Hydrocarbons, C1-4; Petroleum gas; [A complex combination of hydrocarbons provided by thermal cracking and absorber operations and by distillation of crude oil. It consists of hydrocarbons having carbon numbers predominantly in the range of C1 through C4 and boiling in the range of approximately minus 164 °C to minus 0.5 °C (– 263 °F to 31 °F).]