Check Expiry Date of Alarms
Remove alarm. Turn unit over and look for a stamped production date. For propane and CO alarms, add five years to that date to get the expiration date. For smoke alarms, add ten years to get the expiration date. Replace alarm if it has expired.
The expiration date of this alarm is September 14, 2015.
(Sep 14 2010 + 5 years = Sep 14 2015)