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.
Skin allergy / Other evidence
Among people sent for patch testing, quaternium-15 caused a positive reaction in about 9% in North American centers (7.1-9.6%) but about 1% in Europe (0.6-1.9%); the other formaldehyde releasers scored roughly 1-4%.
Moderate evidence.
Caveats
These are referred patients with suspected dermatitis, not the general public; US studies mostly used a 2% test concentration vs 1% in Europe; a review of heterogeneous series with adjusted means.
Skin allergy / Other evidence
Whether a positive patch test to a formaldehyde releaser matters in daily life is poorly documented: only 8 of 33 cited studies reported relevance, the figures ranged from 7% to 90%, and none named the causative products.
Moderate evidence: Narrative review of mostly 1990s-2000s series; 'possible relevance' categories may overstate real cases.
Skin allergy / Review of other studies
The preservative methylisothiazolinone (MI) was allowed alone in cosmetics from 2005 at up to 100 ppm, more than 25 times the roughly 3.75 ppm it could reach when it was only a quarter of the MCI/MI mixture; by 2006-2010 about 1.5% of patch-tested patients in Denmark, Finland, and Germany were allergic to it.
Moderate evidence.
Caveats
Rates are for patients referred for patch testing, not the general population; patch-test concentrations differed fourfold across the studies; narrative review, and the regulatory change and the rise in allergy are an association, not shown causal here.
Source: Lundov 2011, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
In a small repeated-application test, 7 of 11 patients already allergic to MI (64%) reacted to a cream with 50 ppm MI, half the legal cosmetic maximum, and 2 of 11 (18%) reacted at 5 ppm.
Moderate evidence: Eleven already-sensitized patients; the second ROAT disagreed (vehicle may explain it); this shows elicitation in the allergic, not that 50 ppm induces allergy in others.
Source: Lundov 2011, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
Household detergents and cleaners were preserved with MI far more often than cosmetics in two European surveys: 16 of 97 Swedish detergents (16.5%) against 1 of 204 cosmetics, and 30 of 291 Italian cleaning products (10.3%).
Moderate evidence: Secondary summary of ingredient-label surveys from about 2009-2010; counts are small and not recent.
Source: Lundov 2011, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
In a Spanish series of 7,838 patch-tested patients (six hospitals, 2005-2009), 1.72% were allergic to formaldehyde and 2.66% to formaldehyde or at least one of seven formaldehyde-releasing preservatives.
Moderate evidence.
Caveats
Referred dermatitis patients, not the general population; formaldehyde was tested at 1% aq., lower than the 2% later recommended, so true rates are probably higher; single country, retrospective.
Skin allergy / Other evidence
The three most common releaser allergies in that Spanish series were imidazolidinyl urea (1.05%), quaternium-15 (0.88%) and diazolidinyl urea (0.79%); these preservatives are used in cosmetics.
Moderate evidence.
Caveats
Imidazolidinyl and diazolidinyl urea were tested in only 3,900 of 7,838 patients; the other releasers in smaller selected groups, so rates are not directly comparable. Cosmetic exposure is the authors' inference; no product data.
Skin allergy / Other evidence
About one in three Spanish patients allergic to formaldehyde or a releaser (74 of 209) reacted only to releasers, not to formaldehyde itself, so a formaldehyde test alone would have missed them.
Moderate evidence: A negative formaldehyde patch test at 1% can be a false negative; the authors could not exclude that for some of these patients.
Skin allergy / Other evidence
Spanish patients allergic only to formaldehyde more often had work-related dermatitis (25%) and hand involvement (31.7%), while releaser-only allergy more often involved the face (31.3%) and legs (24.6%), with work-relatedness 9.5%.
Moderate evidence: Descriptive comparison of small groups with overlapping confidence intervals for some cells; exposure routes (cleaning products vs cosmetics) are the authors' interpretation.
Skin allergy / Other evidence
Among Spanish patients allergic to quaternium-15, about half (35 of 69, 50.7%) also reacted to formaldehyde, versus 19% for diazolidinyl urea (6 of 31) and 29% for imidazolidinyl urea (12 of 41).
Moderate evidence: Single series; counts for DMDM hydantoin, Grotan BK, methenamine and bronopol were 10 or fewer and too small to conclude from.
