4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid (H Acid) from China
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 — China → United States
44%
Rate breakdown
9903.05.3112.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of China, as provided for in U.S. note 52 to this subchapter
9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
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