A carbon monoxide alarm, also known as a CO alarm, is a device that detects the presence of carbon monoxide gas to prevent carbon monoxide poisoning. Carbon monoxide is a colorless, odorless, and poisonous gas that can cause serious illness and death at high levels. CO alarms are designed to warn you of any unusual build-up of CO in your home, which may occur from improperly maintained, installed, or used fuel-burning appliances, backdrafting appliances or fireplaces, or idling cars in garages.

Here are some key things to know about carbon monoxide alarms:

• CO alarms detect the poisonous gas and help provide an early warning. In the event of a carbon monoxide leak, it is critical that you get to fresh air as soon as possible.
• CO alarms should be certified to the most current Underwriters Laboratory (UL) standard 2034 or the International Approval Services (IAS) 6-96 standard.
• CO alarms should be installed in the hallway near every separate sleeping area, and on every level of your house so all family members can hear the detectors and be alerted to the emergency.
• CO alarms should be tested monthly to ensure they are working properly. To test your CO alarms, press and hold the test button until the alarm sounds.
• CO alarms are designed to be a back-up to proper installation, use, and maintenance of fuel-burning appliances. The U.S. Consumer Product Safety Commission (CPSC) recommends that every home should have at least one CO alarm that meets the requirements of the most recent Underwriters Laboratories (UL) .