Carbon monoxide is produced when a fuel, such as gas, oil, kerosene, charcoal, or wood, is burned.
CO may be found in a number of items that are used by people every day. If fresh air circulation is limited and CO is released in the air, it can reach a dangerously high level. When CO is inhaled, it enters the bloodstream and attaches to a blood cell protein called hemoglobin. Hemoglobin helps blood cells carry oxygen from the lungs to the rest of the body. If CO attaches to hemoglobin, the blood cells are unable to carry oxygen.