Sodium dodecyl sulfate
Systematic name	Sodium dodecyl sulfate
Chemical formula	NaC12H25SO4
Molecular mass	288.38 g mol−1
Density	1.01 g/cm³
Melting point	206 °C
Boiling point	xx.x °C
CAS number	[151-21-3]
SMILES	CCCCCCCCCCCCOS(=O)([O-])=O.[Na+]
Disclaimer and references

Sodium dodecyl sulfate (or sulphate) (SDS or NaDS) (C₁₂H₂₅NaO₄S), also known as sodium lauryl sulfate (SLS), is an ionic surfactant that is used in household products such as toothpastes, shampoos, shaving foams and bubble baths for its thickening effect and its ability to create a lather. The molecule has a tail of 12 carbon atoms, attached to a sulfate group, giving the molecule the amphiphilic properties required of a detergent. Image File history File links Size of this preview: 800 × 167 pixelsFull resolution (1100 × 230 pixel, file size: 14 KB, MIME type: image/png) en:Sodium lauryl sulfate, also known as sodium dodecyl sulfate File links The following pages on the English Wikipedia link to this file (pages on other... Image File history File links Size of this preview: 800 × 254 pixels Full resolution (1100 × 349 pixel, file size: 107 KB, MIME type: image/png) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Sodium dodecyl sulfate ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article does not cite its references or sources. ... The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Standard atomic weight 22. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Standard atomic weight 32. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow robert ford An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... Surfactants are wetting agents that lower the surface tension of a liquid, allowing easier spreading, and lower the interfacial tension between two liquids. ... Modern toothpaste gel Toothpaste is a paste or gel dentifrice used to clean and improve the aesthetic appearance and health of teeth. ... This article or section does not cite its references or sources. ... Shaving cream is a cream that is applied to the face to avoid razor burn. ... The term has two distinct meanings, depending on whether the bubbles are in, or on top of, the bath water. ... In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ... An amphipathic (a. ... Laundry detergents are just one of many possible uses for detergents Detergent is a compound, or a mixture of compounds, intended to assist cleaning. ...

It is prepared by sulfonation of dodecanol (lauryl alcohol, C₁₂H₂₅OH) followed by neutralization with sodium carbonate. It is used in both industrially produced and home-made cosmetics. Chemical structure of sulfonic acid. ... Dodecanol, also known by its IUPAC name 1-dodecanol or dodecan-1-ol, and by its trivial name dodecyl alcohol and lauryl alcohol, is a fatty alcohol. ... Sodium carbonate (also known as washing soda or soda ash), Na2CO3, is a sodium salt of carbonic acid. ...

Like all detergent surfactants (including soaps), it removes oils from the skin, and can cause skin irritation. It is also irritating to the eyes. Laundry detergents are just one of many possible uses for detergents Detergent is a compound, or a mixture of compounds, intended to assist cleaning. ... This article is about the computer protocol. ... In zootomy and dermatology, skin is the largest organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs. ... // A human eye. ...

SDS can be converted by ethoxylation to sodium laureth sulfate (also called sodium lauryl ether sulfate; SLES), which is less harsh on the skin, probably because it is not as much of a protein denaturant as is the unethoxylated substance. Ethoxylation is a chemical process in which ethylene oxide (IUPAC name: 1,2-epoxyethane) is added to fatty acids in order to make them more soluble in water. ... 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 probably the most researched anionic surfactant compound.

In laboratories, SDS is commonly used in preparing proteins for polyacrylamide gel electrophoresis (SDS-PAGE). SDS works by disrupting non-covalent bonds in the proteins, thereby denaturing them, causing the molecules to lose their native shape (conformation). Also, anions of SDS bind to the main peptide chain at a ratio of one SDS anion for every two amino acid residues. This effectively imparts a negative charge on the protein that is proportional to the mass of that protein (about 1.4 g SDS/g protein). This new negative charge is significantly greater than the original charge of that protein. The electrostatic repulsion that is created by binding of SDS causes proteins to unfold into a rod-like shape thereby eliminating differences in shape as a factor for separation in the gel. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Polyacrylamide is an acrylate polymer formed from acrylamide subunits that is readily cross-linked. ... DNA electrophoresis apparatus. ... Picture of an SDS-PAGE. The molecular marker is in the left lane SDS-PAGE stands for Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ... Phenylalanine is one of the standard amino acids. ... The valence shell electron pair repulsion theory or VSEPR is a model in chemistry that aims to generally represent the shapes of individual molecules. ...

It has recently found application as a surfactant in gas hydrate or methane hydrate formation reactions, increasing the rate of formation as much as 700 times.^[1] Hydrates are compounds formed by the union of water with some other substance, generally forming a neutral body, as certain crystallized salts. ... Burning ice. Methane released by heating burns, water drips. ...

