Carbon monoxide (CO) is a colorless, odorless and tasteless gas. It’s produced by incomplete fuel combustion usually caused by a lack of oxygen. In your residence, appliances that rely on natural gas, charcoal, wood or kerosene are at risk. Especially if they are not running correctly or have been installed wrong.
Vehicle exhaust fumes from nearby garages, as well as poorly operating fireplaces could also create carbon monoxide. CO is poisonous to the body and is deadly at high levels or with long exposure.