Specimen bottle containing castor oil seeds

Specimen bottle containing castor oil seeds (Ricinus communis) from Sierra Leone

Across many regions of West Africa, including Sierra Leone, castor seeds have been pressed to extract their versatile oil.

Castor oil has been valued for its wide range of medicinal and practical applications. In medical systems across across Africa, Asia and the Americas, the oil has been used for its laxative and purgative benefits as well as for treating wounds and inflammation. Beyond medicine, it has also been used as lamp oil and engine lubricant.

During the mid-1700s, castor oil became common as a household medicine in colonial America and Caribbean. Castor bean plants were introduced from Africa through the transatlantic trade. Enslaved Africans carried knowledge of the plant and its medicinal properties, passing these uses down to their descendants.

Castor oil can still be found in cosmetic, medicinal, and industrial products. While processed castor oil is safe for human use, ricin, a poisonous protein to humans and animals, can also be found in varied amounts throughout the plant. This could cause health problems for workers that harvest it by hand.