A wide variety of uses exist for the thick and viscous nature of castor oil, extracted from the castor seed, and its derivatives in the food, beauty and pharmaceutical industries. In addition, it is US FDA approved to treat skin disorders and is a component of many drugs. Different formulations (or grades) of castor oil serve distinct purposes.
Cold Pressed
Cold pressed castor oil formulations use expeller pressing---a mechanical, non-chemical method of extracting oil from seeds and nuts---to extract the oil in a heat controlled (under 120 degrees Fahrenheit) environment. Consumers use this type of formulation as a skin care emollient or laxative to ease constipation.
Hydrogenated
The addition of hydrogen with a nickel catalyst produces hydrogenated castor oil or castor wax. This is a brittle, hard and insoluble formulation used to resist oil and moisture in many commercial applications. These include waxes, polishes, crayons, candles, paper coating for food packages and manufacturing greases.
Other Commercial and Industrial Formulations
Numerous formulations of caster oil are used in the production of textile chemicals, electronics, telecommunications, rubber and paints. For example, manufacturers use castor meal, the remaining residue after extracting the oil, to produce fertilizers.
Brown castor oil is a derivative that is more viscous; manufacturers produce it by bubbling air through castor oil at higher temperatures. Companies use this derivative as a plasticizer (a substance that makes materials more pliable) for adhesives, inks and lacquers (see Reference 8).