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.
Health effects / Review of other studies
Cleaning products were the suspected exposure in 236 of 1,915 (12%) confirmed work-related asthma cases across California, Massachusetts, Michigan, and New Jersey (1993-1997); in California, janitors and cleaners had roughly double the confirmed-case rate of all other occupations combined (4.3 vs 2.3 per 100,000 workers).
Moderate evidence.
Caveats
Now traced to its primary source (Rosenman 2003), not a secondary citation. But the underlying surveillance system's own authors say it misses 53-87% of true cases (Michigan capture-recapture) and that up to 37% of confirmed cases in such systems may not be truly work-related (Malo et al., cited by Rosenman); 'cleaning products' is a broad, mostly unspecified chemical category (36% of named agents never identified further than 'cleaning compound'), not fragrance-specific (limonene only 2/300 exposure counts).
Source: Nazaroff & Weschler 2004, Atmospheric Environment Link to this fact
Health effects / Measured in people or real products
In a Toronto clinic for work-related breathing problems, about 1 in 10 referred workers had an irritable larynx (throat) syndrome rather than asthma; perfumes and cleaning agents, bleaches and air fresheners were among the named triggers.
Moderate evidence.
Caveats
Single referral clinic, retrospective, n=30; perfume named by 5/30 and cleaning agents/fresheners by 4/30; 10% of referrals, not of workers. Morrison 1999, the founding case series behind the diagnostic criteria Hoy applied, independently found perfume was a named trigger in only 26% (10/39) of its own ILS cohort, behind reflux (72%) and other airborne irritants (51%) — the syndrome is not fragrance-specific at its point of origin either.
Health effects / Self-reported survey
In the same 2016 US survey, about 1 in 4 adults (25.9%) said they were unusually sensitive to everyday chemicals such as cleaning products, perfume, and detergents, and 81% of them reported health problems from fragranced products.
Moderate evidence: Self-report; adults 18-65 in an opt-in online panel; earlier US telephone surveys gave 11-16%.
Source: Steinemann 2018 (JOEM), Journal of Occupational and Environmental Medicine Link to this fact
Health effects / Measured in people or real products
Cleaning products were the suspected exposure in 236 of 1,915 (12%) confirmed work-related asthma cases across California, Massachusetts, Michigan, and New Jersey, 1993-1997; most were new-onset asthma (80%) and about a fifth were consistent with reactive airways dysfunction syndrome, an irritant-induced, non-allergic asthma type.
Moderate evidence.
Caveats
This is a primary surveillance source, not a population prevalence estimate: the authors' own capture-recapture analysis found the surveillance system misses 53-87% of true work-related asthma cases in Michigan, and up to 37% of confirmed cases in such systems may not be truly work-related (Malo et al., cited by the authors). Fragrance/limonene was a minor named agent (2 of 300 exposure counts); bleach, acids, disinfectants, and quaternary ammonium compounds dominate.
Source: Rosenman 2003, Journal of Occupational and Environmental Medicine Link to this fact
Health effects / Self-reported survey
In a large random sample of Swedish adults (Vasterbotten, n=3,406), 12.2% said they get symptoms from odorous or pungent chemicals such as perfumes and cleaning agents in doses that don't bother most other people, but only 3.3% had actually been given a doctor's diagnosis of a chemical-intolerance condition.
Moderate evidence: Single region (Vasterbotten county), not national; diagnosis status is itself self-reported, not verified against medical records.
Source: Palmquist 2014, International Journal of Hygiene and Environmental Health Link to this fact
Health effects / Self-reported survey
In a 2002-03 US national telephone survey of 1,054 randomly selected adults, 11.2% self-identified as unusually sensitive to everyday chemicals such as cleaning products, perfume, and detergents, and 2.5% said they had been medically diagnosed with multiple chemical sensitivity (MCS).
Moderate evidence.
Caveats
Single national random-digit-dial telephone survey; self-report with no clinical verification of hypersensitivity or diagnosis; the earliest in a cross-country series of self-report chemical-sensitivity prevalence figures.
Source: Caress & Steinemann 2003, Archives of Environmental Health: An International Journal Link to this fact
Health effects / Self-reported survey
In a 10-country European cohort of 3,503 adults who did the cleaning at home and were asthma-free at baseline, using household cleaning sprays at least once a week was associated with a 49% higher rate of new asthma symptoms or asthma-medication use over about 9 years of follow-up.
Moderate evidence: Single multinational cohort (not yet independently replicated by a different research group); exposure and symptom outcomes were both self-reported at one follow-up interview.
