Ingredients with a documented concern, from official datasets and our reviewed database.
surfactant · foaming agent
Sensitive 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: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
Sensitive 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; oxidation products are potent sensitizers.
The citrus-peel scent molecule. Like linalool, it becomes allergenic mainly after oxidizing in opened products.
Sensitive skin: Use with cautionEczema-prone: High caution
- Allergy risk:EU-declarable allergen; oxidized linalool is a common patch-test positive.
A floral scent molecule found in lavender and many essential oils. It oxidizes on air exposure into strongly sensitizing compounds, which is why it must be declared on EU labels.
Sensitive skin: Use with cautionEczema-prone: High caution
- Allergy risk:EU-declarable allergen; use concentrations limited by industry standards.
A synthetic lily-of-the-valley scent and well-documented contact allergen.
Sensitive skin: Use with cautionEczema-prone: High caution
- Allergy risk:American Contact Dermatitis Society Allergen of the Year 2018.
- Irritation:Can irritate compromised skin at higher concentrations.
A workhorse humectant and penetration enhancer that is fine for most, but a recurring culprit in eczema patients' patch tests.
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.
Sensitive skin: Use with caution
- Allergy risk:EU-declarable fragrance allergen.
A common jasmine-scented ingredient in fine fragrance and skincare, declared as an allergen on EU labels.
preservative · solvent · fragrance
Sensitive 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.
- Irritation:Occasional transient stinging or redness on sensitive skin.
A mild food-grade preservative usually paired with sodium benzoate; well tolerated by most skin types.
- 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
