Purine from Canada
Purine is the parent bicyclic heterocyclic compound (imidazole fused with pyrimidine) forming the core of adenine and guanine. Classified in HTS 2934.99.90.01 as other heterocyclic compounds, serving as a nucleic acid base precursor.
Duty Rate — Canada → United States
110%
Rate breakdown
9903.04.6093.5%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• Submit structural formula and IUPAC name in entry summary to prevent classification disputes
• Use UN-approved packaging for air shipment due to potential dust explosion hazard
• Maintain segregation from oxidizing agents during storage per SDS requirements