Statistics show that the risk of dying is twice as high in a home without working smoke alarms than in a home with working smoke alarms.
There are two types of smoke detection technologies currently in widespread use, with additional technologies under development. There is a difference in activation times for the different sensing technologies (photoelectric or ionization), depending upon the type of fire development (fast-flaming fires versus smoldering fires).
The International Association of Fire Chiefs (IAFC) has carefully reviewed recent, credible research and does not find sufficient evidence to warrant a call to eliminate ionization technology. It does, however, recommend installation instructions, which state that ionization alarms need to be spaced farther away from fixed cooking appliances and steam producing sources, such as bathroom showers, than photoelectric alarms to avoid nuisance activations. While a properly installed and maintained alarm of either technology provides a critical baseline of protection, the IAFC strongly recommends the installation of at least one smoke alarm of each type or the installation of dual-sensor alarms, as long as the alarms are tested and listed by a nationally-recognized testing laboratory. Smoke alarms must also be located and spaced properly.
Currently available listed smoke alarms, regardless of the sensing technology, provide an acceptable level of protection if they are properly located, installed and maintained. It is vitally important to note that smoke alarms are only effective if they are maintained in operable condition.
Cooking is the leading cause of nuisance alarms. Users often disable smoke alarms that produce frequent unwanted alarms. The recommendation is to not locate smoke alarms in close proximity to cooking appliances.
Another study showed that 19 percent of the smoke alarms present in reported home fires had dead or discharged batteries. Most of these were probably smoke alarms using replaceable batteries (which should provide a minimum of one year of operation). Occupants are strongly encouraged to not disable smoke alarms and to replace batteries periodically (twice per year). Alternately, the public is encouraged to consider smoke alarms with long-life (nominal 10-year) non-replaceable lithium batteries. Furthermore, smoke alarms cannot last forever and must be replaced when they fail to respond to operability tests, or no later than 10 years from the marked date of manufacture. Homeowners are encouraged to upgrade their battery-operated alarms with approved hard-wired smoke alarms with battery backup.