Carbon Monoxide Alarms: Placement, Testing and What to Do
Install carbon monoxide alarms on every level and outside sleeping areas, test them regularly, replace them at end of life, and leave for fresh air immediately if an alarm sounds.
Timeline
- Before an emergency: Install listed alarms in the locations specified by the manufacturer and local code, then test and maintain them.
- When an alarm sounds: Move everyone into fresh air, call emergency services from outside and do not re-enter until responders say it is safe.
- Afterward: Have the source identified and corrected, and replace any alarm that has reached its stated end of life.
Carbon monoxide, or CO, is a colourless and odourless gas produced when carbon-containing fuel does not burn completely. Furnaces, fireplaces, portable generators, charcoal grills, gas ranges and running vehicle engines can all become sources. People cannot reliably sense CO themselves, so prevention and working alarms provide the warning. A CO alarm serves a different purpose from a smoke alarm, although combination units can contain both sensors. [1][2][4]
The U.S. Consumer Product Safety Commission recommends a CO alarm on every level of a home and outside sleeping areas. Exact mounting height and distance from fuel-burning appliances depend on the model, so follow its instructions and any local building or fire code. CPSC says not to put one in an attic or basement unless that space contains a sleeping area. Choose an alarm listed to the applicable safety standard, and consider battery backup where a power failure could disable a plug-in unit. [1][2]
Avoid treating the alarm as an air-quality meter that can be placed anywhere. Air vents, fans, windows, doors, cabinets, curtains and unusually humid or dusty locations may affect performance, and kitchens or the space directly above a fuel-burning appliance may cause nuisance conditions. The manufacturer specifies whether a model belongs on a wall, ceiling or outlet and the clearances it needs. Interconnected alarms can help alert people elsewhere in a larger home. [2][3]
Test each alarm with its test button every month and replace batteries on the schedule in the instructions; CPSC recommends annual battery replacement for replaceable-battery alarms. The button confirms the alarm circuitry and sounder, not the sensor response to a real CO exposure. Never test with exhaust or another combustion source. Note the manufacture or replacement date because sensors have a finite service life, and replace the unit when its end-of-life signal or instructions say to do so. [1][2]
An alarm is a backup rather than a substitute for prevention. Have fuel-burning heating equipment, chimneys and vents professionally inspected as appropriate. Never run a portable generator, grill or camp stove indoors or in an attached garage; EPA advises keeping generators outdoors and at least 20 feet from buildings, with exhaust directed away. Do not use a gas oven to heat a home, and never leave a vehicle running in an attached garage, even with the door open. [3][4][5]
If a CO alarm sounds, do not spend time searching for the source or deciding that it is false. Move everyone and pets outside into fresh air, call emergency services from there, and follow responder instructions. Do not go back inside until professionals say it is safe. Silencing or resetting the alarm does not prove the air is safe, and opening a window does not correct a faulty appliance or other continuing source. [4][5]
Headache, dizziness, weakness, nausea, chest pain and confusion can occur with CO exposure, and sleeping or intoxicated people may not recognize symptoms. Infants, older adults and people with heart, lung or blood disorders may face greater risk. Anyone with possible exposure or symptoms should get urgent medical advice, with emergency help for severe symptoms. After an incident, have the appliance or source inspected before reuse and review alarm coverage throughout the home. [4][5]
Sources
- CPSC CO Alarms
- CPSC Carbon Monoxide Fact Sheet
- EPA What About Carbon Monoxide Detectors?
- EPA Carbon Monoxide Poisoning Fact Sheet
- EPA Protect Your Family From Carbon Monoxide Poisoning