Castor Oil

castor oil, yellowish oil obtained from the seed of the castor bean. The oil content of the seeds varies from about 20% to 50%. After the hulls are removed the seeds are cold-pressed. Medicinal castor oil is prepared from the yield of the first pressing; this is used as a purgative and laxative. Oil from the second pressing is used as a lubricant for machinery, as a softening agent in making artificial leather, in the dressing of genuine leather, in brake fluids, and in paints and plastic materials. The residue can be used as fertilizer and (after the poisonous substance, ricin, is removed) as cattle feed. Other products having similar properties and uses have been gradually replacing castor oil.

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castor oil

a colourless or yellow glutinous oil obtained from the seeds of the castor-oil plant and used as a fine lubricant and as a cathartic

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castor oil [′kas·tər ¦ȯil]

(materials)

A colorless or greenish nondrying oil extracted from the castor bean; used as a cathartic, in soap, and after processing as a lubricant, and as a leather preservative. Also known as ricinus oil.

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Castor Oil 

a fatty vegetable oil obtained from the seeds of the castor-oil plant. It is one of the nondrying liquid oils; it contains 3–9 percent oleic acid, 3–5 percent linoleic acid, and at least 80 percent ricinoleic acid. The high content of the ricinoleic acid is responsible for the properties of castor oil: high kinematic viscosity (more than X 10 ^-6 m²/sec at 50°C) and density (950–974 kg/m3 at 15°C). Unlike other fatty vegetable oils, it is readily soluble in alcohol but poorly soluble in benzine.

Castor oil is widely known for its medicinal properties. The ancient Egyptians used it to make all kinds of ointments and balms. It is best known for its use as a laxative. Combined with quinine, Pituitrin, pachycarpinum, and other substances, it is used to induce labor. Ointments and balms containing castor oil are used in the treatment of burns and ulcers, softening of the skin, and so forth. Castor oil has also found application in some branches of industry—for example, soap manufacture and oil boiling. Castor oil is a high-grade lubricant.