Carbon monoxide (CO) is a clear, odorless and tasteless gas. It’s made by partial fuel combustion frequently caused by not enough oxygen. In your house, appliances that need natural gas, charcoal, wood or kerosene are at risk. Especially if they are not working correctly or have been installed wrong.
Vehicle exhaust fumes from neighboring garages, as well as fireplaces that aren’t working right could also be a carbon monoxide source. CO is dangerous to the body and is deadly at heightened levels or with long exposure.