Polyethylene, (IUPAC name polyethene), is a thermoplastic commodity heavily used in consumer products (over 60 million tons are produced worldwide every year). It is a polymer consisting of long chains of the monomer ethylene (IUPAC name ethene). In the polymer industry the name is sometimes shortened to PE, in a manner similar to that by which other polymers like polypropylene and polystyrene are shortened to PP and PS, respectively. In the United Kingdom the polymer is called polythene. Polyethylene is created through polymerization of ethene. It can be produced through radical polymerization, anionic addition polymerization, ion coordination polymerization or cationic addition polymerization. This is because ethene does not have any substituent groups which influence the stability of the propagation head of the polymer. Each of these methods results in a different type of polyethylene.