Hydrogenated castor oil occurs as a fine, almost white or pale yellow powder or flakes. The PhEur 6.0 describes hydrogenated castor oil as the oil obtained by hydrogenation of virgin castor oil. It consists mainly of the triglyceride of 12-hydroxystearic acid.
Hydrogenated castor oil — also called HCO or castor wax — is a hard, white, opaque vegetable wax. Its resistance to moisture makes it useful in many coatings, greases, cosmetics, polishes and similar applications.
The wax is created by hydrogenating pure liquid castor oil, which is obtained from castor beans. The oil is heated under extreme pressure using a nickel catalyst during the hydrogenation process. Afterward, the hydrogen creates saturated molecules of castor wax, which gives the oil a higher melting point that allows it to remain solid at room temperature. After hydrogenation, the oil becomes hard and brittle to the touch.
