Ingredients with a documented concern, from official datasets and our reviewed database.
surfactant · foaming agent
Severity 6/10EditorialSensitive skin: Best avoidedDry skin: Best avoidedBabies & kids: Use with cautionEczema-prone: Best avoided
- Irritation:The reference irritant used in dermatology research; strips barrier lipids.
Caredermis curated dermatological review
A powerful foaming cleanser so reliably irritating that dermatology studies use it as the standard positive control for skin irritation. Fine for many in rinse-off use, but a poor match for dry, sensitive or eczema-prone 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 cautionDry skin: High cautionBabies & kids: Use with cautionEczema-prone: High caution
- Irritation:Drying and defatting to the skin barrier.
Rubbing alcohol; used as a solvent in some products and drying to skin in meaningful concentrations.
Pregnancy: Use with caution
- Irritation:Occasional irritation/allergy.
- Environmental impact:Highly toxic to aquatic organisms; banned in EU cosmetics since 2022 as a reprotoxic CMR.
The classic dandruff active banned in EU cosmetics in 2022 (reproductive-toxicity classification) but still standard in US shampoos.
preservative · solvent · fragrance
Severity 3/10Sensitive skin: Use with cautionEczema-prone: Use with caution
- Allergy risk:One of the 26 EU-declarable fragrance allergens.
- Irritation:Mild irritation possible at higher concentrations.
A preservative and fragrance component that must be declared on EU labels because it can trigger contact allergy in a small share of users.
Oily & acne-prone: Use with caution
- Pore-clogging:Cosmetic grade is minimally comedogenic despite its reputation.
Highly refined mineral oil is an inert, non-sensitizing emollient. Its bad reputation comes from industrial-grade oils that are never permitted in cosmetics.
- Environmental impact:Not biodegradable; accumulates in the environment via wash-off.
The workhorse silicone — inert and non-sensitizing on skin (even FDA-approved as a skin protectant), with persistence in the environment as its main criticism.
- Irritation:Can cause transient, non-allergic flushing/stinging on reactive skin.
A food-grade preservative generally regarded as one of the gentler options; occasional non-immune stinging is its main drawback.
hydrochloric acidRegulatory dataIrritationEU CLP Skin Corr. 1A