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
In the US, everyday chemical products (paints, inks, glues, cleaners, personal care products and pesticides) now release about twice as much air-polluting vapor as cars and trucks: 7.6 vs 3.5 million tonnes in 2012.
Strong evidence: All chemical products, not fragrance specifically; coatings/inks/adhesives are 58%.
Fragrance is everywhere / Measured in people or real products
Even in Perth, a city with very clean outdoor air, limonene and pinene (scent chemicals typical of citrus- and pine-scented cleaners and air fresheners) were found in 80-100% of homes when a sensitive test was used.
Strong evidence: Low concentrations (median ~1.5-2.4 µg/m³); sources not measured; 64 weekday-daytime visits.
Source: Maisey 2013, Atmospheric Environment Link to this fact
Fragrance is everywhere / Measured in people or real products
Americans spend about 69% of their time at home and only 7.6% outdoors, so small indoor sources close to people matter far more than their share of total emissions suggests.
Strong evidence: NHAPS time-activity survey.
Source: Weisel 2002, Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Measured in people or real products
In EPA's large 1980s studies of US homes, limonene, the chemical behind lemon scents, was the airborne chemical with the highest average concentration in people's homes.
Strong evidence: 1980-87 TEAM data; no health risk estimated for limonene.
Source: Wallace 1991, Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Government agency
The US Environmental Protection Agency lists air fresheners, cleaners, disinfectants, aerosol sprays and cosmetics among the household products that release volatile organic compounds, both during use and while stored.
Strong evidence.
Source: US EPA 2026 Link to this fact
Fragrance is everywhere / Measured in people or real products
Scientists can identify which everyday products are polluting a city's outdoor air just by measuring a handful of specific chemical fingerprints: a silicone compound (D5-siloxane) for personal-care products and citrus/pine-scent chemicals (monoterpenes, mostly limonene) for fragranced products, confirmed by mobile-lab measurements across New York City, Pittsburgh, Chicago and Denver.
Strong evidence: Outdoor air only; four US cities, no LA data; tracer status is based on population-density correlation and inventory apportionment, not a direct source test.
Source: Gkatzelis 2021, Environmental Science & Technology Link to this fact
Fragrance is everywhere / Measured in people or real products
In blood tests of 100 healthy young adults in Vienna, the synthetic musk galaxolide was found in 91% of samples and musk xylene in 79%; only 7 of the 100 people had no synthetic musks in their blood at all.
Strong evidence: Cross-sectional, healthy university students in one city; no health outcome measured.
Source: Hutter 2009, Science of the Total Environment Link to this fact
Fragrance is everywhere / Measured in people or real products
Two completely different ways of estimating pollution from chemical products, one based on direct air measurements and one based on how much of each product gets sold and used, agreed with each other to within about a quarter.
Strong evidence: Agreement within 25% for the bulk comparison and within 30% for more than half of individual compounds compared, in Boulder and NYC only.
Source: Gkatzelis 2021b, Environmental Science & Technology Link to this fact
Fragrance is everywhere / Measured in people or real products
Musk fragrance chemicals were found in the breast milk of all 101 Swedish first-time mothers tested; the musk chemical galaxolide (HHCB) was detected in every single sample across a seven-year span (1996-2003).
Strong evidence: One Swedish county, single lab/method, N=101; no infant health outcome measured.
Source: Lignell 2008, Environmental Science & Technology Link to this fact
Information, not medical advice. See also: myths we won’t tell you.