Castor Oil

Ricinus communis

Geography

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.

About the Plant

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.

History and Manufacture

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.

Analytical data sheet

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.

Reproduced with permission from AMI and
L’Ami des ingredients Naturel, l’encyclopedie, a multimedia
encyclopedia AMI have produced and distributed for the industry.