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.
Green, natural and unscented / Other evidence
EWG Verified does not mean fragrance-free: fragranced cleaners can be licensed with fragrance up to 1 percent of the formula.
Strong evidence: Pet grooming products are limited to an EWG 'acceptable fragrance list' not reproduced in the document.
Source: EWG Verified criteria for cleaning products (10.24), Environmental Working Group, 2024 Link to this fact
Green, natural and unscented / Journalism
Green-claim auditors named 'all-natural' as a textbook example of a vague green claim and called household cleaning-product makers 'among the worst greenwash offenders'.
Moderate evidence: Opinion of TerraChoice staff; '3 of 397 cleaners' figure not text-verified.
Source: Dahl 2010, Environmental Health Perspectives Link to this fact
Green, natural and unscented / Measured in people or real products
In a chamber test of 30 US cleaning products and air fresheners, fragrance-free green cleaners gave off significantly fewer volatile chemicals than conventional ones: about 500 vs 4,700 ug/m3 total on average (approx., read from Fig. 4A), and about 6 vs 46 distinct VOCs per product (approx., read from Fig. 4D).
Moderate evidence.
Caveats
EWG-authored (advocacy nonprofit that ranks cleaners and licenses EWG VERIFIED to cleaner makers); Skyline Foundation grant; unblinded; 7 fragrance-free vs 14 conventional products, one product per brand, single lab; green products also applied less product per use; chamber concentration, not personal exposure. Group means are read from Fig. 4.
Green, natural and unscented / Other evidence
Study participants were given a free 'starter kit' of unscented cleaning products and 'alternative cleaning recipes' as part of a personalized action plan to reduce indoor VOC exposure, and researchers observed reduced use of scented products at follow-up visits.
Weak evidence.
Caveats
Product-use reduction was assessed by researcher observation during a scheduled visit, not by continuous monitoring, and patients knew they were being evaluated (compliance may be overstated).
Source: Rincón et al. 2024, Primary Health Care Research & Development Link to this fact
Green, natural and unscented / Test-chamber measurement
The limonene given off by a natural fragrant plant is the same chemical as the limonene in cleaners and air fresheners; in this study three plants took room limonene to about 60-84 ug/m3 on average over 3 hours, in the range of a plug-in air freshener and well below the 1,000-6,000 ug/m3 seen right after terpene cleaning in a chamber.
Weak evidence: Cross-study comparison of different averaging times and rooms; the 'after' means are back-calculated from the dose table; plug-in and cleaning values come from other studies.
Information, not medical advice. See also: myths we won’t tell you.