Joseph M. Fleming, deputy fire chief with the Boston Fire Department has preached for many years about the life-saving advantages of working smoke alarms. Also, he trusts the life of his family to the eight smoke alarms installed in his house. Yet, a lot of data on smoke alarms raise disturbing questions about the true effectiveness of smoke alarms in reducing fire deaths in the U.S.
Fleming shows how alarm use has increased over time. Almost all these fire detectors were single station, battery-powered ionization alarms. Consider the following announcement from the U.S. National Institute of Standards and Technology:
“According to estimates by the National Fire Protection Association and the U.S. Fire Administration, U.S. home usage of smoke alarms rose from less than 10% in 1975 to at least 95% in 2000, while the number of home fire deaths was cut nearly in half. Thus the home smoke alarm is credited as the greatest success story in fire safety in the last part of the 20th century because it alone represented a highly effective fire safety technology with leverage on most of the fire death problem that went from only token
usage to nearly universal usage in a remarkably short time.”
If the ionization smoke alarm is accountable for almost all decreases in fire deaths over the last part of the twentieth century, shouldn’t the speed of reduction have been greatest over the period of time while smoke alarm use increased the fastest?
Still, over the years from 1977 to 1987, when the use of smoke alarms went through the roof, the trend remained relatively constant. The fire death rate was trending down before smoke alarms gained popularity and continued to trend down after they saturated the market. It doesn’t seem that ionization smoke alarms have affected the trend line. NIST ignores the trends in better building codes, reduction in smoking, better firefighting equipment, and better emergency health care as many reasons for the reduction in fire deaths.
Fleming analyzes another statistic frequently cited to support the efficacy of smoke alarms: The death rate in fires with working smoke alarms was significantly less than half than the potential risk of death from the fire which didn’t have working smoke alarms, either because no smoke alarm was present or an alarm was present but didn’t function.
Nonetheless, these numbers are skewed by including confined fires, i.e., fires that are contained to the item of origin. During the time between 2005 and 2009, no one died in this kind of fire when the flame was large enough to sounds off the alarm. If utilizing the same report, we only examine “nonconfined”, fires, we get the following mortality rate per 100 fires for homes:
- Smoke alarm present and operated – 1.15 (980 deaths / 85,100 fires)
- No smoke alarm or alarm did not operate – 1.64 (1,640 deaths / 99,800 fires)
This is only a 29% reduction in the death rate. Given that many the reduction is most likely due to
socioeconomics factors that go with smoke alarm ownership, the reduction in risk due to the alarm is
significantly less than this percentage. The numbers for apartments are even more troubling:
- Smoke alarm present and operated – 1.17 (220 deaths / 18,800 fires)
- No smoke alarm or alarm did not operate – 1.43 (200 deaths / 14,000 fires)
In apartments, smoke alarms only reduce the potential risk of dying in the fire by 18 percent It’s extremely probable that the most important reason behind a lack of efficacy of smoke alarms is that most alarms use ionization technology (a cheaper kind of alarm). This technology has been proven to function only after harmful conditions have developed through smoldering fires and these kinds of fires are incredibly common throughout the times when people are sleeping and relying upon the alert to wake them.
It’s one of many reasons that some states, such as Massachusetts and Vermont, as well as the International Association of Firefighters advocates the use of photoelectric smoke alarms (The smoke alarms Fleming uses in his house are all photoelectric). One more reason to use this type is that photoelectric alarms are much less inclined to generate false alarms and, for that reason, are not as inclined to be manually disabled.