3901.90.55.01 - Ethylene copolymers

This HTS category, 3901.90.55.01, specifically classifies ethylene copolymers in their primary forms that do not fall under more specific headings within Chapter 39. It encompasses a broad range of polymers where ethylene is copolymerized with one or more other monomers. These can include materials such as ethylene-vinyl acetate (EVA) copolymers, ethylene-acrylic acid (EAA) copolymers, and ethylene-alpha-olefin copolymers, provided they are in their unprocessed state, such as granules, powders, or bulk liquids.

Distinction from sibling categories is crucial for accurate classification. The sibling category, 3901.90.90.00, designated as "Other," would typically encompass ethylene polymers that are neither homopolymers nor copolymers under other specific subheadings. Therefore, 3901.90.55.01 focuses on the *copolymers* of ethylene, where ethylene is combined with at least one other distinct monomer. This differentiates it from potential homopolymers of ethylene or other forms not explicitly defined as copolymers under this specific subheading.

As this is a leaf node, there are no further subcategories. Classification under 3901.90.55.01 hinges on the definitive identification of ethylene as a primary monomer in a copolymer structure, alongside other specified monomers, and that the material is presented in a primary form as outlined in Note 6 to Chapter 39. The specific percentage of ethylene and the nature of the comonomer(s) are generally not determinative at this level, as long as it qualifies as an ethylene copolymer and is not otherwise classified.