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.
Hidden ingredients / Measured in people or real products
Once in the air, scent chemicals such as linalool, ionones and the woody musk OTNE ('Iso E Super') reacted with ozone to form dozens of new oxidized chemicals, including a hydroperoxide. None of these was in the product.
Moderate evidence: Compound identities are tentative (formula-level mass spectrometry); products unquantified; no hazard testing.
Source: Wu 2024, Environmental Science & Technology Letters Link to this fact
Hidden ingredients / Animal study
The regulatory endocrine dossier on linalool tested 99.7%-pure, freshly handled material — not the air-oxidized linalool that forms in an opened bottle and that accounts for almost all of linalool's known allergy risk. Nobody has tested whether oxidized linalool is hormonally active.
Moderate evidence: This is standard and correct practice for a REACH dossier; it is a limit on what the result covers, not a flaw in the study.
Source: Hareng 2024, Archives of Toxicology Industry-funded Link to this fact
Information, not medical advice. See also: myths we won’t tell you.