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.
Indoor air / Other evidence
A carpet used as the constant pollution source released about 127 micrograms of volatile chemicals per square meter per hour, including toluene, acetic acid, hexanal and small amounts of the scent terpenes limonene and alpha-pinene.
Moderate evidence: One used carpet, lab emission test at 23 C; terpenes were a small part of the mixture; not a fragrance product.
Indoor air / Other evidence
When limonene reacted with ozone in the test chamber, formaldehyde and two other irritant-type chemicals (4-oxopentanal and 3-isopropenyl-6-oxoheptanal) formed within the first hour, at roughly 9-17 micrograms per cubic meter each, along with a burst of ultrafine particles (average about 830 per cm3, maximum about 2,200).
Moderate evidence: Chamber chemistry at 0.7 air changes/h and 22 C with dry air; one run per condition for the chemistry; levels the authors call the upper end of indoor air.
Source: Verstraelen 2024 (J Environ Sci Health A), Journal of Environmental Science and Health, Part A Link to this fact
Indoor air / Other evidence
A computer model of typical US homes finds indoor ozone reacts almost only with terpene scent chemicals: about 99% of its reactions with indoor VOCs, with limonene (citrus) about two-thirds and alpha-pinene (pine) about a quarter.
Moderate evidence: Model, not a measurement; VOC profile is a literature median (Logue 2011), not a home with heavy scented-product use; no validation against field data.
Source: Waring & Wells 2015, Atmospheric Environment Link to this fact
The industry / Lab study (cells or chemistry)
The fragrance industry's own data show its main explanation for how fragrance chemicals cause allergy doesn't cover most of them: 34 of 62 ingredients (55%) sensitize despite having no predicted protein-binding alert.
Moderate evidence.
Caveats
Structural-alert software limitation; metabolic activation explains some. Roberts & Api 2018 (different 57-chemical fragrance dataset, no direct overlap confirmed with this claim's 62-chemical set) adds two further indirect-activation routes the alert software here evidently does not capture — slow autoxidation of tertiary allylic/benzylic C-H compounds to allergenic hydroperoxides/epoxides, and a proposed bio-sulfation route for benzylic alcohols — which could explain part of the unexplained 55% for chemicals with those structural motifs. The same paper separately proposes that some LLNA-positive, alert-free fragrance chemicals (hexyl/benzyl salicylate) may be LLNA false positives rather than true sensitizers at all, which would pull in the opposite direction (shrinking, not explaining, the true no-mechanism fraction) if any such chemicals are present in this claim's 62-ingredient set — not checked here, so the net effect on the 55% figure is unresolved and the grade is left unchanged.
Source: Lee 2024, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
Those models underestimated allergy potency by more than fivefold for 18% of the 188 chemicals tested, and more than tenfold for 11%.
Moderate evidence.
Caveats
Prediction error, not a safety-limit error; worst outliers are non-fragrance chemicals. Natsch 2023 (same author, human-anchored retraining) shows this outlier structure is not simply an artifact of fitting to mouse data: only 6/139 chemicals (4.3%) shift by more than 3.3-fold when the same models are retrained against human-anchored potency values instead of LLNA.
Source: Natsch & Gerberick 2022, ALTEX Industry-funded Link to this fact
The industry / Review of other studies
The industry panel judged each salicylate's safety one chemical at a time, although the same report says all 17 are broken down in the body to the same substance, salicylic acid.
Moderate evidence.
Caveats
The combined-exposure figure (about 1.05 mg/kg/day, group margin roughly 48-69 at the panel's own 100%-absorption default) is a evidence base calculation on the paper's Table 1, not a published number, and sums high-end maxima.
Source: RIFM Expert Panel / Belsito 2007, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Measured in people or real products
In a French fragrance-and-flavor factory, the company's own measurements found the butter-flavor chemical diacetyl (linked to 'popcorn lung' in US factory workers) in workers' breathing air at 0.05–9 ppm during short tasks; 29 of 31 samples were above the 15-minute limit of 0.1 ppm recommended by the EU's scientific committee on occupational limits.
Moderate evidence.
