base reported positive spray-asthma associations (ECRHS, Zock 2007; French EGEA, Pacheco Da Silva 2023); don't cite this cohort as evidence that sprays are safe.
Source: Salonen 2024, Environment International Link to this fact
Information, not medical advice. See also: myths we won’t tell you.