Carbon monoxide (CO) is a colorless and odorless gas that is the byproduct of incomplete combustion of any carbon-containing material
> Sources of CO include inadequate ventilation of heating sources, automobile exhaust, faulty furnaces, exposure to methylene chloride (an industrial solvent often used for cleaning and as paint thinner), as well as cigarette smoke and smoke from fires.
> Exposure to CO raises levels of circulating carboxyhemoglobin (COHb) in the blood.
Carboxyhemoglobin (COHb) is formed by the binding of carbon monoxide to hemoglobin. High COHb levels can be physiologic or pathologic.