Final Report on the Safety Assessment of Cocamidopropyl Betaine

Abstract

Cocamidopropyl Betaine (CAPB) is a zwitterionic ammonium compound that is used primarily as an amphoteric surfactant in shampoos, conditioners, and other cleaning preparations. The oral LD50 of full-strength CAPB was 4.91 g/kg in mice and 7.45 ml/kg in rats. In a 28-day short-term study, CAPB treatment-induced lesions were produced in the nonglandular portion of the stomach in the high-dose group but not in the low-dose group. A test concentration of 4.5% active CAPB produced slight conjunctival irritation in unrinsed eyes and very slight conjunctival irritation in rinsed eyes. CAPB solutions with 7.5 and 10% activity were not irritating to intact or abraded rabbit skin. When a 15% active solution was tested under occlusive patches for 24 h, well-defined erythema and edema were observed. No evidence of delayed contact hypersensitivity was found in guinea pigs topically administered solutions of 10% active CAPB. No irritation or sensitization was reported in human studies when 3.0% active CAPB was tested. CAPB was nonmutagenic in four different assay systems. The number of pulmonary adenomas, hepatic hemangiomas, and malignant lymphomas found in mice administered a nonoxidative hair dye formulation containing 0.01% active CAPB for 20 months was similar to the number found in controls. Due to the irritation potential of CAPB, it is concluded that the maximum activity of CAPB used in leave-on cosmetic formulations should not exceed 3.0%. The limitation is expressed as a 10% v/v dilution of a commercial sample that has an activity of 30%. The use of CAPB in rinse-off products is considered to be safe as currently applied.