What are they exactly?
Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are surfactants and are added to products to increase the foaming action when the product used. They are commonly used in cleaning products, whether cleansers, shampoos, toothpaste, bubble bath or detergents.
Why are they being used?
The reason SLS/SLES are used is because they are cheap ingredients which also gives a “cleaning effect”. For decades, we have been programmed to believing that the foamier the product, the better the cleanse- which in fact is not the case. Especially products such as facial/body cleansers which consists SLS or SLES, they give a squeaky clean feeling as it strips our skin’s protective barrier.
The main difference is that SLES goes through the ethoxylation process so it is less irritation to the skin and hair than SLS. However, a side reaction that sometimes occurs during ethoxylation is that a small amount of 1,4 dioxane is produced. 1,4 dioxane is a known carcinogen.
Although SLS is not contaminated by this way, as a rule of thumb it is best to avoid this ingredient as it can too irritate the skin and is also associated with organ toxicity. Both of these ingredients are a big no-no especially for those with sensitive skin.
In short, best to avoid SLS and SLES.