Skin allergy / Measured in people or real products
At a US referral clinic, about 1 in 3 people (219 of 671, 32.6%) suspected of clothing dermatitis had an allergic patch-test reaction to at least one of 42 textile dyes and finishing resins.
Moderate evidence: Single tertiary center, retrospective, patients preselected for suspected textile allergy; 44.7% of positives were faint macular erythema only; earlier series found 1.9-18%.
Skin allergy / Measured in people or real products
The commonest textile allergens in the Mayo series were two disperse blue dyes (106 at 8.3%, 124 at 8.0%) and the wrinkle-resistance resin melamine formaldehyde (8.0%), followed by urea formaldehyde (6.4%).
Moderate evidence: Referral population, not a prevalence; commercial test preparations whose purity was not checked.
Skin allergy / Measured in people or real products
The old shortcut of testing only p-phenylenediamine (PPD) caught just 5.8% of patients, far below the 32.6% found with a full 42-item textile series.
Moderate evidence.
Caveats
Different denominators (620 vs 671) and one allergen vs 42, so a detection-yield comparison, not a formal sensitivity; Lazarov 2004 and Lisi 2014 independently call PPD a poor textile marker.
Skin allergy / Other evidence
Dyes used on polyester, acetate, and nylon clothing (disperse dyes) are not chemically bound to the fiber, so they can rub or wash onto skin; they are not used on cotton, wool, or linen.
Moderate evidence: Review statement citing industry and textbook sources; says nothing about how much transfers in real wear.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Other evidence
In clinic patients tested for eczema, about 1 to 2% reacted to the textile dyes Disperse Blue 106 (1.9%), Blue 124 (1.7%) and Orange 3 (1.2%), pooled over 12 to 14 studies of 20,000 to 35,000 patients each.
Moderate evidence: Narrative pooling of clinic populations, not general-population rates; test dyes were rarely checked for purity, and dermatologists referred the patients.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Other evidence
Among patients suspected of clothing dermatitis, 10 to 17% reacted to the same dyes in pooled aimed testing (Blue 106 16.7%, Blue 124 15.5%, Orange 3 10.6%).
Moderate evidence: Selected patients; pooling of heterogeneous studies; the dyes in the patients' own garments were seldom confirmed.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Other evidence
Reported clinical relevance of disperse dye patch-test reactions was 75 to 100% in aimed studies and 42 to 78% in screening studies, but it was mostly judged by the rash clearing after dark synthetic clothing was stopped, and chemical analysis of garments rarely found the dye the patient reacted to.
Moderate evidence: Authors say relevance may be overestimated; garment analyses are few (latest 2000, plus Malmo 3 of 121 items), so neither side is well measured.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Other evidence
Commercial patch-test dye preparations were sometimes impure or wrong: Malmo work found raw dye material with 39 to 76% contaminants, and some products labeled Disperse Orange 3 did not contain it.
Moderate evidence: Same Malmo group as the review authors; a few preparations in one period, not all manufacturers.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Other evidence
Children react to disperse dyes too: North American data found 2.1% of children vs 2.4% of adults positive to Blue 106, and a meta-analysis found only Blue 124 above 1% in children.
Moderate evidence: Referred children only, small studies; rates varied 0.3% to 4.0% across studies.
Source: Malinauskiene 2013, Contact Dermatitis Link to this fact
Skin allergy / Measured in people or real products
In a Danish university patch-test clinic, allergy to the preservative methylisothiazolinone (MI) rose from 2.0% of tested patients in 2010 to 3.7% in 2012 (trend p = 0.03), after hovering around 1.1-1.7% in 2006-2009.
Moderate evidence: Single center, patients referred for suspected contact dermatitis (not the general population); retrospective; no confirmation of weak positives.
Skin allergy / Measured in people or real products
About 6 in 10 MI-allergic patients with an identified source were exposed through a cosmetic product (32 of 52, 61.5%); paint was the second source (13 of 52, 25%).
Moderate evidence: Relevance was judged by the clinic from products patients brought in; 52 of 82 MI-positive patients had an identified source. Single center.
Skin allergy / Measured in people or real products
Allergy to MI is not just a by-product of the older MCI/MI mix: about half of MI-allergic patients (49%) did not react to MCI/MI, while 76% of MCI/MI-allergic patients also reacted to MI (up from 37% in 2006-2009).
