|Preferred IUPAC name
Sodium dodecyl sulfate
Sodium monododecyl sulfate; Sodium lauryl sulfate; Sodium monolauryl sulfate; Sodium dodecanesulfate; Sodium coco-sulfate; dodecyl alcohol, hydrogen sulfate, sodium salt; n-dodecyl sulfate sodium; Sulfuric acid monododecyl ester sodium salt
3D model (JSmol)
|E number||E487 (thickeners, ...)|
CompTox Dashboard (EPA)
|Molar mass||288.372 g/mol|
|Appearance||white or cream-colored solid|
|Melting point||206 °C (403 °F; 479 K)|
|8.2 mM at 25 °C|
Refractive index (nD)
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|1288 mg/kg (rat, oral)|
|Sodium laureth sulfate|
Sodium myreth sulfate
|Ammonium lauryl sulfate|
Potassium lauryl sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
what is ?)(
Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula CH3(CH2)11OSO3Na. It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium salt of the 12-carbon an organosulfate. Its hydrocarbon tail combined with a polar "headgroup" give the compound amphiphilic properties and so make it useful as a detergent. SDS is also component of mixtures produced from inexpensive coconut and palm oils. SDS is a common component of many domestic cleaning, personal hygiene and cosmetic, pharmaceutical, and food products, as well as of industrial and commercial cleaning and product formulations.
The critical micelle concentration (CMC) in water at 25 °C is 8.2 mM, and the aggregation number at this concentration is usually considered to be about 62. The micelle ionization fraction (α) is around 0.3 (or 30%).
SDS is mainly used in detergents for laundry with many cleaning applications. It is a highly effective surfactant and is used in any task requiring the removal of oily stains and residues. For example, it is found in higher concentrations with industrial products including engine degreasers, floor cleaners, and car exterior cleaners.
It is a component in hand soap, toothpastes, shampoos, shaving creams, and bubble bath formulations, for its ability to create a foam (lather), for its surfactant properties, and in part for its thickening effect.
Sodium dodecyl sulfate, appearing as its synonym sodium lauryl sulfate (SLS), is considered a generally recognized as safe (GRAS) ingredient for food use according to the USFDA (21 CFR 172.822). It is used as an emulsifying agent and whipping aid. As an emulsifier in or with egg whites the United States Code of Federal Regulations require that it must not exceed 1,000 parts per million (0.1%) in egg white solids or 125 parts per million (0.0125%) in frozen or liquid egg whites and as a whipping agent for the preparation of marshmallows it must not exceed 0.5% of the weight of gelatine. SLS is reported to temporarily diminish perception of sweetness.
SDS is used in cleaning procedures, and is commonly used as a component for lysing cells during RNA extraction and/or DNA extraction, and for denaturing proteins in preparation for electrophoresis in the SDS-PAGE technique.
In the case of SDS-PAGE, the compound works by disrupting non-covalent bonds in the proteins, and so denaturing them, i.e. causing the protein molecules to lose their native conformations and shapes. By binding to proteins at a ratio of one SDS molecule per 2 amino acid residues, the negatively charged detergent provides all proteins with a similar net negative charge and therefore a similar charge-to-mass ratio. In this way, the difference in mobility of the polypeptide chains in the gel can be attributed solely to their length as opposed to both their native charge and shape. It is possible to make separation based on the size of the polypeptide chain to simplify the analysis of protein molecules, this can be achieved by denaturing proteins with the detergent SDS.
Sodium lauryl sulfate is a widely used in the pharmaceutical field as an ionic solubilizer and emulsifier that is suitable for applications in liquid dispersions, solutions, emulsions and micro emulsions, tablets, foams and semi-solids such as creams, lotions and gels. Additionally, SLS aids in tablet wettability, as well as lubrication during manufacturing. Brand names of pharma-grade SLS include Kolliphor SLS and Kolliphor SLS Fine.
SLS is used in an improved technique for preparing brain tissues for study by optical microscopy. The technique, which has been branded as CLARITY, was the work of Karl Deisseroth and coworkers at Stanford University, and involves infusion of the organ with an acrylamide solution to bind the macromolecules of the organ (proteins, nucleic acids, etc.), followed by thermal polymerization to form a "brain–hydrogel" (a mesh interspersed throughout the tissue to fix the macromolecules and other structures in space), and then by lipid removal using SDS to eliminate light scattering with minimal protein loss, rendering the tissue quasi-transparent.
