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.
What you can do / Test-chamber measurement
More fiber sticks in a reed diffuser sharply raise the chemicals it releases: modeling showed one stick could raise the indoor chemical level roughly 9- to 11-fold, and two sticks roughly 19- to 24-fold, compared to the bottle alone.
Moderate evidence: Modeled from one product's fitted transport parameters; relative multiplier, not an absolute health-relevant dose.
Source: Zhang 2024, Cell Reports Physical Science Link to this fact
What you can do / Measured in people or real products
In this 1996 sample, 3 of 73 deodorants labeled "not perfumed" genuinely contained none of the 21 fragrance substances tested, on chemical analysis.
Moderate evidence: Very small sample (n=3) from one country/year snapshot; does not establish that "not perfumed"/"fragrance-free" labels are reliable in general or in other markets/years.
Source: Rastogi et al. 1998, Contact Dermatitis Link to this fact
What you can do / Measured in people or real products
Because hormone-disrupting chemicals cluster by product type, cleaners, synthetic detergents, fabric softeners, air fresheners, and deodorants are the household product categories where checking for isothiazolinone preservatives (such as benzisothiazolinone) and fragrance chemicals (such as hexyl cinnamaldehyde, geraniol, and citronellol) is likely to be most worthwhile.
Moderate evidence: Reflects which chemicals are most often listed in this product database, not which products emit the most or pose the greatest measured exposure.
Source: Lee & Ji 2022, Ecotoxicology and Environmental Safety Link to this fact
What you can do / Government agency
HUD's own 1991-92 guidance gives two concrete examples of reasonable accommodation for chemically sensitive tenants: (1) a tenant sensitive to pesticides can ask for advance notice before the building is fumigated and for boric acid to be substituted for the chemicals normally used; (2) an applicant sensitive to carpet chemicals can ask the housing provider what type of carpeting is used throughout the building before deciding whether to rent.
Moderate evidence.
Caveats
These are HUD's own worked examples from internal guidance, not a binding regulation with a fixed list of required accommodations; HUD explicitly says reasonableness depends on the individual's circumstances and is bounded by undue financial/administrative burden.
Source: HUD guidance (1991) Link to this fact
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 / Government agency
A resident of HUD-assisted housing with a documented chemical sensitivity can cite this HUD exhibit directly when requesting advance notice before common-area cleaning and nonchemical cleaning products where practical, since HUD's own guidance names these as accommodations that are not an undue burden.
Moderate evidence.
Caveats
Applies specifically to HUD-assisted (Section 504-covered) multifamily housing; the same specific accommodations are not guaranteed at privately owned housing covered only by the Fair Housing Act, where the undue-burden analysis is done case by case.
Source: HUD Occupancy Handbook 4350.3 REV-1, Exhibit 2-6 (2007) Link to this fact
What you can do / Government agency
People who want to minimize systemic absorption of chemical UV filters while the additional toxicology studies FDA has requested remain outstanding can choose mineral-only sunscreens with zinc oxide or titanium dioxide as the active ingredient, the two filters FDA's own review has found 'generally recognized as safe and effective,' or rely on protective clothing and shade alongside sunscreen.
Moderate evidence.
Caveats
This is not a claim that chemical-filter sunscreens are unsafe, and it is not advice to avoid sun protection; the paper explicitly says its results do not indicate people should refrain from sunscreen use.
Source: Matta 2019, JAMA Link to this fact
What you can do / Other evidence
Hairdressers, salon workers, and professional or domestic cleaners can reduce workplace asthma risk with ventilation, gloves, and lower-irritancy products or application methods where available, since this population-based cohort found both hairdressing and cleaning occupations, and reactive cleaning/disinfecting chemical exposure specifically, associated with higher adult-asthma risk.
Moderate evidence.
Caveats
The study cannot identify which specific chemicals within 'hairdressing' or 'cleaning/disinfecting' exposure are responsible, so this is general occupational-hygiene advice, not a product-specific recommendation.
What you can do / Review of other studies
Whether an odor affects mood or physiology depends more on how pleasant a person finds it and what they expect it to do than on which specific plant or chemical produced it; hedonic (liking) ratings predicted physiological and psychological outcomes across most of the 18 studies reviewed.
