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 / Measured in people or real products
Childcare air had about three times more limonene than new California homes (33 vs 11 µg/m³), which the authors link to frequent cleaning.
Moderate evidence: Comparison with a different study (Offermann 2009); daytime vs 24-h sampling.
Children and pregnancy / Self-reported survey
In a Brazilian hospital survey, caregivers said two in three children aged 14 and under (182 of 276, median age 4) wore perfume.
Moderate evidence: One Curitiba tertiary-hospital clinic sample, 2015-16; 'perfume' undefined; no frequency, age, or sex breakdown; count identical to children's shampoo (possible copy error).
Source: Melo 2020, Revista Paulista de Pediatria Link to this fact
Children and pregnancy / Measured in people or real products
93% of children's facial-care products in a Danish registry (80 of 86, almost all lip balms) listed fragrance, averaging nearly two named fragrance allergens each.
Moderate evidence: Label data; n=86; registry sample.
Children and pregnancy / Measured in people or real products
In a US label survey of 533 personal care products marketed for babies and children, 48% (255/533) contained a fragrance-category allergen and 55% (294/533) contained at least one of eight screened contact allergens.
Moderate evidence.
Caveats
Single US retail platform (Drugstore.com/Walgreens), one 2018 snapshot; fragrance is a ~20-keyword composite tally, not a per-chemical breakdown; no chemical verification of labels.
Children and pregnancy / Measured in people or real products
Cheaper baby and children's personal care products contain significantly more contact allergens than pricier ones: products with two or more screened allergens averaged $1.39 per ounce versus $4.35 per ounce for products with none.
Moderate evidence.
Caveats
Correlation only, no mechanism tested; a similar but non-significant trend was found in adult moisturizers (Xu 2017), so the effect size and significance may not generalize beyond baby products.
Children and pregnancy / Measured in people or real products
In a small pilot study of 14 Washington DC childcare facilities, chloroform – a byproduct of the chlorine bleach used to clean – was found in every single air sample, at levels averaging 1.4-1.8 times higher than in a comparable California childcare study.
Moderate evidence: Small unfunded pilot (14 facilities), single-day snapshot, convenience sample; measured no fragrance chemicals at all.
Source: Quirós-Alcalá 2016, Environmental Research Link to this fact
Children and pregnancy / Measured in people or real products
In a Czech birth cohort of 3,411 children (ELSPAC-CZ), each 1-SD increase in an 18-product household chemical exposure score measured at 6 months raised the odds of intermediate-onset transient wheeze (adjusted OR 1.27), early-onset persistent wheeze (adjusted OR 1.36) and intermediate-onset persistent wheeze (adjusted OR 1.23) through age 5, and those persistent wheeze phenotypes carried 5-8x higher odds of a doctor-diagnosed asthma by age 7 (pediatrician records, not self-report).
Moderate evidence.
Caveats
Single prospective cohort; exposure and wheeze through age 5 are maternal self-report (only the school-age asthma outcome is medically ascertained); the asthma link runs through the wheeze phenotype, not directly from exposure to asthma, and the paper's own direct exposure-to-asthma model was underpowered. Independently replicates the Canadian CHILD cohort (Parks 2020), which together raises the combined wheeze/asthma claim to strong (see regrade on src-2024-cleaning-products-chemistry-indoor-air-quality-health).
Source: Mikeš 2019, Science of the Total Environment Link to this fact
Children and pregnancy / Measured in people or real products
In the same large study (N=753), urinary levels of diethyl phthalate (DEP), the phthalate most strongly and consistently tied to perfume and fragranced personal-care product use, showed no association with anogenital distance in baby boys, the largest and best-controlled human test yet of this specific fragrance-phthalate reproductive claim, in the same boys where DEHP did show an effect.
Moderate evidence.
Caveats
A null result in one (albeit the largest) cohort cannot fully rule out an effect at higher exposure levels than this population had; two smaller medium-confidence cohorts (Odense, SELMA) were also null, per US EPA's review.
Children and pregnancy / Measured in people or real products
In a national Canadian survey of 98 baby care products, diaper cream — not fragrance — was the largest single modeled source of infant dermal DEP exposure, contributing about half of babies' modeled total.
Moderate evidence: Exposure model uses non-Canada-specific consumer-use-pattern data and a fixed 5% skin-absorption assumption for all phthalates; it is a modeled dose, not a measured biomarker.
Source: Koniecki 2011, Environmental Research Link to this fact
Children and pregnancy / Other evidence
In 1998, EPA's own pesticide-program administrator reported that, per an outside audit of a random 100-chemical sample, 71% of the roughly 3,000 highest-volume industrial chemicals in US commerce had no basic toxicity data publicly available at all, and 63% had not been tested for carcinogenicity.
Moderate evidence.
Caveats
A single external audit (Environmental Defense Fund), not independently replicated or EPA's own primary tabulation; concerns industrial chemicals in general, not fragrance or consumer products specifically.
