Ricinus communis (castor) seed oil is a vegetable oil derived from the castor bean, which is known as a rich source of skin-friendly fatty acids. It is used in skin care formulations as an emollient, although its unique property is that when it dries it forms a solid film that can have water binding properties. It can also increase the absorption of other cosmetic ingredients.
Depending on the other ingredients combined with in a formulation, Ricinus communis (castor bean) seed oil may have a slightly sticky feeling on the skin. It is known to remain liquid at extremely high and very low temperatures.
Ricinus communis (castor bean) seed oil is rarely associated with skin sensitivity and has been deemed safe by the Cosmetic Ingredient Review Expert Panel. Their 2007 report looked at personal care products that use up to 81% of Ricinus communis (castor bean) seed oil. https://www.paulaschoice.com/ingredient-dictionary/ingredient-ricinus-communis-castor-seed-oil.html?q=Rinus%20Communis%20Seed%20Oil&fdid=ingredients