Sodium laureth sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpaste etc.). A cheap and very effective foamer.
If SLES is not present sodium dodecylsulfate (SDS), ammonium lauryl sulfate (ALS) or sodium lauryl sulfate (SLS, much stronger) will probably be.
There is a persistent but unfounded myth that SLES is carcinogenic.
Sometimes listed as Steol-130, 230, 270, 330, 370 or 460; Stepanol; Alkyl Ether Sulfate; Sodium POE(2) Lauryl Ether Sulfate; Sodium Diethylene glycol Lauryl Ether Sulfate; Sodium Lauryl Ether Sulfate.