THE OFFICIAL MAGAZINE OF THE SOCIETY OF FIRE PROTECTION ENGINEERS

FIRE PROTECTION

SPRING 2004 Issue No.22

ASSEMBLY
PROPERTY FIRES
page 8

ALSO:

20 SERVING ASSEMBLY
OCCUPANCIES: LOOKING
BEYOND SPECIFICATIONS

28 FIRES IN CLEAN ROOMS:

THE EFFECTS OF DOWNWARD
AIR FLOW ON CEILING JET FLOW

40 PLASTIC PIPE AND FIRE SAFETY

48 COMBINING EMERGENCY
VOICE AND NONEMERGENCY
PAGING SYSTEMS
 FIRE PROTECTION

Fire Protection Engineering (ISSN 1524-900X) is

published quarterly by the Society of Fire Protection
Engineers (SFPE). The mission of Fire Protection
Engineering is to advance the practice of fire protection
engineering and to raise its visibility by providing
contents SPRING 2004

information to fire protection engineers and allied

professionals. The opinions and positions stated are 8
the authors’ and do not necessarily reflect those of SFPE. Assembly Property Fires
Editorial Advisory Board Deaths occurring during fires in public assembly spaces are tragic, however,
Carl F. Baldassarra, P.E., Schirmer Engineering Corporation “major” fires are not typical of assembly property fires, which tend to have a very
Don Bathurst, P.E. low risk of death in most years. This article presents up-to-date statistics about fires
Russell P. Fleming, P.E., National Fire Sprinkler Association in eating/drinking places, religious/funeral properties, amusements places,
Morgan J. Hurley, P.E., Society of Fire Protection Engineers libraries/museums, theatres/studios, and passenger terminals, and discusses the
William E. Koffel, P.E., Koffel Associates
characteristics of assembly fires.
John R. Hall, Jr., Ph.D.
Jane I. Lataille, P.E., Los Alamos National Laboratory
Margaret Law, M.B.E., Arup Fire
Ronald K. Mengel, Honeywell, Inc.
Edward Prendergast, P.E., Chicago Fire Dept. (Ret.) 20 Fire Alarm Systems Serving Assembly Occupancies:
Warren G. Stocker, Jr., Safeway, Inc. Looking Beyond Specifications
Beth Tubbs, P.E., International Conference of Building Recent nightclub tragedies have highlighted the need to re-visit fire safety in
Officials nightclubs and other assembly occupancies in general. This article focuses
Regional Editors on the characteristics of assembly occupancies and presents a detailed
U.S. H EARTLAND overview of key considerations and challenges involved in the design of fire
John W. McCormick, P.E., Code Consultants, Inc. alarm systems serving them.
U.S. M ID -ATLANTIC Jorge Velasco & Edward L. Fixen, P.E.
Robert F. Gagnon, P.E., Gagnon Engineering, Inc.
U.S. N EW E NGLAND 28 Fires in Clean Rooms: Considerations About the Effects of
