What it is
Ceteareth-25 is made by reacting cetearyl alcohol (a blend of cetyl and stearyl alcohols) with about 25 units of ethylene oxide, giving a nonionic ethoxylated compound. The relatively high degree of ethoxylation makes it water-loving, so it functions as an oil-in-water emulsifier and helps disperse oily ingredients into water-based systems. In sunscreens and lotions it contributes to a stable, uniform emulsion.
Safety & warnings
Ceteareth compounds are widely used and generally well tolerated in rinse-off and leave-on products. Because they are ethoxylated materials, manufacturers control for residual 1,4-dioxane through purification. They are not fragrance allergens.
Origin & sourcing
It is a synthetic ingredient produced by ethoxylating fatty alcohols, which may themselves be derived from plant or petrochemical sources.
Questions everyone asks
What is Ceteareth-25 used for?
It is a nonionic emulsifier that helps blend oil and water phases into a stable cream or lotion.
Is Ceteareth-25 a fatty alcohol?
No. It is an ethoxylated derivative of the fatty alcohol cetearyl alcohol, which makes it more water-compatible and gives it surfactant properties.