4002.19.00.20 - Containing over 50 percent styrene by weight of the dry polymer

This HTS classification pertains to synthetic rubber, specifically styrene-butadiene rubber (SBR) and carboxylated styrene-butadiene rubber (XSBR), where the dry polymer contains a significant amount of styrene. The defining characteristic of this category is that the styrene content exceeds 50 percent by weight of the dry polymer. These materials are typically supplied in primary forms, such as bales or granules, or as plates, sheets, or strip. Their applications are diverse, often serving as raw materials in the manufacturing of tires, footwear, hoses, belts, and various molded rubber goods.

This category is distinguished from its sibling, "Containing 50 percent or less styrene by weight of the dry polymer," solely by the quantitative threshold of styrene content. Goods falling under this classification must demonstrably have a styrene percentage greater than 50% in their dry polymer composition. This precise measurement is crucial for accurate tariff determination and compliance with import/export regulations.

As this is a leaf node in the HTS structure, there are no further subcategories. Therefore, the classification of goods under HTS code 4002.19.00.20 hinges directly on meeting the stipulated styrene content requirement. When classifying, customs officials will refer to technical specifications and laboratory analysis of the polymer to verify its composition and ensure it falls within this specific descriptor of styrene-butadiene rubber.