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
Fragrance is everywhere / Other evidence
Researchers found multiple fragrance sources (cosmetics, air fresheners, cleaning/laundry products, fragrance-emitting devices, or candles) in every one of the 37 homes they surveyed for a chemical-intolerance study.
Moderate evidence.
Caveats
Sample is self-selected chemical-intolerance patients recruited from a specialty clinic, not a general-population sample; fragrance ubiquity may be overrepresented relative to the general population's home inventories.
Source: Rincón et al. 2024, Primary Health Care Research & Development Link to this fact
Fragrance is everywhere / Journalism
An EHP news report on a small Seattle-area study found that scented laundry detergent and dryer sheets sent volatile organic compounds, including several classified by EPA as hazardous air pollutants, out through home dryer vents into outdoor air.
Weak evidence: Secondary news coverage of one small two-home study with no replicates; numbers cross-checked and match the primary study (Steinemann 2013) exactly.
Source: Kessler 2011 (EHP Forum), Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Measured in people or real products
In this study, fibers from ordinary household laundry outnumbered the deliberately added test-blanket fibers in outdoor snow samples at both homes — suggesting day-to-day laundry drying sheds more microfiber than a single garment alone.
Weak evidence.
Caveats
These 'other' fibers were identified only by visual shape and color under a microscope, not confirmed as textile fiber or identified chemically (no FTIR/Raman); their true source was not verified.
Source: Kapp & Miller 2020, PLOS ONE Industry-funded Link to this fact
Information, not medical advice. See also: myths we won’t tell you.