Sodium dodecyl sulfate

Organic sulfate and anionic surfactant
\"Sodium lauryl sulfate\" redirects here. Not to be confused with Sodium laureth sulfate.

Sodium lauryl sulfate

Space-filling model of the sodium dodecyl sulfate crystal

Space-filling model of the dodecyl sulfate ion


Preferred IUPAC name
Sodium dodecyl sulfate

Other names
Sodium monododecyl sulfate; Sodium lauryl sulfate; Sodium monolauryl sulfate; Sodium dodecanesulfate; dodecyl alcohol, hydrogen sulfate, sodium salt; n-dodecyl sulfate sodium; Sulfuric acid monododecyl ester sodium salt


CAS Number

151-21-3 checkY

3D model (JSmol)

Interactive image


CHEBI:8984 checkY


ChEMBL23393 checkY


8677 checkY


DB00815 checkY

ECHA InfoCard

100.005.263 Edit this at Wikidata

E number

E487 (thickeners, ...)

PubChem CID



368GB5141J checkY

CompTox Dashboard (EPA)

DTXSID1026031 Edit this at Wikidata

InChI=1S/C12H26O4S.Na/c1-2-3-4-5-6-7-8-9-10-11-12-16-17(13,14)15;/h2-12H2,1H3,(H,13,14,15);/q;+1/p-1 checkYKey: DBMJMQXJHONAFJ-UHFFFAOYSA-M checkY



Chemical formula


Molar mass

288.372 g/mol


white or cream-colored solid




1.01 g/cm3

Melting point

206 °C (403 °F; 479 K)

Surface tension:


8.2 mM at 25 °C

Refractive index (nD)



ATC code

A06AG11 (WHO)


Lethal dose or concentration (LD, LC):

LD50 (median dose)

1288 mg/kg (rat, oral)

Related compounds

Other anions

Sodium laureth sulfate
Sodium myreth sulfate

Other cations

Ammonium lauryl sulfate
Potassium lauryl sulfate

Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).
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Infobox references

Chemical compound

Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula CH3(CH2)11OSO3Na and structure H3C−(CH2)11−O−S(=O)2−ONa. It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium salt of the 12-carbon organosulfate. Its hydrocarbon tail combined with a polar \"headgroup\" give the compound amphiphilic properties that 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.

Bottle of 20% sodium dodecyl sulfate in distilled water for use in the laboratory

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%).


Cleaning and hygiene

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.

Food additive

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.

Laboratory applications

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.

Denaturation of a protein using SDS

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. This separation based on the size of the polypeptide chain simplifies the analysis of protein molecules.

Pharmaceutical applications

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.

Miscellaneous applications

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.

Other uses

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 in low concentrations according to some studies. 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.

Oral concerns

SDS is a common ingredient in toothpastes due to its low cost, its lack of impact on taste, and its desirable action as a foaming agent.


SDS may reduce the amount of bad breath-causing volatile sulfur compounds (VSCs) in the mouth. 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.

Dry mouth

Primary sources from the group of Irma Rantanen at University of Turku, Finland claim that SLS-containing pastes cause more dry mouth (xerostomia) than their proposed alternative. However, 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.\"

Mouth ulceration

A safety concern has been raised on the basis of several studies regarding the effect of toothpaste SDS on aphthous ulcers (more specifically, mouth ulcers or \"canker sores\"), commonly referred to as canker or white sores. According to the NHS, SLS is a cause for concern for mouth ulcers. As Lippert notes, of 2013, \"very few... marketed toothpastes contain a surfactant other than SLS ,\" and leading manufacturers continue to formulate their produce with SDS.


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