The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of 11 alkyl betaines as used in cosmetics. These ingredients are reported to function as hair and skin conditioning agents, antistatic agents, surfactants-cleansing agents, and viscosity-increasing agents in cosmetic products. Although there are data gaps, the shared chemical core structure, similar functions and concentrations of use in cosmetics, and the expected similarities in physicochemical properties enabled grouping these ingredients and reading across the available toxicological data to support the safety assessment of each individual compound in the entire group. The Panel concluded alkyl betaines were safe as cosmetic ingredients in the present practices of use and concentration, when formulated to be nonirritating.
Keywords: alkyl betaines; cosmetics; safety.