9902.11.38 - 2-Oxepanone polymer with 1,4-butanediol and 5- isocyanato-1-(isocyanatomethyl)-1,3,3- trimethylcyclohexane, 2-ethyl-1-hexanol-blocked (CAS No. 189020-69-7) (provided for in subheading 3909.50.50)

This HTS category, 9902.11.38, covers a specific chemical compound: a polymer formed from 2-oxepanone, 1,4-butanediol, and a blocked isocyanate of 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane with 2-ethyl-1-hexanol. This detailed description, including the CAS number, signifies a highly specialized material within the broader scope of Chapter 99. The presence of this code within Section XXII, "Special Classification Provisions," highlights that it falls under temporary legislation or special trade agreement modifications rather than standard commodity classifications.

Distinguishing this category from its siblings is straightforward, as Chapter 99 is entirely dedicated to temporary and special provisions. Unlike the preceding chapters which classify general merchandise by material or function, such as live animals (Chapters 01-05), this node is not defined by the nature of the goods themselves but by the specific regulatory status it holds. Therefore, it does not share common classification criteria like species, material composition, or intended use with the majority of HTS codes.

As this is a leaf node within the HTS database, there are no further subcategories. Classification under 9902.11.38 is definitive for the described chemical product when it is subject to the particular temporary legislation or trade agreement provisions referenced by its placement in Chapter 99. Its inclusion here means that standard classification under Chapter 39 (Plastics and articles thereof) or other chapters is superseded by these special provisions, typically for reasons related to import restrictions, quotas, or specific trade policy objectives.