A carbon monoxide alarm detects the presence of carbon monoxide, an odorless, colorless gas that can be fatal if inhaled. A smoke alarm detects the presence of smoke, which can be a sign of a fire.

Carbon monoxide alarms should be installed in every bedroom, outside of every sleeping area, and on every level of your home, including the basement.

You should test your carbon monoxide alarm monthly by pressing the test button. You should also replace the batteries in your carbon monoxide alarm every year.

There are two main types of smoke alarms: ionization smoke alarms and photoelectric smoke alarms. Ionization smoke alarms are more sensitive to flaming fires, while photoelectric smoke alarms are more sensitive to smoldering fires.