2929.10 - Isocyanates:

This category, HTS 2929.10, specifically encompasses isocyanates, which are organic compounds characterized by the presence of one or more isocyanate functional groups (-N=C=O). These highly reactive compounds serve as crucial intermediates in the synthesis of a wide range of polymers, particularly polyurethanes. The classification here focuses on the isocyanate moiety itself, irrespective of its specific applications, as long as it meets the chemical definition of an isocyanate.

Unlike its sibling category, 2929.90, which broadly covers "Other" compounds with nitrogen function, HTS 2929.10 provides a dedicated classification for a distinct and industrially significant class of chemicals. The "X. ORGANO-INORGANIC COMPOUNDS, HETEROCYCLIC COMPOUNDS, NUCLEIC ACIDS AND THEIR SALTS, AND SULFONAMIDES" context, while related to nitrogen-containing compounds, represents a different chemical structure and application profile than the isocyanates classified here.

Within HTS 2929.10, further subdivisions exist to distinguish between specific types of isocyanates based on their chemical structure and purity. These subcategories include well-defined toluenediisocyanates, both unmixed and in specific mixtures, as well as other aromatic and aliphatic diisocyanates like Bitolylene diisocyanate (TODI), Xylene diisocyanate, 1,6-Hexamethylene diisocyanate, and various monoisocyanates. The distinctions are important for accurately identifying the specific chemical substance being imported or exported, reflecting variations in reactivity, physical properties, and end-use applications of these isocyanate compounds. The "Other:" subcategory at the lowest level accommodates any isocyanates not specifically enumerated in the preceding subheadings.