9902.11.68 - Ion-exchange resin utilizing a type I quaternary ammonium functional group consisting of benzene (chloromethyl)​ethenyl-​, polymer with diethenylbenzene, compound with N,​N-​diethylethanamine (CAS No. 63453-90-7) in spherical beads with a mean particle size between 0.30 and 1.20 mm (provided for in subheading 3914.00.60)

This classification covers a specific type of ion-exchange resin, characterized by its chemical structure and physical form. It is a polymer composed of benzene (chloromethyl)ethenyl- and diethenylbenzene, functionalized with a Type I quaternary ammonium group and compounded with N,N-diethylethanamine. Crucially, it is supplied in spherical beads with a defined mean particle size range of 0.30 to 1.20 mm. The provision for this item is found under subheading 3914.00.60, indicating its primary classification within the broader category of polymerized and unpolymerized amino-resins, phenolic resins and other products of condensation of artificial resins.

While the HTS database contains numerous sibling categories at the root level, this specific entry is unique due to its highly specialized chemical and physical properties. The distinction lies in the precise chemical composition of the ion-exchange resin, the inclusion of the specific functional group, and its formulation as spherical beads within a particular size range. Unlike general plastic materials or resins classified elsewhere, this item is tailored for specific applications requiring controlled ion exchange, such as water treatment or chemical separation processes. Its placement within Chapter 99 signifies its status under temporary legislation or modifications, separate from standard tariff classifications for basic materials.

As this is a leaf node within the HTS structure, there are no further subcategories. This means that once a product meets the detailed description provided, it is definitively classified under HTS Code 9902.11.68. The specific chemical name, CAS number (63453-90-7), and physical characteristics (spherical beads, particle size) serve as the sole determinants for classification. Importers and exporters should ensure their documentation accurately reflects these precise details to facilitate correct customs processing under this specialized provision.