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 / Other evidence
The FTC stated that for 'the vast majority of OTC homeopathic drugs' there are 'no valid studies using current scientific methods showing the product's efficacy,' so therapeutic claims for them 'lack a reasonable basis and are likely misleading.'
Moderate evidence: A regulator's characterization of the evidence; no trials are cited or reviewed in the statement itself.
Source: FTC 2016 OTC homeopathic enforcement policy statement, Federal Register 81(239):90122-90123 Link to this fact
The industry / Other evidence
The FTC says homeopathic marketers should not undercut a 'no scientific evidence' disclosure with testimonials or other positive efficacy statements, and that the disclosure should sit next to, or be built into, the efficacy claim.
Moderate evidence: Guidance on how the FTC will review ads; it does not itself set penalties.
Source: FTC 2016 OTC homeopathic enforcement policy statement, Federal Register 81(239):90122-90123 Link to this fact
Laws and loopholes / Review of other studies
A 2015 CMAJ editorial (Flegel & Martin, CMAJ 187:1187, DOI 10.1503/cmaj.151097) states hospital environments free from artificial scents 'should become a uniform policy, promoting the safety of patients, staff and visitors alike'; the US CDC's own workplace policy separately says fragrance 'is not appropriate for a professional work environment' (CDC wording still unverified against a primary CDC source).
Moderate evidence.
Caveats
CMAJ quote now verified against the primary editorial, now in our evidence base (src-2015-artificial-scents-no-place-hospitals): exact wording is 'should become a uniform policy' (ASEQ-EHAQ's paraphrase drops the article 'a', not a substantive misquote). The editorial is opinion/commentary, not a study — its own cited prevalence numbers (30% scent sensitivity, 27% of asthmatics worsened) are the same Caress & Steinemann survey figures used elsewhere in our evidence base. CDC portion remains unverified; the CMAJ editorial itself never mentions the CDC.
Source: ASEQ-EHAQ 2020 (quoting CMAJ 2015 and CDC) Link to this fact
Laws and loopholes / Review of other studies
As of 2015, no Canadian hospital accreditation standard required a scent-free policy, and it was not policy in all Canadian hospitals.
Moderate evidence: The editorial's own 2015 assessment; the policy landscape may have shifted since — see Roy 2026 for a later, focus-group-based assessment of implementation gaps.
Source: Flegel & Martin 2015, CMAJ (Canadian Medical Association Journal) Link to this fact
Laws and loopholes / Review of other studies
Only 15.9% of 63 reviewed fragrance-free policies included formal staff training, and only 22.2% specified a review or evaluation cycle, despite 74.6% naming a responsible authority and 95.2% stating a rationale for the policy.
Moderate evidence.
Caveats
Gray-literature document review; the gap between naming an authority and specifying monitoring is a feature of the published text, not a direct measurement of institutional follow-through.
Laws and loopholes / Government agency
In a 1993 letter of findings, the US Department of Justice determined that a public entity is not required to prohibit employees from wearing perfume or other scented products, because that would not be a "reasonable" modification to personnel policy under ADA title II.
Moderate evidence.
Caveats
A technical-assistance letter states DOJ's own enforcement position; it is not a regulation or court ruling and does not bind courts. Addresses title II public access only, not title I employment accommodation.
Source: DOJ Civil Rights Division 1993 (TAL 383) Link to this fact
Laws and loopholes / Government agency
The same 1993 DOJ letter states that failing to adopt any access policy for individuals with environmental illness does not itself violate title II of the ADA, and that nothing in the ADA or its legislative history shows Congress meant to require public entities to regulate employees' use of scented products.
Moderate evidence: DOJ's own stated position at the time; not a court ruling, and DOJ explicitly declined to decide whether environmental illness meets the ADA's disability definition.
