Cocamidopropyl betaine, also known as CAPB, is a surfactant (cleanser) commonly used in personal care products. It is produced by reacting palm or coconut fatty acids with a chemical called Dimethylaminopropylamine (DMAPA), and usually appears as a pale yellow thick liquid with a bland odour. Cocamidopropyl betaine has been associated with contact hypersensitivity for people with atopic dermatitis (AD) and it was named 2004 'Allergen of the Year' by the American Contact Dermatitis Society.

Though CAPB itself was initially considered the cause of allergic reactions, more recent studies have suggested the allergic response is to traces of 3,3-dimethylaminopropylamine (DMAPA) and several fatty acid amidopropyl dimethylamines. These impurities are produced during the manufacturing process of CAPB and, if production standards are not high, may not be completely filtered out from the final solution. For a small percentage of people, topical application of 3,3-dimethylaminopropylamine (DMAPA) has been linked to allergic responses and/or skin irritation. Higher grades of CAPB, containing no impurities, have been linked to fewer allergic responses.

Research generally encourages people with atopic dermatitis to avoid the use of skincare products containing CAPB, as its properties can exacerbate the breakdown of the skin barrier. Though it is considered a mild surfactant, trace impurities in CAPB have the potential to provoke an allergic response in some people, which is why we choose to leave it out of our products.

Other names: C₁₉H₃₈N₂O₃, CAPB, CADG, Cocamidopropyl Dimethyl Glycine, Cocoyl Amide Propylbetaine; Quaternary Ammonium Compounds, (Carboxymethyl)(3-Cocoamidopropyl)Dimethyl, Hydroxides, Inner Salts

REFERENCES

Shaughnessy, C. N., Malajian, D., & Belsito, D. V. (2014). Cutaneous delayed-type hypersensitivity in patients with atopic dermatitis: reactivity to surfactants. Journal of the American Academy of Dermatology, 70(4), 704–708. https://doi.org/10.1016/j.jaad.2013.12.009

Jacob, Sharon E.; Amini, Sadegh Cocamidopropyl Betaine, Dermatitis: May-June 2008 - Volume 19 - Issue 3 - p 157-160 doi: 10.2310/6620.2008.06043

Burnett, C. L., Boyer, I., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D. C., Marks, J. G., Jr, Shank, R. C., Slaga, T. J., Snyder, P. W., Gill, L. J., & Heldreth, B. (2019). Safety Assessment of Fatty Acid Amidopropyl Dimethylamines as Used in Cosmetics. International journal of toxicology, 38(1_suppl), 39S–69S. https://doi.org/10.1177/1091581819836089