Unprocessed or polished gallium arsenide wafers—the substrate material—classify under subheading 285390 in this heading. Finished semiconductor devices or integrated circuits built on those wafers classify under the chapter on electrical machinery and electronics. The key distinction is whether the article is the raw or semi-finished substrate versus a functional electronic component.

Cyanogen chloride is a Schedule 3 chemical under the Chemical Weapons Convention, which means US importers must comply with Commerce Department reporting requirements administered through the Chemical Weapons Convention Regulations. Shipments require advance notification and may be subject to inspection; working with a broker experienced in controlled chemicals is essential.