Methylphosphonic Acid Monomethyl Ester from Mexico
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 — Mexico → United States
3.7%
Rate breakdown
9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 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