3901.30.20.00 - Vinyl acetate-vinyl chloride-ethylene terpolymers, containing by weight less than 50 percent derivatives of vinyl acetate, except those polymerized from aromatic or modified aromatic monomers

This HTS category, 3901.30.20.00, specifically covers vinyl acetate-vinyl chloride-ethylene terpolymers. These are complex polymers formed from three distinct monomer units: vinyl acetate, vinyl chloride, and ethylene. A key defining characteristic for classification under this heading is that these terpolymers must contain by weight less than 50 percent of vinyl acetate derivatives. Furthermore, to be classified here, they must not be polymerized from aromatic or modified aromatic monomers, which are addressed elsewhere in the tariff schedule. These materials are typically used in applications requiring a balance of properties like flexibility, impact resistance, and adhesion, often found in coatings, adhesives, and specialized films.

This specific terpolymer classification is distinguished from its sibling category, 3901.30.60.00, which is designated for "Other" ethylene-vinyl acetate copolymers. The sibling category is a residual provision intended for ethylene-vinyl acetate copolymers that do not meet the specific compositional or chemical criteria of other subheadings. In contrast, 3901.30.20.00 is for a distinct chemical structure: a *terpolymer* with a precise vinyl acetate content limitation and exclusion of aromatic monomers, rather than the simpler *copolymers* of ethylene and vinyl acetate.

As this HTS category is a leaf node, there are no further subcategories. Therefore, classification under 3901.30.20.00 is final for products meeting the described terpolymer composition and criteria. Importers and exporters should carefully verify the percentage of vinyl acetate derivatives by weight and confirm the absence of aromatic monomers in their imported or exported materials to ensure correct classification.