Ingredients with a documented concern, from official datasets and our reviewed database.
Sensitive skin: High cautionPregnancy: Use with cautionBabies & kids: Use with cautionEczema-prone: Best avoided
- Cancer concern:Releases small amounts of formaldehyde (IARC Group 1).
- Allergy risk:Recognized contact allergen, often cross-reacting with other releasers.
A widely used formaldehyde-releasing preservative. Releases less formaldehyde than DMDM hydantoin but still triggers allergy in formaldehyde-sensitized people.
Sensitive skin: Best avoidedPregnancy: Use with cautionBabies & kids: Best avoidedEczema-prone: Best avoided
- Allergy risk:Fragrance is the single most common cause of cosmetic contact allergy.
- Irritation:Frequent trigger of stinging and redness on reactive skin.
Caredermis curated dermatological review
An umbrella term that can hide dozens of undisclosed scent chemicals. Fragrance is the leading cause of allergic contact dermatitis from cosmetics, and dermatologists routinely advise fragrance-free products for eczema, babies and sensitive skin.
Sensitive skin: Best avoidedPregnancy: Use with cautionBabies & kids: Best avoidedEczema-prone: Best avoided
- Allergy risk:Potent sensitizer, typically blended with MIT (Kathon CG).
- Irritation:Corrosive in concentrate; irritating at use levels.
Caredermis curated dermatological review
The chlorinated partner of MIT, restricted in the EU to rinse-off products only. A leading cause of preservative contact dermatitis worldwide.
Sensitive skin: Best avoidedPregnancy: Use with cautionBabies & kids: Best avoidedEczema-prone: Best avoided
- Allergy risk:Caused an epidemic of contact allergy; banned in EU leave-on products.
- Irritation:Irritating even in people without allergy.
A preservative behind one of the largest contact-allergy epidemics in cosmetic history. The EU banned it from leave-on products and restricts it in rinse-off products to 15 ppm.
surfactant · foaming agent
Severity 4/10EditorialSensitive skin: High cautionDry skin: Use with cautionBabies & kids: Use with cautionEczema-prone: High caution
- Irritation:Milder than SLS but still drying for compromised skin.
The gentler cousin of SLS used in most mainstream shampoos and washes. Its manufacturing can leave trace 1,4-dioxane, which reputable makers strip out — an issue of quality control rather than the ingredient itself.
Sensitive skin: Use with cautionEczema-prone: High caution
- Allergy risk:EU-declarable allergen related to cinnamal.
A sweet balsamic scent chemical and recognized contact allergen on the EU declaration list.
Sensitive skin: Use with cautionEczema-prone: High caution
- Allergy risk:EU-declarable allergen; clove-scented sensitizer.
The clove scent molecule, a long-established contact allergen on the EU declaration list.
surfactant · foam booster
Severity 6/10Sensitive skin: Use with cautionPregnancy: Use with cautionEczema-prone: Use with caution
- Cancer concern:IARC Group 2B (possibly carcinogenic); listed under California Prop 65.
- Allergy risk:Recognized contact allergen in rinse-off products.
A foam booster classified as possibly carcinogenic by IARC and largely phased out of reputable formulas since its 2012 Prop 65 listing.
Sensitive skin: Use with cautionEczema-prone: Use with caution
- Allergy risk:Named Allergen of the Year 2004; impurities (amidoamine) drive most reactions.
A mild coconut-derived surfactant in countless 'gentle' cleansers. Most allergy is caused by manufacturing impurities, so quality varies by brand.
- Allergy risk:Rare hypersensitivity reactions, better documented in food than cosmetics.
Tartrazine yellow dye; approved for cosmetics with rare sensitivity reactions reported.
- Allergy risk:Rare reports of sensitivity.
A widely approved blue dye with a benign cosmetic safety record.
Eugenia Caryophyllus OilRegulatory dataAllergy riskEU CosIng Annex III (declarable / restricted)CI 16185Regulatory dataAllergy riskEU CosIng Annex III (declarable / restricted)