Cocamidopropyl Betaine

Generally considered one of the milder surfactants, but CAPB was named 'Allergen of the Year' by the American Contact Dermatitis Society in 2004. Contact sensitisation is documented in 0.27–7.2% of dermatitis patients, with reactions often attributed to manufacturing impurities — primarily dimethylaminopropylamine (DMAPA) and sodium monochloroacetate residuals — rather than pure CAPB. At full concentration it can cause mild skin and eye irritation; at typical cosmetic use concentrations it is well tolerated by most. No EU CosIng Annex II or III restrictions apply. Individuals with known sensitisation or coconut allergy should patch test.

Limited pregnancy-specific data is available. Animal studies found developmental effects only at high doses (LOAEL 40–250 mg/kg depending on betaine type), far above typical cosmetic exposure. The CIR Expert Panel considers alkyl betaines safe when formulated to be non-irritating. Most sources consider topical use at standard cosmetic concentrations low risk during pregnancy, but due to limited human data, consulting a healthcare provider is advisable. (Sources: Motherfigure, CIR Safety Assessment.)