Bismuth above 99.99% purity (810610) commands a premium and is required for pharmaceutical-grade compounds, certain semiconductor dopants, and high-specification alloys. Lower-purity material (810690) is adequate for most metallurgical uses such as free-machining steel additives and solders. The threshold determines both the applicable duty rate and the appropriate subheading.

Yes. Bismuth waste and scrap, along with lower-purity primary bismuth, are grouped under 810690. High-purity primary bismuth above 99.99% is separately classified under 810610. Importers should verify the purity certificate of the material before declaring the subheading.