Classification turns on the primary material: masks constructed principally from paper, cellulose wadding, or webs of cellulose fibers belong in heading 481890 (specifically 4818900020). Masks made primarily from nonwoven textile fabrics classify in textile headings, while rubber or plastic respirators fall elsewhere. When a mask uses multiple materials, the essential character rule and GRI 3 analysis apply — a licensed customs broker can assist with borderline cases.

Paper face masks may be subject to FDA review if they are marketed as surgical masks, medical devices, or personal protective equipment meeting a specific standard. The customs classification under 4818900020 addresses tariff treatment only; FDA admissibility depends on the product's labeling, intended use, and any performance claims. Importers should verify regulatory status before shipment.