Smelter-grade alumina (SGA) is a standardized product with roughly 99.5% Al₂O₃ purity, designed for electrolytic reduction in Hall-Héroult smelters. Specialty or chemical-grade aluminas vary widely in purity, crystal structure (alpha vs. gamma), particle size, and surface area, and command premium pricing for use in ceramics, catalysts, abrasives, and electronics. Both fall under SITC 28520, but buyers and sellers should confirm HTS-level classification because some specialty forms may be classified differently at the 10-digit level.

Importers should verify whether antidumping or countervailing duty orders are in effect for alumina from specific origins, as the aluminum supply chain has historically been subject to trade-remedy investigations. A licensed customs broker can confirm current order scope and whether the specific product form and origin combination is covered.