Dimethyl Methylphosphonate (DMMP)

Dimethyl methylphosphonate is an organophosphorus compound with the formula CH3P(O)(OCH3)2, containing a phosphorus atom bonded to one methyl group and two methoxy groups with no other carbon atoms directly attached to phosphorus. It falls under HTS 2930.90.9225 as it precisely matches the chemical structure specified for phosphorus compounds with one methyl group. Commonly used as a flame retardant and chemical intermediate.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳China3.7%3.7%
🇲🇽Mexico3.7%3.7%
🇨🇦Canada3.7%3.7%
🇩🇪Germany3.7%3.7%
🇯🇵Japan3.7%3.7%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

2931Higher: 13.7% vs 3.7%

If containing other heteroatoms like sulfur directly linked to carbon

Compounds with organo-sulfur linkages shift to heading 2931 per chapter note on organo-inorganic compounds.

2909.19Higher: 15.5% vs 3.7%

If classified primarily as alkyl phosphate ester without specific methylphosphonate structure

Broader phosphate esters fall under Chapter 29 heading 2909; specific structure determines 2930 placement.

3809.91.00.00Higher: 41% vs 3.7%

If when imported as finished finishing agent rather than pure chemical

Formulations for textile finishing are classified by end use in Chapter 38, not as pure organic compounds.

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Import Tips & Compliance

Provide detailed chemical analysis certificates (CAS# 756-79-6) confirming the exact molecular structure to verify classification under 2930.90.9225

Ensure SDS includes phosphorus bonding structure; misclassification as general organophosphorus (2931.00) is common without proof

Declare purity levels accurately as impurities may trigger reclassification if exceeding chapter note tolerances