Castor oil (or ricinus oil) is a nonvolatile fatty oil extracted from plants. It has been used for many years as a purgative, i.e. a material that induces vomiting. It has the advantage over other mineral oils that it is a renewable resource, is bio-degradable and eco-friendly.
Source

Castor oil comes from the seeds of the castor bean. It is extracted by either pressing or solvent extraction.

The beans themselves are produced primarily in India and Brazil and to a lesser extent China.
Characteristics

· Castor oil consists almost entirely of the triglycerides ricinoleic acid

· It is ranges in colour from colourless to greenish.

· It is a viscous liquid

· Non-drying

· It has a faint but characteristic odour

· It has a slightly acrid taste and leaves a nauseating after taste.

· Many derivatives can be produced which have a similar chemical composition to petroleum based oils
Derivatives
Blown Castor Oil

Blown Castor oil is a derivative that has a higher viscosity and specific gravity compared to natural castor oil. These properties are induced by bubbling air thorough it at elevated temperatures. Its main use is as a plasticiser for inks, lacquers and adhesives.
Hydrogenated Castor Oil

Hydrogenated castor oil (HCO) or castor wax is a hard, brittle wax that is insoluble. It is produced by adding hydrogen in the presence of a nickel catalyst. It is mainly used for coatings and greases where resistance to moisture, oils and other petrochemical products is required.