Section 07 PLASTICS AND ARTICLES THEREOF; RUBBER AND ARTICLES THEREOF 40 RUBBER AND ARTICLES THEREOF 40 02 WITH ANY PRODUCT OF THIS HEADING, IN PRIMARY FORMS OR IN PLATES, SHEETS 40 02 31 ISOBUTENE-ISOPRENE (BUTYL) RUBBER (IIR) Commodity Code Description 40 02 31 00 ISOBUTENE-ISOPRENE (BUTYL) RUBBER (IIR)