2920.21.00.00 - Dimethyl phosphite

This HTS category, 2920.21.00.00, specifically covers dimethyl phosphite. Dimethyl phosphite is an organophosphorus compound that serves as a chemical intermediate in the synthesis of various agricultural chemicals, flame retardants, and other organic compounds. Its classification under phosphite esters is based on its molecular structure, featuring a phosphorus atom bonded to oxygen and alkyl groups.

This specific designation distinguishes dimethyl phosphite from its sibling categories, which include other phosphite esters based on their differing alkyl groups. For instance, 2920.22.00.00 covers diethyl phosphite, which has ethyl groups attached to the phosphite ester structure, and 2920.23.00.00 and 2920.24.00.00 cover trimethyl and triethyl phosphite respectively. The "Other" category (2920.29.00.00) is reserved for phosphite esters not otherwise specified within this subgroup.

As a leaf node, there are no further subdivisions under 2920.21.00.00. Therefore, classification within this code relies on the definitive identification of the chemical as dimethyl phosphite, based on its chemical composition and properties, as opposed to other phosphite esters. This ensures accurate import and export duties are applied based on the specific chemical compound being traded.