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.
Health effects / Self-reported survey
Among adults with a diagnosis of autism or autism spectrum disorder, 71.4% (US) and 51.2% (Australia) report health problems from the scent of laundry products coming from a dryer vent — the highest prevalence of any group measured (general population, asthmatics, autistic adults, migraineurs) in either country.
Moderate evidence.
Caveats
These country-specific figures are restated from Steinemann's 2018 autistic-adults survey, which this evidence base has not yet independently ingested and read in full; the primary's own main-text tables report only a pooled 3-country figure (57.5%) for this specific exposure item, so the US/AU split has not been directly verified against the primary's own tables here (only checked for internal arithmetic consistency).
Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact
Health effects / Self-reported survey
Among people who get migraines, 40.8% (US) and 29.1% (Australia) report health problems from the scent of laundry products coming from a dryer vent, with asthma attacks the most frequently reported effect in this group.
Moderate evidence.
Caveats
Restated from Steinemann & Nematollahi's 2020 migraine survey, which this evidence base has not yet independently ingested; self-report only, no clinical migraine diagnosis confirmation described in this source.
Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact
Health effects / Review of other studies
No published study has been found that tests whether quaternary ammonium compounds specifically from laundry fabric softeners or dryer sheets, as opposed to disinfectant or cosmetic-preservative exposure, cause asthma or skin sensitization in consumers.
Weak evidence: This is an evidence-gap statement, not a positive finding; the review also never discusses esterquats, the ester-linked chemistry that dominates modern fabric softeners, at all.
Source: Peyneau 2022, Frontiers in Toxicology Link to this fact
Information, not medical advice. See also: myths we won’t tell you.