Shampooing usage fréquent — ingredient safety report

• Irritation:The reference irritant used in dermatology research; strips barrier lipids.

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.

• Allergy risk:Fragrance is the single most common cause of cosmetic contact allergy.
• Irritation:Frequent trigger of stinging and redness on reactive skin.

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.

• 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.

• Allergy risk:EU-declarable allergen; lemon-scented sensitizer.

The lemon-scent molecule in lemongrass and citrus oils, a recognized contact allergen requiring EU label declaration.

• 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.

• 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.