1,9-Thianthrenedicarboxylic acid from China
1,9-Thianthrenedicarboxylic acid is a polycyclic aromatic heterocyclic compound with sulfur bridges and carboxylic acid groups. Explicitly named in HTS 2934.99.05.00 under 'other heterocyclic compounds: aromatic.' Used in specialty dyes and advanced material synthesis.
Duty Rate — China → United States
100%
Rate breakdown
9903.04.6094.2%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
• Provide molecular weight and carboxylic acid titration data to confirm identity and acid-function classification
• Ensure proper corrosion-resistant packaging due to carboxylic acid properties during ocean freight
• Declare exact CAS registry number to prevent confusion with thianthrene derivatives in other subheadings