Look for the label of an independent testing lab. Make sure the detector has batteries or a combination of batteries and household current.
Number of Detectors
Install smoke detectors on every floor of your home, basement and outside of all bedrooms. Make sure all residents can hear the smoke detectors. For hearing-impaired persons, buy smoke detectors that are louder or flash a bright light.
Where to Install Detectors
Do not install smoke detectors near rooms where cooking-fumes, steam or automobile exhaust could set them off.
Do not place smoke detectors too close to a window or door because drafts could interfere with the operation of the detector.
In stairways that do not have doors at the top or the bottom, install the detector anywhere along the staircase. In stairways with doors, place detectors at the bottom.
Mount detectors high on the wall or better yet on the ceiling. Position wall-mounted detectors with the top of the detector 4- to 12-inches from the ceiling. Place ceiling-mounted detectors at least 4 inches from the nearest wall.In a room with a pitched ceiling, install the detector near the ceiling's highest point.
Test smoke detectors at least monthly (or per manufacturers specifications). Install new batteries once a year (when you turn your clocks back in the fall) or when the detector chirps indicating a low battery. Never paint a smoke detector.
Note: Smoke detectors should be replaced if they are more than 10 years old.