Irritation from surfactants in detergents is a rather frequent reaction in the use of cosmetics and sensitisation to the product is also possible. Cocamidopropyl betaine in the Italian standard (Società Italiana di Dermatologia Allergologica, Professionale e Ambientale [SIDAPA]) gave five positive reactions among 105 patients in a scientific test (1).

Other studies have shown allergies, but to a lesser extent (2).

The Cosmetic Ingredient Review expert group concluded in 2012 that this chemical compound did not present any significant toxicity and was therefore safe for use as a cosmetic ingredient (3).

References____________________________________________________

(1) Corazza M, Lauriola MM, Bianchi A, Zappaterra M, Virgili A. Irritant and sensitizing potential of eight surfactants commonly used in skin cleansers: an evaluation of 105 patients. Dermatitis. 2010 Sep-Oct;21(5):262-8. 

(2) Mertens S, Gilissen L, Goossens A. Allergic contact dermatitis caused by cocamide diethanolamine. Contact Dermatitis. 2016 Jul;75(1):20-4. doi: 10.1111/cod.12580.

(3) Burnett CL, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler D, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Andersen FA. Final report of the Cosmetic Ingredient Review Expert Panel on the safety assessment of cocamidopropyl betaine (CAPB). Int J Toxicol. 2012 Jul-Aug;31(4 Suppl):77S-111S. doi: 10.1177/1091581812447202.