Sodium lauroyl methyl isethionate is the chemical name for the sodium salt of the methyl lauric acid ester of isethionic acid. It serves as a surfactant and cleaning agent in cosmetics and personal care items. It is a very gentle cleaning agent with rich, luxurious foam and a refined after-feel. Additionally, it is very well soluble in water, making it rinsable. It is an alternative to a more widely known surfactant, sodium cocoyl isethionate. As a raw material, sodium lauroyl methyl isethionate is often available as white-to-off-white flakes or chips.
Origin
Lauric acid from coconuts and sodium isethionate can be esterified to create sodium lauroyl isethionate (SLI) in a single step. Then, sodium lauroyl isethionate is converted into sodium lauroyl methyl isethionate (SLMI) by adding a methyl group.
Safety profile
When used in personal care products, sodium lauroyl methyl isethionate was deemed safe by the Cosmetic Ingredient Review Expert Panel. Their study focused on products with a concentration of up to 10.1%. According to the CIR Expert Panel, isethionate salts, such as sodium lauroyl methyl isethionate, are safe for use and concentration in cosmetics when they are formulated to be nonirritating.
With an Environmental Working Group (EWG) score of 1, Sodium Lauroyl Methyl Isethionate is deemed to be very safe, non-toxic, a non irritant, and is biodegradable. Sodium lauroyl methyl isethionate is also produced by ethoxylation, which makes it an environmentally unfriendly ingredient. It is prohibited in the COSMOS specifications.