Petrochemicals or petroleum distillates are substances which are chemically derived from petroleum. Some are obtained from fossil fuels and renewable sources such as coal, natural gas, corn and sugar. The two petrochemical cases are olefins and aromatics. Petrochemicals include: benzene, xylene, toluene, ethylene and propylene. Chemical plants and oil refineries utilize these to make everyday products such as plastics, rubber and synthetic fibers for clothing. Petrochemical engineers qualify and are employed by petrochemical companies such as Dow Chemical, ExxonMobil Chemical, DuPont and BASF.