Mercaptan Polysulfide Elastomer Base M-100 from China
Mercaptan Polysulfide Elastomer Base M-100 is a low-viscosity primary resin for two-part sealants. Classified in HTS 3911.90.10.00 for elastomeric polysulfides, with thiol groups enabling crosslinking. Primary form ensures it stays in heading 3911, not as finished rubber.
Duty Rate — China → United States
35%
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
9903.88.0225%Except as provided in headings 9903.88.12, 9903.88.17, 9903.88.20, 9903.88.54, 9903.88.59, 9903.88.61, 9903.88.63, 9903.88.66, 9903.88.67, 9903.88.68, 9903.88.69, or 9903.88.70, articles the product of China, as provided for in U.S. note 20(c) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(d)
Import Tips
• Require supplier declaration of no fittings/attachments to maintain heading 3917 exclusion note applicability
• Test for polymer purity; impurities >5% may reclassify per predominant monomer rule
• Avoid bulk packaging confusion with retail sets that could invoke 3924 household exclusions