1
Running Head: TIME TO EVACUATE
Time to Evacuate: Fire Alarms Systems Are Failing to
Address Their Intended Purpose
Christopher O’Neil
University of Cincinnati
Milestone 4: Term Paper
June 9, 2012
Author Note
This is an extensive study of the course material prepared for Analytical Approaches for the Fire
and Emergency Services, Section 707, taught by Professor John Glass.
2
TIME TO EVACUATE
Abstract
Fire alarm systems’ limitations in prompting adequate evacuation were analytically argued. This
paper presented quantified information to support the Temporal-Three sound’s lack of
recognisability and perceived urgency, the lack of adequate messages to building occupants, and
the lack of direction provided by fire alarm systems’ audible devices. All three areas are
discussed in relation to occupant behaviour (i.e. roles) during evacuations. Arguments were
further integrated with a review of relevant legislation, standards, and regulations. The use of
course material such as review of statistical studies, presenting quantified data, using statistical
measures, and cost-benefit analysis were used to support arguments. This paper concluded with
recommendations to increase the control over building evacuation. These were: educating the
public on the T-3 sound, its characteristics, and where/when it may be encountered; creating
standards and regulations to guide users in constructing effective messages that are used in mass
notification and emergency communication systems; using building codes to enforce mass
notification and emergency communication systems; and using building codes to enforce
directional sound technology in applications that require a cost effective approach to optimize
evacuation times.
3
TIME TO EVACUATE
Table of Contents
Abstract
………………………………………………
3
Introduction
………………………………………………
4
Analysis
………………………………………………
5
Argument 1
………………………………………………
5
Argument 2
………………………………………………
6
Argument 3
………………………………………………
8
Discussion
………………………………………………
10
Conclusion & Recommendations
………………………………………………
11
References
………………………………………………
13
Appendices
………………………………………………
15
4
TIME TO EVACUATE
Time to Evacuate: Fire Alarms Systems Are Failing to Address Their Intended Purpose
Fire alarm systems provide early detection of environmental changes associated with fire
(smoke, heat, etc.) to stimulate two actions in people. These are emergency response and
building evacuation. Emergency response has been increasingly better and easier to achieve over
the years because governments have reinforced inspections and ensured code compliance
through legislation, which directly improves early detection. However, fire alarm systems fail to
control building evacuation. The same bodies of legislation that reinforces early detection and
emergency response inadequately supports evacuation by failing to acknowledge a fire alarm
system’s limitations in the area. It is not a technology problem, but rather fiscal support and the
lethargic process of policy and governance (Boynowski, 2010). Academia in the fire and
evacuation fields acknowledges this loophole and advocate for a change. Within these fields, it is
believed that occupants respond to fire in an adaptable way from a variety of influences beyond
what fire alarm systems currently address. The current legislation assumes occupants evacuate
immediately after the sound of a fire alarm; falsely assuming complete control over evacuation.
There is a disconnection between the built environment governed by legislation and the
philosophical and psychological understanding of human behaviour supported by academia.
In support for academia, legislation needs to address the short comings of a fire alarm
system. Presented are three analytical arguments that reinforce this notion with respects to
building evacuation. Fire alarm systems fail to produce a sound that is widely recognisable and
perceived with urgency, fail to deliver adequate messages to building occupants, and fail to
provide direction that influences an evacuee’s choice of egress. It is hoped that fire
5
TIME TO EVACUATE
administrators become educated on the assumptions made by fire alarm systems and advocate for
a change in their community.
Analysis
Argument One
The temporal-three (T-3) patterns is a sound that is widely used in North American fire
alarm systems to promote building evacuation (Proulx & Laroche, 2003). It is regulated by ISO
8201 and adopted by NFPA 72, and the National Building Code of Canada (Proulx & Laroche,
2003). Despites T-3 integration into legislation, it fails to be recognized by the general public.
An unrecognized sound could promote building occupants to desire more information rather than
evacuating, which is common role adopted by humans after a fire alarm sounds (Bryan, 2003, p.