Thomas L. Caisse, P.E., C.S.P., Robert M. Currey & Downward Air Flow on Ceiling Jet Flow and FDS Application for
Associates, Inc.
Temperature Prediction
U.S. S OUTHEAST
Jeffrey Harrington, P.E., The Harrington Group, Inc.
The differentiation among several classes of cleanliness in clean rooms is
important for fire protection engineering purposes, because, as covered in
U.S. W EST C OAST
Michael J. Madden, P.E., Gage-Babcock & Associates, Inc.
this article, different downward air flow velocities may affect system compo-
nents in different ways. The article provides suggestions for new methods to
A SIA
Peter Bressington, P.Eng., Arup Fire
address today’s challenges.
Massimo Manganaro
A USTRALIA
Brian Ashe, Australian Building Codes Board
C ANADA
40 Plastic Pipe and Fire Safety
J. Kenneth Richardson, P.Eng., Ken Richardson Fire This article looks at the use of plastic piping in design elements and the
Technologies, Inc. issues that relate to it. It also covers the extensive research and testing in the
N EW Z EALAND use of plastic piping related to fire performance.
Carol Caldwell, P.E., Caldwell Consulting Joseph B. Zicherman, Ph.D.
U NITED K INGDOM
Dr. Louise Jackman, Loss Prevention Council 48 Combining Emergency Voice and Nonemergency Paging Systems
Personnel This article explores the functional similarities and differences of emergency
and nonemergency systems and discusses how and why the systems might
EXECUTIVE DIRECTOR, SFPE
Kathleen H. Almand, P.E. be combined.
National Electrical Manufacturer’s Association
T ECHNICAL E DITOR
Morgan J. Hurley, P.E., Technical Director, SFPE
P UBLISHER
Terry Tanker, Penton Media, Inc.
Cover photo by SuperStock
A SSOCIATE P UBLISHER
Joe Pulizzi, Custom Media Group, Penton Media, Inc. Online versions of all articles can be accessed at www.sfpe.org.
M ANAGING E DITOR
Invitation to Submit Articles: For information on article submission to Fire
Joe Ulrich, Custom Media Group, Penton Media, Inc.
Protection Engineering, go to http://www.sfpe.org/sfpe/fpemagsubmit.htm
A RT D IRECTOR
Pat Lang, Custom Media Group, Penton Media, Inc.
M EDIA S ERVICES M ANAGER
Erika Eustance, Custom Media Group, Penton Media, Inc.
C OVER D ESIGN
Dave Bosak, Custom Media Group, Subscription and address change correspondence should be sent to: Fire Protection Engineering,
Penton Media, Inc. Penton Media, Inc., 1300 East 9th Street, Cleveland, OH 44114 USA. Tel: 216.931.9180. Fax: 216.931.9969.
E-mail: asanchez@penton.com.
Copyright © 2004, Society of Fire Protection Engineers. All rights reserved.

