2-Naphthylamine-1-sulfonic Acid (Tobias Acid) from Japan
Tobias Acid is the 1,2-isomer used in reactive dye synthesis for cotton textiles. HTS 2921.45.90 covers it as 'other' β-Naphthylamine derivative; salts thereof. Chapter 29 notes confirm amine-function precedence over sulfonation.
Duty Rate — Japan → United States
12.5%
Rate breakdown
9903.05.4912.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of Japan, with an ad valorem (or ad valorem equivalent) rate of duty under column 1 less than 12.5 percent, as provided for in U.S. note 52 to this subchapter
Import Tips
• Specify 1-sulfonic vs 6-sulfonic (Laurent's) isomer; CAS 84-89-9 critical
• Often imported as sodium salt; declare salt form explicitly
• Reactive dye manufacturers prefer >99% purity; test certificates prevent disputes