Mercaptosuccinic Acid from Japan
Mercaptosuccinic acid (HSCH₂CH(COOH)CH₂COOH) is a di-carboxylic acid with thiol functionality, classified under HTS 2930.90.4950. Contains sulfur directly bonded to carbon; excluded from cyclic anhydrides per note 8. Used in heavy metal chelation and polymer modification.
Duty Rate — Japan → United States
12.5%
Rate breakdown
9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%
Import Tips
• Provide molecular weight and functional group analysis confirming non-cyclic structure
• Certify heavy metals <10ppm for chelation grade material
• Document acid dissociation constants to validate di-carboxylic acid status