Laureth-4 is a non-ionic surfactant with emulsifying, wetting and stabilising properties. It can be found in most products for skin hygiene and care, including washing agents, creams, hair styling products and other leave-on compositions. It is also readily used as a component in textile industry processes.
Laureth-4 is the INCI name of the surfactant, which is an ethoxylated derivative of lauryl alcohol. The chemical name of this compound is polyethylene glycol dodecyl ether or polyethylene glycol lauryl ether. For Laureth-4, the CAS number, which is frequently stated in the description/characteristics of a substance and helps to identify it, is 68439-50-9. The substance may be obtained from plants or produced fully synthetically.
The basic physical and chemical properties that characterise Laureth-4:
The substance is a popular surfactant used as an ingredient of body care and hygiene products. As a surfactant, Laureth-4 lowers the surface tension between two immiscible phases (two liquids or a liquid and a solid) and enables them to combine, i.e. form an emulsion (cosmetics largely come as emulsions). A molecule of Laureth-4 has a hydrophilic part that is attracted to the water phase and a hydrophobic part that is attracted to the oil phase. On account of those properties, surfactants such as Laureth-4 can remove oily impurities, dirt and other contaminants accumulated on the skin. As an emulsifier, Laureth-4 improves the consistency of cosmetic products, which helps ensure even application and achieve local care benefits. It is particularly important because cosmetic formulations, as emulsions, tend to break due to improper storage or settlement of the product over time. Thus emulsifiers are for example used to maintain the constant dispersion of phases. Laureth-4 also boosts the effects of other detergents, increases the viscosity of formulations and as an ingredient of shampoos prevents the hair from picking up static.
Non-cosmetic applications of Laureth-4 are mostly based on its emulsifying properties. As an emulsifier, it is used in household products (cleaners, dishwashing liquids) and in lubricating products (mostly preparations based on silicone).
The textile industry uses Laureth-4 as an additive in formulations for removing oily stains from woven/knitted fabrics that appear during industrial knitting/weaving processes. Laureth-4 features good wetting properties. When in contact with cotton fabrics, the drops of a liquid containing this surfactant are freely spread all over the surface and also penetrate the pores of a textile (reducing the surface tension, which makes it possible to wet the fabric quickly). Due to its wetting capacity, Laureth-4 is an ingredient of bleaching compositions used in the processes of bleaching raw cotton woven/knitted fabrics. It is also an important ingredient that removes excess dyes from dyebaths at the final stages of textile dyeing stages.
The following products contain Laureth-4 as one of their ingredients:
