HTS subheadings within Chapter 56 for nonwovens are structured around weight thresholds — typically expressed as grams per square meter — that determine which tariff line applies. A roll that tests above or below a threshold falls into a different subheading with a potentially different duty rate, so importers should obtain certified weight test results from the manufacturer rather than relying on nominal specifications.

Both spunbond and meltblown nonwovens are classified under HTS Chapter 56 nonwoven headings, and the bonding method itself is not a formal classification criterion. The distinction matters commercially because meltblown fabric — used as the filtration core in N95-type respirators — was subject to acute supply disruptions and export controls by some countries during the COVID-19 pandemic, making supply-chain diversification and strategic inventory a persistent concern for buyers in the filtration and PPE sectors.