Oils, fats and waxes are an essential constituent of many cosmetic products with many sources, properties and claims. For the purpose of this feature, oils will be considered as any liquid that is immiscible with water including hydrocarbons, vegetable oils and esters, but excluding silicones.
Vegetable oils comprise natural esters of glycerol and various fatty acids which are liquid at room temperature, whereas fats are solid at room temperature. Waxes are esters of long-chain alcohols and a fatty acid – and (except for Simmondsia chinensis (jojoba) seed oil) they are solid at room temperature.