Caveats
Limit comparison is our (paper makes none); samplers on clothing, respirator use per task not reported; flavor chemical, factory workers, not consumers; industry-funded (V. Mane Fils).
Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact
The industry / Measured in people or real products
The standard EU (REACH) screening tool for estimating workers' chemical exposure predicted lower levels than were actually measured in 61% of 431 measurements in a fragrance-and-flavor factory, sometimes by more than 100-fold.
Moderate evidence: One plant; evidence base count from the paper's S4 table (paper: 37% of tool predictions were above the measurement); short task samples.
Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
When the same lab-dish tests that replace animal testing are checked against real human allergy-test panels instead of mouse data, they explain only about 32-45% of how strongly a chemical causes allergy in people, and the mouse test itself does barely better, explaining only 43%.
Moderate evidence: The strictly-human comparison dataset (n=62) is small and the author flags it as biased/non-representative; a larger human dataset might do better.
Source: Natsch 2023, ALTEX Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
Whether a chemical is irritating to cells in a dish, not just whether it reacts with proteins, drives a lot of the mouse allergy test's readout in ways that don't reflect real human allergy.
Moderate evidence: Statistical inference from regression coefficients across three chemical subsets, not a direct mechanistic experiment.
Source: Natsch 2023, ALTEX Industry-funded Link to this fact
The industry / Measured in people or real products
In RIFM's own comparison of 57 fragrance chemicals, the mouse test used to set fragrance skin-allergy safety limits agreed with real human sensitization thresholds within about 3-fold for 76% of the chemicals tested, but was off by up to nearly 800-fold for others, including hexyl and benzyl salicylate.
Moderate evidence.
Caveats
Single paper/author group (RIFM staff plus an industry consultant), though a large (57-chemical), systematically protocolled primary dataset; the authors themselves call the outlier groups 'an alert for consideration, rather than… a general rule' given only 7 materials populate each. Corroborates, from a different metric and era, the LLNA-human accuracy gap C230 documents for the newer non-animal replacement tests.
Source: Api, Basketter & Lalko 2014, Cutaneous and Ocular Toxicology Industry-funded Link to this fact
The industry / Measured in people or real products
A musk fragrance chemical called ATTN (Versalide) disappeared entirely from human tissue in this 1996 study because industry had already stopped making it in 1980, after animal testing showed it damaged nerves – a real-world example of a musk being phased out after a toxicity finding.
Moderate evidence: Absence in 19 samples is consistent with, but does not by itself prove, the discontinued-production explanation the authors give; based on a small single-country sample.
The industry / Animal study
When RIFM's own scientists restrict the comparison to fragrance chemicals without known problematic chemistry, the mouse test used to set fragrance safety limits correlates strongly with real human sensitization thresholds (R-squared = 0.78 for 35 chemicals).
Moderate evidence.
Caveats
This correlation excludes, by design, the 14/57 chemicals already known (from the same underlying RIFM dataset) to disagree badly between mouse and human data, some by up to ~790-fold (Api 2014). Only 2 of those 14 exclusions could have been identified before seeing the human data; the other 12 were fit to the very outliers they exclude.
Source: Roberts & Api 2018, Regulatory Toxicology and Pharmacology Industry-funded Link to this fact
The industry / Measured in people or real products
This foundational human PGME irritation study has a direct Dow Chemical link stronger than later PGME papers in the wiki: one author was a Dow Chemical employee and the test material was Dow-supplied ('Dowtherm 209'), yet the study documents substantial irritation at concentrations relevant to Dow's own radiator-coolant product rather than minimizing it.
Moderate evidence: A single industry-linked study reporting an adverse finding is still one study; the funding link is recorded for transparency, not as proof the finding is unbiased in general.
Source: Stewart 1970 (Arch Environ Health), Archives of Environmental Health: An International Journal Industry-funded Link to this fact
The industry / Other evidence
In a random sample of 100 high-production-volume industrial chemicals, 47 were also listed on EPA's Toxics Release Inventory (meaning they are emitted into air, land, or water in quantities over 10,000 pounds a year), and toxicity data were publicly available for less than half of those 47.
Moderate evidence: A single external audit, not independently replicated; concerns industrial chemicals broadly, not a named fragrance or consumer-product ingredient.
