This U.S. industry comprises establishments primarily engaged in one or more of the following: (1) manufacturing shortening and margarine from purchased fats and oils; (2) refining and/or blending vegetable, oilseed, and tree nut oils from purchased oils; and (3) blending purchased animal fats with purchased vegetable fats. Cross-References. Establishments primarily engaged in-- ? Refining and/or blending soybean oil in soybean crushing mills--are classified in U.S. Industry 311222, Soybean Processing; ? Refining and/or blending corn oil made by wet corn milling--are classified in U.S. Industry 311221, Wet Corn Milling; ? Refining and/or blending oilseeds (except soybeans) and tree nuts in crushing mills--are classified in U.S. Industry 311223, Other Oilseed Processing; and ? Rendering or refining animal fats and oils--are classified in Industry 31161, Animal Slaughtering and Processing.