What it is
Beheneth-20 is the polyethylene glycol ether of behenyl (C22) alcohol with an average of about 20 ethylene oxide units, making it a nonionic, water-dispersible surfactant. In cosmetics, including sunscreens, it is used to emulsify oil and water phases and to stabilize the formula, helping create a uniform, spreadable product. Its long behenyl chain also lends a smooth skin feel to the finished emulsion.
Safety & warnings
Ethoxylated fatty alcohols like Beheneth-20 are generally well tolerated as emulsifiers at usual concentrations. As a mild nonionic surfactant it has low irritation potential, though as with PEG-type ingredients, trace processing impurities are controlled by good manufacturing practice. It is not a recognized fragrance allergen.
Origin & sourcing
Synthetic; manufactured by ethoxylating behenyl alcohol, which is typically derived from plant oils, with ethylene oxide.
Questions everyone asks
What is Beheneth-20 used for?
It is a nonionic surfactant and emulsifier that helps blend oil and water and stabilize the texture of a formula.
Is it a UV filter?
No. It is a formulation aid and does not provide sun protection.