Castor oil is a vegetable oil obtained from the castor bean (technically castor seed as the castor plant, Ricinus communis, is not a member of the bean family).
Castor oil has an unusual composition and chemistry, which makes it quite valuable. Ninety percent of fatty acids in castor oil are ricinoleic acid. Ricinoleic acid, a monounsaturated, 18-carbon fatty acid, has a hydroxyl functional group at the twelveth carbon, a very uncommon property for a biological fatty acid. This functional group causes ricinoleic acid (and castor oil) to be unusually polar, and also allows chemical derivitization that is not practical with other biological oils. Since it is a polar dielectric with a relatively high dielectric constant (4.7), highly refined and dried Castor oil is sometimes used as a dielectric fluid within high performance high voltage capacitors.
Castor oil maintains its fluidity at both extremely high and low temperatures. Sebacic acid is chemically derived from castor oil. Castor oil and its derivatives have applications in the manufacturing of soaps, lubricants, hydraulic and brake fluids, paints, dyes, coatings, inks, cold resistant plastics, waxes and polishes, nylon, pharmaceuticals and perfumes. In internal combustion engines, castor oil is renowned for its ability to lubricate under extreme conditions and temperatures, such as in air-cooled engines. The lubricants company Castrol takes its name from castor oil. However, castor oil tends to form gums in a short time, and its use is therefore restricted to engines that are regularly rebuilt, such as motorcycle race engines.
The poison ricin is made from the byproducts in the manufacture of castor oil.
Medicinal use of castor oil
The medical use of castor oil was originally discovered by the Ancient Egyptians possibly as early as 4000 BC. Currently, about 1 % of global castor oil production goes into medical or health store products. It is used to ease constipation and as an emetic to induce vomiting. Consumption of large amounts of castor oil (below lethal doses, such as one bottle) can induce labor in near-term pregnant women. Castor oil, in early American times, was often administered to children as a disciplinary measure.
Castor oil as a tool of political terror
In Fascist Italy under the regime of Benito Mussolini, castor oil was one of the tools of the blackshirts. Political dissidents were force-fed large quantities of castor oil by Fascist paramilitary groups. This technique was said to have been originated by Gabriele D'Annunzio. Victims of this treatment would experience severe diarrhea and dehydration, often resulting in death.
Sometimes when the blackshirts wished to make sure that the victim would die rather than simply be badly disabled, they would mix gasoline with the castor oil.
It is said that Mussolini's power was backed by "the bludgeon and castor oil."
See also
Categories: Laxatives | Lubricants | Vegetable oils | Dielectrics | Cosmetic chemicals
