Sodium dodecyl sulfate
[CAS# 151-21-3]

Identification

• Classification: Surfactant >> Anionic surfactant >> Sulfate type
• Name: Sodium dodecyl sulfate
• Synonyms: Lauryl sulfate sodium salt; Sulfuric acid monododecyl ester sodium salt
• Molecular Formula: C₁₂H₂₅NaO₄S
• Molecular Weight: 288.38
• CAS Registry Number: 151-21-3
• EC Number: 205-788-1
• SMILES: CCCCCCCCCCCCOS(=O)(=O)[O-].[Na+]

Properties

• Melting point: 206 °C
• Flash point: 170 °C
• Water solubility: ca. 150 g/L (20 °C)

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07 Danger
• Risk Statements: H228-H302-H315-H318-H319-H332-H335-H412
• Safety Statements: P210-P240-P241-P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P370+P378-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Flammable solids	Flam. Sol.	1	H228
Flammable solids	Flam. Sol.	2	H228
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	4	H312
Skin corrosion	Skin Corr.	1B	H314
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	3	H302
Skin corrosion	Skin Corr.	1A	H314
Flammable liquids	Flam. Liq.	1	H224
Respiratory sensitization	Resp. Sens.	1	H334
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	2	H300
Specific target organ toxicity - single exposure	STOT SE	3	H336

• Transport Information: UN 2926

Discovery and Applications

Discovered in the early 20th century, sodium dodecyl sulfate is derived from lauryl alcohol, a naturally occurring fatty alcohol found in coconut and palm kernel oils. Through a process of sulfonation and neutralization, lauryl alcohol is converted to SDS, an amphiphilic compound that possesses both hydrophilic (water-attracting) and hydrophobic (water-repelling) properties.

One of the defining characteristics of SDS is its exceptional surfactant properties. As a surfactant, SDS has the ability to reduce the surface tension of aqueous solutions, enabling it to act as an emulsifier, foaming agent, and detergent. This unique property has led to its widespread use in industries ranging from pharmaceuticals and personal care to agriculture and food.

In the pharmaceutical field, SDS plays an important role in drug formulation and delivery. It is often used as a solubilizer in the preparation of oral and topical medications, helping to disperse poorly water-soluble drugs and improve their bioavailability. Additionally, SDS is used in the production of diagnostic reagents and laboratory assays, where its surfactant properties aid in the solubilization and stabilization of biomolecules.

SDS is a major ingredient in personal care products, including shampoo, soap, and toothpaste. Its foaming and cleansing properties make it an effective surfactant that removes dirt, oil, and debris from the skin and hair, giving a clean, fresh feeling. In addition, SDS is a key ingredient in cosmetic and skincare formulations, helping to stabilize emulsions and improve product texture.

In agriculture, SDS is used as a wetting agent and dispersant in pesticide formulations. By reducing the surface tension of spray solutions, SDS allows pesticides to more evenly cover and penetrate plant surfaces, thereby increasing their effectiveness in pest control. SDS is also used in soil science research to help disperse soil particles for analysis and testing.

In the food industry, SDS plays an important role in all aspects of food processing and production. It is used as a food additive and emulsifier in dairy products, baked goods, and processed foods to help improve texture, stability, and shelf life. In addition, SDS is used in analytical techniques such as gel electrophoresis to denature proteins and separate DNA fragments based on size.

Despite its wide range of uses, SDS use is not without controversy, especially regarding its potential environmental impact and health risks. While safe when used at regulated concentrations, excessive exposure to SDS may cause irritation to the skin, eyes, and respiratory tract. Additionally, SDS has been linked to aquatic toxicity and environmental contamination, highlighting the importance of responsible disposal practices.

References

2025. Activated carbon co-modified by chitosan and SDS for targeted removal of aflatoxins from fragrant peanut oil. Food Chemistry, 463(Pt 2).
DOI: 10.1016/j.foodchem.2024.141479

2025. Quantitative analysis of excipients to the permeability of BCS class III drugs. International Journal of Pharmaceutics, 664.
DOI: 10.1016/j.ijpharm.2024.124958

2025. Chromosome mis-segregation triggers cell cycle arrest through a mechanosensitive nuclear envelope checkpoint. Nature Cell Biology, 27(1).
DOI: 10.1038/s41556-024-01565-x