K-acid (4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid) from Canada
K-acid serves as an important coupling component for substantive dyes due to its multiple sulfonic groups enhancing water solubility. HTS 2922.21.4000 applies per U.S. note 3 listing for quota purposes. The compound exemplifies oxygen-function amino-naphthols with salt-forming capability.
Duty Rate — Canada → United States
16.5%
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
• Monitor Federal Register notices for annual quota reallocations affecting note 3 products
• Include molecular structure diagrams in entry documentation for complex salt identification
• Validate against chapter exclusion (g) by confirming not finished coloring matter