Moderate evidence: Single-clinic patch-test data; cross-reactivity pattern, not proof of which exposure sensitized each patient.
Skin allergy / Other evidence
In a Danish cohort retested 15 years apart (403 people, age about 14 then 28-30), none of the 11 teenagers who reacted to fragrance mix I on a patch test reacted again as adults; by comparison 24 of 31 (77%) nickel reactions persisted.
Moderate evidence.
Caveats
One cohort, one screening mix, 11 people; 36.7% of invited adults were patch tested; a lost patch-test reaction does not prove the allergy is gone (irritant or false-positive reactions in 1995 were not excluded; reformulation or less exposure are alternative explanations).
Source: Mortz 2013, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
Among 442 Danish adults aged 28-30, only 0.7% tested positive to fragrance mix I, although 33.0% (293/889) said perfumed products had given them eczema.
Moderate evidence.
Caveats
Self-report is lifetime recall of any eczema from perfumed products; the patch panel was the narrow TRUE Test (no FM II, no own products, no day-7 reading), so the gap partly reflects test sensitivity and irritant reactions.
Source: Mortz 2013, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
In an unselected Danish cohort followed from age 14 to 28-30, new contact allergies appeared in 13.4% (46/343) of those negative at baseline over 15 years, and prevalence of any contact allergy rose from 15.2% to 20.1%.
Moderate evidence.
Caveats
TRUE Test panels only; participation 36.7%, with atopic dermatitis and hand eczema over-represented among those tested; no day-7 reading (about 10% underestimate according to the authors). Nickel, not fragrance, drove most of it.
Source: Mortz 2013, British Journal of Dermatology Link to this fact
Skin allergy / Other evidence
In an Italian series of 277 people with confirmed clothing (textile) dermatitis, 58.3% had a true skin allergy and the rest an irritant reaction; about 8 in 10 of the allergic were allergic to textile dyes, and Disperse Blue 124 alone was positive in 54.5%.
Moderate evidence.
Caveats
Referral case series of patients who already had textile dermatitis, so these are shares among affected people, not how common clothing allergy is; only strong (++/+++) patch reactions counted; Disperse Blue 106/124 test preparations can contain impurities, which may inflate the figures.
Skin allergy / Other evidence
At the Mayo Clinic, 8.8% of 8,448 patients patch tested to benzalkonium chloride (BAK), a disinfectant and preservative, in 2000-2012 had a positive reaction, up from 5.5% in 1998-2000, and only 1.3% were called irritant.
Moderate evidence.
Caveats
Single referral center; patients were already suspected of contact dermatitis; more than half of positives were the mildest grade (macular erythema), relevance was history-based, and the authors' own cited NACDG data rate BAK as prone to false-positive irritant reactions. Rates rose between the first and later periods, then plateaued (8.3% vs 8.8% not significant).
Skin allergy / Other evidence
About one third of the positive BAK patch-test reactions at the Mayo Clinic (33-39% across periods) were judged clinically relevant to a product the patient used; most of the rest were only 'questionably relevant' (56-63%).
Moderate evidence.
Caveats
Relevance rests on exposure history and was assigned at the final reading, before any avoidance; no repeat open application test is reported for the cohort, so 'relevant' does not prove allergy.
Skin allergy / Other evidence
In a Boston patch-test clinic, 32% of 615 dermatitis patients reacted to benzalkonium chloride (BAK), a preservative and disinfectant, and about 1 in 10 (10%) reacted strongly; the authors say weak reactions may be irritation rather than allergy.
Moderate evidence.
Caveats
Single tertiary referral clinic of patients already suspected of contact allergy; counts any + reaction as positive; authors' own positivity ratio and reaction index flag likely false positives; no irritant-versus-allergy test (no dilution series or repeat open application test).
Skin allergy / Other evidence
In a 27-year series from one Belgian referral clinic, 118 of 16,065 patch-tested patients (0.7%) had allergic contact dermatitis from eye drops or ointments or their ingredients, mostly on the eyelids.
Moderate evidence: Single tertiary referral center, retrospective; patients were referred for suspected allergy, so this is not the rate among eye-drop users.