Source: Goldman 1998, Environmental Health Perspectives Link to this fact
The industry / Animal study
The paper's proposed inhalation systemic TTC ranges from 16.4 μg/kg/day for the least-toxic Cramer Class 1 chemicals down to 2.8 μg/kg/day for the more toxicity-presumptive Class 3 chemicals (roughly a 6-fold spread), while its separate local respiratory-tract TTC ranges from 2.1 to 0.73 μg/g lung tissue/day (about a 3-fold spread) — equivalent to 980/170 μg/day and 1400/470 μg/day respectively for a 60 kg adult.
Moderate evidence.
Caveats
Derived from the 5th percentile of NOAEC/NOAEL across 92 rat studies plus a 25-fold uncertainty factor; a conservative statistical screening threshold, not a measured no-harm level, and the paper treats local and systemic thresholds as two separate comparisons that later citations sometimes conflate.
Source: Carthew, Clapp & Gutsell 2009, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Animal study
The dataset behind these inhalation TTCs excluded genotoxic carcinogens, in vivo mutagens, heavy metals, dioxins/PCBs, organophosphates, and polymers — chemical classes the authors say would already be disqualified from consumer aerosol use on other safety grounds — before applying a default uncertainty (safety) factor of 25 to the 5th-percentile NOAEC/NOAEL of the remaining 92 rat studies.
Moderate evidence.
Caveats
Exclusion criteria and the 25-fold uncertainty factor are the authors' own choices, following precedent from the oral/dietary TTC literature; not independently audited by a regulator.
Source: Carthew, Clapp & Gutsell 2009, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Animal study
Only 5 of the 92 chemicals in the database had local (respiratory-tract) NOAECs below the study's own 5th-percentile benchmark — sulfuric acid, trimellitic acid, glutaraldehyde, hydrogen peroxide, and 1,2-dichloro-4-nitrobenzene — and all were strong acids, bases, or reactive irritants that the authors say would already be excluded from consumer aerosol use on physicochemical grounds alone.
Moderate evidence.
Caveats
A post-hoc observation about which chemicals happened to fall below the benchmark in this specific 92-study set; not a claim that physicochemical screening alone catches every locally toxic inhalable chemical.
Source: Carthew, Clapp & Gutsell 2009, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Review of other studies
When RIFM's own scientists switched from mainly human patch-test data (their 2017 categorization) to a full weight-of-evidence approach that also folds in animal, computer-model, and lab-dish data, the assigned allergy-potency category changed for 29% of the same 82 fragrance chemicals — moving to a weaker category for 20.5% of them and a stronger one for 8.5%.
Moderate evidence.
Caveats
Same authors and institution comparing their own two categorization schemes; independent validation of either scheme against real-world human sensitization rates is not addressed in this paper.
Source: Na et al. 2022, Dermatitis Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
In lab dish tests, three human smell receptors that detect the sulfur gases methanethiol and hydrogen sulfide (OR2T1, OR2T6, OR2T11) only responded strongly when copper was added to the mix, and a copper-grabbing chemical shut the response back down, indicating these malodor receptors sense sulfur gases by using copper ions to grab onto them.
Moderate evidence.
Caveats
Heterologous cell-culture assay only, at concentrations far higher than natural environmental levels, per the authors' own discussion; not directly observed in olfactory neurons or in vivo.
Source: Fukutani et al. 2023, Current Biology Industry-funded Link to this fact
The industry / Government agency
Benzophenone is widely used as a UV-curing photoinitiator for inks and varnishes, a fragrance fixative/enhancer and flavoring agent, a UV blocker in plastic packaging, and an additive in coatings, adhesives, laundry and household cleaning products; the US EPA classified it a high-production-volume chemical in 2003, with US annual production exceeding 1 million pounds (453,000 kg).
Moderate evidence: Production/use figures are the Working Group's synthesis of industry and HSDB/NTP secondary sources, not independently verified primary measurement.