Along with sodium dodecylbenzene sulfonate and Triton X-100, aqueous solutions of SDS are popular for dispersing or suspending nanotubes, such as carbon nanotubes.
SLS has been proposed as a potentially effective topical microbicide, for intravaginal use, to inhibit and possibly prevent infection by various enveloped and non-enveloped viruses such as the herpes simplex viruses, HIV, and the Semliki Forest virus.
Liquid membranes formed from SDS in water have been demonstrated to work as unusual particle separators. The device acts as a reverse filter, allowing large particles to pass while capturing smaller particles.
SDS is synthesized by treating lauryl alcohol with sulfur trioxide, oleum, or chlorosulfuric acid to produce hydrogen lauryl sulfate. Lauryl alcohol can be used in pure form or as a mixtures of fatty alcohols. When produced from these sources, "SDS" products are a mixture of various sodium alkyl sulfates with SDS being the main component. For instance, SDS is a component, along with other chain-length amphiphiles, when produced from coconut oil, and is known as sodium coco sulfate (SCS). SDS is available commercially in powder, pellet, and other forms (each differing in rates of dissolution), as well as in aqueous solutions of varying concentrations.
SDS is not carcinogenic. Like all detergents, sodium lauryl sulfate removes oils from the skin, and can cause skin and eye irritation. It has been shown to irritate the skin of the face, with prolonged and constant exposure (more than an hour) in young adults. SDS may worsen skin problems in individuals with chronic skin hypersensitivity, with some people being affected more than others.
The low cost of SDS, its lack of impact on taste, its potential impact on volatile sulfur compounds (VSCs), which contribute to malodorous breath, and its desirable action as a foaming agent have led to the use of SDS in the formulations of toothpastes. A series of small crossover studies (25–34 patients) have supported the efficacy of SLS in the reduction of VSCs, and its related positive impact on breath malodor, although these studies have been generally noted to reflect technical challenges in the control of study design variables. While primary sources from the group of Irma Rantanen at University of Turku, Finland conclude an impact on dry mouth (xerostomia) from SLS-containing pastes, a 2011 Cochrane review of these studies, and of the more general area, concludes that there "is no strong evidence… that any topical therapy is effective for relieving the symptom of dry mouth." A safety concern has been raised on the basis of several studies regarding the effect of toothpaste SDS on aphthous ulcers, commonly referred to as canker or white sores. A consensus regarding practice (or change in practice) has not appeared as a result of the studies. As Lippert notes, of 2013, "very few… marketed toothpastes contain a surfactant other than SLS [SDS]," and leading manufacturers continue to formulate their produce with SDS.
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Obtaining high-resolution information from a complex system, while maintaining the global perspective needed to understand system function, represents a key challenge in biology. Here we address this challenge with a method (termed CLARITY) for the transformation of intact tissue into a nanoporous hydrogel-hybridized form (crosslinked to a three-dimensional network of hydrophilic polymers) that is fully assembled but optically transparent and macromolecule-permeable.
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[Quoting:] Carcinogenesis. A one-year chronic oral study using beagles showed that Sodium Lauryl Sulfate at concentrations up to 2% in the diet was not tumorigenic or carcinogenic. [p. 157] / Summary… In mutagenesis studies, rats fed 1.13% and 0.56% Sodium Lauryl Sulfate in the diet for 90 days produced no more chromosomal aberrations or clastogenic effects than did a control diet. [p. 175]. / Conclusion. Sodium Lauryl Sulfate 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 contact with skin, concentrations should not exceed 1%. [p. 176.].
[Quoting:] Sodium Lauryl Sulfate 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 contact with skin, concentrations should not exceed 1%… New studies confirmed the irritant properties of these ingredients and reinforced the concentration limit of 1% or leave-on uses established by the [earlier] Panel. [p. 89] / The available studies that looked for carcinogenesis failed to find evidence that Ammonium Lauryl Sulfate are [sic.] carcinogenic. None of the available data suggested that SLS or Ammonium Lauryl Sulfate could be carcinogenic. Despite assertions to the contrary on the Internet, the carcinogenicity of these ingredients is only a rumor. [pp. 89ff]
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[Quoting abstract:] There is no strong evidence from this review that any topical therapy is effective for relieving the symptom of dry mouth.See Rantanen, et al. (2003) J. Contemp. Dent. Pract. 4(2):11–23, , and Rantanen, et al. (2003) Swed. Dent. J. 27(1):31–34, , referenced therein.