2-Mercaptopropionic Acid from Canada
2-Mercaptopropionic acid (CH₃CH(SH)CH₂COOH) contains both carboxylic acid and thiol functions with sulfur directly bonded to carbon, classified under HTS 2930.90.4950 as other organo-sulfur acids. Meets Chapter 29 criteria for chemically defined compounds; the sulfur-carbon linkage distinguishes it from Chapter 28 inorganic acids. Used in chelating agents and metal extraction.
Duty Rate — Canada → United States
100%
Rate breakdown
9903.04.6095.8%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• Submit assay reports showing acid value and thiol content to confirm dual functionality required for heading 2930
• Ensure packaging prevents oxidation; stabilizers permitted under Chapter 29(g) for safety
• Distinguish from thioglycolic acid (specific subheading) in entry documentation