Source: IARC 2013 Link to this fact
The industry / Lab study (cells or chemistry)
Cosmetics Europe (the European cosmetics industry trade association) funded a standardized, OECD-compliant lab study measuring 24-hour skin penetration of 56 cosmetic-relevant chemicals, authored by scientists employed by L'Oreal, Unilever, Pierre Fabre, Procter & Gamble, BASF, Coty, and Beiersdorf, with the explicit goal of replacing a flat 50% default assumption about how much of an applied chemical passes through skin with chemical-specific measured data.
Moderate evidence.
Caveats
Industry-funded and industry-authored throughout; the paper states 'the authors state no conflict of interest,' which addresses personal financial conflicts, not the industry funding and employment of the entire author list.
Source: Hewitt 2020, Journal of Applied Toxicology Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
For the 7 chemicals in this dataset with published human in vivo comparison data (hydrocortisone, testosterone, ibuprofen, benzoic acid, caffeine, DNCB, and nitrobenzene — none of them fragrance ingredients), measured skin penetration ranged from about 3% to 63% of the applied dose, a more than 20-fold spread that straddles the industry's flat 50% dermal-absorption default from well below to just above it.
Moderate evidence.
Caveats
Only 7 of the 56 chemicals had in vivo comparison data available; none of the 7 is a fragrance ingredient; single industry-funded lab, though methodology follows OECD test guideline 428.
Source: Hewitt 2020, Journal of Applied Toxicology Industry-funded Link to this fact
The industry / Lab study (cells or chemistry)
In this standardized dataset, several volatile test chemicals lost most of their applied dose to evaporation from the skin surface rather than to skin absorption — naphthalene's mass balance was only 27% of the applied dose and 4-tolunitrile's only 20% — but the study measures only dermal delivery (skin plus receptor fluid) and never quantifies or discusses the airborne exposure that this evaporation implies for someone wearing a product containing these chemicals.
Moderate evidence.
Caveats
This is a methodological gap in the study's design (dermal-only endpoints), not a measured inhalation finding; extends our C178 entry on the fragrance/cosmetics industry's recurring lack of an inhalation branch in its safety-assessment research.
Source: Hewitt 2020, Journal of Applied Toxicology Industry-funded Link to this fact
The industry / Other evidence
A fragrance fixative left on skin for hours in a lotion or perfume penetrates far more than the same chemical in a soap that is quickly rinsed off: an FDA lab's modeled estimate for musk xylol found roughly 50-60 times more absorbed mass from a 12-hour lotion application than from a 4-minute soap wash, at realistic in-use concentrations and body-surface areas.
Moderate evidence: Modeled, not directly measured for this scenario; the Kp was derived from more-permeable hairless guinea pig skin, which the authors themselves say overestimates human absorption.
Source: Hood 1996, Food and Chemical Toxicology Link to this fact
The industry / Other evidence
The flavor trade association says workplace exposure to flavor chemicals, at 'relatively high concentrations' by dermal and inhalation routes, is not evaluated by its Expert Panel and falls to OSHA; it names the butter-flavor chemical diacetyl as a 'potential respiratory hazard' in flavor and popcorn manufacturing while it remains GRAS for its food flavor use.
Moderate evidence.
Caveats
The paper reports no workplace measurements or health data itself. Written by two FEMA employees and supported by FEMA (the flavor industry trade association); it is the industry's own account of its own program.
Source: Hallagan 2009, Food and Chemical Toxicology Industry-funded Link to this fact
The industry / Other evidence
Skin Deep's own FAQ says its product hazard ratings do not account for how much of a chemical you are exposed to or how sensitive you are, so they describe ingredient hazard, not your actual risk.
Moderate evidence: EWG's own description of its method; no independent audit. The score is still a label-based proxy.
Source: EWG, Skin Deep FAQ (web page, accessed 2026-10-16), EWG web page (Skin Deep FAQ) Link to this fact
The industry / Other evidence
The 2006 ADBAC reregistration database was supported by a registrant consortium (Lonza, Mason Chemical, Stepan), with EPA reviewing the data it submitted.
Moderate evidence: EPA reviewed the studies; the point is that the underlying studies are registrant-submitted, not independent.
Source: EPA RED 2006 Link to this fact
Laws and loopholes / Measured in people or real products
More than 70% of the chemicals measured in childcare air had no health-based safety limit; several fragrance compounds were among 12 the authors flagged for further study.
