Ammonium Laureth Sulfate vs Cocamidopropyl Betaine: which is worse?

What is Ammonium Laureth Sulfate?

Ammonium laureth sulfate is an anionic surfactant very similar in structure to SLES but uses an ammonium counterion instead of sodium. It produces abundant foam and provides excellent conditioning to the hair shaft during washing.

What is Cocamidopropyl Betaine?

Cocamidopropyl betaine is an amphoteric (zwitterionic) surfactant derived from coconut oil and dimethylaminopropylamine. It serves as both a primary and secondary surfactant and is known for being gentler than traditional sulfate surfactants. It also has antistatic and conditioning properties.

Documented risks

Ammonium Laureth Sulfate: Ammonium laureth sulfate shares a similar safety profile to SLES. The CIR has concluded it is safe for cosmetic use. Like SLES, it may contain trace 1,4-dioxane from ethoxylation, addressed by standard manufacturing controls. It is not a carcinogen or endocrine disruptor. Mild skin irritation is possible in sensitive individuals at high concentrations but is not a concern at typical use levels in rinse-off products.

Cocamidopropyl Betaine: CAPB itself is well-tolerated by most people. However, it was named Allergen of the Year by the American Contact Dermatitis Society in 2004, indicating it can cause contact allergic reactions in a subset of sensitized individuals. The sensitizer is typically not CAPB itself but trace impurities from manufacturing (amidoamine or 3-dimethylaminopropylamine). High-purity CAPB has a very low sensitization rate. It is not a carcinogen or endocrine disruptor. The CIR concluded CAPB is safe for cosmetic use.