Petrochemistry is a science that can readily be applied to fundamental human needs, such as health, hygiene, housing and food. Petrochemical are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from additional fossil fuels, including coal or propane or renewable sources including corn or sugars cane. The two most frequent petrochemical classes are olefins including ethylene with propylene; and aromatics which includes benzene, toluene along with xylene isomers.