Skin allergy / Other evidence
About 3 in 10 positive reactions (54 of 183, 29.5%) were to non-active ingredients of eye medicines, mainly wool alcohols, thiomersal and benzalkonium chloride, so the preservative, or base can be the allergen rather than the drug.
Moderate evidence: One referral clinic; excipients were tested less systematically than drugs, and some patients reacted to both.
Skin allergy / Other evidence
Allergy to one aminoglycoside antibiotic eye drop (tobramycin, neomycin, gentamicin) often comes with reactions to others in the family: 15 of 27 tobramycin-allergic and 10 of 19 neomycin-allergic patients also reacted to another aminoglycoside.
Moderate evidence: Patch-test cross-reactions at one clinic; positive patch tests do not always mean clinical reactions to the other drug.
Skin allergy / Other evidence
The American Contact Dermatitis Society has named an annual Allergen of the Year since 2000; the 2000-2020 list is disperse blue dyes, gold, thimerosal, bacitracin, cocamidopropyl betaine, glucocorticoids, p-phenylenediamine, fragrance (2007), nickel, mixed dialkyl thioureas, neomycin, dimethyl fumarate, acrylates, methylisothiazolinone (2013), benzophenones, formaldehyde (2015), cobalt, alkyl glucosides, propylene glycol (2018), parabens and isobornyl acrylate (2020).
Moderate evidence.
Caveats
Single narrative review reproducing the Society's own list; selection reflects professional judgment (new exposures, testing problems, even 'nonallergens'), not a prevalence ranking.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
US dermatologists' society review: fragrance was the 2007 Allergen of the Year; the industry's RIFM database lists more than 2,800 fragrance ingredients, at least 100 of them known allergens, and fragrance allergens can be hidden in cleaning and cosmetic products, even ones marketed as fragrance free.
Moderate evidence: Narrative review relaying other papers' statements; no original data and no counts of products.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
In North American Contact Dermatitis Group patch testing for 2015-2016, nickel was still the most common positive allergen at 17.5%, and women had about 4 times the relative risk of men for nickel dermatitis.
Moderate evidence: Secondary relay of NACDG referral-clinic data, not general-population prevalence.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
Neomycin contact sensitization in North American patch-test clinics peaked at 13.1% in 1996-1998 and was 7% in 2015-2016, still the seventh most common positive patch test.
Moderate evidence: Referral-clinic patients; secondary relay; the two periods are separate cross-sections.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
Isobornyl acrylate, the 2020 Allergen of the Year, has caused allergy from adhesive glucose monitoring sensors (such as FreeStyle Libre) and insulin pumps since 1995, and routine screening with other acrylates may miss it.
Moderate evidence: Based on case reports; no prevalence given; the Dexcom 'isobornyl acrylate-free' remark rests on one cited study.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
The Society also names 'Nonallergens of the Year': thimerosal (2002), because only 16.8% of its frequent positive patch tests (10.9% of 4,087 patients in 1996-1998) were relevant, and parabens (2019), which it calls one of the least allergenic preservatives.
Moderate evidence: Skin-allergy label only; says nothing about endocrine or other health endpoints for parabens.
Source: Militello 2020, Dermatologic Clinics Link to this fact
Skin allergy / Other evidence
In a Melbourne skin clinic, allergy to benzalkonium chloride (BAK), a preservative and disinfectant in eye drops, antiseptics, wipes, and sanitizers, was rare (0.4% of 7,390 patch-tested patients had a clinically relevant reaction) but rose about tenfold in 2017-2019 compared with 2003-2016.
Moderate evidence.
Caveats
One referral clinic, not the general population; some positives may be irritant rather than allergic (positivity ratio 92, reaction index 0.2); cause of the rise unexplained; test material supplier found no abnormality but this is relayed.
Skin allergy / Other evidence
Among patients whose BAK allergy was judged relevant, the most common sources were eye drops (31%) and topical antiseptics (27%), followed by cosmetics, disinfectant solutions, hand sanitizers, hand washes, a plaster-of-Paris cast, and a laundry rinse.
Moderate evidence: Only 26 cases; sources identified from products patients brought in, so exposures may be undercounted.
Skin allergy / Other evidence
In a Bangkok patch-test clinic, 17% of dermatitis patients (175 of 1,032) reacted to at least one of four standard fragrance allergens (two fragrance mixes, balsam of Peru, HICC).
