Chlorotrimethylsilane from Mexico
Chlorotrimethylsilane (TMSCl, (CH3)3SiCl) serves as a protecting group in organic synthesis. This organo-silicon compound with direct C-Si bonds is properly classified under HTS 2931.90.90.10 per Chapter 29 organo-inorganic provisions.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6096.3%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
• ,Include GC/MS purity certificate; impurities >5% may trigger mixture classification
• Watch for stabilizer additions—must be for preservation/transport per note (f)