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
4.2%
Rate breakdown
9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 to this subchapter
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