Moderate evidence: Narrative synthesis across 18 heterogeneous studies using different odors, doses and measures; not a meta-analysis.
Source: Herz 2009, International Journal of Neuroscience Industry-funded Link to this fact
What you can do / Other evidence
Ozone-generating 'air purifiers' can turn the scent chemicals in air fresheners and cleaners into fine particles; the authors advise avoiding indoor ozone sources and cutting back on terpene-heavy scented products, especially on high-ozone summer days.
Moderate evidence: The advice is the authors' inference from chamber results; no health outcome was measured and ozone levels were set by a generator, above typical outdoor-to-indoor ozone.
Source: Sarwar 2004, Journal of the Air & Waste Management Association Link to this fact
What you can do / Other evidence
Obstetric and gynecologic bodies (FIGO 2015, RCOG 2013) advise that pregnant women be told the sources of chemical exposure and how to reduce them, as a precaution despite uncertain evidence; in a French survey, 54.3% of 300 women had never heard of endocrine disruptors.
Moderate evidence: Advice is precautionary and says causal evidence is lacking; the review does not test whether avoidance improves birth outcomes.
Source: Street 2020, International Journal of Molecular Sciences Link to this fact
What you can do / Other evidence
The industry panel warned that cetrimonium bromide and palmitoyl carnitine can enhance skin penetration of other chemicals (phenylazoaniline, benzocaine, benzoic acid), so products combining them with ingredients whose safety depends on low absorption need careful formulation.
Moderate evidence.
Caveats
Penetration enhancement shown in artificial membranes (enhanced below 0.5%, inhibited above 1.0%); no human product data. CIR is financed by the Personal Care Products Council, the cosmetics industry trade association.
Source: Becker et al. 2012 (CIR), Int J Toxicol, International Journal of Toxicology Industry-funded Link to this fact
What you can do / Other evidence
CTV reported that the Environmental Health Association of Québec (ASEQ-EHAQ), after the woman's death, launched a national campaign and fundraiser to get housing for people with MCS across Canada, and its president advocates a national program to build chemical-free homes.
Moderate evidence: Advocacy group's own account as relayed by CTV; the group is not independent of the cause. Article subject is a death by MAiD; 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
What you can do / Other evidence
OSHA recommends scheduling cleaning or maintenance work when other occupants are absent and limiting the amount and location of chemicals used near workers.
Moderate evidence: Advisory administrative controls; no evidence of effectiveness given.
Source: OSHA 3430-04, 2011 Link to this fact
Children and pregnancy / Measured in people or real products
In the same 2018 NGO test, a children's shampoo had 24 unlabeled chemicals flagged for health hazards (17 on the fragrance-industry list), and a baby shampoo had 6.
Weak evidence: Counts, not amounts; single samples; not peer reviewed; not a risk ranking.
Source: BCPP 2018 Link to this fact
Children and pregnancy / Government agency
In animal studies, a pregnant female's exposure to an endocrine-disrupting chemical can affect not only her offspring but her offspring's offspring, because developmental exposure can alter reproductive-cell programming that carries across generations.
Weak evidence: Evidence for these transgenerational effects comes from animal studies cited in the report; no multigenerational human dataset is cited for this specific claim.
Source: WHO/UNEP 2012 Link to this fact
Children and pregnancy / Other evidence
A 2020 review states that endocrine-disrupting chemicals found in the placenta (pesticides, personal care product chemicals, flame retardants, BPA, PCBs) could be associated with fetal growth restriction, thyroid dysfunction, and neurological disorders, but the mechanisms are largely unknown.
Weak evidence: Association stated through a single cited review; mechanisms rest largely on animal and small human studies; not a demonstrated causal risk.
Source: Street 2020, International Journal of Molecular Sciences Link to this fact
Children and pregnancy / Other evidence
In the same Korean first-trimester cohort, triclosan, benzophenone-3 and methyl-, ethyl-, propyl- and butylparaben (personal-care-product chemicals) were not associated with TSH or with the oxidative-stress markers MDA and 8-OHdG.
Weak evidence: A null from one small cohort with one spot urine per woman; it does not show safety, and it contradicts earlier cohorts the authors cite (propylparaben, BPS).
