Sodium Lauryl Sulfate Guide

Sodium lauryl sulfate (SLS), sodium laurilsulfate or sodium dodecyl sulfate (SDS or NaDS) (C12H25SO4Na) is an anionic surfactant used in many cleaning and hygiene products. The molecule has a tail of 12 carbon atoms, attached to a sulfate group, giving the molecule the amphiphilic properties required of a detergent.

SLS is a highly effective surfactant and is used in any task requiring the removal of oily stains and residues. For example, it is found in higher concentrations with industrial products including engine degreasers, floor cleaners, and car wash soaps. It is used in lower concentrations with toothpastes, shampoos, and shaving foams. It is an important component in bubble bath formulations for its thickening effect and its ability to create a lather.

SLS has not been proven to be carcinogenic when either applied directly to skin or consumed.[1] It has however been shown to irritate the skin of the face with prolonged and constant exposure (more than an hour) in young adults.[2] In a clinical double-blind crossover study, SLS was found to have a significantly higher frequency of aphthous ulcers than both cocoamidopropyl betaine or a detergent-free paste, on 30 patients with frequent occurrences of recurrent aphthous ulcers.[3] However, another double blind crossover trial comparing toothpastes with and without SLS found that it had no significant effect on ulcer patterns.[4]...