Source: Goldman 1998, Environmental Health Perspectives Link to this fact
Children and pregnancy / Measured in people or real products
In a Belgian study of 234 schoolchildren aged 10-13, those living in homes cleaned with chlorine bleach at least once a week had a much lower rate of doctor-diagnosed or test-confirmed asthma than other children (3.8% vs 13.5%; adjusted odds ratio 0.10, 95% CI 0.02-0.51).
Moderate evidence.
Caveats
Single cross-sectional study, one city, self-reported weekly-or-more bleach use with no dose or brand detail; a large adjusted OR from a small event count (3 vs 21 cases) gives a wide confidence interval, and residual confounding by household type cannot be fully excluded despite adjustment.
Source: Nickmilder, Carbonnelle & Bernard 2007, Pediatric Allergy and Immunology Link to this fact
Children and pregnancy / Measured in people or real products
In the same study, children in bleach-cleaned homes were also less likely to have doctor-diagnosed eczema (3.8% vs 14.1%, adjusted OR 0.22) and to be sensitized to indoor aeroallergens, especially house dust mite (adjusted OR 0.53 and 0.43 respectively), but showed no difference in sensitization to pollen allergens.
Moderate evidence.
Caveats
Same single-study, single-city limitations as the asthma finding; sensitization was measured by serum allergen-specific IgE, a marker of sensitization, not of clinical allergic disease.
Source: Nickmilder, Carbonnelle & Bernard 2007, Pediatric Allergy and Immunology Link to this fact
Children and pregnancy / Measured in people or real products
The protective association between bleach cleaning and reduced allergy/asthma risk was abolished in households with parental smoking; in that subgroup, bleach use was instead linked to a higher rate of recurrent bronchitis (adjusted OR for the smoking-by-bleach interaction, 2.03, 95% CI 1.12-3.66).
Moderate evidence: Subgroup/interaction analysis from a single cross-sectional study; the recurrent-bronchitis outcome is parent-reported, not medically confirmed.
Source: Nickmilder, Carbonnelle & Bernard 2007, Pediatric Allergy and Immunology Link to this fact
Children and pregnancy / Self-reported survey
Black women recalled far more childhood hair oil use than Hispanic or white women (94% of African-American and 74% of African-Caribbean women, vs. 33% of Hispanic and 9% of white women) in this New York City sample.
Moderate evidence: Self-reported recall in a convenience sample from one city (New York, 2004-2005); does not measure the chemical content of the products used.
Source: James-Todd 2011, Annals of Epidemiology Link to this fact
Children and pregnancy / Other evidence
In a retrospective cohort of 266 pediatric ICU admissions treated with continuous nebulized albuterol, benzalkonium-chloride-containing albuterol was not associated with worse PICU or hospital length of stay, need for adjunctive respiratory support, or mortality than preservative-free albuterol — if anything, length of stay was shorter in the benzalkonium-chloride group.
Moderate evidence.
Caveats
Single-center, retrospective, non-randomized before/after institutional-practice comparison, not allocated exposure; the LOS difference disappeared (both directions non-significant) in a pre-specified critical-asthma-only sub-analysis, and the authors attribute it to confounding by a higher share of non-asthma (bronchiolitis/undetermined ARF) admissions in the control group.
Source: Al-Subu et al. 2023, Respir Care 68(6):734-739, Respiratory Care Link to this fact
Children and pregnancy / Other evidence
Children who received benzalkonium-chloride-containing continuous nebulized albuterol in this cohort were started on a significantly higher initial albuterol dose (median 15, later 20 mg/h in the critical-asthma sub-analysis) than children who received preservative-free albuterol (median 10-15 mg/h), a difference that persisted even after restricting to a diagnostically matched critical-asthma sub-group.
Moderate evidence.
Caveats
Dosing was clinician-directed (per intensivist discretion), not protocolized or blinded, so the dose difference itself may reflect practice patterns around the two formulations rather than a physiological effect of benzalkonium chloride, and could independently confound the study's length-of-stay comparison.
Source: Al-Subu et al. 2023, Respir Care 68(6):734-739, Respiratory Care Link to this fact
Children and pregnancy / Other evidence
When the comparison was restricted to children over age 2 with a critical-asthma diagnosis specifically (n=160), there was no significant difference between the benzalkonium-chloride and preservative-free albuterol groups in PICU length of stay, hospital length of stay, or any secondary outcome except the (still higher) initial albuterol dose.
Moderate evidence.
Caveats
Sub-analysis sample is smaller (n=160) than the full cohort (n=266), reducing power to detect a true difference; a null result here is consistent with, but does not prove, no effect.
Source: Al-Subu et al. 2023, Respir Care 68(6):734-739, Respiratory Care Link to this fact
Children and pregnancy / Measured in people or real products
In FDA's 2010 follow-up survey, 5 of 24 baby-care products (shampoos, body washes, creams, lotions, and oils) contained diethyl phthalate (DEP), at levels up to 274 ug/g — the only phthalate ester found in any baby-care product tested.
Moderate evidence: N=24 baby-care products from one FDA survey; no infant absorbed-dose or health-outcome data were collected.
Source: Hubinger 2010, Journal of Cosmetic Science Link to this fact
Children and pregnancy / Animal study
In mice, a single prenatal dose of the plasticizer DEHP to a pregnant female can alter reproductive traits (puberty timing, ovarian follicle numbers, fertility, reproductive aging) not just in her directly exposed pups, but in her never-exposed great-grandpups (the F3 generation), an effect attributed to epigenetic changes carried through the germline.
