Any fuel burning appliance can be a source of Carbon Monoxide. CO is produced when any type of fuel (wood, charcoal, oil, kerosene, natural gas, propane, etc.) is incompletely burned or exposed to heat, as in a fire.
Typical appliances that we rely on for comfort such as: furnaces, fireplaces, grills, clothes dryers, stoves, space heaters, hot water heaters and automobiles, are often the main source of CO. When they malfunction or are not properly vented, CO levels rise quickly.
Carbon Monoxide (CO) enters the body through the lungs during the normal breathing process, just like oxygen. The problem is, CO competes with the oxygen by combining with the red blood cells, replacing the oxygen. This prevents the flow of oxygen to the brain and other vital organs causing a variety of medical problems. Once CO enters the bloodstream, it is not easy to remove, and can continue to block out oxygen over a period of time.