Ammonium Lauryl Sulfate vs Sodium Lauryl Sulfate: 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 Lauryl Sulfate?

Sodium lauryl sulfate is an anionic surfactant derived from lauryl alcohol (from coconut or palm oil). It is one of the oldest and most-studied cosmetic surfactants, prized for its powerful foaming and degreasing properties. Unlike SLES, it is not ethoxylated.

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 Lauryl Sulfate: SLS is safe at cosmetic use concentrations per the CIR Expert Panel. It is more irritating than SLES to skin and mucous membranes, particularly at concentrations above 2% with prolonged contact; this is why most rinse-off products keep it at 1–2% or opt for SLES. It can disrupt the skin barrier transiently, which is why some people with canker sores or eczema avoid SLS toothpastes and cleansers. It is not carcinogenic, not a hormone disruptor, and is not absorbed systemically in meaningful amounts. It biodegrades rapidly in the environment.