2-Naphthylamine-1-sulfonic Acid (Tobias Acid) from Canada
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 — Canada → 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
• 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