Moderate evidence: Flags come from database/QSAR hazard scores, not measured effects.
Laws and loopholes / Measured in people or real products
US product rules written to limit smog (ozone) exempt several chemicals that still form fine particles, and fragrance ingredients do not have to be disclosed.
Moderate evidence: Regulatory analysis in the paper.
Laws and loopholes / Review of other studies
In the US, "fragrance-free" means that no ingredient is used solely to give a smell. A fragrance chemical that also does another job, such as benzyl alcohol used as a preservative, can legally be in a "fragrance-free" product.
Moderate evidence: US definition as quoted by dermatologists in 2007; not a legal analysis; FDA has no binding definition of "fragrance-free".
Laws and loopholes / Review of other studies
More than 40% of US occupational exposure limits are set to prevent eye, nose, and throat irritation, and a systematic comparison of 18 agencies confirms that US, German, and EU regulators set substantially different limits for the same chemicals, overall stringency ranges from Poland's geometric-mean level of 0.23 to US OSHA's 0.61 (a 2.67-fold spread), with the EU's own 'health-based' indicative limits sitting above Germany's stricter national MAK limits.
Moderate evidence.
Caveats
Workplace limits, not consumer or home limits. The >40%-for-irritation figure is still secondhand (Edling & Lundberg 2000, not independently in our evidence base). The 'agencies differ' clause is now backed by a large, systematic primary (Schenk et al. 2008: 18 agencies, 1,341 substances), but the claim stays below 'strong' because the irritation-basis figure remains unverified.
Source: Dalton & Jaén 2010, Current Opinion in Allergy and Clinical Immunology Industry-funded Link to this fact
Laws and loopholes / Review of other studies
A fragrance-and-flavor company reported that about half of the chemicals it handles are classified hazardous, and that few of the more than 3,000 flavoring substances in use have workplace exposure limits.
Moderate evidence: Industry self-description, no inventory published; flavor materials at one company.
Source: Angelini 2016, PLoS ONE Industry-funded Link to this fact
Laws and loopholes / Review of other studies
US product labels only have to say "fragrance", not which chemicals, and household products need not list ingredients at all; MoCRA (2022) requires companies to name on cosmetic labels the fragrance allergens FDA designates by regulation (proposed rule was due June 2024), which the authors expect to be many, but not all.
Moderate evidence: Check current MoCRA rule status before quoting; household products are outside MoCRA; statute §609(b) is a mandate; check final rule status.
Laws and loopholes / Review of other studies
The EU bans or restricts more than 1,500 chemicals in personal care products and Canada about 800, while the US restricted 11.
Moderate evidence: Secondhand from a 2018 JAMA Intern Med commentary; EU count includes substances never used; US rules changed after MoCRA 2022.
Source: Khalid & Abdollahi 2021, Iranian Journal of Pharmaceutical Research Link to this fact
Laws and loopholes / Review of other studies
People with chemical sensitivities asked the US Justice Department to consider fragrance as an access barrier during its 2008 ADA rulemaking.
Moderate evidence: Shows the issue was raised in the record; the attachment makes no legal argument and our evidence base has no record of DOJ's response.
Source: DONTSPRAYCALIFORNIA 2008 (DOJ ADA docket) Link to this fact
Laws and loopholes / Government agency
In the US, fragrance sensitivity or multiple chemical sensitivity can count as a disability under the Americans with Disabilities Act, but not automatically: it is decided case by case, usually on whether breathing is substantially limited.
Moderate evidence: Authors' reading of statute in a 2009 business-conference paper; no case survey; the 2008 ADA Amendments postdate their cases.
Laws and loopholes / Review of other studies
US law has never defined "fragrance-free"; the only definition is of fragrance itself ("used solely to impart an odor", 21 CFR 700.3(d)), so an ingredient that smells but is also claimed as a preservative or moisturizer can go into a "fragrance-free" product. FDA's own website said in 1999 that "fragrance-free" products, like "unscented" ones, may contain fragrance chemicals.
Moderate evidence.
