It07:Sodium Lauryl Sulfate
Sodium Lauryl Sulfate | |
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General | |
Systematic name | Sodium Dodecyl Sulfate |
Other names | Sodium Lauryl Sulfate, SLS, Sodium Dodecyl Sulfate |
Molecular formula | NaC12H25SO4 |
Molar mass | 288.38 gmol-1 |
CAS number | 151-21-3 |
Properties | |
Density & phase | Density 1.01 g/cm³ |
Melting point | 206 °C |
Supplementary data page | |
Structure and properties |
n, εr, etc. |
Thermodynamic data |
Phase behaviour Solid, liquid, gas |
Spectral data | UV, IR, NMR, MS |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Sodium Lauryl Sulfate (Also Sodium Dodecyl Sulfate)
Sodium Lauryl Sulfate (SLS) is a widely used chemical, mainly used to thicken up products and to create a lather. It is most commonly used in shampoos, shower gels, bubble baths, toothpastes and shaving gels.
The Chemistry of Sodium Lauryl Sulfate
Sodium Lauryl Sulfate is made by the sulfonation of dodecanol, followed by neutralisation using sodium carbonate.
Sodium Laureth Sulfate, a similar chemical that is less harsh on human skin, can be manufactured from SLS by ethoxylation.
Due to SLS's uses both in industrial and home-made cosmetics, it is currently one of the most researched anionic surfactant compounds.
Sodium Lauryl Sulfate can denature proteins by disrupting their non-covalent bonds, causing them to lose their normal shape. For this reason, SLS is commonly used to prepare proteins for polyacrylamide gel electrophoresis (SDS-PAGE). It also works in this process by its anions binding to the peptide chain of the protein, causing a negative charge on the protein. This results in electrostatic repulsion, which unravels the protein and allows the gel separation to occur without the proteins' shape as a factor.
Health and Safety Concerns
Sodium lauryl sulfate is rumoured to be a carcinogen, although many sources have said this is only the case when used in concentrations much higher than those used in common cosmetics.
However, there are other health concerns regarding SLS - including it causing dermatitis, skin irritation and ulcers.
Whilst using sodium lauryl sulfate in its solid form, it is recommended that dust masks are worn as if inhaled, it can prove to be a choking hazard.