Castor oil’s shelf life depends on storage conditions, reactions, and spoilage. Optimal storage includes cool temperatures, minimal light, minimal air exposure, and low humidity. Over time, castor oil can oxidize and become rancid due to chemical reactions. Spoilage may occur with unpleasant odor, discoloration, or separation. To preserve castor oil, store it properly in a dark, cool place and discard it if spoiled or beyond its recommended shelf life for safety and effectiveness.