Refined Castor Oil

About This Product

Castor oil is expressed from the seed of Ricinus communis, the castor bean plant, and refined to remove the toxic protein ricin, which stays in the seed meal and is not present in the oil. It carries CAS number 8001-79-4 and the INCI name Ricinus Communis Seed Oil. India dominates world production. The refined oil is a pale, viscous liquid with a faint odour. What sets castor oil apart is chemical rather than agricultural. Ricinoleic acid makes up 85 to 90 percent of its fatty acids, and is the only common fatty acid carrying a hydroxyl group on the chain, at carbon 12. That single hydroxyl group changes everything: it lets the molecules hydrogen-bond to one another, which is why the oil is roughly ten times more viscous than most vegetable oils, and polar enough to dissolve in alcohol, which almost no other vegetable oil does. Typical values are an iodine value of 82 to 90, saponification value 176 to 187 and viscosity of 650 to 700 centipoise at 25 degrees Celsius. The hydroxyl functionality makes castor oil a chemical building block, not just an oil. It is used to make polyurethane polyols, alkyd resins, sebacic acid, undecylenic acid and 12-hydroxystearic acid for lithium greases, and directly in cosmetics and lip products for gloss and pigment wetting, in printing inks, textile finishing and lubricants. Bio Green Oils and Fats supplies cold-pressed and refined castor oil to specification on ricinoleic content, iodine value, acid value, moisture, colour and viscosity.