Methylphosphonic Acid Monomethyl Ester from Japan
This partial ester (CH3P(O)(OH)(OCH3)) has phosphorus bonded to one methyl group, meeting the HTS 2931.49.0055 specification precisely. The single methoxy group counts as the allowed C1 substituent. Used in specialty polymer flame retardants.
Duty Rate — Japan → United States
23.8%
Rate breakdown
9903.04.6211.3%Patented pharmaceutical articles that are the product of Japan, of a European Union member country, of South Korea, of Switzerland, or of Liechtenstein as provided for in subdivisions (c) and (f) of U.S. note 40 to this subchapter
9903.05.4912.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of Japan, with an ad valorem (or ad valorem equivalent) rate of duty under column 1 less than 12.5 percent, as provided for in U.S. note 52 to this subchapter
Import Tips
• Label with exact CAS number (25989-52-0) and IUPAC name for customs verification
• Declare stabilization additives separately to avoid mixture classification issues