Carbon monoxide (CO) is an invisible, odorless and tasteless gas. It’s produced by insufficient fuel combustion often caused by insufficient oxygen. In your house, appliances that rely on natural gas, charcoal, wood or kerosene are vulnerable. Especially if they are not operating correctly or have been installed wrong.
Vehicle exhaust fumes from attached garages, as well as poorly operating fireplaces may also produce carbon monoxide. CO is toxic to the body and is lethal at high levels or with long exposure.