Source: Zock et al. 2007, American Journal of Respiratory and Critical Care Medicine Link to this fact
Health effects / Self-reported survey
Using household cleaning sprays at least 4 days a week was linked to roughly double the rate of new physician-diagnosed asthma (HR 2.11, 95% CI 1.15-3.89) compared with light or no spray use, with a clear dose-response across frequency categories (P for trend 0.041) and number of different sprays used (P for trend 0.022).
Moderate evidence: Physician-diagnosed asthma relied on participant report of a doctor's diagnosis, not independent verification; single cohort.
Source: Zock et al. 2007, American Journal of Respiratory and Critical Care Medicine Link to this fact
Health effects / Self-reported survey
Cleaning products that were not applied as a spray (liquid multiuse cleaners, washing powders, polishes, bleach, ammonia, decalcifiers) showed no significant association with new-onset asthma in this study, while glass-cleaning, furniture, and air-refreshing sprays did.
Moderate evidence.
Caveats
Correlation between spray use and other product use was generally weak but not zero (Spearman's r up to 0.41 for some product pairs), so residual confounding by broader cleaning intensity cannot be fully excluded.
Source: Zock et al. 2007, American Journal of Respiratory and Critical Care Medicine Link to this fact
Health effects / Self-reported survey
The single highest-risk activity for asthma and nasal symptoms was manual dilution of concentrated disinfectant products (adjusted OR 4.01, 95% CI 1.34-12.00 for asthma; 1.90, 95% CI 1.13-3.18 for nasal symptoms), higher than general disinfection or cleaning tasks alone.
Moderate evidence.
Caveats
Task-level self-report from a single cross-sectional study; the authors interpret this as likely reflecting dilution errors that create exposure peaks to concentrated, strongly irritant product, not a tested causal mechanism.
Source: Gonzalez 2014, Clinical & Experimental Allergy Link to this fact
Health effects / Self-reported survey
Weekly use of disinfectant/cleaning sprays at work was associated with worse asthma control in US nurses (OR 1.50, 95% CI 1.16-1.94 for poorly controlled; OR 1.38, 95% CI 1.00-1.92 for very poorly controlled), and the association held even among nurses who used sprays less than once a week.
Moderate evidence.
Caveats
Self-reported spray use; the paper attributes the effect to higher inhalation potential from spray application rather than to a specific chemical, since sprays covered multiple product types (surface, patient care, air-refreshing).
Source: Dumas 2017, European Respiratory Journal Link to this fact
Health effects / Review of other studies
Formaldehyde, released by household cleaning products both directly and via reaction with indoor ozone, is described as a human carcinogen as well as a respiratory irritant.
Moderate evidence.
Caveats
This is a background descriptive statement in an emissions-chamber study, not new primary carcinogenicity data; it does not itself cite IARC or NTP classifications by name. Corroborated separately in our evidence base by US EPA's own indoor-air VOC guidance, which states plainly that benzene is 'a known human carcinogen' (src-2026-epa-voc-impact-indoor-air-quality) — so both halves of the video's statement (benzene and formaldehyde) are independently backed by evidence base source pages, though not yet as a combined graded claim.
Source: Rossignol 2013, Atmospheric Environment Link to this fact
Health effects / Other evidence
Four cleaning occupations (unspecified cleaners, domestic helpers and cleaners, helpers/cleaners in offices and hotels, and hand-launderers) were associated with adult onset asthma in this cohort, with odds ratios from 1.58 to 2.26; the offices/hotels cleaning code (OR 1.82, 95% CI 1.34-2.48) and home-based personal care workers (OR 1.94, 95% CI 1.40-2.69) remained significant after correcting for testing 61 occupations.
Moderate evidence: Job-title-level exposure, not product-level; the lowest estimate (unspecified cleaners, OR 1.58) did not reach significance on its own (p=0.078).
Health effects / Other evidence
Using a job-exposure matrix built specifically for asthma research (ASJEM), lifetime exposure to low-molecular-weight reactive cleaning or disinfecting products was associated with 67% higher odds of adult onset asthma (OR 1.67, 95% CI 1.26-2.22), the single exposure category that remained significant after correcting for 18 tested high-risk exposures (q<0.001).
Moderate evidence.
Caveats
The ASJEM exposure category is an expert judgment covering an unspecified mix of cleaning/disinfecting chemicals, not a named ingredient; single-cohort, not yet independently replicated.
Health effects / Self-reported survey
Among the same 113 migraineurs, 90.2% had migraine crises triggered by odors, and of those, perfume was by far the most common odor trigger (95.1%), followed by cleaning products (81.3%), cigarette smoke (71.5%) and motor vehicle exhaust (70.5%).