Moderate evidence: Single hospital, referred patients with suspected contact allergy, 2012-2019; not a general-population rate and only four markers were tested.
Skin allergy / Other evidence
Among patients who tested positive to fragrance allergens, 57.7% had a product exposure that fit their rash, versus 19.8% of patients allergic to other things.
Moderate evidence: Relevance was judged by clinicians (history, own-product tests, label checks); the Discussion gives 59.9% for the same figure; single center.
Skin allergy / Other evidence
Fragrance allergy was more common in older patients, in people with eczema lasting over a year, and in those with rashes on the arms and legs rather than the face.
Moderate evidence: Retrospective single-center; the age effect rests on only 2 positive patients under 20, and the metal-allergy link is borderline (P = .05).
Skin allergy / Other evidence
The fragrance-mix tests overlap only partly: most fragrance-positive patients reacted to just one of the four, so a single negative marker does not rule out fragrance allergy.
Moderate evidence: Single Thai clinic; patterns may differ by region and period, as the authors note.
Skin allergy / Review of other studies
Aluminum skin allergy is uncommon in adults but not rare in children: in a Swedish clinic series, 0.9% of 5,448 adults and 5.1% of 196 children patch-tested positive to aluminum salts, and a meta-analysis found 0.4% of adults and 5.6% of children.
Moderate evidence.
Caveats
Narrative review relaying Swedish and Danish clinic data from related groups; tested patients are dermatitis patients or children referred for suspected allergy, not the general population.
Source: Novack 2022, Cutis Link to this fact
Skin allergy / Review of other studies
Antiperspirants are the commonest consumer-product source of aluminum on skin; allergy shows up as a rash in the armpit (axillary-vault dermatitis), and aluminum-free antiperspirants are available.
Moderate evidence: Expert review statement without a cited prevalence for antiperspirant allergy; fragrance is a more common cause of armpit dermatitis and must be excluded.
Source: Novack 2022, Cutis Link to this fact
Skin allergy / Review of other studies
A small share of children develop persistent itchy lumps at the injection site after aluminum-containing vaccines (under 1% in large studies of up to about 76,000 children); about 77-95% of them test allergic to aluminum, and the lumps usually fade over a median of 18-49 months.
Moderate evidence: Relayed from two Swedish cohorts, one tied to a single manufacturer's vaccines; this is not a vaccine safety study.
Source: Novack 2022, Cutis Link to this fact
Skin allergy / Other evidence
In patch-tested patients, allergy to formaldehyde and its releasers was about 8% in North America against about 1.5-2.5% in Europe, and quaternium-15 alone was 7.7% in the US vs 0.7-1.7% in Europe.
Moderate evidence.
Caveats
Narrative review quoting different clinics, years and test preparations; patients referred for patch testing, not the general public. The authors attribute the gap to looser US cosmetic rules, which is interpretation.
Skin allergy / Other evidence
Formaldehyde-releasing preservatives (quaternium-15, DMDM hydantoin, diazolidinyl urea, imidazolidinyl urea, bronopol) can cause allergy through the formaldehyde they release or, for some, through their breakdown products, so a negative formaldehyde patch test does not rule out releaser allergy.
Moderate evidence: Narrative synthesis of cited studies; degradation-product mechanisms (2-bromoethanol, bromonitromethane) are reported from chemistry studies, not shown here.
Skin allergy / Review of other studies
Lanolin allergy mostly strikes people with chronic inflamed skin (leg ulcers and stasis dermatitis, eczema, anal or genital dermatitis) rather than people with healthy skin.
Moderate evidence: Narrative review of mostly referral-clinic data; mechanism (more exposure and barrier penetration) is proposed, not shown here.
Source: Johnson 2023, Cutis Link to this fact
Skin allergy / Other evidence
Among 43,691 North American patients patch-tested in 2001-2018, 3.3% reacted to lanolin; in a European general-population sample (3,119 people) only 0.4% did, so lanolin allergy is real but uncommon.
Moderate evidence: Secondary citation; referral-clinic patients are not the general public, and the two used different test preparations.