Source: Kim 2025, Environmental Analysis Health and Toxicology Link to this fact
Children and pregnancy / Other evidence
The authors write that oxidative stress mediates EDC effects on thyroid function, but their data show no such link: none of the three TSH-associated chemicals was associated with MDA or 8-OHdG, and no mediation analysis was run.
Weak evidence: Absence of association in one underpowered cohort is not evidence against a ROS pathway either; the point is that the paper did not test it.
Source: Kim 2025, Environmental Analysis Health and Toxicology Link to this fact
Children and pregnancy / Other evidence
In the ECHO cohorts, prenatal paraben and benzophenone levels showed stronger associations with eczema in girls than boys (girls: parabens OR 1.21, 1.04-1.42; benzophenones 1.18, 1.00-1.38; bisphenol S 1.21, 1.03-1.43), a pattern the authors call consistent across chemicals.
Weak evidence: Stratified estimates with no correction for multiple tests and no interaction p reported for the eczema comparisons in the main text; subgroup finding.
Source: Miller 2025 (ECHO), Environment International Link to this fact
Children and pregnancy / Other evidence
The positive estimates for the pregnancy chemical mixture came mainly from the Cincinnati HOME cohort, which had higher exposure levels (behavior symptom index about 5 points higher per quartile, CI -1.6 to 11.6), while the Canadian MIREC cohort showed essentially none (-0.06, CI -1.65 to 1.52).
Weak evidence: Small HOME subsample (n=139), wide CIs including zero, results as reported in the text rather than checked in the supplement.
Source: Puvvula 2026, Environ Int, Environment International Link to this fact
Children and pregnancy / Review of other studies
The review treats thyroid disruption by endocrine-disrupting chemicals in early pregnancy as a route to fetal neurodevelopmental harm, but it presents no test of that chain and does not cite the Norwegian MoBa analysis in which maternal thyroid hormones did not mediate the DEHP and child ADHD association (indirect OR 1.00).
Weak evidence.
Caveats
Engel 2018 used one mid-pregnancy sample, total hormones, no thyroid antibodies and one outcome, so it does not rule out a thyroid route; the review's chain is plausible but untested.
Children and pregnancy / Other evidence
A 2026 systematic review of 127 studies called the link between early-life exposure to endocrine-disrupting chemicals (phthalates, BPA, pesticides, PBDEs) and ADHD 'consistent', but it did no meta-analysis, gave no effect sizes or per-chemical grades, and says causality is not established.
Weak evidence: Ungraded wording; the EPA systematic review grades phthalate-ADHD/behavior evidence slight or indeterminate for most pairs; Table 1 details do not all match the primaries.
Source: Wu 2026, Biological Psychiatry Global Open Science Link to this fact
Fragrance is everywhere / Measured in people or real products
Pine-scent chemicals were also common in Korean household products: alpha-pinene from 19% and beta-myrcene from 12%.
Weak evidence: Headspace presence only; high detection threshold.
Source: Kwon 2007, Journal of Hazardous Materials 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 / Self-reported survey
Among Atlanta-area adults who reported chemical hypersensitivity, symptom onset was reported before age 20 in about a third of cases (32.4%), suggesting hypersensitivity is not exclusively an adult-onset condition.
Weak evidence.
Caveats
Retrospective self-report of childhood/adolescent onset in adults; no pediatric clinical verification; age-of-onset table has an internal mismatch with the running text for the older age brackets (see the page's Notes).
Source: Caress & Steinemann 2003 (EHP), Environmental Health Perspectives Link to this fact
Fragrance is everywhere / Other evidence
Flavor chemicals are added to foods at ppm levels and are largely volatile, with up to 80% lost on heating for some; the authors say most are simple chemicals also found naturally in food, but this does not address exposure from non-food sources.
Weak evidence.
Caveats
Industry description with a cited loss figure of 'as much as 80%' for some volatiles; no exposure data for non-food uses. 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
Fragrance is everywhere / Other evidence
After spraying a car air freshener, benzene and several other aromatic VOCs measured in the cabin went down by an average of about 40% for benzene (except in recirculation mode) while limonene went up, so the product masks rather than removes the car's own chemicals.
Weak evidence: The sprays contained no benzene; the drop was transient, came with no unsprayed control, and the authors' masking/displacement explanation was not tested.