Caveats
Legal point from a 1999 commentary quoting the FDA's own website of that era, not a legal analysis or product survey. The US statute (MoCRA 2022) still has not defined 'fragrance-free' 23 years later.
Source: Scheinman 1999, Journal of the American Academy of Dermatology Link to this fact
Laws and loopholes / Review of other studies
A 2006 Lancet review found that of roughly 3,000 US high-production-volume industrial chemicals, basic toxicity data were publicly unavailable for nearly half, and 80% had no information on developmental or pediatric toxicity at all.
Moderate evidence.
Caveats
Cites the US EPA's own 1998 Chemical Hazard Data Availability Study directly, one citation hop closer to a primary than the Goldman 1998 chain behind our other testing-gap claim. Concerns general developmental/pediatric toxicity testing, a broader category than the narrower 'developmental neurotoxicity' endpoint in the related claim — not a strict numeric confirmation of it. About industrial chemicals in general (solvents, metals, pesticides); no fragrance ingredient named.
Source: Grandjean & Landrigan 2006, Lancet Link to this fact
Laws and loopholes / Government agency
Under the EPA's Safer Choice program, 'fragrance-free' and 'unscented' are not the same claim: 'unscented' still allows a masking chemical added to cover other ingredients' smell, while 'fragrance-free' specifically bars masking scents as well as added scent.
Moderate evidence.
Caveats
This is the program's own written definition (evidence/agency), not a product-testing result; it applies only to products certified under this specific EPA program, not to any product that merely uses the words on its own label.
Source: US EPA Safer Choice Link to this fact
Laws and loopholes / Review of other studies
Multiple chemical sensitivity has no dedicated diagnostic code and is instead coded, when coded at all, under nonspecific ICD-10 codes for unspecified respiratory conditions from inhaled fumes/gas/chemical vapors (J68.9) or unspecified allergy/hypersensitivity/idiosyncrasy (T78.4); some countries and agencies (US EPA, US ADA, Germany, Austria) have given the condition some form of recognition, while Italy's health ministry has declined to recognize it as a rare disease due to diagnostic-nosology difficulty.
Moderate evidence.
Caveats
Regulatory-recognition landscape as of this review's 2015 search cutoff and largely focused on Italy; recognition status in individual US states, agencies or other countries may have changed since, and the review does not cite the specific EPA/ADA source documents establishing "recognition.".
Source: Rossi 2018, Journal of Occupational & Environmental Medicine Link to this fact
Laws and loopholes / Review of other studies
Under the EU's REACH chemical regulation, data from the mouse sensory-irritation bioassay are generally not accepted to classify a chemical as causing respiratory tract irritation (that classification is limited to tests showing direct tissue damage); the bioassay's data can only be used case-by-case to help set a short-term safe-exposure value.
Moderate evidence.
Caveats
Describes the regulation's stated scope as the authors summarize it (citing ECHA 2012, 2017 guidance documents), not an independent legal analysis; the authors argue this restriction rests on a misreading of an earlier study by a different group.
Source: Nielsen & Wolkoff 2017, Regulatory Toxicology and Pharmacology Industry-funded Link to this fact
Laws and loopholes / Government agency
In 1995 the US Department of Justice told a member of the public that under the ADA, it would 'usually' not be legally required for a medical facility to make its staff stop wearing fragrance to accommodate a patient with multiple chemical sensitivity, because fragrance use is treated as an employee's personal choice rather than a business policy.
Moderate evidence.
Caveats
Informal technical assistance to one inquirer, not a regulation or case law; DOJ's own letter states it 'does not constitute a legal interpretation of the statute' and 'is not binding on the Department.' 30 years old; predates the 2008 ADA Amendments Act's broadened definition of disability (a separate legal question this letter does not address).
Source: DOJ TAL605, 1995 Link to this fact
Laws and loopholes / Government agency
HUD's own Occupancy Handbook (4350.3 REV-1, Exhibit 2-6, June 2007) states that for a HUD-assisted housing resident with chemical sensitivity disorder, it is not an undue financial and administrative burden for the owner to give advance notice before cleaning common areas and to use nonchemical alternative cleaning methods where practical.
Moderate evidence.
