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.
Laws and loopholes / Journalism
As of 2010, the US FTC's Green Guides on environmental marketing claims had not been updated since 1998.
Weak evidence: Outdated: the Green Guides were revised in 2012 (and an update was proposed in 2022); do not use as a current fact.
Source: Dahl 2010, Environmental Health Perspectives Link to this fact
Laws and loopholes / Review of other studies
Fewer than 20% of the roughly 3,000 high-production-volume (HPV) chemicals in the US have been tested for potential to cause developmental neurotoxicity.
Weak evidence.
Caveats
Sealey 2016 relays this figure faithfully from Landrigan 2010, but Landrigan 2010's own citation to Goldman 1998 (Environ Health Perspect), now read directly in this evidence base (src-1998-chemicals-childrens-environment-risks), is not supported: Goldman 1998 contains no '20%' statistic and no developmental-neurotoxicity-specific testing figure. Its actual EDF-sourced figures (71% no basic toxicity data at all, 63% not tested for carcinogenicity, <50% tested for any chronic toxicity) describe different, broader endpoints.
Source: Sealey 2016 (citing Landrigan 2010), Environment International Link to this fact
Laws and loopholes / Measured in people or real products
Musk ambrette, banned in the EU for years, was still detected in the blood of 2 of 100 young Austrians tested, and testing the specific lotion and perfume one of them used did not find musk ambrette in the product itself, so the source of the banned chemical could not be pinned down.
Weak evidence.
Caveats
N=2; the tested products were negative for musk ambrette, so contamination, an unlisted supply-chain source, or a different untested product cannot be distinguished; no source identified.
Source: Hutter 2009, Science of the Total Environment Link to this fact
Laws and loopholes / Review of other studies
A leading pediatric environmental-health review states that fewer than 20% of the roughly 3,000 high-production-volume industrial chemicals in the US have been tested for potential to cause developmental neurotoxicity.
Weak evidence.
Caveats
Landrigan 2010 attributes this figure to Goldman 1998 (Environ Health Perspect), now read directly in this evidence base (src-1998-chemicals-childrens-environment-risks): Goldman 1998 contains no '20%' statistic and no developmental-neurotoxicity-specific testing figure. Its actual EDF-sourced figures (71% no basic toxicity data at all, 63% not tested for carcinogenicity, <50% tested for any chronic toxicity) describe different, broader endpoints. The citation does not support the specific number or endpoint claimed.
Source: Landrigan 2010, Current Opinion in Pediatrics Link to this fact
Laws and loopholes / Government agency
Allergy UK's product-endorsement page does not disclose who pays for testing or endorsement; it sits under a business-facing URL and ends in a manufacturer submission form, consistent with (but not confirmation of) a manufacturer-initiated, fee-based process.
Weak evidence: Fee/payer structure is inferred from page layout, not stated by the source; do not cite this page for a fee claim.
Source: Allergy UK 2026 Link to this fact
Laws and loopholes / Review of other studies
No law requires manufacturers of scented candles to prove the safety of their products before releasing them onto the market in the US or EU, per the authors.
Weak evidence: General regulatory claim by the review authors, not independently verified against current statute text in this ingest.
Source: Adamowicz 2019, Cancer Prevention Research Link to this fact
Laws and loopholes / Other evidence
Scented-candle manufacturers should be required to disclose indoor-pollution and health risks on labels or packaging under new labeling and packaging laws.
Weak evidence: A policy recommendation with no current legal requirement cited; no such disclosure law exists today per this source.
Source: Nazir et al. 2024, Annals of Medicine & Surgery Link to this fact
Information, not medical advice. See also: myths we won’t tell you.