Pollutants Carbon Monoxide (CO)

Description:
CO is a colorless, odorless gas that is poisonous in high concentrations. Carbon monoxide is less dense than air.

Source:
CO is created when the carbon in fuel is not burned completely. Most fuels we use, such as natural gas, are made out of molecules containing carbon. When there is not enough oxygen present during combustion to form carbon dioxide (CO₂), CO is the result.

CO can come from appliances fueled by natural gas, liquid petroleum, oil, and kerosene. Approximately 60% of nationwide CO emissions comes from automobiles. According to the EPA, motor vehicles generate over 90% of urban CO pollution. The remainder comes primarily from industrial processes and fuel combustion in sources such as boilers and incinerators, from electricity production, and from natural sources such as wild fires.