Source: Lee 2024, Science of The Total Environment Link to this fact
Green, natural and unscented / Lab study (cells or chemistry)
A cold-atmospheric-plasma prototype device killed over 90% of two underarm-odor bacteria (Staphylococcus hominis 99.81%, Corynebacterium xerosis 90.99%) after 3 minutes of exposure in lab culture, and cut total electronic-nose sensor response to two major axillary-odor chemicals by about 51% (HMHA) and 34% (3M3SH) after 5 minutes, without applying antimicrobial chemicals or fragrance to skin.
Weak evidence.
Caveats
Antibacterial test used agar-cultured bacteria; deodorizing test used excised porcine skin dosed with pure synthetic odor compounds in methanol, not human sweat. Single lab, single prototype, no independent replication, no human skin testing.
Source: Bok et al. 2024, Scientific Reports Link to this fact
Green, natural and unscented / Test-chamber measurement
The limonene given off by a natural fragrant plant is the same chemical as the limonene in cleaners and air fresheners; in this study three plants took room limonene to about 60-84 ug/m3 on average over 3 hours, in the range of a plug-in air freshener and well below the 1,000-6,000 ug/m3 seen right after terpene cleaning in a chamber.
Weak evidence: Cross-study comparison of different averaging times and rooms; the 'after' means are back-calculated from the dose table; plug-in and cleaning values come from other studies.
Health effects / Hypothesis
Silent Spring Institute researchers name house cleaners and nurses as priority jobs for cutting exposure to fragrance, cleaning, and personal-care chemicals linked to breast cancer in lab and animal studies.
Weak evidence: No exposure or cancer data in these workers.
Source: Knox 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Health effects / Review of other studies
Many everyday chemicals, including some released by scented and cleaning products, act on the same irritant-sensor nerves in the nose and airways (TRPA1 and TRPV1), one reason very different products can cause similar symptoms.
Weak evidence: Mechanism largely from lab/animal studies; dose relevance to homes untested.
Source: Molot 2023, Neuroscience and Biobehavioral Reviews Link to this fact
Health effects / Animal study
In animal and lab studies, common scent chemicals such as linalool, limonene, and eugenol act on brain signaling systems; what lifelong low-level exposure does in healthy people has never been studied.
Weak evidence: Mostly high-dose animal/in-vitro pharmacology; often protective effects in disease models.
Source: Pinkas 2017, Environmental Research Link to this fact
Health effects / Other evidence
California state scientists estimate that cosmetics may account for at least 4% (and plausibly much more, given wide uncertainty) of the PFOA-related chemicals measured in San Francisco Bay Area wastewater.
Weak evidence.
Caveats
The comparison spans a very wide range (roughly 4% to several hundred percent of the median measured loading) because of unreliable use-concentration inputs; this is an environmental-loading estimate, not a personal health-exposure estimate.
Source: Balan 2024, Environmental Science & Technology Link to this fact
Health effects / Review of other studies
Estimated prevalence of multiple chemical sensitivity across the reviewed epidemiological literature ranges from about 1% to more than 15% of the population, a spread the review attributes to diagnostic difficulty, lack of standardized case-definition criteria, and differing recognition of the condition across countries.
Weak evidence.
Caveats
Secondhand synthesis of several distinct primary studies with different case definitions and populations, not a single standardized measurement; the review does not report the underlying studies' individual case definitions in enough detail to weight the range.
Source: Rossi 2018, Journal of Occupational & Environmental Medicine Link to this fact
Health effects / Review of other studies
A cohort of laborers acutely exposed to gasoline vapors above allowed limits during an underground tunnel-excavation job later developed symptoms similar to those reported in multiple chemical sensitivity, and the study authors argued the workers' sociocultural profile made simple psychosomatic suggestibility an unlikely sole explanation.
Weak evidence.
Caveats
Cited secondhand from Davidoff et al. (primary study not yet in our evidence base); occupational cohort with no independent control for pre-existing chemical sensitivity, and "unlikely to be suggestible" is the original authors' qualitative judgment, not a tested exclusion of a psychological contribution.
Source: Rossi 2018, Journal of Occupational & Environmental Medicine Link to this fact
Health effects / Review of other studies
Some solvents can theoretically sensitize the heart muscle to the body's own adrenaline-type hormones, raising a theoretical risk of arrhythmia or cardiac arrest under chemical exposure in people with multiple chemical sensitivity.
