4,4'-Thiodianiline from China
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 — China → United States
125%
Rate breakdown
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)
9903.04.6093.5%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
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