Safety concerns relating to SDS

A number of safety concerns about SDS have been raised in published reports.^[2][3][4] These include claims that:

• SDS causes a number of skin issues (for which the non-specific term is dermatitis), with some people being affected more than others.^[4][5][6]
• When combined with certain chemicals, SDS may become a carcinogen.^{[citation needed]}
• Although SLES is slightly less irritating than SDS, the liver is unable to metabolize SLES.^{[citation needed]}
• SDS is known to cause aphthous ulcers, commonly referred to in some countries as "canker sores".^[7][8]
• SDS may be used in place of the less irritant SLES in many soaps, shampoos, washing powders, toothpastes and other bathroom products because of its lower cost.

The American Cancer Society denied that SDS is carcinogenic, and points out that the substance, while undoubtedly a skin irritant, is dangerous only at higher concentrations than those used in cosmetics.^[9] Furthermore, the Environmental Working Group has claimed in their Skin Deep Report that SLS is a penetration enhancer.^[10] Dermatitis is a blanket term literally meaning inflammation of the skin. It is usually used to refer to eczema, which is also known as Dermatitis eczema. ... The hazard symbol for carcinogenic chemicals in the Globally Harmonized System. ... An aphthous ulcer or canker sore is a type of mouth ulcer which presents as a painful open sore inside the mouth caused by a break in the mucous membrane. ... The Environmental Working Group is a public watchdog group specializing in environmental investigations in the areas of toxins, agricultural subsidies, public lands, and corporate accountability. ... Skin Deep is an ongoing research project of the Environmental Working Group to catalogue and evaluate the botanical and chemical ingredients in cosmetics products. ...

Data

• The critical micelle concentration in pure water at 25°C is 0.0082 M, and the aggregation number at this concentration is usually considered to be about 50. The micelle ionization fraction (α) is around 0.3 (or 30%).^[11]
• The Optical refractive index increment of a pure aqueous solution at wavelength 532 nm is about 0.1070 ml/g.^{[citation needed]}

In chemistry, the critical micelle concentration (CMC) is defined as the concentration of surfactants in free solution in equilibrium with surfactants in aggregated form. ...

See also

• Sodium laureth sulfate

Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpaste etc. ...

References

1. ^ Kazuyoshi Watanabe, Shuntaro Imai and Yasuhiko H. Mori. Surfactant effects on hydrate formation in an unstirred gas/liquid system: An experimental study using HFC-32 and sodium dodecyl sulfate. Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522. Japan.Chemical Engineering Science. Volume 60, Issue 17, September 2005, Pages 4846-4857. Abstract
2. ^ Agner T. Susceptibility of atopic dermatitis patients to irritant dermatitis caused by sodium lauryl sulphate. Acta Derm Venereol. 1991;71(4):296-300. PMID 1681644
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} Marrakchi S, Maibach HI. Sodium lauryl sulfate-induced irritation in the human face: regional and age-related differences. Skin Pharmacol Physiol. 2006;19(3):177-80. Epub 2006 May 4. PMID 16679819
5. ^ CIR publication. Final Report on the Safety Assessment of Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate. Journal of the American College of Toxicology. 1983 Vol. 2 (No. 7) pages 127-181.
6. ^ Loffler H, Effendy I. Skin susceptibility of atopic individuals. Department of Dermatology, University of Marburg, Germany. Contact Dermatitis. 1999 May;40(5):239-42. PMID 10344477
7. ^ Chahine L, Sempson N, Wagoner C. The effect of sodium lauryl sulfate on recurrent aphthous ulcers: a clinical study. Compend Contin Educ Dent. 1997 Dec;18(12):1238-40. PMID 9656847
8. ^ Herlofson BB, Barkvoll P. The effect of two toothpaste detergents on the frequency of recurrent aphthous ulcers. Acta Odontol Scand. 1996 Jun;54(3):150-3. PMID 8811135
9. ^ Debunking the Myth. American Cancer Society. 1998/09/23. Article
10. ^ Skin Deep Report. Environmental Working Group. Revised October 1995. SLS Rating
11. ^ Barney L. Bales, Luis Messina, Arwen Vidal, Miroslav Peric, and Otaciro Rangel Nascimento. Precision Relative Aggregation Number Determinations of SDS Micelles Using a Spin Probe. A Model of Micelle Surface Hydration. J. Phys. Chem. B. 1998 102(50)10347-10358. Abstract

External links

• Sodium Lauryl Sulfate: chemical data sheet from chemicalland21.com
• Tom of Maine's FAQ: Is sodium lauryl sulfate (SLS) safe for use?
• Urban Legends Reference Pages: Shampoo Sham, snopes.com