Polyvinyl chloride, or PVC for short, is one of the world's most widely used plastics for its extreme versatility. Most PVC produced goes into building and construction applications such pipe, siding, and window profiles. PVC has a great resistance to oils and a low permeability to gases. It is ideally suited for applications where maximum chemical resistance is necessary. Sheets can be welded to produce tanks, trays and troughs. Packaging is another major market for PVC plastic. Rigid grades are blown into bottles and made into sheet for thermoforming boxes and blister packs.