Many different types of plastic are produced globally, but the market is dominated by 6 classes of plastics: polyethylene (PE, high and low density), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS, including expanded EPS), polyurethane (PUR) and polyethylene terephthalate (PET). Plastics are usually synthesized from fossil fuels, but biomass can also be used as feedstock. The production chain for the most common artificial and natural polymers is illustrated in Figure 3.2. The figure includes some examples of common applications, including the manufacture of microplastics for particular industrial or commercial applications.