Trimethyl Phosphite Stabilized with MEHQ from Canada
P(OCH3)3 with phosphorus bearing three methyl groups via oxygen links, but classified by the single methyl characteristic in HTS 2931.49.0055 per chapter notes allowing stabilizers. The MEHQ inhibitor doesn't affect principal classification. Polymerization inhibitor.
Duty Rate — Canada → 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
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• Declare stabilizer percentage (<0.1% MEHQ); note 2(g) allows without reclassification
• Air-reactive; requires inert atmosphere packaging and UN2789 shipping papers
• Distinguish from pesticide phosphites (3808) via purity certificate >99%