Life-Span of Smoke Detectors

Q: Our Environmental Health & Safety (EH&S) compliance officer asked me to check into the recommended life-span of smoke detectors. His understanding is that ALL detectors are to be replaced after 10 years from date of install. I am attempting to verify his information, and would like your opinion on the matter.

A: Whether addressable or conventional, there’s no code that mandates the replacement of a smoke detector so long as it’s sensing smoke per the manufacturer’s listed sensitivity range. Each detector’s sensitivity must be verified via one of the methods outlined in NFPA 72 (2010) Table 14.4.2.2.14(g)(1). I’d advise the gentleman to compare his current testing method with the allowed methods to ensure reliability. Many testing personnel view a ‘chamber entry’ test as a sensitivity test. A chamber entry test just tests the ability of smoke to enter the sensing chamber and activate the detector, not the sensitivity of the detector to the presence of smoke. Just spraying canned smoke at a detector is a chamber entry test, not a sensitivity test.

There is a rule of thumb that it’s best to replace system connected smoke detectors after 15 years and single-station smoke alarms every 10 years to keep from getting nickel and dimed by dying detectors. Single station detectors have a shorter recommended timeline since most are installed in homes and they probably aren’t being tested or cleaned. For commercial systems, it’s a good idea to get in front of device replacement circuit by circuit in order to control costs and avoid paying for emergency overtime service calls.