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Response Time Impact of Smoke Alarms



Stanley W. Gilbert, Thomas Cleary, Paul A. Reneke, Richard Peacock, David Butry


It can be assumed that smoke alarms reduce reported fires and casualties by reducing on average the amount of time it takes to detect a fire. This paper sets out to determine by how much that detection time is reduced. It does so by comparing the effect of smoke-alarm presents (and time of day) to the effect of fire-department travel time using data from the National Fire Incident Reporting System. On average, smoke alarms reduce reporting time by 19.2 (± 0.016) minutes. This is comparable to the average time delay from having a fire at night. If smoke alarms are present, having a fire at night (between the hours of 11 and 6) adds 18.1 (± 0.013) minutes, and without an alarm, having a fire at night adds on average 20.5 (± 0.024). Smoke alarms are more effective at night, saving 2.4 (± 0.016) minutes more at night than during the day.
Technical Note (NIST TN) - 2174
Report Number


Fire, Home Fires, Smoke Alarms, Response Time


Gilbert, S. , Cleary, T. , Reneke, P. , Peacock, R. and Butry, D. (2021), Response Time Impact of Smoke Alarms, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 22, 2024)


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Created September 9, 2021, Updated November 29, 2022