Behenyl alcohol is a plant-based emulsifier and thickening agent. It is considered a fatty alcohol which is by far the best type of alcohol for skin care and cosmetics. This is because it acts as both an emulsifier and emollient, but more on that below.
As an emulsifier, behenyl alcohol, holds the water and oils together in cosmetics. It is typically made from the fats in vegetable oils.
However, the greatest thing about fatty alcohols is they aren't drying or irritating on your skin, as some other alcohols might be. Instead, because of the "fatty" part of the molecule, they also act as an emollient. This means that they protect your skin and keep the moisture in your skin.
Behenyl alcohol is actually a really common ingredient, and unfortunately can be made synthetically as well. It is important to look out for natural behenyl alcohol in your products, but all in all, this is one of the best fatty alcohols and is healthy for your skin.