Moderate evidence.
Caveats
Animal (mouse and rat) evidence only; most positive DEHP transgenerational findings come from one research group (the reviewing authors' own lab), and some effective doses were well above estimated daily human DEHP exposure (~3-30 micrograms/kg/day).
Children and pregnancy / Measured in people or real products
Olive oil was the single most commonly used infant moisturizer in this UK cohort, in both infants with visible eczema (18.2%) and without (23.1%), consistent with a UK maternity-unit survey in which most units recommending oil for baby skincare recommended olive oil specifically; none of the top-20 products used contained trilipid/ceramide ingredients.
Moderate evidence: Product-name self-report; brand/product list is UK-specific (2009-2012) and may not generalize to other countries or eras.
Source: Perkin 2021 (EAT cohort), Journal of Allergy and Clinical Immunology Link to this fact
Children and pregnancy / Other evidence
Pregnant French women used more cosmetics than non-pregnant women across the board — 104 of 139 surveyed products reached at least 10% use among pregnant women, versus 88 among non-pregnant women — and shifted markedly toward baby-care products before the birth: 50% used anti-stretch-mark cream (vs. 6% of non-pregnant women), and about 1 in 5 already used baby shampoo or baby shower gel (vs. 5-6% of non-pregnant women).
Moderate evidence.
Caveats
Single study, self-report, French-only; pregnant women were deliberately oversampled (8% of the adult-women sample vs. the true ~3% French rate), which does not bias the within-group percentages but means absolute national totals should not be read off this sample directly.
Source: Ficheux et al. 2015, Food and Chemical Toxicology Link to this fact
Children and pregnancy / Other evidence
Pregnant women had the single highest modeled exposure of any group studied for dry shampoo (90th percentile 10.24 mg/kg bw/day, 95th percentile 15.19 mg/kg bw/day), but were the least-exposed group for styling lacquer and styling wax — pregnancy changed which hair products carried the most exposure, not just how much.
Moderate evidence.
Caveats
Amount-per-use data specific to pregnant women were too sparse (only 5 of 844 face-to-face survey participants were pregnant) to model separately, so non-pregnant women's amount-per-use data were substituted into the pregnant-women exposure calculation; only frequency of use and body weight were pregnancy-specific inputs.
Source: Ficheux et al. 2016 (exposure assessment), Food and Chemical Toxicology Link to this fact
Children and pregnancy / Measured in people or real products
Infants exposed to more baby care products (lotion, shampoo, powder) had progressively higher combined phthalate metabolite levels: about 60% higher with one product used in the past day, roughly doubled with two, and nearly 5-fold higher with three.
Moderate evidence: "Number of products" counts product types used, not amount applied; amount of product used was not quantified in this study.
Source: Sathyanarayana et al. 2008, Pediatrics Link to this fact
Children and pregnancy / Other evidence
Baby products in the CIR draft contain polysorbate 60 at up to 1.5% (11 reported uses in 2015) and polysorbate 80 at up to 10%, while the same report advises care with polysorbate penetration enhancement in infant formulations.
Moderate evidence: Concentrations are maximum reported use levels from an industry survey; the advice is a caution, not a finding of harm.
Source: CIR 2015 draft Industry-funded Link to this fact
Children and pregnancy / Measured in people or real products
In 106 pregnant women in Puerto Rico, higher urinary MEP (the breakdown product of diethyl phthalate, a fragrance and personal-care solvent) went with about 11% lower blood progesterone per interquartile-range increase in MEP (95% CI -17.6% to -2.8%).
Moderate evidence.
Caveats
One small cohort, two blood draws (about 18 and 26 weeks), no multiple-comparison correction, no product-use data so the MEP could not be tied to perfume, and association only; the effect was significant at about 18 weeks and not at 26 weeks.
Source: Johns 2015, Reproductive Biology and Endocrinology Link to this fact
Children and pregnancy / Review of other studies
A 2024 narrative review of thyroid and environmental contaminants concludes that studies of chemicals and thyroid function are scarce for pregnancy, the newborn period and childhood, and that the evidence on bisphenols and phthalates is not yet complete across ages and critical windows.
Moderate evidence: Narrative review without grading or counts; it summarizes single cited studies.
Source: Street 2024, Front Endocrinol, Frontiers in Endocrinology Link to this fact
Children and pregnancy / Other evidence
In a 2019-2022 Riyadh pregnancy cohort of 672 women, urinary MEP (the breakdown product of diethyl phthalate, a fragrance and personal-care solvent) was found in every sample, with a median of about 213 ug/L across pregnancy, several-fold above US and European surveys.
Moderate evidence: One hospital clinic in Saudi Arabia; spot urine; perfume and cosmetic use was reported by participants but not analyzed, so MEP cannot be tied to fragrance specifically.
Source: Al-Saleh 2024, International Journal of Hygiene and Environmental Health 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
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
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
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
Information, not medical advice. See also: myths we won’t tell you.