What is Cocamidopropyl hydroxysultaine?
Cocamidopropyl hydroxysultaine is used as a surfactant or co-surfactant (for cleansing properties and lather) in products such as shampoos, shampoo bars, body washes, and hand soaps. Often touted as "natural," cocamidopropyl hydroxysultaine is made by reacting sodium bisulfite and epichlorohydrin with fatty acids from coconut oil (mainly lauric acid). (Source, pg 23) The coconut oil is reacted first with dimethylaminopropylamine, an irritant that can remain in the finished product if not purified properly. EWG rates cocamidopropyl betaine, a similar chemical, with a 1-5 rating due to dimethylaminopropylamine contamination concerns. Cocamidropropyl hydroxysultaine carries the same risk, however EWG hasn't caught on.
Is Cocamidopropyl hydroxysultaine natural?
Cocamidopropyl hydroxysultaine is not a naturally-occurring compound. Part of cocamidopropyl hydroxysultaine is made from coconut oil and glycerin, however, the other half is made from dimethylaminopropylamine, sodium bisulfite and epichlorohydrin. Epichlorohydrin is an organochloride and probable carcinogen. (Source) Sodium bisulfite is an irritant and mutagen. (Source)
Is Cocamidopropyl hydroxysultaine toxic?
Cocamidopropyl hydroxysultaine, the finished and purified product, has not been found to be genotoxic, a reproductive toxin, and is not a known carcinogen. However, it is created with carcinogenic and mutagenic compounds, as noted above. (Source)
Is Cocamidopropyl hydroxysultaine vegan?
Cocamidopropyl hydroxysultaine is not made from any animal-derived ingredients, and is thus vegan.
Is Cocamidopropyl hydroxysultaine eco-friendly?
While cocamidopropyl hydroxysultaine is partially made from coconut oil, and may have a lower ecological footprint than some other surfactants, depending on the working conditions, manufacturing workers and the environment may be exposed to epichlorohydrin, a carcinogen. Studies have found an increase in lung cancer in people exposed to epichlorohydrin on the job. (Source) Cocamidopropyl hydroxysultaine is touted as "sustainable" or "natural" in many cases, but these claims are, in my opinion, unsubstantiated.
Is Cocamidopropyl hydroxysultaine a skin irritant?
In general cocamidopropyl hydroxysultaine is not a skin irritant when used in a properly-formulated product. However, if the surfactant is not purified, it can contain traces of dimethylaminopropylamine or derivatives thereof that can be irritating. This seems to be not a prevalent issue with most suppliers, however.
Cocamidopropyl hydroxysultaine is touted as "natural" or "safer" and may be gentle on skin and non-toxic in general. However, the manufacturing process may expose workers and the environment to carcinogens, irritants, and mutagens.