Tetramethylguanidine (TMG) from China
Tetramethylguanidine is a strong organic base classified under HTS 2925.29.70.00 as an imine-function compound and derivative. It features a guanidine structure with four methyl groups, making it a chemically defined compound fitting Chapter 29 note (a). Primarily used as a catalyst in chemical synthesis.
Duty Rate — China → United States
17.5%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.88.157.5%Except as provided in headings 9903.88.39, 9903.88.42, 9903.88.44, 9903.88.47, 9903.88.49, 9903.88.51, 9903.88.53, 9903.88.55, 9903.88.57, 9903.88.65, 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(r) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(s)
Import Tips
• Verify purity certificate (≥98%) to confirm classification as chemically defined compound per Chapter 29 note (a); impurities may shift to mixtures
• Include Safety Data Sheet (SDS) showing non-specific use additives to avoid reclassification under note (g)
• Declare exact CAS number (80-70-6) on entry documents to prevent customs scrutiny