Carbon monoxide (CO) is a colorless, odorless and tasteless gas. It’s made by partial fuel combustion usually caused by not enough oxygen. In your house, appliances that rely on natural gas, charcoal, wood or kerosene are at risk. Especially if they are not running correctly or have been installed incorrectly.
Vehicle exhaust fumes from attached garages, as well as poorly operating fireplaces can also be a carbon monoxide source. CO is toxic to the body and is deadly at increased levels or with prolonged exposure.