Source: DOJ Civil Rights Division 1993 (TAL 383) 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 / Other evidence
Under FDA policy a flavor's GRAS status applies only to the designated use (its function in food, the food categories, and the use levels), not to the substance itself, so a flavor judged GRAS as a flavoring is not GRAS for a different use such as sweetening.
Moderate evidence: Industry-authored summary of FDA policy, which it quotes at length; enforcement is described as selective (FDA often comments only on the technical effect).
Source: Hallagan 2020, Food and Chemical Toxicology Industry-funded Link to this fact
Laws and loopholes / Other evidence
Before 2016 the FTC had 'rarely challenged' misleading claims for homeopathic products, and FDA's 1988 Compliance Policy Guide let marketers sell OTC homeopathic products without demonstrating efficacy.
Moderate evidence: The FTC's own description of its enforcement history and of the FDA policy; not independently counted.
Source: FTC 2016 OTC homeopathic enforcement policy statement, Federal Register 81(239):90122-90123 Link to this fact
Laws and loopholes / Other evidence
FDA's homeopathic enforcement policy is nonbinding and risk-based: many unapproved homeopathic products fall outside its six priority categories, so they stay on shelves although they lack approval.
Moderate evidence: FDA also states any illegally marketed product is subject to enforcement at any time; 'tolerated' is an inference from priority-setting.
Source: FDA 2022 Homeopathic Drug Products guidance 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 / Government agency
The CHRC lists implementing and enforcing a scent-free policy, using least-toxic scent-free products, and notifying workers and clients before construction or maintenance as part of keeping facilities accessible and safe for people with environmental sensitivities.
Moderate evidence: Guidance wording, not a statute; the page gives no outcome evidence that these measures work.
Source: CHRC 2026 web Link to this fact
What you can do / Review of other studies
Occupational lung specialists treating irritable larynx syndrome recommend a 'low-scent' workplace policy or respiratory protection to limit exposure to triggers.
Moderate evidence: Clinical recommendation, not tested as an intervention.
What you can do / Review of other studies
When relying on a workplace, clinic, or school's fragrance-free policy, check whether it (1) defines what's covered beyond perfume, especially cleaning and laundry products, (2) sets a default fragrance-free expectation rather than a complaint-triggered one, (3) controls what cleaning/laundry products the institution buys, and (4) names a real consequence for non-compliance — a 2026 scoping review of 63 such policies found these structural features present in well under half of cases.
Moderate evidence: Based on a gray-literature document review of North American policies; individual policies may vary, and having these features on paper does not guarantee enforcement.
What you can do / Government agency
After a 1993 ADA complaint over municipal-employee perfume use, San Francisco voluntarily adopted a policy requiring public meeting notices to ask attendees to refrain from wearing perfume or other scented products, to let people with environmental illness or multiple chemical sensitivity attend.
Moderate evidence: One city's voluntary accommodation, reported secondhand in DOJ's own letter; not evidence the policy was enforced or effective, and not a legal requirement.
Source: DOJ Civil Rights Division 1993 (TAL 383) Link to this fact
What you can do / Self-reported survey
65.5% of autistic adults would support a fragrance-free workplace policy and 77.2% would prefer fragrance-free health care facilities and professionals, compared with 46.1% and 45.8% support among non-autistic adults.
Moderate evidence: Stated preference, not an intervention study; self-report survey.
Source: Steinemann 2018, Air Quality, Atmosphere & Health Link to this fact
What you can do / Other evidence
The FTC says 'has not been evaluated by the Food and Drug Administration' or 'based on traditional homeopathic theory' alone does not adequately warn shoppers that a homeopathic product's claims lack scientific support, and perfunctory disclaimers are unlikely to work.
Moderate evidence: The Commission's judgment about consumer perception; it cites no consumer survey and instead advises marketers to run their own.
Source: FTC 2016 OTC homeopathic enforcement policy statement, Federal Register 81(239):90122-90123 Link to this fact
Information, not medical advice. See also: myths we won’t tell you.