Carbon monoxide, chemical symbol CO, is a colorless, odorless, tasteless, flammable, and highly toxic gas. It is a product of the incomplete combustion of carbon and carbon compounds, and it burns in air with a blue flame, producing carbon dioxide or CO2.
CO is produced during combustion, and this can be caused by an incorrect air-fuel ratio. Carbon monoxide emissions have been reduced in modern vehicles as a result of better engine design, as well as by treatment of the exhaust gas.
Most engine fuels except pure hydrogen are carbon-based, so unless the combustion process is perfect and complete, any internal combustion engine will tend to produce some carbon monoxide emissions. This is especially so when the temperature is too low to completely oxidize the hydrocarbons in the fuel; or if there is insufficient time in the chamber for complete combustion, or if there is not enough oxygen present. Cigarette smoke also contains small but significant concentrations of carbon monoxide .
Toxicity
Carbon monoxide is an extremely poisonous gas. Since you cannot see it or smell its presence, it is very dangerous. Because inhaling it in a confined space can be lethal, it is important not to allow any engine to run inside a workshop without venting the exhaust gases directly to the open air outside.
Victims of CO poisoning can sometimes look abnormally healthy and pink-cheeked. This is because concentrations of CO in the bloodstream give the blood a brighter red color than normal. CO binds extremely well with hemoglobin, which is the blood component that carries life-giving oxygen around the body. As the hemoglobin becomes saturated with CO, it becomes unable to carry oxygen. When the brain is starved of oxygen, the victim becomes unconscious, resulting in brain damage, or death by anoxia. In effect, although still breathing, the victim gradually suffocates, and dies of oxygen deprivation.
First aid
Without endangering yourself, remove the victim of CO poisoning from further exposure, then call for qualified help. If you are able to, apply CPR to keep the victim breathing normal oxygenated air, and if possible, give oxygen first aid as well.