4-1). Proulx and Laroche (2003) conducted an experiment that tested the T-3 recognisability
alongside other commonly encountered sounds. These sounds were a car horn, a reverse alarm,
fire alarm bell, the slow whoop, fire alarm bell, and an industrial warning buzzer (National
Research Council Canada, 2010). The two other fire alarms, slow whoop and fire alarm bell,
were common to the United States and extensively used in Canadian industrial buildings at the
time of the study, respectively (Proulx & Laroche, 2003). After considering Bennett and Briggs
(2003) guidelines to analyzing statistical studies, it was concluded that findings presented by
Proulx and Laroche (2003) are reliable to reproduce (p. 311-316). That is, the source is unbiased,
the variables of interest were well defined and measured sufficiently, results were presented
fairly, and the study is reproducible (Bennett & Biggs, 2003, p. 311-316). Table A displays
Proulx and Laroche (2003) findings in terms of recollection, identification, and perceived
urgency. For example, the T-3 was recalled by 71% of the participants, correctly identified as a
fire alarm sound by 6% of the participants, and had a mean urgency of 3.97 on a scale of one to
6
TIME TO EVACUATE
ten with ten being of highest urgency. Recollection was any prior experience with the sound,
identification was attributing the sound to a name or description, and perceived urgency was the
level of a required response to the sound (Proulx & Laroche, 2003).
Table A – Recollection, Identification, and Perceived Urgency of T-3
SOUND
T-3
Industrial Buzzer
Car Horn
Reverse Alarm
Slow Whoop
Fire Alarm Bell
RECOLLECTION (%)
YES /
NO
71
29
81
19
97
3
91
9
52
48
58
42
IDENTIFICATION (%)
CORRECT / INCORRECT
6
94
2
98
98
2
71
29
23
77
50
50
PERCEIVED URGENCY
MEAN / STD. DEV.
3.97
2.42
4.91
2.74
4.93
2.46
5.60
2.78
6.01
2.50
7.17
2.74
Table A suggests that the T-3 is not correctly identified by most people. Participants commonly
related the T-3 to domestic sounds such as a busy phone signal, phone beep, or PA preannouncement (Proulx & Laroche, 2003). Proulx (2007) later noted that fire alarm sounds can be
misinterpreted as a burglar alarm, elevator fault, or security door alarm in non-domestic
environments. From Table A, it can be further suggested that most people fail to perceive the T-3
as urgent. It has the lowest level of perceived urgency in comparison to the other sounds. Proulx
and Laroche (2003) noted that the Fire Alarm Bell and Slow Whoop were identified within a
high urgency range whereas the T-3 was within a low urgency range. The other sounds were
within a medium urgency range (Proulx & Laroche, 2003). Fire alarm systems fail to promote
evacuation, especially when their T-3 sound is not widely recognizable and not perceived as
urgent.
Argument Two
Beyond being recognizable and perceived as urgent, fire alarm systems fail to deliver
sufficient messages to inform building occupants during emergencies. New trends have joined
7
TIME TO EVACUATE
fire alarm systems with mass notification or emergency communication systems to access a more
flexible level of communication. Both have been standardized by NFPA 72 and regulated by
UFC 4-021-01, but fail to be recognized by the National Building Code of Canada (Boynowski,
2010). They provide real-time information to all building occupants by utilizing a variety of
interfaces (i.e. SMS text, email, voice communication) during emergency situations to ensure
delivery of messages promoting faster evacuation (Boynowski, 2010; Mircom Group, 2012).
Their application stemmed from the realization of a misconceived notion; fire alarms are
sufficient to prompt evacuation. In actuality, humans do not respond to fire alarms like ball
bearings by immediately evacuating via the closest egress point upon the sound of an alarm
(Galea, 2009). They require more information to effectively evaluate their level of risk and
assume adoptive roles based on their current knowledge of the situation. The less information
provided equates to less desirable roles like searching for fire. This was evident during the MGM
Grand Hotel Fire where a series of communication errors led up to a devastating outcome (see
Appendix A for a complete list of data). Bryan (2003) discovered that males were more likely to
initially notify others (16.3%), searched for fire (14.9%), or handle an extinguisher (6.9%);
instead of leaving the building (4.2%; p. 4-22). Females were more likely to initially notify
others (13.8%), call the fire department (11.4%), and locate family (11%); instead of leaving the
building (10.4%; Bryan, 2003, p. 4-22). Despite the NFPA 72 and UFC 4-021-01 existence, they
do not entirely address all the problems associated with communication (Kuligowski, 2011, p. 2).
