4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid (H Acid) from Mexico
H acid is a multi-substituted 1-naphthylamine derivative essential for direct and reactive dyes in cotton dyeing. Classified in HTS 2921.45.90.90 as 'other' α-naphthylamine derivative, the amine group defines its place despite phenolic and sulfonic functions. Chapter 29 classification rules ensure amine-function precedence.
Duty Rate — Mexico → United States
16.5%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Import Tips
• Include chromatograms showing >95% purity; multi-functional nature invites classification challenges
• Declare as 'amine-function compound' explicitly on commercial invoice with structure diagram
• For EU-sourced material, verify REACH compliance as it affects US import documentation