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
In 34 California childcare centers, the chemicals at the highest levels in the air children breathed came from cleaning and personal-care products: a silicone ingredient called D5 (median 51 µg/m³) and the citrus-scent chemical limonene (median 33 µg/m³).
Strong evidence: Single-day samples; upper values capped by calibration (underestimates).
Children and pregnancy / Review of other studies
About half of children's cosmetics in a Danish registry (634 of 1,179, 53.8%) listed perfume or a named fragrance allergen, and a US survey of 533 baby/child personal care products found a closely similar share (255/533, 47.8%; Bonchak 2018); in Danish baby-care products the commonest named allergens were linalool, limonene, and benzyl alcohol (the US primary does not report limonene or linalool by name).
Strong evidence.
Caveats
Danish half is primary (Botvid 2023): baby-care products specifically were 38.0% (178/468), the least fragranced category — do not write 'half of baby products' for Denmark. 'Fragranced' there includes products naming only an allergen such as benzyl alcohol (often a preservative). US half is now also primary (Bonchak 2018): 47.8% (255/533) across wipes/diaper care/soap/moisturizer/shampoo/sunscreen — but Bonchak's fragrance count is a ~20-keyword composite that does not report limonene or linalool individually, so the 'top three' allergen list is confirmed only for Denmark. Label counts remain lower bounds.
Source: Sukakul 2024, Acta Dermato-Venereologica Industry-funded Link to this fact
Children and pregnancy / Review of other studies
Indoor irritant limits are built on studies of healthy young adults; a 2024 toxicology review found only one controlled irritation study in children (none under age 5) and concluded no evidence-based safety factor for children could be set.
Strong evidence: Absence of data, not evidence of harm; the review lists reasons children could be more or less susceptible (e.g. more stable tear film).
Source: Kleinbeck & Wolkoff 2024, Archives of Toxicology Industry-funded Link to this fact
Children and pregnancy / Measured in people or real products
16.5% of children and adolescents patch tested in 9 population studies had a contact allergy, and in Swedish 16-year-olds fragrance (2.1%) was the second most common allergen after nickel.
Strong evidence: Any allergen, not fragrance only; some adolescent studies read too early and underestimate.
Children and pregnancy / Review of other studies
Children exposed to household chemical/cleaning products before birth or in their first year wheeze more often, now replicated in four independent prospective birth cohorts. The founding ALSPAC cohort (UK, n=7,019, Sherriff et al. 2005) found that an 11-product, frequency-weighted prenatal household chemical (TCB) score was significantly associated with persistent wheeze through 3.5 years (adjusted OR 1.06 per unit increase; top-vs-bottom-decile adjusted OR 2.3), but not with transient early or late-onset wheeze; this is the same ALSPAC cohort and composite-score methodology that both Casas 2013 and Mikeš 2019 name as their model. In the Canadian CHILD cohort (n=2,022), frequent use in early infancy was linked to higher odds of recurrent wheeze (adjusted OR 1.35) and asthma diagnosis (adjusted OR 1.37) by age 3, but not isolated skin-prick allergy (adjusted OR 1.14, ns), though wheeze combined with allergy was itself raised (adjusted OR 1.49). In the Czech ELSPAC-CZ cohort (n=3,411), each 1-SD increase in an 18-product household chemical exposure score at 6 months raised the odds of intermediate-onset transient, intermediate-onset persistent, and early-onset persistent wheeze phenotypes through age 5 (adjusted OR 1.23-1.36), and those persistent phenotypes carried 5-8x higher odds of doctor-diagnosed asthma at age 7 (pediatrician records, not self-report). In the pooled Spanish INMA cohorts (n=2,292), prenatal (third-trimester) use of cleaning sprays raised the odds of both wheezing (OR 1.37) and lower respiratory tract infection (OR 1.29) in the first year of life, with solvents raising wheezing odds (OR 1.30) and air fresheners raising LRTI odds (OR 1.29); bleach, ammonia, and non-spray cleaners showed no association.
Strong evidence.