Source: Johnson 2023, Cutis Link to this fact
Skin allergy / Other evidence
When a patch test to lanolin is positive it is usually relevant: in North American data 83% to 87% of positives were judged a current cause of the patient's dermatitis.
Moderate evidence: Clinician-judged relevance in tertiary patch-test clinics; contested by Kligman, who called lanolin allergy a myth of over-testing.
Source: Johnson 2023, Cutis Link to this fact
Skin allergy / Review of other studies
Lanolin allergy is not wool allergy: true wool allergy probably does not exist, and wool mainly causes irritation, especially in people with eczema.
Moderate evidence: Narrative statement from a secondary source.
Source: Johnson 2023, Cutis Link to this fact
Skin allergy / Review of other studies
Case reports document allergic contact dermatitis from quaternary ammonium disinfectant and antiseptic ingredients (benzalkonium chloride, didecyldimethylammonium chloride, cetrimide, cetylpyridinium chloride, benzethonium chloride), from sources such as eye drops, hand sanitizers, disinfectant wipes, bandages, and a shoe-refresher spray; most were patch-test confirmed and cleared when the product was stopped.
Moderate evidence: Case reports only; no stated search method and no prevalence; it shows these reactions happen, not how often.
Source: Okeke 2023, Clinical, Cosmetic and Investigational Dermatology Link to this fact
Skin allergy / Review of other studies
Antiseptics and disinfectants are known skin irritants, especially when strong, used for long periods, under occlusion, or on damaged skin, and many can also cause true contact allergy that reviewers think is under-diagnosed.
Moderate evidence: Narrative, non-systematic PubMed review by two dermatologists; prevalence figures are relayed from older primaries.
Source: Lauriola 2025, Italian Journal of Dermatology and Venereology Link to this fact
Skin allergy / Other evidence
A rash after an antiseptic product is not always caused by the named antiseptic: in a Swiss study relayed by this review, benzoxonium chloride and lauramine oxide, not chlorhexidine, were the culprit allergens in a popular antiseptic, and fragrance or benzyl alcohol can also be responsible.
Moderate evidence: Relayed from case series; the review gives no numbers for these.
Source: Lauriola 2025, Italian Journal of Dermatology and Venereology Link to this fact
Skin allergy / Other evidence
Benzalkonium chloride, a cationic disinfectant and antiseptic ingredient, can cause both irritant and allergic contact dermatitis; the standard patch-test preparation is only 0.1% in water because higher concentrations irritate, and some authors think sensitization is likelier from disinfectant-strength use (above 1%) than from preservative use (0.01% or less).
Moderate evidence: Dose comparison is relayed from other authors (refs 34-35), not shown in this review; irritant-versus-allergy status of BAK patch tests is disputed.
Source: Lauriola 2025, Italian Journal of Dermatology and Venereology Link to this fact
Skin allergy / Other evidence
Povidone-iodine reactions are often due to the povidone carrier or to irritation rather than iodine; the review says iodine itself has not been shown to be the allergen in reactions to povidone-iodine, contrast media, or amiodarone.
Moderate evidence: Relayed reasoning from reviews; false-positive patch tests are also possible, so ROAT is advised.
Source: Lauriola 2025, Italian Journal of Dermatology and Venereology Link to this fact
Skin allergy / Measured in people or real products
Four EU-listed fragrance allergens (limonene, eugenol, lilial, benzyl salicylate) were missing from the label of at least one of the tested products, although EU rules require naming them above 0.001% in leave-on products.
Moderate evidence: Products were bought in the US and Canada, where this EU rule did not apply, so the omissions were lawful there; counts are 3, 2, 2 and 1 products.
Source: Sarantis et al. 2010 (Not So Sexy, Canadian edition) Link to this fact
Skin allergy / Other evidence
A 2012-13 Danish EPA screen of 31 mostly polyester garments (about 10 for children) found none of 23 allergenic disperse dyes, after a second LC-MS method showed eight first-pass Disperse Blue 124 and Yellow 49 hits were false positives.
Moderate evidence: Small, deliberately targeted sample from Danish shops; 31 garments and 23 dyes; the interfering compound was never identified; no certified garments tested.
Source: Danish EPA 2014, Survey of Chemical Substances in Consumer Products No. 129 Link to this fact
Information, not medical advice. See also: myths we won’t tell you.