cocamidopropylbetaïne

Cocamidopropyl betaine, commonly abbreviated CAPB, is a zwitterionic amphoteric surfactant derived from coconut oil. In cosmetic formulations it functions as a mild cleansing and foaming agent and is widely used in shampoos, body washes, facial cleansers, and many other personal care products. CAPB is valued for its compatibility with other surfactants and its ability to boost foam while reducing irritation from harsher detergents.

Production and composition

CAPB is produced from coconut oil–derived fatty acids through a sequence that typically involves forming a cocamidopropyl amide with dimethylaminopropylamine, followed by reaction with a chloracetic acid derivative to yield the betaine. The resulting compound is water-soluble and acts as an amphoteric surfactant, meaning it can behave as anionic or cationic depending on the pH and formulation.

Uses and functional role

In formulations, CAPB acts as a surfactant and foam booster, improving cleansing while contributing to a milder feel on skin and hair. It is commonly combined with anionic surfactants to balance foam, viscosity, and irritation potential. Beyond cleansing, CAPB can contribute conditioning properties in some products.

Safety and regulatory notes

CAPB is generally considered mild, but some individuals may experience irritation or allergic contact dermatitis, particularly if impurities such as dimethylaminopropylamine (DMAPA) are present. High-purity CAPB and strict manufacturing controls are used to minimize such risks. Regulatory labeling and quality testing requirements vary by region. Environmentally, CAPB is reported to be readily biodegradable with relatively low acute aquatic toxicity when formulated and used as directed.

Overall, cocamidopropyl betaine is a common, versatile surfactant in modern personal care products, valued for its cleansing performance and relative mildness, with safety dependent on product quality and individual sensitivities.