2-Mercaptopropionic Acid from Mexico
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 — Mexico → 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
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
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