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.
The industry / Review of other studies
The cosmetics industry's own safety panel judged PGME 'safe' only for nail products and calculated only skin absorption; it did not estimate how much users or nail-salon workers breathe in, and relied on the smell to limit inhalation.
Strong evidence: Verdict probably right for occasional home users; the weakness is in the reasoning, not a demonstrated harm.
Source: CIR 2008, International Journal of Toxicology Industry-funded Link to this fact
The industry / Review of other studies
All but one author of this fragrance-industry potency review were full-time, fully paid employees of the Research Institute for Fragrance Materials (RIFM) at the time of the work, and the remaining author was paid by RIFM for the time spent preparing the paper — a fully industry-funded and industry-staffed study that sets the potency categories RIFM and IFRA use to justify their own safety limits.
Strong evidence: Disclosed by the authors themselves in the paper's own conflict-of-interest statement.
Source: Na et al. 2022, Dermatitis Industry-funded Link to this fact
The industry / Measured in people or real products
In a French fragrance-and-flavor factory, the company's own measurements found the butter-flavor chemical diacetyl (linked to 'popcorn lung' in US factory workers) in workers' breathing air at 0.05–9 ppm during short tasks; 29 of 31 samples were above the 15-minute limit of 0.1 ppm recommended by the EU's scientific committee on occupational limits.
Moderate evidence.
Caveats
Limit comparison is our (paper makes none); samplers on clothing, respirator use per task not reported; flavor chemical, factory workers, not consumers; industry-funded (V. Mane Fils).
Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact
The industry / Measured in people or real products
The standard EU (REACH) screening tool for estimating workers' chemical exposure predicted lower levels than were actually measured in 61% of 431 measurements in a fragrance-and-flavor factory, sometimes by more than 100-fold.
Moderate evidence: One plant; evidence base count from the paper's S4 table (paper: 37% of tool predictions were above the measurement); short task samples.
Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact
The industry / Industry source
Even after this 2017 update, the fragrance industry's own aggregate exposure model still explicitly excluded household cleaning and laundry products — the product category the industry's own 2003 safety-process paper says accounts for about 60% of fragrance volume — and named their inclusion as future work.
Moderate evidence.
Caveats
Single industry methods paper describing its own model's scope; the gap was closed industry-wide only in a later 2024 paper (Lee et al.), which this claim's caveat should be read alongside.
Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact
The industry / Industry source
To build this exposure model, the fragrance industry combined three surveys that were never designed to work together — a 7-day product diary, a monthly recall survey, and a categorical daily-frequency questionnaire — by matching subjects only on age and gender and assuming they share the same habits for entirely unrelated products.
Moderate evidence.
Caveats
The paper's authors are explicit about this assumption's uncertainty and do not test it directly; a companion validation paper (Safford et al. 2017) is not yet in this evidence base to check how much this integration step affects final exposure estimates.
Source: Comiskey 2017 (RIFM/Creme Global), Regulatory Toxicology and Pharmacology Industry-funded Link to this fact
The industry / Review of other studies
All three named authors of this inhalation-TTC methodology paper were Unilever employees at Unilever's own research center (Colworth Science Park, UK), and the paper states 'The authors declare that there are no conflicts of interest' even though the work was industry research explicitly aimed at reducing inhalation-toxicology testing requirements on the authors' own company's aerosol consumer products under REACH and the EU Cosmetics Directive's 2013 animal-testing ban.
Moderate evidence.
Caveats
A self-declared 'no conflicts of interest' statement from an industry-employed author group performing industry-funded research aimed at reducing regulatory testing burden on their own company's products.
Source: Carthew, Clapp & Gutsell 2009, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Review of other studies
After a separate 'exception letter' sent in March 2015 by the National Candle Association, the original study's authors deleted a sentence reporting that formaldehyde in three scented-candle types (925, 1022, and 2098 ppb) exceeded workplace TLV (325 ppb) and PEL (730 ppb) limits, and softened a paper highlight from 'exposure levels of some species are high enough to exceed guideline values' to 'can approach or exceed certain guideline values.'
Moderate evidence.
Caveats
This is a documented instance of a trade association prompting language softening and deletion of a specific hazard finding in an academic paper's corrigendum; it does not mean the underlying revised emission-factor numbers (which went up, not down) are wrong.
Source: Kim et al. 2016, Journal of Hazardous Materials Link to this fact
The industry / Self-reported survey
The cosmetics industry generated its own dataset for how much lipstick, body lotion, and face cream people actually use, written by staff of the cosmetics trade association (CTFA), the fragrance industry's safety institute (RIFM), a contract statistics firm, and personal-care manufacturers including P&G, Unilever, Avon, Johnson & Johnson, Mary Kay, L'Oreal, Bath & Body Works and Takasago.
Moderate evidence.
Caveats
No funding statement is printed in the paper, but every author's affiliation is a cosmetics/fragrance trade body or personal-care manufacturer; absence of a disclosure is not evidence of independence.
Source: Loretz 2005, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Other evidence
This review of BAK's harms to the trabecular meshwork was partly funded by Merck, Inc., and its senior author, Paul Kaufman, discloses paid consultant, honoraria, and financial-support relationships with Alcon and Allergan, both manufacturers of BAK-free alternative eye-drop preservatives (SofZia and Purite respectively) that the review discusses favorably.
Weak evidence.
Caveats
This is a conflict-of-interest disclosure, not an evidentiary finding. The funding pattern runs opposite to a typical 'industry defends its own product' case: the paper argues against a preservative (BAK) while its senior author has financial ties to companies selling competing, BAK-free alternatives.
Source: Rasmussen et al. 2014, Journal of Ocular Pharmacology and Therapeutics Industry-funded Link to this fact
Information, not medical advice. See also: myths we won’t tell you.