www.sfpe.org 1
letters to the editor

Dear Editor, rienced trial lawyers maintain that the three false alarm, regardless of the facts. This re-
keys to successful litigation are preparation, sponse is neither unusual nor unexpected.
Because of the great costs involved, more preparation, and preparation. Assuming that it was not preplanned (evac-
than 95% of all lawsuits are settled before trial. Hazard #4 is the fee question. During cross- uation drill), then if the evacuees are told:
Dr. Schroeder’s article regarding the Fire Pro- examination, one of the standard questions • there was a trashcan fire (real fire), or
tection Engineer’s responsibilities in preparing opposing counsel will ask relates to how • there was a puff of dust from cleaning the
a response to a lawsuit clearly describes the much the expert is being paid for his or her lint out of the laundry (nuisance), or
pretrial efforts and the value of well-prepared testimony. This implies that the expert’s testi- • the ambulance had to take someone away
deposition testimony in reaching a satisfactory mony is being bought and is purposely asked (other emergency), or
settlement. However, pretrial deposition testi- in a manner intended to be embarrassing. A • whatever it was, then the future response is
mony, while it may be very searching in its reasonable reply is that the expert is being much more positive because a learning
scope, is not subject to cross-examination. If a paid for his or her time, not his or her testi- process has taken place, and intuition is
case does go to trial, a major difference is that mony. Another way to avoid this hazard is for properly developed.
expert’s testimony will be subject to cross-ex- the expert to have his or her own lawyer pre- These types of improvements occur in
amination. If not prepared for it, this can be a empt the question by asking it during direct many fields. For example, if you go to the
very hazardous situation for the expert. examination. A dependent hazard is that the motor vehicles department, then you will see
Hazard #1 is failure to recognize that the expert’s client loses the case, blames the ex- where you are in the queue, giving you much
opposing attorney is an adversary, out to dis- pert’s efforts for the outcome, and refuses to more confidence (after an hour’s wait!) that
credit the expert’s testimony and destroy his pay. you haven’t been forgotten.
or her credibility as an expert witness. This is Any technical expert should remember that
also known as impeachment. This adversarial their primary function is to convince the deci- Walter W. Jones, Ph.D.
situation is a basic part of the U.S. judicial sion-makers that his or her point of view is the
system and is intended to ensure factual correct one. The expert must be a credible wit-
truth. All such proceedings are, of course, in- ness. Experts are simply wasting every one’s Response
cluded in the trial record and may appear in time if others don’t believe them. In that re-
various reporting services accounts of the gard, testifying as an expert is something of a Dr. Jones makes a very good point. In the
case. In replying to cross-examination ques- selling job, making a believer of the prospect. first part of this article, published in the Fall
tions, the expert should answer the question, Experts must have the facts, know that they 2003 issue, it was pointed out that, “In order
and only the question, in the briefest possible are correct, and remember that honesty is not to reduce the Cry Wolf syndrome associated
manner. The expert should never volunteer only the best but also the only policy. with fire alarm systems, it is necessary to de-
any additional information. crease the ratio of false-to-real alerts. Assum-
Hazard #2 is the lawyer who plays the Thomas A. Hunter, P.E. Ph.D. ing it is not desirable to increase the number
odds. Knowing that most cases settle without Principal Consultant of real alerts, it becomes necessary to decrease
trial, some lawyers will attempt to save the Forensic Engineering Consultants, Inc. the number of false alerts. A second way to
expense of hiring an expert until it becomes minimize the Cry Wolf syndrome is to reduce
clear that no settlement is possible. Only the impact of false alerts so that they are not
then, with the attorney’s back to the wall, are Dear Editor, perceived as being bad.”
the services of a qualified expert requested. In the Summer 2003 article titled “Messag-
Obviously, having little or no factual informa- The series entitled “Cry Wolf Syndrome” ing and Communication Strategies for Fire
tion available and limited access to what is addressed the concern that those who are Alarm Systems,” this point was also discussed:
on the record puts the expert in a difficult sit- buggered by false or nuisance alarms are less “In addition to reducing false and nuisance
uation. In any situation like this, the best likely to respond. alarms, there are other ways to increase sys-
choice is usually to decline the case rather The article on the NEMA perspective was tem accuracy and occupant confidence. One
than work with a person whose judgment is well written as usual, but I think they have way is to always follow-up any unwanted
already suspect. missed a crucial issue. alarm by communicating to the occupants the
Hazard #3 is the attorney who doesn’t A critical component (mostly missing these reason for the alarm and, if possible, what is
know what he or she doesn’t know. In this days) for fire alarms, real or nuisance, is that being done to prevent further occurrences,”
situation, the technical details need to be ex- those responding to these alarms need to be and “If every unwanted alarm is followed up
plained to the lawyer so that, come testimony told what happened. And it needs to be done with a voice message, the perceived system
time, the proper questions can be asked and immediately rather than weeks or months error is reduced from 100% to 50%.”
in the proper sequence. It is the process of later.
preparing the lawyer, although they may pre- Intuition is the process of learning cause Robert Schifiliti, P.E.
fer to call it preparing the expert. Either way, and effect. If you have to evacuate a space R.P. Schifiliti Associates, Inc.
it is part of the process of preparation and and later return to the space without explana- Author, NEMA Supplement to Fire Protection
should be carried out very thoroughly. Expe- tion, your assumption will be that there was a Engineering

