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 / Review of other studies
As early as 2004, a letter in Environmental Health Perspectives warned that fragrances can draw on thousands of chemicals and that most fragranced products had never been tested for human toxicity.
Weak evidence.
Caveats
The '4,000' figure comes from a 1991 book (Ashford & Miller) and describes untested products, not chemicals; later counts run ~3,000. Date 2020, now read as primary, corroborates 'thousands' as the right order of magnitude for the RIFM inventory (~2,600 active + ~3,500 discontinued) and separately states many individual fragrance materials lack toxicity data for standard endpoints — closer to Curtis's 'never tested' claim than any inventory count — but that is about individual chemicals with read-across-fillable data gaps, not about untested products, and does not confirm Curtis's specific '>4,000' figure.
Source: Curtis 2004, Environmental Health Perspectives Link to this fact
Hidden ingredients / Other evidence
A 2015 student lab analysis of 12 popular US perfumes and body sprays found 14-33 separate organic chemicals in each product (130 in all), while US law lets the label say just "fragrance".
Weak evidence: Identities are unconfirmed library matches and were never published; counts depend on the detection threshold. Pair with Steinemann 2011 rather than citing alone.
Source: Lee 2015, Young Scientist Journal (Vanderbilt University) Link to this fact
Hidden ingredients / Government agency
The industry safety panel's own risk calculation for PFOA (a persistent 'forever chemical' associated with PTFE manufacture) in lipstick relies on a single chemical supplier's claim of under 25 parts per billion in the raw material before it is formulated into a product — no actual PTFE-containing lipstick was tested for PFOA.
Weak evidence.
Caveats
The <25 ppb figure and the resulting '755-fold below EPA's advisory' conclusion are worst-case arithmetic on an unverified, pre-formulation raw-material claim, not a measurement of any real cosmetic product.
Source: CIR 2018 Industry-funded Link to this fact
Hidden ingredients / Other evidence
In a check by the review's authors, 11 of 22 randomly selected GRAS notices that FDA let pass with 'no questions' included no data on how the body absorbs, distributes, metabolizes, and excretes (ADME) the chemical.
Weak evidence: Very small sample (22), selection described in one sentence, notices up to about 2011; no statistical analysis. A signal of a gap, not a national rate.
Source: Maffini 2013, Comprehensive Reviews in Food Science and Food Safety Link to this fact
Hidden ingredients / Other evidence
GOTS 8.1's list of prohibited hazard statements for general chemical inputs covers carcinogens, mutagens, reproductive toxicants, organ toxicants, and endocrine disruptors but, as printed, not skin (H317) or respiratory (H334) sensitizers, so sensitizing chemicals are only banned by name for dyes.
Weak evidence: Reading of the printed list; other GOTS documents may add restrictions, and certification relies on approved inputs, not this list alone.
Source: GOTS 8.1 (2026) Link to this fact
Hidden ingredients / Measured in people or real products
In the same study, scented household cleaning products were not linked to higher levels of any measured chemical, and urine BPA was lower in children from homes that used them (ratio 0.69, 95% CI 0.49-0.98), so 'scented products' did not behave as one exposure.
Weak evidence: Likely chance or residual confounding on a wide multi-model estimate; shows heterogeneity of product categories rather than a protective effect.
Source: Fandiño-Del-Rio 2024, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Hidden ingredients / Other evidence
Few surveyed UAE women knew how fragrance is regulated: only 11.9% knew fragrance chemicals need not be fully disclosed on labels, 30.2% knew fragranced products emit hazardous air pollutants, and 82.2% believed natural ingredients are healthier.
Weak evidence.
Caveats
Open-link snowball sample of 461 women, mostly young and university-educated; self-report, no exposure measurement; not weighted, so not a UAE prevalence. Knowledge items copied from Klaschka/Steinemann; Germany 2019 gave 27.5% and 55.6% on the disclosure and natural items.
Source: AlBlooshi 2026, Frontiers in Toxicology Link to this fact
Information, not medical advice. See also: myths we won’t tell you.