A drying oil obtained chiefly from menhaden, pilchard, sardine, and herring. Extracted from the entire body of the fish by cooking and compressing. Should not be confused with fish-liver oil. It contains approximately 20% polyunsaturated fatty acids, which enables it to lower cholesterol content of the human diet. Chemically modified fish oil is used in soaps, detergents, protective coatings, and alkyd resins. The hydrogenated product is used as a base for margarines and shortenings and as an industrial dispersing agent.