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
Information, not medical advice. See also: myths we won’t tell you.