Ingredients with a documented concern, from official datasets and our reviewed database.
Sensitive skin: High cautionPregnancy: Use with cautionBabies & kids: Best avoidedEczema-prone: Best avoided
- Cancer concern:Slowly releases formaldehyde, an IARC Group 1 carcinogen.
- Allergy risk:Frequent cause of preservative contact dermatitis.
A formaldehyde-releasing preservative used in creams, shampoos and wipes. The slow formaldehyde release preserves the product but exposes skin to a known carcinogen and allergen.
Sensitive skin: Use with cautionDry skin: High cautionPregnancy: Use with cautionBabies & kids: Best avoidedEczema-prone: High caution
- Irritation:Dryness and peeling at exfoliating concentrations (0.5–2%).
The pore-clearing BHA exfoliant. Not for young children (salicylate absorption), used cautiously in pregnancy at low leave-on concentrations, and drying for compromised barriers.
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; 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.
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
- Irritation:Irritating at higher concentrations or in leave-on products.
- Allergy risk:Occasional contact allergen.
A pH adjuster that is safe in itself but should not be combined with formaldehyde releasers or bronopol, which can convert it to nitrosamines.
- Environmental impact:Synthetic polymer counted as a microplastic under the EU restriction when in particle form.
A common film-forming polymer scrutinized under the EU's microplastics restriction; skin safety itself is well established.