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6. Limitations of Smoke Alarms
 WARNING:  PLEASE READ CAREFULLY AND THOROUGHLY
 • Life safety from fire in residential occupancies is based primarily on early notification to occupants of the 
need to escape, followed by the appropriate egress actions by those occupants.
 • Fire warning systems for dwelling units are capable of protecting about half of the occupants in 
potentially fatal fires. Victims are often intimate with the fire, too old or young, or physically or 
mentally impaired such that they cannot escape even when warned early enough that escape 
should be possible. For these people, other strategies such as protection-in-place or assisted 
escape or rescue are necessary.
 • Leading authorities recommend that both ionization and photoelectric smoke alarms be installed 
to help insure maximum detection of the various types of fires that can occur within the home. 
Ionization sensing alarms may detect invisible fire particles (associated with fast flaming fires) sooner 
than photoelectric alarms. Photoelectric sensing alarms may detect visible fire particles (associated 
with slow smoldering fires) sooner than ionization alarms.
 • A battery powered alarm must have a battery of the specified type, in good condition and 
installed properly (This model has a sealed backup battery).
 • Smoke alarms must be tested regularly to make sure the battery and the alarm circuits are in good 
operating condition.
 • Smoke alarms cannot provide an alarm if smoke does not reach the alarm. Therefore, smoke 
alarms may not sense fires starting in chimneys, walls, on roofs, on the other side of a closed door 
or on a different floor.
 • If the alarm is located outside the bedroom or on a different floor, it may not wake up a sound 
sleeper.
 • The use of alcohol or drugs may also impair one’s ability to hear the smoke alarm. For maximum 
protection, a smoke alarm should be installed in each sleeping area on every level of a home.