4-Mercaptobenzoic Acid from China
4-Mercaptobenzoic acid features para-substituted mercapto and carboxylic groups on benzene ring. HTS 2930.90.4920 classification as aromatic mercaptocarboxylic acid per Chapter 29 organo-sulfur provisions. Utilized in nanotechnology and self-assembled monolayers.
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)
9903.04.6095.8%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
• Require HPLC purity certificate >99%; CAS 107-91-5 for customs verification
• Static dissipative packaging required for nano-electronics grade material
• Avoid 2930.90.49.40 misclassification by confirming acid vs amide function