Alumina (aluminum oxide) is the refined intermediate product produced from bauxite before smelting; it is classified in HTS Chapter 28 as a chemical compound. Primary aluminum metal, produced by electrolyzing alumina, is classified in HTS Chapter 76. Section 232 tariffs target aluminum articles and primary aluminum, while alumina's Section 232 treatment has been handled separately. Importers should verify current applicability for each product form with a licensed customs broker.

Primary aluminum smelting is among the most electricity-intensive industrial processes, so production concentrates in regions with low-cost hydroelectric or other power. This structural cost advantage for foreign smelters — particularly in countries with subsidized energy — has historically driven antidumping and countervailing duty petitions in the US market. Trade professionals sourcing primary aluminum should monitor active trade remedy proceedings, as new investigations can alter landed cost calculations significantly.