9902.11.88 - Expanded poly(tetrafluoroethylene) (PTFE) nonadhesive cellular sheets, of a thickness greater than 1.5 mm but not more than 3.0 mm, certified by the importer as having a tensile strength of at least 48.3 MPa (7,000 psi) per ASTM F-152 (CAS No. 9002-84-0) (provided for in subheading 3921.19.00)

This HTS category, 9902.11.88, specifically covers expanded poly(tetrafluoroethylene) (PTFE) nonadhesive cellular sheets that meet precise physical specifications. The material must have a thickness exceeding 1.5 mm but not surpassing 3.0 mm. Crucially, importers must certify that these sheets possess a minimum tensile strength of 48.3 MPa (7,000 psi) as determined by ASTM F-152, with the material identified by CAS No. 9002-84-0. This detailed description and testing requirement are essential for proper classification, distinguishing it from other forms of PTFE or cellular sheets not meeting these exact parameters.

As a leaf node within Chapter 99, this classification represents a specific temporary modification or provision. Its existence under Section XXII signifies its unique status outside the standard HTS structure, likely due to trade agreements or specific import restrictions. Unlike the broad categories of live animals found in Chapter 01, which deal with live mammals and birds, this HTS code addresses a specialized industrial material. The focus here is on the precise physical and material properties of a processed polymer product rather than biological commodities.