Weak evidence.
Caveats
Cited from a toxicology reference textbook (Olson, Acute Intoxications, Poisons, Pharmaceutical Substances and Drugs), not from any MCS-specific study; the review's own authors state this risk "has not been detected in any epidemiological study so far." Mechanistic/theoretical only.
Source: Rossi 2018, Journal of Occupational & Environmental Medicine Link to this fact
Health effects / Review of other studies
A review of MCS mechanism studies describes hyperosmia (heightened smell sensitivity from a lowered odor-detection threshold) as common in multiple chemical sensitivity, and cites a small brain-imaging study where MCS patients showed stronger brain responses than healthy controls specifically at odor-recognition-threshold and normal-perceived odor levels.
Weak evidence.
Caveats
Secondhand summary of a single small study (Azuma et al. 2016, 12 patients/7 controls) not independently read or verified in this evidence base; runs counter to other reviews' claim that MCS patients have normal odor thresholds.
Source: Palmieri et al. 2020, Reviews on Environmental Health Link to this fact
Health effects / Review of other studies
Small studies cited in this review report MCS patients have lower catalase and glutathione S-transferase (GST) enzyme activity than healthy controls, potentially impairing detoxification of chemical substances.
Weak evidence: Secondhand from a single research group's studies (De Luca et al.), not independently verified; enzyme-activity differences do not establish that they cause MCS symptoms.
Source: Palmieri et al. 2020, Reviews on Environmental Health Link to this fact
Health effects / Review of other studies
A review proposes that TRPV1 and TRPA1, chemical-sensing nerve receptors in the nose, airway, and elsewhere, become upregulated and sensitized (a lower threshold and bigger response to normally tolerated triggers) in both neurodegenerative disease and multiple chemical sensitivity, following long-term exposure to air pollution, oxidative stress, and inflammation.
Weak evidence.
Caveats
Narrative, not systematic review; mechanism is a synthesis of others' receptor biology, oxidative-stress, and imaging studies, not new experimental data; shares its primary capsaicin-challenge evidence base with Molot 2023 (a single small, unreplicated Gothenburg research lineage).
Source: Molot 2022, Reviews on Environmental Health Link to this fact
Health effects / Review of other studies
People with multiple chemical sensitivity do not show the brain-mass loss or olfactory-nerve damage seen in neurodegenerative diseases such as Alzheimer's or Parkinson's; instead, brain-imaging studies find altered processing of odors without evidence of nerve damage, while trigeminal-nerve sensitization is the feature specific to MCS.
Weak evidence.
Caveats
Based on a qualitative present/absent/unknown comparison table (the review's Table 2) built by the authors, not a quantitative meta-analysis; no inter-rater or per-cell sourcing detail given.
Source: Molot 2022, Reviews on Environmental Health Link to this fact
Health effects / Review of other studies
A clinical allergist's practice review proposes that idiopathic environmental intolerance (IEI, formerly multiple chemical sensitivity) commonly involves a genetic anxiety/panic-disorder predisposition and a classically conditioned pairing of specific odors with physiologic sympathetic arousal, citing IEI patients' panic-like responses to sodium lactate infusion and CO2 inhalation challenges and an elevated frequency of a panic-disorder-associated cholecystokinin B receptor allele in a pilot study.
Weak evidence.
Caveats
Built almost entirely on the same author's own small, largely unreplicated 1990s-2000s pilot studies from one Toronto clinic; the paper does not cite or engage the TRPV1/TRPA1 capsaicin-cough-hypersensitivity evidence for a peripheral biological mechanism.
Source: Binkley 2023, Journal of Allergy and Clinical Immunology: In Practice Industry-funded Link to this fact
Health effects / Measured in people or real products
In a small genetic study of 6 people with multiple chemical sensitivity and 5 controls, every single MCS patient carried at least one rare, homozygous variant in a gene from the SLC "solute carrier" transporter family, compared to only 1 of 5 controls.
Weak evidence.
Caveats
Single unreplicated pilot cohort (n=11 total); at least 8 uncorrected statistical comparisons across four gene groups; no odds ratios or effect sizes reported for any variant; no independent replication cohort tested.
