Yes. Phosphate fertilizers and certain potash-related products have been the subject of antidumping and countervailing duty investigations in recent years. Importers of these materials should check the Commerce Department's and ITC's active order lists to determine whether their specific product and country of origin are covered before filing entry.

A mineral's tariff classification can shift significantly based on processing: crude phosphate rock, calcined phosphate, and superphosphate each fall under different HTS headings with different duty rates. Importers should obtain detailed technical specifications — particle size, chemical composition, calcination status — from the supplier to support accurate classification and avoid post-entry reclassification.