2920.22.00.00 - Diethyl phosphite

The HTS category 2920.22.00.00 encompasses diethyl phosphite, a specific ester derived from phosphorous acid. This compound is characterized by its chemical structure where two ethyl groups are attached to the phosphorus atom through oxygen linkages, with a hydrogen atom also bonded to the phosphorus. Diethyl phosphite functions as an intermediate in various organic syntheses, particularly in the production of phosphonate compounds, flame retardants, and antioxidants.

This classification is distinguished from its siblings by the specific alkyl group present in the ester. For instance, 2920.21.00.00 covers dimethyl phosphite, which features methyl groups, while 2920.23.00.00 refers to trimethyl phosphite and 2920.24.00.00 to triethyl phosphite, each differing in the number of ethyl groups or the presence of a third ethyl group replacing the acidic hydrogen. Category 2920.29.00.00 is a residual category for other phosphite esters and their salts not otherwise specified.

As this node is a leaf node within the HTS, there are no further subdivisions. Classification within 2920.22.00.00 is determined by the precise chemical identity of the substance as diethyl phosphite, often confirmed by chemical analysis or supplier documentation detailing its composition. The scope of this heading remains within "Phosphite esters and their salts; their halogenated, sulfonated, nitrated or nitrosated derivatives," focusing specifically on the diethyl ester of phosphorous acid.