Caveats
Binding operational guidance for HUD-assisted multifamily housing, not a court ruling; applies only to owner-controlled common-area cleaning, not to other tenants' or staff's personal fragrance/scent use, and 'where practical' is left case-by-case.
Source: HUD Occupancy Handbook 4350.3 REV-1, Exhibit 2-6 (2007) Link to this fact
Laws and loopholes / Government agency
The same HUD guidance states it would be an undue administrative burden for a HUD-assisted housing owner to survey every tenant in a building for what chemicals they use to clean their own units and when, and compile that into a weekly report for a chemically sensitive resident.
Moderate evidence.
Caveats
HUD's stated reason is administrative capacity ('could not be handled by the existing staff'), not cost; this refusal is specific to a full building-wide, ongoing, per-tenant monitoring and reporting scheme, not to lesser accommodations.
Source: HUD Occupancy Handbook 4350.3 REV-1, Exhibit 2-6 (2007) Link to this fact
Laws and loopholes / Government agency
EU law now states, as a general principle, that fragrance substances able to transform into known contact allergens via air oxidation or bioactivation ('prehaptens and prohaptens') should be regulated the same as the allergens they become — but this 2023 amendment does not apply a specific hydroperoxide limit or peroxide-value restriction to limonene or linalool, the two chemicals most discussed in the oxidized-fragrance-allergen literature.
Moderate evidence.
Caveats
Recital 7 states the principle in general terms; reading the Annex directly shows no limonene- or linalool-hydroperoxide entry and no peroxide-value cross-reference for either chemical (only the new Pinene entry is linked to an existing peroxide-value restriction).
Source: Regulation (EU) 2023/1545 Link to this fact
Laws and loopholes / Review of other studies
The EU's Scientific Committee on Food said in 2003 that the toxicology data on parabens were inadequate, and the food ADI from 1974 rests on 1950s-60s studies without reproductive or developmental testing.
Moderate evidence: Reported secondhand from SCF 2003 and WHO 1974 as of 2004; later regulatory opinions exist and are not covered by this review.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Laws and loopholes / Other evidence
In the 2005 procedure, safety of an essential oil is judged from its chemical constituents compared with generic intake thresholds (1,800, 540, or 90 micrograms a day by structural class), not from toxicity tests on the oil itself, unless a constituent group exceeds its threshold.
Moderate evidence: A screening threshold, which the paper itself describes as a trigger for more data, not a proof of safety. Industry-authored (FEMA).
Source: Smith 2005, Food and Chemical Toxicology Industry-funded Link to this fact
Laws and loopholes / Other evidence
A 2013 audit of FDA's own toxicology database found that 63.9% of the 3,941 chemicals allowed to be added directly to US food had no animal feeding study of any kind on file.
Moderate evidence: Counts studies in databases, not safety; authors are Pew-affiliated (Pew funded the work, not industry); route-based definition ignores study quality; data from 2012.
Source: Neltner et al. 2013, Reprod Toxicol, Reproductive Toxicology Link to this fact
Laws and loopholes / Other evidence
Only about 1 in 5 chemicals added directly to US food (21.6%) has an oral study of the type used to estimate a safe level of intake in FDA's database, and 6.7% have any reproductive or developmental toxicity data.
Moderate evidence.
Caveats
'Oral study' is defined by route only; 47% of FDA-graded oral studies fail FDA's core standards, so the share with adequate data is lower still. Absence of data is not evidence of harm.
Source: Neltner et al. 2013, Reprod Toxicol, Reproductive Toxicology Link to this fact
Laws and loopholes / Other evidence
Since 1997 companies can bring a new food chemical to market through a voluntary 'GRAS notice' to FDA; more than 60% of 191 chemicals notified this way had no published feeding study, even though the regulation says a GRAS decision must rest on published studies.
Moderate evidence: Published-literature database only; some notices cite unpublished company studies, which this count does not capture.
Source: Neltner et al. 2013, Reprod Toxicol, Reproductive Toxicology Link to this fact
Laws and loopholes / Other evidence
In a review of 327 FDA GRAS notices, just 1% assigned the chemical a 'Concern Level' (FDA's tool for deciding how much testing is needed), and only 37% reported reproductive toxicity results.
