9902.11.40 - Oxirane, 2-methyl-, polymer with oxirane, ether with 1,2,3-propanetriol (3:1), polymer with 2,4-diisocyanato-1-methylbenzene and α-hydro-ω-hydroxypoly[oxy(methyl-1,2-ethanediyl)] ether with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (3:1), caprolactam-blocked (CAS No. 936346-53-1) (provided for in subheading 3909.50.50)

This HTS category, 9902.11.40, specifically covers a complex chemical compound identified by its CAS number 936346-53-1. This substance is a caprolactam-blocked polymer, formed through a series of reactions involving oxirane, 2-methyl-oxirane, 1,2,3-propanetriol, 2,4-diisocyanato-1-methylbenzene, and a poly(oxy(methyl-1,2-ethanediyl)) ether with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol. The parenthetical reference to subheading 3909.50.50 indicates its underlying classification as a polyurethane, but this 9902 classification denotes a temporary or special trade provision.

As a leaf node within Chapter 99, this category does not have further subdivisions. Its existence signifies specific temporary legislative actions or trade agreement modifications pertaining to this particular chemical compound, as opposed to general classifications of broader chemical families found in other chapters. It is crucial for importers and exporters to consult the specific trade agreement or legislative proclamation associated with this HTS code to understand the applicable duty rates, quotas, or other restrictions beyond the standard tariff.

The distinction from sibling categories at the same level (e.g., live animals in Chapter 01) is profound. This category deals with highly specialized, synthesized chemical materials, whereas the initial chapters of the HTS often classify goods based on their biological origin or primary physical form. The placement within Section XXII underscores its status as a provision outside the standard commodity chapters, reserved for unique trade circumstances.