Sodium lauryl ether sulfate
[CAS# 68585-34-2]

Identification

• Classification: Surfactant >> Industrial surfactant
• Name: Sodium lauryl ether sulfate
• Synonyms: (C10-C16) Alcohol ethoxylate sulfated sodium salt
• Molecular Formula: C₁₂H₂₅O.(C₂H₄O)₂.SO₃.Na
• Molecular Weight: 376.48
• CAS Registry Number: 68585-34-2
• EC Number: 500-223-8

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H315-H318-H319-H412
• Safety Statements: P264-P264+P265-P273-P280-P302+P352-P305+P351+P338-P305+P354+P338-P317-P321-P332+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Sodium lauryl ether sulfate (SLES) is synthesized by the ethoxylation and sulfation of lauryl alcohol, resulting in a surfactant with excellent cleansing and foaming properties. Chemically, it is an anionic detergent and surfactant with the molecular formula C12H25(OCH2CH2)nOSO3Na, where n represents the average number of ethylene oxide units. This structure helps reduce surface tension and enhances the dispersibility of water-insoluble materials.

The main application of SLES is in personal care products such as shampoos, body washes, and facial cleansers. It acts as a primary surfactant, removing dirt, oil, and impurities from the skin and hair. SLES produces rich foam, enhancing the sensory experience of cleansing while effectively dispersing active ingredients and fragrances throughout the formulation.

In addition to its cleansing properties, SLES contributes to the mildness of the formulation and helps maintain emulsion stability in creams and lotions. Its compatibility with a wide range of skin types makes it a top choice for dermatologically tested products, ensuring consumer safety and product efficacy.

Sodium lauryl ether sulfate is widely used in household and industrial cleaning products for its superior degreasing and soil-suspending abilities. In dishwashing detergents, laundry detergents, and all-purpose cleaners, SLES effectively removes stains and residue while leaving surfaces looking clean and fresh. Its foaming properties help suspend and remove soil particles, thereby improving overall cleaning performance.

The environmental impact of SLES is carefully managed through strict regulations and sustainable manufacturing and product formulation practices. Biodegradability studies ensure that SLES breaks down into non-toxic materials after use, minimizing its environmental impact. Manufacturers continue to explore environmentally friendly alternatives and technologies to further reduce environmental impact and promote sustainability in product development.

Sodium lauryl ether sulfate is safe for use in personal care and cleaning products when formulated according to regulatory guidelines. Rigorous testing ensures its safety for consumers and compatibility with other ingredients in the formulation. Adherence to quality control measures and safety protocols mitigates potential risks associated with skin and eye irritation, especially when used in high concentrations.

Ongoing research focuses on optimizing SLES formulations to meet consumers' evolving preferences for natural and sustainable ingredients. Innovations in biodegradable surfactants and green chemistry are designed to improve performance while reducing environmental impact. The move to sulfate-free and gentler alternatives reflects the industry's efforts to meet the needs and preferences of diverse consumers.

References

1. Synthesis: Weil, J. K., et al. (1954). "Sulfated fatty alcohols: Preparation of sodium laureth sulfate." Journal of the American Oil Chemists' Society, 31(10), 444-447.
DOI: 10.1007/BF02638574

2. Applications: Hunting, A. L. L. (1983). "Encyclopedia of shampoo ingredients: Sodium laureth sulfate as a surfactant." Cosmetics & Toiletries, 98(6), 59-62.

3. Review: Rieger, M. M. (1997). "Surfactants in cosmetics: Overview of sodium laureth sulfate." Surfactant Science Series, 68, 123-135.
DOI: 10.1201/9780203739273