These systems can increase negligence in building occupants when messages are too long
(Kuligowski, 2011, p. 7). Kuligowski, in a preliminary NIST report, provided benchmarks to
construct effective messages. These were supported by other research studies. Chandler
concluded that messages should contain 27 words, 3 sentences, 9 seconds long, and be front
8
TIME TO EVACUATE
loaded with most important and relevant information (as cited in Kuligowski, 2011, p. 7).
Furthermore, Doug and Fung noted that a live voice that does not deliver daily non-emergency
messages is most effective (as cited in Kuligowski, 2011, p. 7). Chandler also concluded that text
messages are most effective when written at a 6th grade level, or four grades below the United
States average reading level (as cited in Kuligowski, 2011, p. 8). Standardizing requirements that
stipulate the construction and content of messages to occupants during emergencies will improve
the effectiveness of these systems. Also, the recognition by legislation will ensure their use in the
built environment.
Argument Three
In addition to effective messages, building occupants would be prompted to evacuate
quicker if a fire alarm system provided audible direction. Directional sound utilizes people’s
ability to localize sound sources, even around corners, which helps navigate occupants to exits
(O’Connor, 2005). This provides flexibility over line-of-sight methods (i.e. fire exit signs) since
building users unconsciously learn to neglect their presence over time. An experiment conducted
by the University of Ulster randomly sampled 500 people after leaving a store that had 14
emergency exit signs (O’Connor, 2005). It was concluded that 75.2 % of participants did not
notice or identify correctly any emergency exit signs (O’Connor, 2005). Directional sound
supplements a traditional fire alarm system’s alarm sound. Traditional alarm sounds (i.e. T-3) are
prescribed by codes to achieve specific sound levels in all building areas, whereas directional
sound provides sound cues assisting occupants in locating nearby exits (O’Connor, 2005).
Directional sound achieves exit localization by using different frequencies of sounds ranging
from fast and slow; faster sounds indicate closer exits (see Appendix B for an illustration).
Directional sound is not recognized by legislation, creating a missed opportunity for fire alarm
9
TIME TO EVACUATE
systems to promote faster and more effective building evacuation (O’Connor, 2005). University
of Leeds Professor Withington has conducted several pilot trials that exemplify faster evacuation
times in a variety of settings when comparing the use of visual signs and the combination of
directional sound and visual signs. Table B reports these findings from three of Withington’s
(2002) pilot trails, which involved smoke and non-smoke filled environments (p. 5-7).
Table B – Evacuation Times in Pilot Trials testing Directional Sound
PILOT TRAIL
VISUAL SIGNS (s)
COMBINATION (s)
Complex Maze (smoke)
124
Complex Maze (no smoke)
14
Open Space (smoke)
14.5
Open Space (no smoke)
5.5
Left/Right (smoke)
67.8
Left/Right (no smoke)
8.8
1
jointly uses directional sound and visual signs
51.3
7
7.3
4.9
7
6
1
DIFF. (s)
DIFF. (%)
72.7
7
7.2
0.6
60.8
2.8
58.6
50
49.7
10.9
89.7
31.8
The data above suggests that the combination of directional sound and visual signs hastens
evacuation in different circumstances. Pilot trials Complex Maze led participants through a series
of rooms to a safe exit, Open Space required participants to locate an exit after being positioned
in the centre of a large open spaced room, and Left/Right required participants to locate the
available exit positioned directly to their left or right (Withington, 2002, p. 5-7). Smoke filled
pilot trials resulted in the greatest differences in evacuation times. Further evidence to support
the effectiveness of directional sound can be illustrated in a cost-benefit analysis (CBA). Table C
provides a CBA outlining the additional costs and benefits awarded to a fire alarm system that
integrates directional sound with its current system.
10
TIME TO EVACUATE
Table C – Cost Benefit Analysis for Directional Sound
COST
Directional Sound
Install (%)
Per Unit ($)
4 - 8% more
130.93
BENEFITS (EGRESS TIME)
Average Improvement (s) Average Improvement (%)
25.2
40.95
The average cost would only be an additional 4 – 8 % of the current fire alarm system
(O’Connor, 2005). Individual units range in cost depending on features, supplier, and quantity.
