Yes, for many plastics articles the specific polymer composition is a classification determinant. HTS Chapter 39 organizes plastics articles partly by polymer type, so a container made of polyethylene may be classified differently than an identical-looking container made of polypropylene. When a product is made from a blend or composite, the dominant polymer by weight or value typically governs, though CBP rulings can clarify ambiguous cases.

CBP applies the 'dedicated use' test: if a semi-finished plastics form is already dedicated to a specific end use by its shape, dimensions, or surface treatment, it may be classified as a finished article rather than as a primary form or semi-manufacture. This distinction affects both the applicable HTS heading and the duty rate, so importers of plastics blanks, preforms, or profiles should confirm classification before entry.