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Sodium laureth sulfate



Sodium laureth sulfate
Identifiers
CAS number 009004-82-4
Properties
Molecular formula CH3(CH2)10CH2(OCH2CH2)nOSO3Na
Molar mass around 420 g/mol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

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 foamer.

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 SDS.

Sodium dodecyl sulfate (also known as sodium lauryl 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]

Additional recommended knowledge

Contents

Effects on sensitive skin

Products containing these substances can affect those prone to eczema and other irritants. These substances provide a foaming quality to the product, allowing for better distribution of the product while washing hair or skin and while brushing teeth. When rinsed off, the product will have cleaned the area but will have taken moisture from the top layers of skin. In people with sensitive skin (prone to dermatitis, acne, eczema, psoriasis and chemical sensitivity), the drying property of these type of detergents can cause flare-ups of skin conditions or may worsen existing conditions.[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 metre).[8] While the U.S. Food and Drug Administration encourages manufacturers to remove this contaminant, it is not currently required by federal law.[9]

Connections to ulcers

The large majority of toothpastes sold in the U.S. contain Sodium laureth sulfate (SLS), which is known to cause aphthous ulcers in certain individuals. Using a toothpaste without SLS will reduce the frequency of aphthous ulcers in persons who experience aphthous ulcers caused by SLS.[10][11][12] However, some studies find no connection between SLS in toothpaste and mouth ulcers.[13]

Alternative names

  • Sodium Alkyl ether sulfate
  • Sodium POE(2) lauryl ether sulfate
  • Sodium diethylene glycol lauryl ether sulfate
  • Sodium lauryl ether sulfate
  • Sodium 2-(2-dodecyloxyethoxy) ethyl sulfate

See also

References

  1. ^ Sodium Laureth Sulfate POE(2). Chemical Land 21, Seoul, Korea. Product Identification
  2. ^ Agner T. Susceptibility of atopic dermatitis patients to irritant dermatitis caused by sodium lauryl sulphate. Acta Derm Venereol. 1991;71(4):296-300. Abstract
  3. ^ A. Nassif, S. C. Chan, F. J. Storrs and J. M. Hanifin. Abstract: Abnormal skin irritancy in atopic dermatitis and in atopy without dermatitis. Arch Dermatol. November 1994;130(11):1402. Abstract
  4. ^ a b Magnusson B, Gilje O. Allergic contact dermatitis from a dish-washing liquid containing lauryl ether sulphate. Acta Derm Venereol. 1973;53(2):136-40. Abstract
  5. ^ a b Van Haute N, Dooms-Goossens A. Shampoo dermatitis due to cocobetaine and sodium lauryl ether sulphate. Contact Dermatitis. 1983 Mar;9(2):169. Abstract
  6. ^ Rumor: Sodium Lauryl Sulfate Causes Cancer. The Cosmetic, Toiletry, and Fragrance Association. 13, October 2000. Consumer Information
  7. ^ Roderick E. Black, Fred J. Hurley, Donald C. Havery. Occurrence of 1,4-Dioxane in Cosmetic Raw Materials and Finished Cosmetic Products. Journal of AOAC International.2001 May;84(3):666-670. Abstract
  8. ^ 1,4-Dioxane (1,4-Diethyleneoxide). Hazard Summary. U.S. Environmental Protection Agency. Created in April 1992; Revised in January 2000. Fact Sheet
  9. ^ FDA/CFSAN--Cosmetics Handbook Part 3: Cosmetic Product-Related Regulatory Requirements and Health Hazard Issues. Prohibited Ingredients and other Hazardous Substances: 9. Dioxane
  10. ^ Herlofson B, Barkvoll P (1994). "Sodium lauryl sulfate and recurrent aphthous ulcers. A preliminary study." (PDF). Acta Odontol Scand 52 (5): 257–9. PMID 7825393.
  11. ^ Herlofson B, Barkvoll P (1996). "The effect of two toothpaste detergents on the frequency of recurrent aphthous ulcers.". Acta Odontol Scand 54 (3): 150–3. PMID 8811135.
  12. ^ Chahine L, Sempson N, Wagoner C (1997). "The effect of sodium lauryl sulfate on recurrent aphthous ulcers: a clinical study.". Compend Contin Educ Dent 18 (12): 1238–40. PMID 9656847.
  13. ^ Healy C, Paterson M, Joyston-Bechal S, Williams D, Thornhill M (1999). "The effect of a sodium lauryl sulfate-free dentifrice on patients with recurrent oral ulceration.". Oral Dis 5 (1): 39–43. PMID 10218040.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Sodium_laureth_sulfate". A list of authors is available in Wikipedia.
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