Source: Alcorta & Gomez-Diaz 2025, International Journal of Molecular Sciences Link to this fact
Health effects / Self-reported survey
In this Atlanta sample, women were reported as chemically hypersensitive at roughly 1.75 times the rate of men (about 15.7% of women vs 8.95% of men, wiki arithmetic from the paper's cross-tabulation), a smaller sex skew than the same authors' national survey found (F:M about 4.0).
Weak evidence.
Caveats
Our arithmetic, not stated by the authors; the primary brief gives sample counts of 926 women / 600 men and 71.7/28.3% sensitive, which implies roughly 15.3% vs 9.3% (F:M about 1.6), not the 905/592 denominators behind 1.75; single regional self-report survey.
Source: Caress & Steinemann 2003 (EHP), Environmental Health Perspectives Link to this fact
Health effects / Measured in people or real products
In the same chamber study, particles formed when the citrus fragrance chemical d-limonene reacted with ozone tended to shift that same heart-rhythm marker in the opposite direction from candle smoke, at particle levels similar to everyday cleaning or air-freshener use.
Weak evidence.
Caveats
This tendency was not statistically significant on its own versus clean air (HF -7.2%, p=0.41); only its difference from candle smoke's opposite-direction change reached significance (p=0.02, 12-subject paired comparison). Not replicated.
Source: Hagerman et al. 2014, Atmospheric Environment Link to this fact
Health effects / Hypothesis
A 2019 minireview proposes that frequent, long-term burning of scented candles in poorly ventilated rooms may increase bladder cancer risk, based on chemicals in candle emissions (PAHs, benzo[a]pyrene, formaldehyde, phthalates) that are separately linked to bladder cancer via occupational and other non-candle exposure routes.
Weak evidence.
Caveats
No case-control, cohort, or biomonitoring study has ever tested candle use against bladder cancer; the authors' own conclusion calls for that study to be done. This is a narrative minireview with no original data.
Source: Adamowicz 2019, Cancer Prevention Research Link to this fact
Health effects / Other evidence
In two of three reported chemical-intolerance case studies, QEESI Chemical Intolerance and Symptoms scores fell substantially after a home intervention that reduced fragrance and other VOC sources (Case 1: 80→43 and 63→23; Case 3: 74→54 and 59→23, each on a 0-100 scale).
Weak evidence.
Caveats
Open-label, no control group or blinding, cases selected for notable improvement (not representative of the full 37-patient cohort), and symptom change could reflect counseling/expectation effects rather than VOC reduction specifically.
Source: Rincón et al. 2024, Primary Health Care Research & Development Link to this fact
Health effects / Review of other studies
In one study, (R)-(-) and (S)-(+) linalool at concentrations below participants' own detection threshold — undetectable, not perceived as different — produced opposite heart-rate and mood changes, the one result in Herz's 18-study review that offers direct evidence for a chemical (pharmacological) rather than a learned-association mechanism.
Weak evidence.
Caveats
Single study, not independently replicated; per the Kuroda primary the heart-rate difference is significant versus water but the mood difference is significant only between the two forms, not versus water; 7 analyzed subjects; undetectability checked by questionnaire only. Herz's overall conclusion still favors the psychological account for the other 17 studies.
Source: Kuroda et al. 2005, via Herz 2009, International Journal of Neuroscience Industry-funded Link to this fact
Health effects / Review of other studies
A 2004 review in the Journal of Applied Toxicology proposed, as a hypothesis, that parabens in underarm and body care products might contribute to breast cancer, and stated that no causal link is proven.
Weak evidence: Narrative review with no new data; the question is the title; the second author's lab supplies much of the paraben data.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Health effects / Review of other studies
Breast cancer researchers reviewing the evidence in 2004 said the link between paraben-containing body care products and breast cancer needed rigorous testing, because tumor detection, cell tests, and rodent studies cannot show human causation.
Weak evidence: Authors' own framing; the review lists Bradford-Hill criteria as a plan, not as applied.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Health effects / Review of other studies
Two studies on underarm products and breast cancer disagreed in 2002-2003: one with 813 cases and 793 controls found no association with antiperspirant use, the other, of 437 women already diagnosed, linked heavier use to earlier diagnosis.
