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
14.2%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
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