Castor oil
Castor is an annual herbaceous plant in our regions but can reach the size of a small tree in tropical Africa. Native to Abyssinia, it spread all over the world and acclimatized. Its big green or reddish-brown stem is hollow, with isolated and petiolate large alternate leaves. Up to one metre wide, they are palmate with 5 to 11 lobes, more or less deep and dentate. The inflorescence forms clusters or tops at the axil of the bracts. The plant is monoecious with the female flowers above the male flowers. The fruit is a capsule spiked with thorns which contains greyish, oval, fleshy and spotted seeds. Castor grows quickly. After picking, the capsules are laid out in sheds, in thin layers, until they are completely mature and then displayed to sunlight until total drying. Seeds are then harvested. The culture dates back to remote times, the Ancients already appreciated castor for its purgative properties. It was used in France from the Middle Ages to the 16th century and then seems to have sunk into oblivion until 1764. The Egyptians used it as a purgative, but also on hair and against ulcers. Dioscorides held the plant for an "unpleasant and painful purgative" but used to recommend it to get rid of "skin defects". The root has been used against kidney disorders and Hindus still use castor as an anti-rheumatic and against gout. Castor oil is extracted from the seeds after they have dried in the sun, and have been sorted, crushed, squeezed and warmed up. It is a thick and viscous liquid with a sickly sweet taste. Castor has many other uses besides its medicinal virtues : it makes dressing for fabrics, lighting, or a lubricant which was actually very sought after during World War I. It is also used in Chinese cooking. In China again, the leaves are used to breed a silkworm the silk of which is very appreciated. Castor oilcakes are a very good fertilizer. Castor is also cultivated as an ornamental plant.
Ricinus means tick in Latin. The origin remains nonetheless uncertain and it is unknown if it is because the seeds look very much like ticks that the plant earned its name or vice versa. Castor's magic powers are related to protection. Castor beans are believed to be protective in many areas : they are let to dry in small dishes, carefully out of reach of children because they are toxic. In northern Africa, castor oil is the staple element for many magic ointments. In Muslim countries, people having drunk alcohol are forced to take some.
Chemical composition
Average composition in fatty acids Ricinoleic acid 90 % Oleic acid 3 to 4 % Linoleic acid 3 to 4 % Castor oil moreover contains 0.5 to 1% unsaponifiables.
Cosmetic uses
Castor oil has hair conditioning and hair stimulant properties. It also has moisturizing virtues. It can be a compound of the oily phase. Like nearly all vegetable oils, it is a staple ingredient in soaps and detergents. Hydrogenated castor oil stabilizes emulsions. Castor oil is an excellent active principle in :
- products for normal, damaged and delicate hair, products for the scalp ;
- body products (sun oils, bath oils) ;
- face products for normal, combination and dry skin ;
- lip balms.
Usage level
Castor oil can be used in any cosmetic product as an active principle or as a carrier in the oily phase, without any proportion limit.
INCI name Castor (Ricinus communis) oil Customs tarification 15-15-30-90 CAS number 8001-79-4 EINECS number 232-293-8 Japan Castor oil : 001515 Virgin castor oil
Organoleptic analysis Colour Pale yellow Odour Specific Physico-chemical characteristics Density at 20°C 0.950 - 0.970 Solubility in ethanol Soluble Refractive index at 20°C 1.4750 - 1.4850 Acid index < 5.0 Iodine index 82 - 90 Peroxide value < 5.0 Percentage of unsaponifiables < 1 % The standard norm of this analytical data sheet are only indicative and could undergo modifications.
Keep away from light and heat.