Sodium laureth sulfate

Sodium lauryl ether sulfate (SLES), usually contracted as sodium laureth sulfate, and also called sodium alkylethersulfate, is an anionic detergent and surfactant found in many personal care products (soaps, shampoos, toothpaste, etc.) and for industrial uses. SLES is an inexpensive and very effective foaming agent.<ref name="Ullmann">Kurt Kosswig,"Surfactants" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, 2005, Weinheim. Template:Doi</ref> SLES, sodium lauryl sulfate (SLS), ammonium lauryl sulfate (ALS), and sodium pareth sulfate are surfactants that are used in many cosmetic products for their cleaning and emulsifying properties. It is derived from palm kernel oil or coconut oil. In herbicides, it is used as a surfactant to improve absorption of the herbicidal chemicals<ref>Template:Cite web</ref> and reduces time the product takes to be rainfast, when enough of the herbicidal agent will be absorbed.

The chemical formula for this family of surfactants is Template:Chem2. Sometimes the number represented by n is specified in the name, for example laureth-2 sulfate. The product is however heterogeneous in that the number of ethoxyl groups, where n is the mean. Laureth-3 sulfate is the most common one in commercial products. Compared to the parent sodium lauryl sulfate (Template:Chem2), SLES is more surface-active owing to the presence of the ethoxy groups.<ref>Template:Cite journal</ref>

Production

SLES is prepared by ethoxylation of dodecyl alcohol, which is produced industrially from palm kernel oil or coconut oil. The resulting ethoxylate is converted to a half ester of sulfuric acid, which is neutralized by conversion to the sodium salt.<ref name=Ullmann /> The related surfactant sodium lauryl sulfate or SLS (also known as sodium dodecyl sulfate or SDS) is produced similarly, but without the ethoxylation step. SLS and ammonium lauryl sulfate (ALS) are commonly used alternatives to SLES in consumer products.<ref name=Ullmann/>

Environmental impacts

SLES is toxic to aquatic animals.<ref name=":aquatic1">Template:Cite journal</ref><ref name=": aquatic2">Template:Cite journal</ref> Low concentrations can cause severe effects and even death in fish.<ref name=":SLESfish">Template:Cite journal</ref>

Safety

SLES does not induce any adverse responses in any toxicology testing. SLES is a skin and eye irritant but not a sensitizer.<ref>Template:Cite journal</ref>

SLES may retain trace amounts of the probable human carcinogen 1,4-dioxane,<ref name="EPA">Template:Cite web</ref> an unintended chemical by-product formed during the ethoxylation and subsequent sulfonation steps used to synthesize it. Since the presence of 1,4-dioxane was recognized, many manufacturers have implemented purification processes, such as vacuum and steam stripping, to reduce its concentration in finished products.<ref name="Mohr 2020">Template:Cite book</ref><ref name="Bettenhausen 2020">Template:Cite web</ref>

See also

• Sodium lauroyl sarcosinate
• Sodium dodecyl sulfate
• Sodium myreth sulfate
• Sodium pareth sulfate
• Magnesium laureth sulfate
• Sodium dodecylbenzenesulfonate

External links

• Template:CPID