A light liquid fraction obtained when bituminous coal undergoes pyrolysis (a process also known as coking in the iron and steel industry, where it is used primarily to produce coke, a base component in the manufacture of cast iron and steel). Benzol is made up of benzene, toluene and all three xylene isomers, all of which are important intermediates in the manufacture of numerous derivatives, in particular polystyrenes and polyamides (benzene), polyurethane (toluene), and polyethylene terephthalate (PET) plastic and polyesters (paraxylene).