Dictionary.com defines petroleum ether as a low-boiling, flammable hydrocarbon mixture that is produced from fractional distillation of petroleum. The solvent is dangerous and a fire hazard.
Petroleum ether, which the Science Company markets, contains high-alkane hydrocarbons, and the mixture is volatile. Petroleum ether is more commonly known as ligroin, petroleum naphtha or benzine, which is different from the light, ring-shaped molecule called benzene. The solvent consists of groups of many highly flammable, liquid hydrocarbon mixtures. The main function of petroleum ether is to be used as a nonpolar solvent. Chemically, petroleum ether is a light hydrocarbon, not a diethyl ether.