Laureth-4
Lauryl alcohol ethoxylate
I. Basic Information
Laureth-4 (INCI name: Laureth-4, CAS No. 68439-50-9, EC No. 500-213-3) is a non-ionic surfactant belonging to the ethoxylated fatty alcohol family, with the general formula ( \text{C}{12}\text{H}{25}\text{O}(\text{C}_2\text{H}_4\text{O})_4\text{H} ) and a molecular weight of approximately 370 g/mol ^.
It is also known by numerous synonyms, including Alcohols, C12-14, ethoxylated, PEG-4 lauryl ether, polyoxyethylene(4) lauryl ether, and trade names such as Brij® L4, ROKAnol® L4, and Dehydol LS 2 ^. The Cosmetic Ingredient Review (CIR) Expert Panel has concluded that Laureth-4 is safe for use in cosmetics when formulated to be non-irritating, with no evidence of mutagenicity or developmental toxicity ^.
II. Physical & Chemical Properties
Laureth-4 is typically a clear to slightly turbid, colorless liquid at room temperature, with a faint, characteristic odor and a Hazen color scale maximum value of 70 ^. Key properties include:
Thermal characteristics: Melting point of 5.55°C, boiling point of 266.95°C at 101.4 kPa, and a vapor pressure of 1.47 Pa at 38°C ^.
Solubility: Sparingly soluble in water (1.3 mg/L at 20°C) but readily miscible with low aliphatic alcohols (methanol, ethanol), acetone, and non-polar organic solvents ^.
Rheological behavior: Forms gel phases at medium concentrations when mixed with water, which can be suppressed by adding warm water, alcohols, or electrolytes during processing ^.
Chemical stability: Stable under recommended storage conditions, with a pH range of 5.0–7.0 in 1% aqueous solution, and exhibits resistance to hard water, acids, and alkalis ^.
III. Production Methods
Laureth-4 is produced via the ethoxylation of lauryl alcohol (C12–C14 fatty alcohol) with 4 moles of ethylene oxide (EO) under controlled temperature and pressure, typically using a basic catalyst such as potassium hydroxide ^.
The process involves:
Initiation: Lauryl alcohol reacts with ethylene oxide to form a monoethoxylated intermediate.
Propagation: Subsequent addition of 3 more moles of ethylene oxide to achieve the target 4 EO units.
Neutralization and purification: The final product is neutralized, filtered, and refined to remove unreacted starting materials and byproducts ^.
The raw materials can be derived from renewable plant sources (e.g., coconut oil) or produced synthetically, with the linear, even-numbered carbon chain contributing to its biodegradability ^.
IV. Applications
Laureth-4's unique combination of emulsifying, wetting, and stabilizing properties makes it versatile across multiple industries:
Cosmetics & Personal Care: Used as an emulsifier, surfactant, and antistatic agent in shampoos, body cleansers, hair styling products, skin creams, and cosmetics. It stabilizes oil-water emulsions, improves texture, enhances foam formation, and reduces static electricity in hair ^.
Household & Industrial Cleaning: Functions as a decontaminant and foaming agent in hand sanitizers, laundry detergents, and metal cleaners, effectively removing soil and grease while maintaining mildness ^.
Textile Industry: Serves as an emulsifier and wetting agent in textile printing and dyeing processes, improving dye penetration and uniformity ^.
Other Applications: Used as a pesticide emulsifier, crude oil demulsifier, and lubricating oil emulsifier, and as a pharmaceutical excipient in topical formulations ^.
V. Application Cases
Cosmetics: Hydrating Facial Emulsion
A leading skincare brand incorporated 2–3% Laureth-4 into its daily moisturizing emulsion to stabilize the oil-in-water (O/W) system. The surfactant improved the spreadability of the product, enhanced skin hydration by forming a protective barrier, and prevented phase separation during 24-month shelf-life testing ^.Household Cleaning: Mild Hand Sanitizer
A consumer goods manufacturer used Laureth-4 as a co-surfactant in an alcohol-based hand sanitizer. It reduced the harshness of ethanol on skin, improved the solubility of emollient ingredients, and provided a non-sticky afterfeel, while maintaining effective germ-killing properties ^.Textile Industry: Dyeing Auxiliary
A textile mill applied Laureth-4 as a wetting agent in cotton fabric dyeing. It reduced the surface tension of the dye bath, ensuring uniform dye penetration and reducing water and energy consumption by 15% compared to traditional surfactants
Shanghai Better Chemical Co., Ltd. was established in 2005, specializing in fatty alcohols, fatty acids, glycerin, white oil, and petroleum jelly. These products serve a wide range of industries, including personal care, flavor & fragrance, textiles, plastics, food, pharmaceuticals, stationery, construction, and coatings. With 21 years of professional experience, the company has earned consistent recognition across the industry and established partnerships with over 4,000 clients. It maintains a skilled technical team, efficient warehouse operations, high-quality pre- and after-sales services, and lightning-fast logistics. We look forward to collaborating with you. For inquiries, please call: +86 21 5102 9963.