L-Histidine from Canada
L-Histidine is an essential amino acid featuring imidazole ring, classified as oxygen-function amino-acid under HTS 2922.49.4950. Used in allergy medications, metal chelation, and buffering agents.
Duty Rate — Canada → United States
110%
Rate breakdown
9903.04.6095.8%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
• Imidazole ring purity testing prevents heterocyclic misclassification
• USP/NF monograph compliance for pharmaceutical intermediates
• Moisture content <0.5% specification stability