Sodium laureth sulfate

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Not to be confused with Sodium lauryl sulfate.
Sodium laureth sulfate
Sodium laureth sulfate structure.png
Names
Other names
Sodium lauryl ether sulfate; sodium laureth sulphate; sodium lauryl ether sulphate
Identifiers
9004-82-4 YesY
Abbreviations SLES
PubChem 23665884 sodium;2-dodecoxyethyl sulfate
UNII ZZQ59TY3KG sodium laureth-2 sulfate N
BPV390UAP0 sodium laureth-3 sulfate N
410Q7WN1BX sodium laureth-5 sulfate N
Properties
CH3(CH2)11(OCH2CH2)nOSO3Na
Molar mass around 420 g/mol
(288.38 + 44.05n) g/mol
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Sodium laureth sulfate (SLES), an accepted contraction (Lauryl + Ether = Laureth) of 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, 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. They behave similarly to soap.

Its chemical formula is CH3(CH2)11(OCH2CH2)nOSO3Na. Sometimes the number represented by n is specified in the name, for example laureth-2 sulfate. The product is heterogeneous in the number of ethoxyl groups, where n is the mean. It is common for commercial products for n= 3.

Production[edit]

SLES is prepared by ethoxylation of dodecyl alcohol. The resulting ethoxylate is converted to a half ester of sulfuric acid, which is neutralized by conversion to the sodium salt.[1] The related surfactant sodium lauryl sulfate (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.[1]

Safety[edit]

Tests in the US indicate that it is safe for consumer use.[2] The Australian government's Department of Health and Ageing and its National Industrial Chemicals Notification and Assessment Scheme (NICNAS) have determined SLES does not react with DNA.[3]

Irritation[edit]

Like many other detergents, SLES is an irritant.[4] It has also been shown that SLES causes eye or skin irritation in experiments conducted on animals and humans.[4] The related surfactant SLS is a known irritant.[5][6][7][8]

1,4-Dioxane contamination[edit]

Some products containing SLES contain traces (up to 279 ppm) of 1,4-dioxane, which is formed as a by-product during the ethoxylation step of its production. The U.S. Food and Drug Administration recommends that these levels be monitored.[9] The U.S. Environmental Protection Agency classifies 1,4-dioxane as a probable human carcinogen (not observed in epidemiological studies of workers using the compound, but resulting in more cancer cases in controlled animal studies), and a known irritant with a no-observed-adverse-effects level of 400 milligrams per cubic meter at concentrations significantly higher than those found in commercial products.[10] Under Proposition 65, 1,4-dioxane is classified in the U.S. state of California to cause cancer.[11][12] The FDA encourages manufacturers to remove 1,4-dioxane, though it is not required by federal law.[13]

See also[edit]

References[edit]

  1. ^ a b c Kurt Kosswig,"Surfactants" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, 2005, Weinheim. doi:10.1002/14356007.a25_747
  2. ^ Cara, A.M. Bondi, Julia L. Marks, Lauren B. Wroblewski, Heidi S. Raatikainen, Shannon R Lenox, Kay E Gebhardt "Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products" Environ Health Insights. 2015, volume 9: 27–32. doi:10.4137/EHI.S31765. PMC4651417.
  3. ^ NICNAS SLES animal test
  4. ^ a b "Final report on the safety assessment of sodium laureth sulfate and ammonium laureth sulfate". Journal of the American College of Toxicology. 2 (5): 1–34. 1983. doi:10.3109/10915818309140713. 
  5. ^ Agner T (1991). "Susceptibility of atopic dermatitis patients to irritant dermatitis caused by sodium lauryl sulphate". Acta Dermato-venereologica. 71 (4): 296–300. PMID 1681644. 
  6. ^ Nassif A, Chan SC, Storrs FJ, Hanifin JM (November 1994). "Abnormal skin irritancy in atopic dermatitis and in atopy without dermatitis". Archives of Dermatology. 130 (11): 1402–7. doi:10.1001/archderm.130.11.1402. PMID 7979441. 
  7. ^ Magnusson B, Gilje O (1973). "Allergic contact dermatitis from a dish-washing liquid containing lauryl ether sulphate". Acta Dermato-venereologica. 53 (2): 136–40. PMID 4120956. 
  8. ^ Van Haute N, Dooms-Goossens A (March 1983). "Shampoo dermatitis due to cocobetaine and sodium lauryl ether sulphate". Contact Dermatitis. 9 (2): 169. doi:10.1111/j.1600-0536.1983.tb04348.x. PMID 6851541. 
  9. ^ Black RE, Hurley FJ, Havery DC (2001). "Occurrence of 1,4-dioxane in cosmetic raw materials and finished cosmetic products". Journal of AOAC International. 84 (3): 666–70. PMID 11417628. 
  10. ^ 1,4-Dioxane (1,4-Diethyleneoxide). Hazard Summary. U.S. Environmental Protection Agency. Created in April 1992; Revised in January 2000. Fact Sheet
  11. ^ "1,4-Dioxane cancer 123-91-1 January 1988" (PDF). Office of Environmental Health Hazard Assessment. 
  12. ^ "California Files Prop 65 Lawsuit Against Whole Foods, Avalon". Bloomberg. 
  13. ^ FDA/CFSAN--Cosmetics Handbook Part 3: Cosmetic Product-Related Regulatory Requirements and Health Hazard Issues. Prohibited Ingredients and other Hazardous Substances: 9. Dioxane

External links[edit]