Copper, zinc, and nickel products have each been subject to antidumping or countervailing duty investigations at various points, and Section 232 measures have been applied to certain derivative articles. The specific coverage varies by product form and country of origin, so importers should check the current status of any active orders or measures for each metal and form they are importing.

For nonferrous metals, the country of origin is generally the country where the substantial transformation occurred — typically where smelting or refining took place rather than where ore was mined. When metal passes through multiple processing stages in different countries, a formal origin ruling from CBP may be advisable to ensure correct duty treatment and compliance with any applicable trade-remedy orders.