For example, Amazon sells a System Sensor PF24V ExitPoint Direct Sounder with Voice
Messaging for $191.79 (Amazon, 2012). Total Computing Life Safety sells the same model
starting at $130.93 and declining as higher quantities are purchased (Total Computing Life
Safety, 2012). The benefits are associated with egress times. They reflect the mean differences in
seconds and percentage derived from the different trials in Table B, which indicate evacuation
improvements. Directional sound is a cost effective approach to improve on the short comings of
fire alarm systems by providing direction for occupants during evacuation.
Discussion
Three arguments supporting the notion that fire alarm systems inadequately evacuate
building occupants were provided all of which address academia’s position on human behaviour
during fire. Roles that are adopted by occupants are influenced by a variety of environmental
interpretations including the fire alarm system. Acknowledging the fact that fire alarm systems
are responsible for building occupant behaviour and their adopted roles generates a space to
create changes that account for their short comings. For example, since fire alarm sounds (i.e. T3) were recognized as ambiguous, the implementation of voice communication systems helped
clarify emergency incidents by providing messages. The same philosophy can be used to change
the framework of today’s fire alarm systems. By standardizing the structure and content of
11
TIME TO EVACUATE
messages used in mass notification and emergency communication systems accepts the fact the
more can be done to increase the control over building evacuation. As mentioned earlier,
technology does not seem to be the problem. The current financial burdens and slow paced
policy has staged the built environment, as directed by building and fire codes, far behind
technological advancements and research findings. Both, directional sound and mass notification
systems fail to be enforced by the National Building Code of Canada. The T-3 has been enforced
since 1996 by the National Building Code of Canada, but Proulx & Laroche’s (2003) research
indicated low recognisability and perceived urgency even years after its enactment making
participants in the fields of fire and evacuation question the disconnect between public education
and public policy. There is a gap between what we know is safe for building occupants and how
we legislate it.
Conclusion and Recommendations
In conclusion, fire alarm systems fail to adequately evacuate building occupants. A
common role assumed by occupants after interpreting a fire alarm sound is to look for more cues.
This can be influenced in the lack of recognition of the T-3 sound, commonly used in North
American fire alarm systems, by mistakenly identifying it with domestic sounds, burglar alarms,
elevator faults, or security door alarms. This misidentification could attribute to its low sense of
urgency by the general public. It is recommended that programs should be developed to educate
the general public on the T-3 sound, its characteristics, and when it may be encountered (see
Appendix C for a listed format of recommendations). Furthermore, the ambiguous sounds of a
fire alarm system (i.e. T-3) can lead occupants to adopting unfavorable roles like searching for
fire. Mass notification and emergency communication systems are aimed at engaging building
occupants by delivering real-time information through a variety of interfaces to promote
12
TIME TO EVACUATE
favorable roles like evacuating the endangered area. However, since they have been newly
standardized and regulated there is a lack of guidance in constructing effective messages. Too
long of a message may produce negative effects like negligence. It is recommended that
standards and regulations guide users in constructing effective messages. In addition to a lack of
guidance, mass notification and emergency communication systems have not been recognized by
the National Building Code of Canada. It is recommended that building codes of all levels
enforce their use in applications where communication requires real-time information exchange
with all occupants. Lastly, current legislation fails to enforce directional sound which can be a
cost effective approach to reducing evacuation times. Directional sound helps occupants to
localize exits faster than line-of-sight devices in smoke and non-smoke filled environments. This
technology can improve evacuation times by 40.95% while only costing 4-8% of the current fire
alarm system. It is recommended that building codes enforce directional sound technology in
applications that require a cost effective approach to optimize evacuation times. Fire
administrators should continue to advocate for changes that can enhance control over building
evacuation.
13
TIME TO EVACUATE
References
Amazon. (2012). System sensor pf24v exitpoint direct sounder with voice messaging. Retrieved
on June 9, 2012 from www.amazon.com/PF24V-ExitPoint-Directional-SounderMessaging/dp/B001VS4MXG
Bennett, J. O., & Briggs, W. L. (2003). Essentials of Using and Understanding Mathematics: A
Quantitative Reasoning Approach. New York, NY: Addison Wesley.
