Chemically Modified Animal, Vegetable, or Microbial Fats and Oils; Inedible Mixtures

Heading 1516 covers hydrogenation, interesterification, reesterification, and elaidinization. Heading 1518 captures more extensive chemical transformations — boiling, oxidation, dehydration, sulfurization, blowing, or polymerization — as well as inedible mixtures. If a product has undergone any of these latter processes, it classifies under 1518 rather than 1516, regardless of the original fat or oil source.

Customs may scrutinize whether a product is truly inedible or merely a food-grade fat in a different form. Importers should provide a manufacturer's specification sheet confirming the chemical modification process, the intended industrial end-use, and any denaturants or additives that render the product unfit for human consumption. This documentation supports the 1518 classification and helps avoid referral to FDA for food-admissibility review.