4,4'-Thiodianiline from Mexico
4,4'-Thiodianiline contains sulfur linkage between aromatic amine rings, used in rubber chemicals and polymer synthesis. HTS 2921.59.80.90 applies as it qualifies as aromatic polyamine rather than organo-sulfur compound per Chapter 29 note exclusion. Sulfur maintains thioether functionality.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6093.5%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Elemental analysis confirming amine > sulfur functionality required
• Odor control packaging essential due to volatile sulfur compounds
• Rubber chemical end-use declaration prevents dye intermediate misclassification