4-Amino-5-Hydroxy-2,7-Naphthalenedisulfonic Acid (H Acid) from Mexico
H Acid is premier dye intermediate with amino-naphthalene core structure. HTS 2921.45.90 as 'other' naphthylamine derivative; multiple functions but amine principal. Widely used in reactive/direct dyes for cotton.
Duty Rate — Mexico → United States
16.5%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
Import Tips
• CAS 90-64-2; sodium salt form CAS 5182-63-2 most common
• Light-sensitive; dark packaging mandatory
• 97% min purity standard; HPLC certificate required by dye manufacturers