17 Semi-worked plastic substances, biodegradable, namely, semi-processed plastic in the form of films, sheets, tubes, bars, rods, powder, pellets or flakes; biodegradable plastic film for use in commercial or industrial manufacturing; plastic films for electrical insulation; chemical fiber, namely, chemical fiber thread and yarn not for textile use; semi-synthetic fibers, not for textile use, namely, plastic fibers not for textile use, carbon fibers not for textile use, natural cellulose acetate fibers not for textile use, and cellulose fibers not for textile use; cellulose acetate, semi-processed; biodegradable cellulose acetate, semi-processed; plastic substances, semi-processed; semi-processed plastic in the form of sheet; semi-processed biodegradable plastic in the form of sheet; semi-processed foams of plastic in the nature of filtering materials for use in wastewater treatment, gas separation and artificial dialysis; chemical fiber thread and yarn for use in making cigarette filters, not for textile use; chemical fiber thread and yarn made of cellulose acetate for use in making cigarette filters, not for textile use; chemical fiber thread and yarn made of cellulose acetate in the form of tow for use in making cigarette filters, not for textile use; chemical fiber of thread and yarn for use in making wadding for filtering, not for textile use