Weak evidence: Both secondhand; the second had no cancer-free comparison and measured age at diagnosis, not risk; neither tested parabens.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Health effects / Hypothesis
A 2004 review noted that breast tumors are disproportionately found in the upper outer quadrant and left breast and suggested, conditionally, that underarm product use might explain it, with no data presented.
Weak evidence: Conditional suggestion ("if this cannot be explained by … anatomical differences"); not tested in the review.
Source: [[src-2004-endocrine-disrupters-estrogenic-chemicals-body-care-cosmetics|Harvey & Darbre 2004]], Journal of Applied Toxicology Link to this fact
Health effects / Other evidence
A few patients reported breathing-related symptoms during the chamber tests, including two who rose 2-10-fold in respiratory symptom score after the control chemical geraniol as well as HICC; these symptoms did not match any measured change in the lungs.
Weak evidence: Two people drive the group-level result; the control geraniol is itself a fragrance allergen; self-reported scores.
Source: Schnuch 2010, British Journal of Dermatology Link to this fact
Health effects / Other evidence
A 2020 narrative review of the human literature reports that prenatal studies of whether endocrine-disrupting chemicals lower birth weight or shorten pregnancy give mixed results; for BPA, one meta-analysis found no significant link and another review saw differences of only about 100-200 g, possibly not clinically relevant.
Weak evidence: Narrative review, not systematic; no quality appraisal; authors' selection of studies; BPA only is quantified.
Source: Street 2020, International Journal of Molecular Sciences Link to this fact
Health effects / Other evidence
EWG's 2006 report said its biomonitoring program ('toxome') found 455 industrial chemicals in the blood, urine, or breast milk of more than 100 individuals, including babies in the womb.
Weak evidence: Advocacy-group summary with no sample description, methods or per-chemical data in this document; not population-representative as presented, and detection is not harm.
Source: EWG 2006 Annual Report, EWG annual report (PDF) Link to this fact
Health effects / Other evidence
Maltol and furaneol, common sweet flavor chemicals, damage DNA in laboratory dishes by binding iron or copper and producing hydroxyl radicals; the flavor panel says they did not cause cancer in rodents at doses at least 10,000 times food intake.
Weak evidence: In vitro mechanism plus industry-summarized rodent studies; no human data; says nothing about inhaled or skin exposure to the same chemicals in perfumes.
Source: Smith et al. 2009 (FEMA Expert Panel), GRAS Flavoring Substances 24, Food Technology 63(6), Food Technology Industry-funded Link to this fact
Health effects / Review of other studies
EWG identified 12 chemicals in the tested fragrances with published lab evidence of hormone activity (11 of 12 estrogenic), an average of four per product.
Weak evidence.
Caveats
Evidence is mostly cell-culture and animal studies; the report itself says human data at current exposures are scarce; no dose or exposure assessment; EWG is an advocacy organization.
Source: Sarantis et al. 2010 (Not So Sexy, Canadian edition) Link to this fact
Health effects / Measured in people or real products
Of the 530 VOCs emitted, 193 appear on California DTSC's Candidate Chemicals List or the EU's ECHA hazard inventory (42 DTSC, 191 ECHA, 40 on both), including neurotoxicants, carcinogens, and reproductive toxicants.
Weak evidence.
Caveats
EWG-authored (advocacy nonprofit that ranks cleaners and licenses EWG VERIFIED to cleaner makers); Skyline Foundation grant; unblinded; List membership is hazard, not risk; ECHA entries include company self-classifications; no dose or health outcome measured.
Health effects / Review of other studies
EWG said that about 53 percent of the cleaning products it assessed contain ingredients known to harm the lungs and about 22 percent contain chemicals reported to cause asthma to develop.
Weak evidence: Hazard flags from databases on an unspecified product set, not exposure or effect measures from product use; denominators and databases not named.
Source: EWG press release, Sept. 10, 2012, EWG press release (web page) Link to this fact
Health effects / Other evidence
EWG said 1,4-dioxane, a suspected human carcinogen, is a common contaminant of widely used detergent chemicals, and chloroform can escape in fumes from chlorine bleach products.
Weak evidence: Advocacy-group statements with no measurements on this page; 1,4-dioxane is a by-product that does not appear on labels.
Source: EWG press release, Sept. 10, 2012, EWG press release (web page) Link to this fact
Information, not medical advice. See also: myths we won’t tell you.