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