Naphthalene Trisulfonic Acid Trisodium Salt from Canada
1,3,6-Naphthalenetrisulfonic acid trisodium salt is a multi-sulfo derivative of naphthalene used in azo dye synthesis. Contains only sulfo groups, qualifying for HTS 2908.99.1500 as sulfonated phenol derivative.
Duty Rate — Canada → United States
15.5%
Rate breakdown
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• HPLC purity >98% certification required; light-sensitive - opaque packaging
• Common issue: Dye coupling agents scrutinized for Chapter 32 colorant classification