3907.21.00.00 - Bis(polyoxyethylene) methylphosphonate

This HTS category, 3907.21.00.00, specifically classifies Bis(polyoxyethylene) methylphosphonate. This substance is a type of polyether characterized by the presence of both polyoxyethylene chains and a methylphosphonate group. These chemical features impart specific properties that are distinct from general polyethers or other polyesters, influencing its applications, often in areas such as flame retardancy or as a component in polymer formulations.

Within the broader classification of "Other polyethers," this subcategory stands apart from its sibling, 3907.29.00.00, which covers all other polyethers not specifically enumerated elsewhere. The defining characteristic of 3907.21.00.00 is the precise chemical structure of Bis(polyoxyethylene) methylphosphonate, which includes both the polyoxyethylene ether linkages and the methylphosphonate functional group. This specificity differentiates it from more general polyether compounds that may lack the phosphonate moiety or have a different ether chain structure.

As this is a leaf node within the HTS, there are no further subcategories. Classification under this heading is determined by the presence of the specific chemical entity, Bis(polyoxyethylene) methylphosphonate, in its primary form. Importers and exporters should confirm that the material's chemical composition aligns precisely with this description to ensure accurate classification.