Carbon monoxide is a colorless, odorless, tasteless, highly toxic gas that is undetectable to the human senses. It is a by-product of combustion, present whenever fuel is burned from kerosene, charcoal, diesel fuel, wood, gasoline, natural or liquefied petroleum (LP) gas, coal, propane, oil, methane, and tobacco smoke.
Because the gas is odorless, victims may become disoriented before realizing any danger, unable to call for help or exit the premises. CO displaces oxygen in the blood, causing the brain, heart, and other tissues, muscles and organs to become oxygen starved, a condition called carboxyhemoglobinor COHb.
Energy-efficient homes may be more susceptible to CO poisoning because they do not allow enough air in the home to dissipate normal CO output.
It is estimated 300 deaths occur each year from CO poisoning and 10,000 people seek medical attention due to CO inhalation.