9902.10.87 - Mixture of poly(1-[difluoro(trifluoromethoxy)methoxy]-1,1,2,2-tetrafluoro -2-(trifluoromethoxy)ethane) (CAS No. 69991-61-3) and Perfluoropolymethylisopropyl ether (CAS No. 69991-67-9) (provided for in subheading 3904.69.50)

This HTS category, 9902.10.87, specifically covers a mixture of two distinct perfluorinated compounds: poly(1-[difluoro(trifluoromethoxy)methoxy]-1,1,2,2-tetrafluoro -2-(trifluoromethoxy)ethane) (CAS No. 69991-61-3) and Perfluoropolymethyl isopropyl ether (CAS No. 69991-67-9). The inclusion of these specific CAS numbers is crucial for accurate identification, as it points to precisely defined chemical substances. These are specialized fluoropolymers with unique chemical and physical properties, often used in demanding industrial applications.

It is important to distinguish this category from others at the same level, particularly those that might broadly cover polymers or chemicals. While other sections of the HTS might classify these materials based on their chemical composition under Chapter 39 (Plastics and articles thereof) or other chemical-related chapters, 9902.10.87 falls under Chapter 99, which is reserved for temporary legislation and specific import restrictions. This signifies that the classification here is driven by trade policy or specific regulatory measures, rather than solely by the intrinsic nature of the material itself. The parenthetical note "(provided for in subheading 3904.69.50)" further clarifies that while these are perfluorinated polymers, their import under this specific 9902 code is subject to additional provisions.

As a leaf node, this category does not have further subcategories. Therefore, the focus remains on the precise definition of the mixture it covers. Classification within this HTS code is definitive when the imported goods precisely match the described mixture of poly(1-[difluoro(trifluoromethoxy)methoxy]-1,1,2,2-tetrafluoro -2-(trifluoromethoxy)ethane) and Perfluoropolymethyl isopropyl ether, as identified by their respective CAS numbers. Any deviation from this specific composition or the absence of one of the components would necessitate a review of alternative HTS classifications.