4,4'-Diamino-3-biphenylsulfonic Acid (3-Benzidinesulfonic Acid) from China
A sulfonated aromatic polyamine used as a dye intermediate, specifically listed under HTS 2921.59.0800. It features two amine groups and a sulfonic acid function on a biphenyl structure. Classified here as it qualifies as a derivative of aromatic polyamines.
Duty Rate — China → United States
40.8%
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
9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Import Tips
• Confirm sulfonic acid content doesn't trigger organo-sulfur exclusion (note to 2930); remains in 2921 as sulfonated derivative
• Require EPA TSCA certification; sulfonic acids often regulated for wastewater discharge
• Label with GHS pictograms for corrosivity due to sulfonic acid group