Carbon monoxide (CO) is a colorless, odorless and tasteless gas. It’s made by partial fuel combustion frequently caused by insufficient oxygen. In your house, appliances that use natural gas, charcoal, wood or kerosene are susceptible. Especially if they are not operating correctly or have been installed improperly.
Vehicle exhaust fumes from attached garages, as well as poorly operating fireplaces may also create carbon monoxide. CO is poisonous to the body and is lethal at high levels or with extended exposure.