S PRING 2004 www.sfpe.org 2

viewpoint

While this performance language was

Life Safety in not adopted for the 1986 edition of

NFPA 102, the term “Smoke-Protected
Assembly Seating” was introduced.

Large Assembly
Moreover, this term, along with the con-
cept of “Life Safety Evaluation,” was
adopted – as an option – in the 1988
edition of NFPA 101 for places of assem-

Occupancies bly occupancy where 2,000 or more

people were seated in a single space
and egress width per person was re-
duced. The definition of “Life Safety
By Jake Pauls of a severe weather condition for an out- Evaluation” was: “a written review deal-
door place of assembly or the progres- ing with the adequacy of life safety fea-

I n the few years following the disas-

ters of September 11, 2001, safety
professionals, government authori-
ties, the mass media and the public,
among others, have questioned the
sive failure of a roof for an enclosed sta-
dium could trigger urgent desires to
move out of a seating area. An example
of this occurred – fortunately shortly be-
tures relative to fire, storm, collapse,
crowd behavior, and other related safety
considerations.”
Over several editions of NFPA 101,
fore a major-occupancy event – when Life Safety Evaluation was applied to
degree to which buildings are safe and an unusual snow load on the Pontiac Sil- several difficult-to-enforce problems in
perceived to be safe. With the night- verdome in Michigan caused successive assembly occupancies including, for ex-
club disasters of February 2003 the failure of membrane roof panels and de- ample, “Festival Seating.” Much addi-
questioning grew. Yet as bad as these struction of seat sections under tons of tional detail on what constituted a Life
disasters were, they may pale in com- crushing snow. Safety Evaluation was introduced to the
parison to the potential scale of life But rapid escape is not an option for Annex A of NFPA 101 beginning in the
loss in a large assembly occupancy. which such large assembly buildings are 2000. This detail, in the form of orga-
An occupancy of 15,000 people typically designed, constructed or man- nized topics to consider in doing a Life
within a single space of an assembly aged. Should they be? Alternatively, Safety Evaluation, included the need to
building is not large relative to the esti- what prevention and mitigation mea- consider terrorism, for example, as one
mated occupancy of the two World sures should be used to assure, as be- type of condition addressed in a facility
Trade Center towers an hour or two be- nign, an evacuation time of many min- operations manual.
fore their final destruction. Assembly utes or even the unavailability of Today, fire protection engineers (and
buildings such as large enclosed stadia another place to evacuate to? What form others) must recognize that a Life Safety
can easily hold 75,000 people. But un- should such prevention and mitigation Evaluation is not merely an assessment
like in a typical high-rise building, a measures take-facility design, construc- of fire safety. For example, in large as-
great deal of awareness of a particular tion, management, etc? sembly facilities, the chance of injury,
situation can be communicated instanta- These were the central questions even death, due to a crowd crush is sim-
neously to almost everyone in a large raised in 1983 when the author submit- ilar to that due to fire. The extent to
stadium. The very sightlines that make ted all of the public proposals for what which non-fire hazards are given short
the building work for an entertainment became the 1986 edition of NFPA 102 in- shrift in the treatment of design, con-
event can also make almost all occu- cluding one that suggested an exception struction and operation for large assem-
pants vulnerable simultaneously to a to designing means of egress in accor- bly occupancies raises even more ques-
real or perceived danger. dance with the relatively demanding tions that warrant careful examination
Sometimes an emergency condition in egress capacity requirements of NFPA by SFPE and other organizations con-
an assembly occupancy is treated by 101: cerned about life safety.
spectators as a non-threatening bonus “In outdoor grandstands and in very
on top of the event they paid to see. large indoor stadia, for which a pro- Jake Pauls is an independent consul-
One of the classic examples of this be- fessionally conducted hazards evalua- tant in building use and safety. Ideas for
havior was the spectators’ response to a tion shows that fire and other life this Viewpoint come from his presenta-
fire in a grandstand at a Kentucky safety hazards are sufficiently con- tion, “Life Safety Evaluation: What is it?
Derby; they stayed to watch. The fire in trolled in all occupied areas and in How is it used? How is it misused?” in
the Bradford, England, soccer grand- means of egress, the width of means 1994 to the International Association of
stand was another example of this but of egress from large seating areas shall Assembly Managers (IAAM) Crowd
the outcome was disastrous for many be at least sufficient to permit a flow Safety Conference and two years later to
caught by the rapid fire growth. But time not exceeding 10 minutes at any the NFPA Fall Meeting. The paper may be
some events, such as the sudden onset point in the egress system...” downloaded from www.crowdsafe.com.

S PRING 2004 www.sfpe.org 3

 flashpoints
fire protection industry news

Authors Awarded for Paper on Fire • Establish a research program investigating

Plume and Sprinkler Interaction the factors affecting human decision-mak-
On January 23, 2004, The Fire Protection ing and evacuation behavior during emer-
Research Foundation of the National Fire gencies in buildings.
The SFPE Corporate 100 Program was founded in
Protection Association (NFPA) presented the NCST is comprised of ten building and fire 1976 to strengthen the relationship between industry
third annual William M. Carey Award to the experts and was established to advise the and the fire protection engineering community.
Commerce Department’s National Institute of Membership in the program recognizes those who
authors of a paper titled “Fire Plume and Fire support the objectives of SFPE and have a genuine
Sprinkler Interaction.” The award was pre- Standards and Technology (NIST) in its con-
concern for the safety of life and property from fire.
sented at the Foundation’s eighth annual Fire ducting of technical building failure investiga-
Suppression and Detection Research Applica- tions as authorized under the NCST Act. BENEFACTORS