Caveats
All four cohorts are observational and use self-reported product-use frequency, not measured indoor air chemistry. The ALSPAC/Sherriff 2005 and ELSPAC-CZ signals are specific to persistent-type wheeze phenotypes, not wheeze in general; ALSPAC found no association with transient early or late-onset wheeze. The 'not atopy' finding remains single-cohort (CHILD only); ELSPAC-CZ's atopic-rash variable is a covariate, not an outcome, and Casas 2013 measured neither atopy nor a physician asthma diagnosis, only maternal-reported LRTI and any-wheezing through 12-18 months, so it neither confirms nor refutes the atopy finding; ALSPAC/Sherriff 2005 did not assess atopy or asthma at all. Casas 2013 is the only cohort among the three post-2010 cohorts with genuinely prenatal (rather than early-postnatal) exposure measurement, but ALSPAC/Sherriff 2005 is also prenatal and its composite score behaved like CHILD's and ELSPAC-CZ's (significant), not like Casas's (null) — evidence against prenatal timing per se explaining the Casas null. Casas 2013's own summed cleaning-product-count score was NOT a significant predictor, unlike ALSPAC's, CHILD's, and ELSPAC-CZ's frequency-weighted composite scores — an open methodological tension (register entry C262) that means 'more products used' is not yet a uniformly replicated exposure metric across all cohorts, even though several specific products (sprays consistently, plus solvents and air fresheners) are.
Source: Salonen 2024, Environment International Link to this fact
Children and pregnancy / Review of other studies
The government scientists who first linked lavender and tea tree oils to breast growth in children agree that four case reports cannot prove the oils caused it, and have called for epidemiological studies.
Strong evidence: Correspondence; the same letter also calls ER-agonist exposure 'substantial evidence of causality'.
Source: Ramsey et al. 2020 (JCEM reply), The Journal of Clinical Endocrinology & Metabolism Link to this fact
Children and pregnancy / Measured in people or real products
A perfume ('eau de cologne') marketed for babies listed 16 different fragrance allergens, the most of 1,179 children's products in a Danish registry.
Strong evidence: A single product (the maximum), not typical; mean 0.4-1.8 named allergens per product by category; label presence, not dose.
Children and pregnancy / Measured in people or real products
Even products marketed 'fragrance free' for children commonly contain contact allergens: of 52 US pediatric products so labeled in 2013, 42 (80.8%) contained at least one NACDG-tray allergen and 29 (55.8%) contained two or more.
Strong evidence: Label-based; allergens are not broken down by which ones appeared specifically in the 'fragrance free' subgroup beyond the count, and no concentration data exist.
Source: Hamann 2015, Journal of Allergy and Clinical Immunology Link to this fact
Children and pregnancy / Government agency
Because of endocrine-disruption concerns, the EU has banned bisphenol A from baby bottles and other food containers for infants and young children, set very low BPA migration limits for other food-contact materials, and banned or restricted several parabens in cosmetics 'in particular to protect infants and young children.'
Strong evidence: These are specific, named EU regulations (bisphenol A: Reg. (EU) No 10/2011 and 2018/213; parabens: Reg. (EU) No 358/2014 and 1004/2014), not a general endocrine-disruptor rule.
Source: EU Commission 2018 Link to this fact
Children and pregnancy / Other evidence
FDA says it prioritizes enforcement against homeopathic products marketed to vulnerable populations including children, pregnant women, and the elderly, and against products for serious diseases such as cancer, non-oral/topical routes, injury reports, risky ingredients, and quality problems.
Strong evidence: Enforcement priorities, not a ban; the guidance is nonbinding and many products fall outside the six categories.
Source: FDA consumer page: Homeopathic Products, FDA web page Link to this fact
Children and pregnancy / Other evidence
The EU's colors warning is a disclosure label that says an effect 'may' occur in children; it is not a ban on the six colors and does not change any acceptable daily intake.
Strong evidence: The Regulation's text gives no rationale; the link to the Southampton trial and EFSA's opinion comes from those source pages, not from this text.
Source: EU Reg 1333/2008 Link to this fact
Children and pregnancy / Other evidence
In a Swedish register study of 768,227 children (19,891 with ADHD), smoking in pregnancy went with about 2 times the ADHD risk (1-9 cigarettes/day HR 1.89; 10 or more HR 2.50), but the risk fell to 1.45 and 1.69 when cousins were compared and to 0.88 and 0.84 (not significant) when siblings were compared.
Strong evidence.
Caveats
One national register cohort (replicates smaller sibling studies in Finland, UK, US); ADHD ascertained from hyperkinetic diagnoses and medication, which likely captures severe cases; sibling designs are sensitive to non-shared confounders; tobacco smoke is not a fragrance exposure.
Source: Skoglund 2014, Journal of Child Psychology and Psychiatry Link to this fact
Children and pregnancy / Other evidence
In a Danish register study of about 968,000 children born 1991-2006, children whose mothers smoked in pregnancy had about twice the rate of ADHD (hazard ratio 2.01, 95% CI 1.94-2.07), rising to 2.77 for 10 or more cigarettes a day.
Strong evidence: Observational association in an ordinary cohort; the authors attribute it largely to family factors, not a proven effect of smoking.
Source: Obel 2016, Journal of Child Psychology and Psychiatry Link to this fact
Information, not medical advice. See also: myths we won’t tell you.