Sodium laureth sulfate (SLS), or sodium lauryl ether sulfate (SLES), is an anionic detergent and surfactant found in many personal care products (soaps, shampoos, toothpaste etc.). SLES is an inexpensive and very effective foaming agent.[1] SLES, SLS, ALS and sodium pareth sulfate are surfactants that are used in many cosmetic products for their cleaning and emulsifying properties. They behave similarly to soap.