Tungsten Trioxide Hydrate (Yellow Tungstic Acid) from Canada
Hydrated WO3, known as yellow tungstic acid (5WO3·H2O), used in catalyst impregnation. Falls under HTS 2825.90.30.00 as tungsten oxides; hydrates of metal oxides remain classified as oxides, not acids unless specified otherwise. Common intermediate in refining.
Duty Rate — Canada → United States
5.5%
Rate breakdown
9903.05.860%Articles provided for in subdivision (b) of U.S. note 52 to this subchapter
Import Tips
• Water content declaration critical; calculate duty on anhydrous basis if required by customs
• Distinguish from tungstic acid solutions (2811.19) by solid form and hydrate status
• Hygroscopic nature requires sealed packaging; document moisture at time of packing