K-acid (4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid) from Mexico
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 — Mexico → 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
• 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