3902 - Polymers of propylene or of other olefins, in primary forms:

This HTS category, 3902, encompasses polymers derived from propylene or other olefins, presented in their primary forms. Primary forms generally refer to bulk materials such as powders, granules, flakes, lumps, or liquid or paste forms that are not yet manufactured into specific articles. This includes a broad range of synthetic resins that serve as foundational materials for plastic production.

Unlike its sibling categories which span diverse product groups from live animals to prepared foodstuffs, 3902 is specifically dedicated to a particular class of plastic raw materials. Its focus on olefin polymers distinguishes it from categories covering other types of plastics or manufactured articles thereof. The key classification criterion here is the chemical composition and the unprocessed state of the material.

Within category 3902, subcategories further refine the classification based on the specific type of olefin polymer. For instance, 3902.10 covers polypropylene, a widely used thermoplastic. 3902.20 addresses polyisobutylene, and 3902.30 details propylene copolymers, which are mixtures of propylene with other olefins to achieve specific properties. Finally, 3902.90.00 serves as a residual category for other olefin polymers not otherwise specified.