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.
Fragrance is everywhere / Review of other studies
In California's 1997 inventory, air fresheners were the single largest category of cleaning-product chemical emissions: 7.5 metric tons a day, just ahead of general-purpose cleaners.
Moderate evidence: 1997 sales-based inventory; later SoCAB inventory had air fresheners <2.5 t/d.
Source: Nazaroff & Weschler 2004, Atmospheric Environment Link to this fact
Fragrance is everywhere / Measured in people or real products
Scented product categories (personal care and cleaning) made about half of the ozone from consumer and industrial chemical products in New York, mostly through their alcohol and glycol solvents rather than the fragrance molecules.
Moderate evidence: Box-model budget, one city/episode; 'fragranced VCP' is a product category: fragrance compounds are ~6% of VCP ozone, oxygenates 24%, and ethanol 15%.
Source: Coggon 2021 Link to this fact
Fragrance is everywhere / Self-reported survey
In a 1995 population-based telephone survey of 4,046 California adults, 15.9% said they were 'allergic or unusually sensitive to everyday chemicals' (like cleaning supplies, paints, perfumes, or soaps) and 6.3% reported a doctor's diagnosis of environmental illness or multiple chemical sensitivity.
Moderate evidence.
Caveats
Self-report only, no clinical verification of diagnosis or symptoms; California-specific, not national; the study's own authors take no position on whether this reflects a real physiologic condition or societal apprehension about chemicals.
Source: Kreutzer, Neutra & Lashuay 1999, American Journal of Epidemiology Link to this fact
Fragrance is everywhere / Other evidence
In a 2016 barcode-scan inventory of 2,963 household products from 131 German homes, EU-regulated biocidal active substances (preservatives, disinfectants, insecticides, repellents) were found in every single household, and personal care products plus washing/cleaning agents accounted for 90% of all such ingredient observations, far outnumbering the biocidal products the regulation is actually built around.
Moderate evidence.
Caveats
German sample; convenience sampling in 2 of 3 neighborhoods (response rate not calculable there); 65% response rate in the rural site; ingredient-list presence, not measured wastewater concentration or biological exposure.
Source: Wieck 2016, Environment International 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 / Other evidence
Perchloroethylene in Suffolk County groundwater: not detected in about 92% of supply wells sampled 2009-2013, but found in three times as many wells in 2013 as in 1987 with the average concentration doubled; public-supply maximum 93 ppb against a 5 ppb limit, and orders of magnitude higher at dry-cleaning sites.
Moderate evidence: Local county data summarized second-hand; trend reflects the wells sampled and is not attributed to dry cleaning alone.
Source: SCDHS 2018 Link to this fact
Fragrance is everywhere / Hypothesis
Immigrant women in the US most often work as house cleaners and make up 71% of manicurists; an expert job-exposure tool rates both jobs as probably exposed to fragrance chemicals, and house cleaning also to cleaning-product ingredients such as alkylphenols and antimicrobials.
Weak evidence: Exposure ratings from job descriptions (WORC), not measurements.
Source: Knox 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Fragrance is everywhere / Other evidence
About 65 percent of 500 randomly called Hong Kong households (323) said they had a dry-cleaning habit, and 93 percent of them keep the clothes in a wardrobe; 44 percent leave the cleaner's plastic bag on until they wear the item.
Weak evidence: Self-report, 1996 Hong Kong, random phone-book sample; not a measure of exposure.
Source: Chao 1998, Building and Environment Link to this fact
Information, not medical advice. See also: myths we won’t tell you.