Moderate evidence: Self-report, unvalidated questionnaire, single clinical sample, no provocation testing of the named odors.
Source: Fornazieri 2016, Headache: The Journal of Head and Face Pain Link to this fact
Health effects / Measured in people or real products
Among hotel workers directly handling cleaning products, bleach, and laundry chemicals, the average estimated excess lifetime cancer risk from inhaled VOCs (4.1 in 100,000) was about 40 times the EPA's 1-in-a-million screening threshold, driven more than two-thirds by formaldehyde (then chloroform and benzene), even though measured VOC concentrations were at the low end of those reported in US buildings generally.
Moderate evidence: Preliminary/screening-level risk estimate extrapolated from short-term (6-9h) measurements to a 40-hr workweek; small sample (2 hotels); not a measured cancer incidence.
Health effects / Measured in people or real products
Despite directly and repeatedly handling cleaning products and bleach all shift, hotel housekeepers', laundry, maintenance, and office workers' calculated non-cancer hazard ratios for VOC exposure all fell below the standard threshold of 1 (ranging 0.3-0.5 across worker groups), though all remained above the more conservative 0.1 margin-of-safety benchmark the authors mention; formaldehyde contributed most of the hazard for every group except the single maintenance worker, where a lubricant-derived alkane (n-nonane) contributed slightly more (54% vs 46%).
Moderate evidence: Preliminary screening-level estimate from short-term sampling; maintenance-worker group size n=1.
Health effects / Other evidence
In a Belgian referral clinic, 17 of 44 workers (39%) who had asthma symptoms they linked to cleaning or disinfecting products had a measurable asthmatic reaction (a sustained 20% or greater fall in FEV1) when exposed to their own work products under controlled conditions.
Moderate evidence.
Caveats
Retrospective single-center chart review of workers referred (mostly via compensation claims); not a prevalence among cleaners. No blinding described; products were commercial mixtures and exposure was not measured.
Health effects / Other evidence
Of the 17 workers who reacted to cleaning products, 10 reacted to products containing quaternary ammonium compounds (mainly benzalkonium and didecyldimethylammonium chlorides), 3 to glutaraldehyde, 1 to both, and 2 to ethanolamines.
Moderate evidence.
Caveats
The causal agent was inferred from product ingredients, not isolated; 9 workers challenged with QAC-containing products did not react (derived from Table 1). Authors name lack of quantitative exposure assessment as the main limitation.
Health effects / Review of other studies
A 2016 review of professional clothing-cleaning methods reports that perchloroethylene (perc), the most widely used dry-cleaning solvent, is classed by the International Agency for Research on Cancer as probably carcinogenic to humans (group 2A), with kidney cancer, liver cancer, and non-Hodgkin lymphoma among the cancers linked to it in workers or residents.
Moderate evidence.
Caveats
Secondary review funded by Australian Wool Innovation (wool industry body); 'systematic' is a self-label with no study counts or appraisal; relies on agency, trade and manufacturer sources. The review restates other studies' findings; it contains no new exposure or outcome data, and the IARC class is a hazard rating, not a risk estimate for wearing dry-cleaned clothes.
Source: Troynikov 2016, Journal of Environmental Management Industry-funded Link to this fact
Health effects / Other evidence
The panel says frequent use of bleach, ammonia and degreasing sprays has been consistently associated with asthma in cleaning workers, but the specific chemicals and mechanisms are unclear because cleaning products contain many ingredients, some irritants and some sensitizers.
Moderate evidence: Occupational cleaners, not consumers; consensus statement; cited studies used qualitative exposure assessment.
Health effects / Review of other studies
Published cases of lasting asthma after a single accidental inhalation (RADS) have most often involved chlorine or chlorine-releasing chemicals, including cleaning of bathrooms, kitchens and toilets (44 cases in one series) and accidentally mixed chemicals at work.
Moderate evidence: Review of case reports, series and conference abstracts; mostly workplace accidents; frequency of report is not potency or incidence; no exposure levels.
Source: Walters 2020, Occupational Medicine Link to this fact
Health effects / Other evidence
In a random survey of 1,582 adults in the Atlanta, Georgia metro area (1999-2000), 12.6% said they were allergic or unusually sensitive to everyday chemicals like cleaning products, paints, perfumes, detergents and insect spray, and 3.1% said a doctor had diagnosed multiple chemical sensitivity or environmental illness.
Moderate evidence: Self-report only, one metro area; sampling frame, interview mode and response rate are not reported in this brief; no clinical verification.
Source: Caress & Steinemann 2004 (AJPH), American Journal of Public Health Link to this fact
Information, not medical advice. See also: myths we won’t tell you.