Moderate evidence: Text-search of notice documents for key terms; a notice could use different wording.
Source: Neltner et al. 2013, Reprod Toxicol, Reproductive Toxicology Link to this fact
Laws and loopholes / Other evidence
A 2013 review by Pew Charitable Trusts staff matched 28 of the 35 suggestions FDA's own 1970s-80s expert committee (SCOGS) made for testing food chemicals to concerns that scientists raised at 2011 workshops, whose organizers had not read the SCOGS report.
Moderate evidence: Authors' own judgment of what counts as a match and as 'unresolved'; Pew-funded and co-convened the workshops; no independent rater; shows process gaps, not harm from any chemical.
Source: Maffini 2013, Comprehensive Reviews in Food Science and Food Safety Link to this fact
Laws and loopholes / Other evidence
In 1995 FDA exempted food-contact chemicals expected to be below 0.5 parts per billion in the diet from additive regulation (unless a carcinogen is suspected) and asks only for genotoxicity tests up to 50 ppb; the Pew review says the 0.5 ppb value came from cancer potency data and does not consider hormonal or behavioral effects.
Moderate evidence.
Caveats
FDA and TTC authors argue a cancer-based threshold covers other endpoints; the review's position is the critics'. Applies to food-contact substances, not to food flavors or fragrance.
Source: Maffini 2013, Comprehensive Reviews in Food Science and Food Safety Link to this fact
Laws and loopholes / Other evidence
The Canadian Human Rights Commission's 2019 information sheet says a reaction to much lower levels of chemicals or perfumes than the average person tolerates "is a medical condition. It is a recognized disability."
Moderate evidence: Agency position stated without citation or test; a two-page information sheet, not a ruling. Says 'allergies or environmental sensitivity', never 'multiple chemical sensitivity'.
Source: [[src-2019-chrc-environmental-sensitivity-scent-free-policies|CHRC 2019]] Link to this fact
Laws and loopholes / Other evidence
For environmental sensitivities, the CHRC says making facilities 'accessible and safe' means reducing chemical use, having a scent-free policy, buying less toxic products, and notifying people before construction or maintenance work.
Moderate evidence: Recommended measures from the regulator; the sheet cites no outcome evidence that they work.
Source: [[src-2019-chrc-environmental-sensitivity-scent-free-policies|CHRC 2019]] Link to this fact
Laws and loopholes / Other evidence
CTV wrote: "The underlying problem is that there is no government agency that is assigned to help people with environmental sensitivities get housing free from chemicals."
Moderate evidence: A journalist's statement without a cited source; not checked against program inventories. Attribute to CTV. Death by MAiD is the article's subject; add 988 line in published use.
Source: CTV News, April 2022 (via Smoke-Free Housing BC; redacted copy), CTV News (news article) Link to this fact
Laws and loopholes / Government agency
The CHRC describes environmental sensitivity as an umbrella term that includes allergies, asthma, and disabilities such as multiple chemical sensitivity, ME/CFS and fibromyalgia.
Moderate evidence: Agency framing, not a diagnostic definition; MCS appears as one example.
Source: CHRC 2026 web Link to this fact
Laws and loopholes / Other evidence
The authors say two obstacles stall control of developmental neurotoxicity: large gaps in testing chemicals for it, and the very high level of proof demanded before regulation, so few chemicals have been regulated on these grounds.
Moderate evidence: Authors' policy argument; both are long-standing advocates of precautionary regulation.
Source: Grandjean & Landrigan 2014, Lancet Neurology, The Lancet Neurology Link to this fact
Laws and loopholes / Other evidence
Grandjean and Landrigan propose three reforms: legally mandated testing of existing chemicals and pesticides, legally mandated premarket evaluation of new chemicals with precautionary methods, and an international neurotoxicity clearinghouse modeled on IARC that would not require absolute proof of toxicity.
Moderate evidence: A proposal, not an adopted policy; the clearinghouse was a recommendation in 2014.
Source: Grandjean & Landrigan 2014, Lancet Neurology, The Lancet Neurology Link to this fact
Information, not medical advice. See also: myths we won’t tell you.