Inorganic chemicals span multiple HTS chapters depending on purity, form, and intended use. For example, a metal oxide may classify differently depending on whether it meets pharmaceutical-grade purity thresholds or is presented as a mixture. Consulting a licensed customs broker with chemical expertise is advisable for complex inorganic compounds.

Antidumping and countervailing duty orders cover a number of specific inorganic chemicals, including certain sodium compounds and metal salts. Additionally, Section 301 tariffs apply to a broad range of inorganic chemicals of Chinese origin. Importers should conduct a line-by-line review of applicable orders before sourcing.