NFPA 72 code sections · Case Studies & Incident Reviews
Smoke alarms expire: replace them 10 years from the date of manufacture
Smoke alarm sensing chambers degrade and the electronics drift. The code requires household smoke alarms to be replaced when they fail to respond to a test, and in any case within 10 years of the date of manufacture printed on the back — not the date of installation. Alarms are tested monthly per the manufacturer, batteries replaced on schedule, and alarms are cleaned as instructed. Incident reviews routinely find alarms 15-25 years old with a chirping battery compartment pulled open.
NFPA 72 reference
Chapter 29 — Household Fire Alarm Systems
29.10 Maintenance and Tests (29.11 in the 2019 edition): monthly testing per manufacturer; replace when the alarm fails to respond or 10 years after the date of manufacture; battery replacement per manufacturer
References use NFPA 72 2019/2022 numbering — section numbers can shift between editions, so confirm in the edition your AHJ has adopted.
On the job
A rental inspection program adds one step — turn each smoke alarm over and read the date — and finds that 38 percent of alarms in a 300-unit complex are past 10 years. The owner replaces them with sealed 10-year-battery, interconnected units; the next inspection cycle is a line item instead of an argument.
Quick check
1. A household smoke alarm must be replaced no later than:
2. The 10-year replacement clock starts at:
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