Ethylene dibromide, a colorless, nonflammable hydrocarbon, is primarily employed as an additive in leaded gasoline to scavenge lead oxide residues from the combustion chambers of gasoline engines. Atmospheric measurements made near major suspected emission sources (service stations, refineries, production facilities) reveal ethylene dibromide concentrations several orders of magnitude below the threshold limit value of 25 ppm established by the American conference of Governmental Industrial Hygienists. Ethylene dibromide generally acts as a central nervous system depressant, although it is not as effective as many of the other halohydrocarbons. In cases of death, pneumonia is normally the cause due to lung damage induced by the chemical. Symptoms of acute exposure include lung inflammation, congestion, edema, and hemorrhaging. A significant environmental hazard does not appear to be present in regard to ethylene dibromide; however, due to the lack of available data documenting long term, low level exposure in humans the compound cannot be considered environmentally innocuous.