Castor oil is used as an ingredient in food, medicine and cosmetics. Despite its advantages, like all oils, castor oil leaves a greasy, stubborn stain when spilled on fabric. The oil seeps into delicate clothing and, if not treated quickly, it will stain the fabric permanently. Pretreatment before laundering the item is the best way to prevent this from happening. Most aerosol stain removers get rid of castor oil if applied to soiled fabric soon after the spill occurs.
Apply a pretreatment aerosol laundry stain remover to the castor oil stain. Allow the stain remover to soak into the castor oil for one minute.
Rub the castor oil stain with heavy-duty liquid laundry detergent.
Launder the item according to its care tag instructions. Take the item to a dry cleaner if the tag says "dry clean only." Do not attempt to wash it in your washing machine.
Rub dry cleaning solvent on the back of the stained area if laundering the item did not remove the stain. Apply the solvent while holding the item over paper towels to catch any spills.
Add oxygen bleach or chlorine bleach to the washing machine. Launder the item again.