Helpful explanation of the concerns behind SLS and SLES -
SLS, and its milder cousin Sodium Laureth Sulfate (SLES), are esters of Sulphuric acid. SLS and SLES are linked to skin and eye irritation. We’ve all experienced the intense stinging when shampoo gets in our eyes and studies done on animals show permanent eye damage due to the regular use of SLS. Many conventional shampoo manufacturers use chemical ingredients thought to have an anesthetizing effect, masking the true reaction the SLS is causing.
While both SLS and SLES have been dismissed as cancer-causing chemicals, they are known penetration enhancers which alter the epidermal structure, allowing other chemicals to more easily penetrate the skin.
And while it is true that SLES is milder than the harsh SLS, SLES is often contaminated with 1,4-dioxane, a chemical by-product linked to cancer and is thought to have longer lasting effects than SLS.
Ammonium Lauryl Sulfate(ALS) and Sodium Lauryl Sulphoacetate(SLSA) are similar sounding cosmetic ingredients with the same job as SLS and SLES – they are used as foaming agents. ALS is the ammonium salt of lauryl sulfate and, though the health risks are the same as SLS, this one is said to be milder.
But SLSA is different. This one is a plant-derived surfactant, usually from palm or coconut oils, and is very mild. The molecular size of SLSA is much larger than the others, too large to penetrate the skin. SLSA is commonly used in natural cosmetics to produce lather and keep ingredients from separating.
The Cosmetic Trade Industry Association (CIR) says sulphates “appear to be safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin.” Doesn’t sound so safe, huh? If you have to limit your use of a product to “discontinuous” and “brief” for it to be safe, you may want to not use the product in the first place. Germany will not allow a cosmetic product to be labeled “natural” if it contains any ingredients from the sulfate family (lauryl, laureth or ammonium).