Boynowski, D. (2010, August 8). Mass notification systems. Canadian Fire Alarm Association,
August 2010, 8-15.
Bryan, J. L. (2003). Human behaviour in fire. In Arthur E. Cote (Ed.), Fire protection
handbook (Vol 1). (20th ed.). Quincy, MA: National Fire Protection Association.
Galea, E. (2009, May 6). 7 of 8: burning questions, model answers – the simulation of fire and
human behaviour [Video file]. Retrieved from www.youtube.com/watch?v=kV7bEm
9D4ko&feature=related
Kuligowski, E. D. (2011, February). Communicating the emergency: preliminary findings on the
elements of an effective public warning message. Washington, DC: National Institute of
Standards and Technology. Retrieved from www.nist.gov/customcf/get_pdf.cfm
?pub_id=907983
Mircom Group. (2012). Mircom mass notification system. Retrieved from www.mircomgroup
.com/products/product-lines/fx-mns.html
National Research Council Canada. (2010, August 26). Study shows low public recognition of
the temporal-three evacuation signal. Retrieved from http://www.nrccnrc.gc.ca/eng/ibp/irc/ci/volume-6-n4-1.html
14
TIME TO EVACUATE
O’Connor, D. J. (2005). Directional sound. NFPA Journal, 99, 50-56.
Proulx, G. (2007). Response to fire alarms. Retrieved from www.fpemag.com/archives/article
.asp ?issue_id=40&i=267
Proulx, G. & Laroche, C. (2003). Recollection, identification, and perceived urgency of the
temporal-three evacuation signal. Journal of Fire Protection Engineering, 13, 67-72.
Total Computing Life Safety. (2012). System sensor pf24v, exitpoint direct sounder with voice
messaging Retrieved on June 9, 2012 from http://www.totalcomputing.net/SystemSensor-PF24V-ExitPoint-Directional-Sounder-wVoice-Messaging_p_1203.html
Withington, D. (2002). Life saving applications of directional sound. Retrieved from
www.systemsensor.com/exitpoint/pdf/life_saving_directional_sound.pdf
15
TIME TO EVACUATE
Appendix A
First Actions by Occupants during the MGM Grand Hotel Fire
FIRST ACTION
Notified others
Searched for fire
Called fire department
Got dressed
Left building
Got family
Fought fire
Got extinguisher
Left area
Woke up
Nothing
Had others call fire department
Got personal property
Went to fire area
Removed fuel
Entered building
Tried to exit
Went to fire alarm
Telephoned others
Tried to extinguish
Closed door to fire area
Pulled fire alarm
Turned off appliances
Checked on pets
Other
Total (N = 25)
MALE (%)
16.3
14.9
6.1
5.8
4.2
3.4
5.8
6.9
4.6
3.8
2.7
3.4
1.5
1.9
1.1
2.3
1.5
1.1
0.8
1.9
0.8
1.1
0.8
0.8
6.5
262
Note reproduced from Bryan, 2003, p. 4-22.
FEMALE (%)
13.8
6.3
11.4
10.1
10.4
11.0
3.8
2.8
4.1
2.5
2.8
1.3
2.5
2.2
2.2
0.09
1.6
0.19
1.6
0.6
1.3
0.6
0.9
0.9
2.5
318
16
TIME TO EVACUATE
Appendix B
Illustration of Directional Sound in a Building
Exit sign shaded quadrant represents visible face
Exit sign with designation of directional arrow
Directional sounder
Note reproduced from O’Connor, 2005.
17
TIME TO EVACUATE
Appendix C
Recommendations
1. Programs should be developed to educate the general public on the T-3 sound, its
characteristics, and where/when it may be encountered
2. Standards and regulations should guide users in constructing effective messages for their
application in mass notification and emergency communication systems
3. Building codes should enforce the use of mass notification and emergency
communication systems in applications where communication requires real-time
information exchange with all occupants
4. Building codes should enforce directional sound technology in applications that require a
cost effective approach to optimize evacuation times