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.
Fragrance is everywhere / Measured in people or real products
A lab analysis of 59 soaps, surface cleaners, laundry and dish-washing products from four European countries found the citrus-scent chemical limonene in 78% of them, linalool in 61% and citronellol in 47%; all three are fragrance chemicals linked to skin allergy.
Moderate evidence: Products c. 2000, EU only; parent terpenes measured, not the allergenic oxidized forms; Unilever co-author.
Source: Rastogi 2001, Contact Dermatitis Industry-funded Link to this fact
Fragrance is everywhere / Measured in people or real products
In a test of 59 best-selling Korean household products, the citrus-scent chemical limonene was the chemical most often given off: it came from 44% of products, including bleach, dish soap, laundry detergent, disinfectant and even a liquid pesticide.
Moderate evidence: Heated headspace, library-match ID, presence not exposure.
Source: Kwon 2007, Journal of Hazardous Materials Link to this fact
Fragrance is everywhere / Measured in people or real products
Tumble drying real household laundry released 256-342 milligrams of textile microfiber per kilogram of fabric dried, whether the dryer vented outdoors or condensed the moisture indoors, a similar order of magnitude to what washing machines release.
Moderate evidence: One UK lab, one detergent, one condenser model and one vented model, n=8 real loads per dryer type; measures plain cotton/polyester fiber, not fragrance or VOCs.
Source: Cummins 2023, PLOS ONE Industry-funded Link to this fact
Information, not medical advice. See also: myths we won’t tell you.