Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpaste etc.). It is an inexpensive and very effective foaming agent.
Its chemical formula is CH3(CH2)10CH2(OCH2CH2)nOSO3Na. Sometimes the number represented by "n" is specified in the name, for example laureth-2 sulfate. The commercial product is heterogeneous, both in the length of the alkyl chain (12 being the mode of the number of carbon atoms), and in the number of ethoxyl groups, where n is the mean. n=3 is common in commercial products. SLES can be derived from ethoxylation of dodecyl alcohol used to make SDS.
Sodium lauryl sulfate (also known as sodium dodecyl sulfate or SLS) and ammonium lauryl sulfate (ALS) are commonly used alternatives to SLES in consumer products.[1]
While SLS is a known irritant,[2][3] some evidence and research suggest that SLES can also cause irritation after extended exposure.[4][5]
Toxicology
The Cosmetic, Toiletry, and Fragrance Association (CTFA) and the American Cancer Society have stated that the common belief that SLES is a carcinogen is an urban legend, a view confirmed by toxicology research by the OSHA, NTP, and IARC.[6] SLES and SLS, and subsequently the products containing them, have been found to contain parts-per-thousand to parts-per-million levels of 1,4-dioxane, with the recommendation that these levels be monitored.[7] The U.S. Environmental Protection Agency considers 1,4-dioxane to be a probable human carcinogen (having observed an increased incidence of cancer in controlled animal studies, but not in epidemiological studies of workers using the compound), and a known irritant (with a no-observed-adverse-effects level of 400 milligrams per cubic meter).[8] While the U.S. Food and Drug Administration encourages manufacturers to remove this contaminant, it is not currently required by federal law.[9]
Source: Wikipedia
