Ammonium lauryl sulfate: Difference between revisions

| Watchedfields = changed

| verifiedrevid = 418418913

| Name = Ammonium lauryl sulfate

| ImageFile = Ammonium dodecyl sulfate.svg

| OtherNames = • monododecyl ester, ammonium salt<br>• Ammonium dodecyl sulfate

| Appearance = yellowish viscous liquid

| Density = 1.02 g/cm³

| MeltingPt =

| BoilingPtC = 418

'''Ammonium lauryl sulfate''' ('''ALS''') is the common name for ammonium dodecyl sulfate (CH₃(CH₂)₁₀CH₂OSO₃NH₄). The anion consists of a nonpolar hydrocarbon chain and a polar sulfate end group. The combination of nonpolar and polar groups confers [[surfactant]] properties to the anion: it facilitates dissolution of both polar and non-polar materials. This salt is classified as a [[sulfate ester]]. It is made from coconut or [[palm kernel oil]] for use primarily in [[shampoo]]s and body-wash as a foaming agent.<ref>{{CPID|id=5}}</ref><ref name=Ullmann/> Lauryl sulfates are very high-foam [[surfactants]] that disrupt the [[surface tension]] of water in part by forming [[micelles]] at the surface-air interface.

Above the [[critical micelle concentration]], the anions organize into a micelle, in which they form a sphere with the polar, [[hydrophilic]] heads of the sulfate portion on the outside (surface) of the sphere and the nonpolar, [[hydrophobic]] tails pointing inwards towards the center. The water molecules around the micelle in turn arrange themselves around the polar heads, which disrupts their ability to hydrogen bond with other nearby water molecules. The overall effect of these micelles is a reduction in surface tension of the solution, which affords a greater ability to penetrate or "wet out" various surfaces, including porous structures like cloth, fibers, and hair. Accordingly, this structured solution allows the solution to more readily dissolve soils, greases, etc. in and on such substrates. Lauryl sulfates however exhibit poor soil suspending capacity.<ref name=Ullmann>{{Ullmann|doi=10.1002/14356007.a25_747|title=Surfactants|book=Ullmann's Encyclopedia of Industrial Chemistry|year=2000|last1=Kosswig|first1=Kurt|isbn=3527306730}}</ref>

ALS is an innocuous detergent. A 1983 report by the [[Cosmetic Ingredient Review]], shampoos containing up to 31% ALS registered 6 health complaints out of 6.8 million units sold. These complaints included two of scalp itch, two allergic reactions, one hair damage and one complaint of eye irritation.<ref>{{cite web|url=http://www.nicnas.gov.au/Publications/Information_Sheets/Existing_Chemical_Information_Sheets/ECIS_ALS_PDF.pdf |title=Chemical Information Sheet – Ammonium Lauryl Sulfate |accessdate=2007-01-25 |url-status=dead |archiveurl=https://web.archive.org/web/20060823055845/http://www.nicnas.gov.au/Publications/Information_Sheets/Existing_Chemical_Information_Sheets/ECIS_ALS_PDF.pdf |archivedate=2006-08-23 }}</ref><ref>{{cite journal | title = Final Report on the Safety Assessment of Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate | journal = JACT, CIR Publication | year = 1983 | volume = 2 | issue = 7 | pages = 127–81}}</ref>

The CIR report concluded that both [[sodium dodecyl sulfate|sodium]] and ammonium lauryl sulfate "appear to be safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin. In products intended for prolonged use, concentrations should not exceed 1%".

The Human and Environmental Risk Assessment (HERA) project performed a thorough investigation of all alkyl sulfates, as such the results they found apply directly to ALS. Most alkyl sulfates exhibit low acute oral toxicity, no toxicity through exposure to the skin, concentration dependent skin irritation, and concentration dependent eye-irritation. They do not sensitize the skin and did not appear to be [[carcinogenic]] in a two-year study on rats. The report found that longer carbon chains (16–18) were less irritating to the skin than chains of 12–15 carbons in length. In addition, concentrations below 1% were essentially non-irritating while concentrations greater than 10% produced moderate to strong irritation of the skin.<ref>{{ cite web | url = http://www.heraproject.com/files/3-HH-04-%20HERA%20AS%20HH%20web%20wd.pdf | title = Human and Environmental Risk Assessment – Health Risks of Alkyl Sulfates | accessdate = 2007-01-25}}</ref>

The [[Centers for Disease Control and Prevention|CDC]] has reported on occupations which were routinely exposed to ALS between 1981 and 1983. During this time, the occupation with the highest number of workers exposed was registered nurses, followed closely by funeral directors.<ref>{{cite web|url=https://www.cdc.gov/noes/noes4/m2632sco.html |title=National Exposure Survey (1981–1983) |accessdate=2007-01-25 |url-status=dead |archiveurl=https://web.archive.org/web/20060327205021/http://www.cdc.gov/noes/noes4/m2632sco.html |archivedate=2006-03-27 }}</ref>

The HERA project also conducted an environmental review of alkyl sulfates that found all alkyl sulfates are readily biodegradable and standard wastewater treatment operations removed 96–99.96% of short-chain (12–14 carbons) alkyl sulfates. Even in anaerobic conditions at least 80% of the original volume is biodegraded after 15 days with 90% degradation after 4 weeks.<ref>{{cite web|url=http://www.heraproject.com/files/3-E-04-HERA%20AS%20Env%20web%20wd.pdf |title=Human and Environmental Risk Assessment for Alkyl Sulphates |accessdate=2007-01-25 |url-status=dead |archiveurl=https://web.archive.org/web/20061107201838/http://www.heraproject.com/files/3-E-04-HERA%20AS%20Env%20web%20wd.pdf |archivedate=2006-11-07 }}</ref>

* [[Potassium lauryl sulfate]]

* [[Sodium pareth sulfate]]

{{Ammonium salts}}

[[Category:Sulfate esters]]

[[Category:Dodecyl compounds]]