Castor wax, also called hydrogenated castor oil, is a hard, brittle, vegetable wax. It is produced by the hydrogenation (chemical combination with hydrogen) of pure castor oil, in the presence of a nickel catalyst. It is odorless and insoluble in water.
Castor wax is used in polishes, cosmetics, electrical capacitors, carbon paper, lubrication, and coatings and greases where resistance to moisture, oils and petrochemical products is required. Castor wax is also useful in polyurethane coating formulation, as it contains three secondary hydroxyl group. These coating compositions are useful as a top coat varnish for leather, wood & rubber. Castor wax can also be added to beeswax for encaustic painting.