What Is It?

Laureth-4 and Laureth-23 are polyoxyethers of lauryl alcohol. They are a clear, colorless liquids. In cosmetics and personal care products, Laureth-4 and Laureth-23 are used in the formulation of a variety of bath, eye, facial, hair, cleansing and sunscreen products. They are also used in cuticle softeners, deodorants and moisturizing products.

Why Is It Used?

Laureth-4 and Laureth-23 both function as surfactants. Laureth-4 functions as a surfatant – emulsfying agent, while Laureth-23 functions as a surfactant – cleansing agent and a surfactant – solubilizing agent.

Scientific Facts

Laureth-4 and Laureth-23 are produced by reacting ethylene oxide with lauryl alcohol. The numerical designation refers to the average number of repeating ethylene oxide units in the molecule. As the numerical value of Laureths increases, the viscosity of the ingredient increases until they become white, waxy solids.

Safety Information

The safety of Laureth-4, and Laureth-23, has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Laureth-4 and Laureth-23 were safe as cosmetic ingredients in the present practices of use and concentration. In 2003, as part of the scheduled re-evaluation of ingredients, the CIR Expert Panel considered available new data on Laureth-4 and Laureth-23 and reaffirmed the above conclusion.

CIR Safety Review: In preparing the report on Laureth-4 and Laureth-23, the CIR Expert Panel also reviewed safety test data on closely related Laureths and other ethoxylated lauryl alcohol compounds that are in consumer products, but not in cosmetics and personal care products. Developmental toxicity, multiple generation and fertility data, as well as mutagenicity data were all negative for these compounds. These data supported the CIR Expert Panel’s conclusion that Laureth-4 and Laureth-23 were safe for use in cosmetics and personal care products.

Small amounts of 1,4-dioxane, a by-product of ethoxylation, may be found in the Laureth ingredients. The potential presence of this material is well known and can be controlled through purification steps to remove it from the ingredients before blending into cosmetic formulations.

Link to more information about what the Food and Drug Administration (FDA) is doing to assure that cosmetics do not contain unsafe levels of 1,4-dioxane.

Laureth-4 and Laureth-23 may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.

More Scientific Information

Laureth-4 is the polyethylene glycol ether of lauryl alcohol that contains an average value of 4 repeating ethylene oxide units, while Laureth-23 contains an average of 23 repeating ethylene oxide units. These ingredients are useful in cosmetic and pharmaceutical products as surfactants, emulsifiers and solubilizers. Their use is particularly attractive in light of their chemical inertness to hydrolytic decomposition.