9902.11.51 - 3,5-Dimethyl-1H-pyrazole-oligo(hexamethylene diisocyanate) in solvents (CAS No. 163206-31-3) (provided for in subheading 3911.90.90).

This HTS code, 9902.11.51, specifically designates "3,5-Dimethyl-1H-pyrazole-oligo(hexamethylene diisocyanate) in solvents (CAS No. 163206-31-3)". This is a specialized chemical product, identified by its Chemical Abstracts Service (CAS) number, which is provided for under subheading 3911.90.90 of the Harmonized Tariff Schedule. Its classification within Chapter 99 signifies that it is subject to temporary legislation, modifications, or additional import restrictions.

Distinguishing this category from its siblings in the HTS Database Root is straightforward. The sibling categories, such as those for live animals (Chapters 01), represent fundamentally different types of goods. This node, however, focuses on a specific chemical compound, highlighting its nature as a polymer precursor or component, rather than biological entities. The primary classification criteria here are the chemical identity and the presence of solvents.

As a leaf node, HTS code 9902.11.51 does not have further subcategories. Therefore, the focus for classification purposes rests entirely on accurately identifying the described chemical substance and ensuring it meets the conditions stipulated under the temporary provisions of Chapter 99. Importers must verify that the imported material precisely matches the chemical name, CAS number, and solvent content as specified to ensure correct customs declaration and compliance.