Smoke alarms are designed to emit a loud, locally audible or visible signal from a wall or ceiling-mounted unit when smoke or fire is detected by that unit. The signal is intended to be disruptive enough to alert people of the need to evacuate the facility or home due to imminent danger.
The first smoke alarm was invented in 1890 by Francis Robbins Upton. It was not until the 1960s that households could benefit from an inexpensive version, and by the 1980s the latest models were becoming standard equipment in newly constructed homes and apartments. Now, 93 percent of American homes have smoke alarms installed.
There are two primary types of smoke alarms:
- Photoelectric – Photoelectric smoke detectors optically sense smoke through use of sensitive light beams which are deflected by smoke, thus triggering an alarm for evacuation. These alarms work best when a very smoky fire is present.
- Ionic – Ionic alarms are triggered through disruption of electrical current within the detector unit. The otherwise consistent current between two sensor plates is interrupted by smoke through its neutralization of ions within the chamber. When that current is absent, the alarm sounds.
Detectors are generally installed on ceilings or high on walls within inches of the ceiling, as both smoke and heat rise and will most effectively be detected by the alarm at the highest level of the room.
According to the Consumer Product Safety Commission, residential smoke alarms should be installed on each level of the home, inside bedrooms, and just outside sleeping areas. But, each local or state government mandates very specific residential smoke detector placement and the fire marshal or building inspectors are always the best source regarding alarm regulations in a specific geographic area. When properly installed and working, smoke alarms offer the potential of escape from a deadly fire and reduce the risk of death by almost 50 percent.
Besides general failure due to faulty manufacture or improper installation, there are other causes of smoke alarm malfunction. The biggest and most basic concern is that of battery replacement. Homeowners often remove batteries due to a false alarm or fail to annually check functionality of existing batteries. Because they consist of electronic components, smoke detectors themselves do not age well. It is estimated by the National Fire Protection Association that standard smoke alarms require replacement every 10 years.
Beyond the battery and component longevity issues, each of the two main types of smoke alarms respond differently to emergency situations. Ionization alarms have been proven to respond better to flaming fire, yet perform below photoelectric alarms in situations of smoldering, smoky fires.
General Product Failure
According to the National Fire Protection Association, there are several major areas of vulnerability and defect in smoke alarms:
- Children under the age of 16 sleep more deeply and for longer periods of deep sleep than adults and currently available alarms are not reliable for waking children younger than age 16
- Seniors who are hearing impaired may not be reliably notified or alerted to wake in the event of a fire or smoke
- Mobility, awareness and lack of hearing attribute to inability of seniors to react to smoke alarms
- Home configurations may limit effectiveness of smoke alarm signals
According to the International Study of Sublethal Effects of Fire Smoke on Survivability and Health, somewhere between 310,000 and 670,000 people are exposed to smoke within their home environment each year. From these exposures, a confirmed average of 3,300 deaths and 11,500 injuries result. It is estimated that at least half of those deaths were incidences of smoke inhalation that would have not been lethal if the person had been removed from continued exposure.
The National Fire Protection Association reports that the fire death rate for Americans across all ages averages 10.3 deaths per million. For those over the age of 65, the death rate is over twice the average at 25.3 people per million. For those over age 75 years, the death rate increase to 32.9 deaths per million, three times the national average. Preschool children are also highly vulnerable, at 19.9 deaths per million.
Some examples of general product failure of smoke alarms include:
- In November 1983, Electro Signal Lab, Inc of Rockland, Massachusetts recalled 500,000 of its smoke alarms due to malfunction and the alarms’ failure to properly alert during presence of smoke or fire.
- In May 2000, Universal Security Instruments, Inc. of Owings Mills, Maryland recalled 34,000 smoke alarms due to their failure to properly operate in the presence of smoke or fire. The detectors became a hazard of their own, as a defective internal capacitor in affected units could burn out, release smoke and melt the alarm cover.
- In May of 2006, approximately 146,000 First Alert® ONELINK™ Battery-Powered Smoke Alarms were recalled due to their rapid draining of batteries, rendering the alarms useless during emergency situations.
- In 1977, MasterLock Company of Milwaukee, Wisconsin recalled 32,000 smoke alarms due to one consumer complaint that the alarm was not functioning properly during a routine test. Resulting findings determined that internal device components were not properly cleansed after soldering during assembly.
Below are some examples of death, property damage, and injury legal actions arising from smoke alarm failures or the failure of home owners to ensure the detectors were present and operational:
- In August of 1981, Stephen Butler and his family were awakened by the smell of smoke in their Western New York home. The home was heavily damaged although Butler, his wife, and children safely evacuated the burning structure. While firefighters were working to fight the fire, one of the home’s First Alert smoke detectors manufactured by Pittway Corporation finally started to sound its alarm. Only after the damage was done to the home and firefighters had already arrived did any of the alarms function. Stephen Butler pursued damages through the court system of the Western District of New York.
- On December 27, 1976, the Albin Laaperi family suffered the death of three sons and serious injuries to their daughter due to burns over 12 percent of her body. Their Pittway Corporation smoke alarm sold by Sears and properly installed within the home was designed for electrical power only. When an electrical fire started while the family slept, the alarm failed to signal an alert as the lack of electricity due to the fire rendered the alarm useless. Laaperi’s complaint was that Sears did not properly notify him at the time of alarm purchase that the alarm would not function in the event of an electrical fire. In March 1986, the Laaperi family was awarded more than $1 million in their legal appeal against Sears for the death of their three sons.