PASS Audibility Project

Inherent Dangers of Fire Fighting
 

Firefighting is a dangerous profession. In 2008, U.S. fire departments responded to an estimated 1,451,500 fires. These reported fires caused 3,320 civilian deaths, 16,705 civilian injuries, $15.5 billion in direct property damage, 105 on-duty firefighter fatalities and 79,700 on-duty firefighter injuries [1-3]. In calculations of total cost of fire, these losses translate into a combined total of $62 billion in 2008 [4].

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Based on 2007 data compiled in an NFPA profile report of the U.S. fire service, there are approximately 30,000 fire departments in the U.S. with roughly 1.1 million firefighters. Just under three-fourths (73%) of the 1.1 million firefighters are volunteers, and nearly half of these volunteers serve in communites with less than 2,500 population. Only one in 15 fire departments is all-career, but 43% (or about 2 of every 5) U.S. residents are protected by such a department. Approximately two-thirds of fire departments also handle emergency medical service (EMS) activities [5].

 

History of PASS Device

 

The development of the PASS device was a result of fireground experiences of firefighters. According to the International Association of Firefighters, the necessity for an audible way to locate a downed firefighter resulted from a study of line-of-duty deaths. This study was conducted after three incidents in 1978 and 1979. In 1978, four firefighters in Syracuse, NY died in a dormitory fire after getting disoriented in a smoke-filled room. In 1979, three firefighters died in a restaurant fire in Lubbock, TX after getting lost in the smoke-filled restaurant. Later that year in Los Angeles, a firefighter died in a warehouse fire where his would-be rescuers were close, but could not see through the smoke [6]. As a result, the fire service requested in 1980 that the National Fire Protection Agency (NFPA) develop a device (and subsequently a standard specification document for the device) that would emit an audible signal when a firefighter became incapacitated. 

 

The first edition of NFPA 1982: Standard on Personal Alert Safety Systems was first introduced at NFPA's Annual Meeting in Kansas City in June of 1983. 

 

There have been five revisions to the standard since 1983. The 1998 revision included PASS devices that were integrated with the Self-Contained Breathing Apparatus (SCBA) used by firefighters and required that these devices be automatically activated. The 2007 revision took into consideration recommendations made by the National Institute for Occupational Safety and Health (NIOSH) about testing protocols for heat exposure and water ingress.

 

Throughout these revisions, the audible alarm of the PASS device has gone through several progressive developments. The signal requirements, as of the edition released in 2007, include specifications of frequencies and levels for the audible alarm and pre-alarm for the PASS device.

 

The standard specifies that the PASS device will go into pre-alarm mode after 20 seconds of inactivity and full alarm mode at 30 seconds of inactivity. The alarm can also be activated manually. The pre-alarm is required to reach a maximum level between 100 dBA and 110 dBA in six seconds. Two primary frequencies are required between 1 kHz and 2 kHz. The primary alarm must have a minimum level of 95 dBA at one meter and be able to maintain the level for at least one hour. The standard specifies three primary frequencies: 500 Hz and two frequencies between 1 kHz and 4 kHz. 

 

This non-unique specification of alarm signals has led to a variety of PASS alarm signals appearing in the commercial market and thus on the fireground environment. This issue was brought to the attention of the technical committee, and the search for an optimized PASS signal through scientific research is part of our project mission.