Ammonium Lauryl Sulfate vs Sodium Cocoyl Isethionate: which is worse?

What is Ammonium Lauryl Sulfate?

Ammonium lauryl sulfate is an anionic surfactant analogous to SLS but with an ammonium cation. It provides strong foaming and cleansing. It is slightly more water-soluble than SLS.

What is Sodium Cocoyl Isethionate?

Sodium cocoyl isethionate is a mild anionic surfactant derived from coconut fatty acids and isethionic acid. It exists as a solid powder and produces a creamy, conditioning lather that leaves skin feeling soft. It is the primary surfactant in most syndet (synthetic detergent) bars.

Documented risks

Ammonium Lauryl Sulfate: ALS is slightly more irritating than ALES and comparable to SLS at equivalent concentrations. At typical shampoo concentrations (2–10%), it is considered safe by the CIR. It is not carcinogenic, not a hormone disruptor, and does not accumulate in body tissues. Prolonged skin contact at high concentrations can cause irritation; this is not a concern in rinse-off applications.

Sodium Cocoyl Isethionate: Sodium cocoyl isethionate has an excellent safety record. It is one of the surfactants recommended by the National Eczema Association for sensitive and atopic skin. No carcinogenic, mutagenic, or endocrine-disrupting effects are known. Potential contact sensitization is extremely rare. It performs well at physiological pH, minimizing skin barrier disruption.