tion Symposium held in Orlando. The 23-page report is availale online at Koffel Associates, Inc.
www.nist.gov/ncst. Rolf Jensen & Associates, Inc.
The authors are Dr. Richard Lueptow of SimplexGrinnell
Northwestern University, and John A. Schwille Specified Technologies, Inc.
and Dr. Pravin Gandhi, both of Underwriters NIST Reports Current Smoke Alarms
Laboratories Inc. The award recognizes the Save Lives if Properly Used PATRONS
conference’s best paper from the previous A report issued on February 26, 2004, from Ansul, Inc.
Code Consultants, Inc.
year, voted by attendees. the Commerce Department’s National Institute
Edwards Systems Technology
In the paper, the authors describe experi- of Standards and Technology (NIST) states Gage-Babcock & Associates, Inc.
ments in which the interaction of a fire plume that both types of commercially available home Hughes Associates, Inc.
with a sprinkler spray was directly measured. smoke alarms consistently provide people National Fire Protection Association
The shape and height of the fire plume was enough time to escape most residential fires. It Schirmer Engineering Corporation
measured using infrared thermography. By stresses the need for immediate response to Tyco Fire and Building Products
measuring both the fire plume and the spray, an activated alarm and shows that individuals MEMBERS
the authors were able to quantify the degree caught in a flaming fire (as opposed to a smol- Altronix Corporation
of fire suppression based on the fire size and dering fire) have an average of three minutes Arup Fire
the spray characteristics. from an alarm’s first warning to escape. Cybor Fire Protection Company
The award honors the late William Carey, “The three-minute escape window for flam- FM Global Corporation
P.E., senior staff engineer at Underwriters ing fires differs from the 17 minutes NIST re- GE Global Asset Protection Services
Harrington Group, Inc.
Laboratories Inc. Carey made many major corded in its seminal smoke alarm tests in the
HSB Professional Loss Control
contributions to new fire suppression tech- 1970s,” says Richard Bukowski, the NIST re- James W. Nolan Company (Emeritus)
nologies and served on various technical searcher who conducted both studies. “It con- Marsh Risk Consulting
advisory committees of the Foundation. firms what fire scientists have recognized for National Fire Sprinkler Association
For more information, visit www.nfpa.org. some time: Fires today seem to burn faster Nuclear Energy Institute
and kill quicker because the contents of mod- The Protectowire Co., Inc.
The Reliable Automatic Sprinkler Company
Four Major Recommendations to ern homes (such as furnishings) can burn
Reliable Fire Equipment Company
faster and more intensely. Our new research,
Improve Future Building Failure however, proves that even with a three-
Risk Technologies LLC
TVA Fire and Lifesafety, Inc.
Investigations minute warning, smoke alarms still offer Underwriters Laboratories, Inc.
In its first annual report to Congress, The enough time to save lives.” Wheelock, Inc.
National Construction Safety Team (NCST) The report, “Performance of Home Smoke Williams Fire and Hazard Control
Advisory Committee made the following four Alarms: Analysis of the Response of Several SMALL BUSINESS MEMBERS
major recommendations to improve future Available Technologies in Residential Fire Bourgeois & Associates, Inc.
building failure investigations: Settings,” may be downloaded at The Code Consortium, Inc.
• Create an NCST Office within NIST’s Build- http://smokealarm.nist.gov. Davidson & Associates
ing and Fire Research Laboratory with Demers Associates, Inc.
permanent staff and initial funding of $2 Fire Consulting Associates, Inc.
million. Fire Suppression Systems Association
• Establish a safety team investigation re- Correction: On page 39 of the Winter, Futrell Fire Consult and Design Inc.
2004 issue, article “Opportunities to Learn from Gagnon Engineering, Inc.
search fund of $2 million to be used at the
9/11,” the units for the estimated total jet fuel Grainger Consulting, Inc.
discretion of the NIST Director to fund J.M. Cholin Consultants, Inc.
burning rate over one floor were misstated. The
investigations when warranted. correct units are kg/s. Additionally, the second MountainStar Enterprises
• Establish a program to familiarize local and equation should have read: Poole Fire Protection Engineering, Inc.
state investigating authorities about the Risk Logic, Inc.
28, 500 kg − 9, 400 kg
NCST Act. = 79s Slicer & Associates, LLC
242 kg s S.S. Dannaway & Associates, Inc.
Van Rickley & Associates

4 Fire Protection Engineering N UMBER 22

 Assembly Property
Fires

By John R. Hall, Jr., Ph.D. The assembly fire problem is neither as or mosques
severe as it tends to seem in the immediate – Religious education facilities

O
aftermath of one of these horrific tragedies – Religious meeting or fellowship halls
n February 20, 2003,
nor as thoroughly tamed as it can seem in – Funeral parlors
a fast-moving fire in the often-lengthy intervals between such • Amusement places
The Station night- incidents. The purpose of this article is to – Ballrooms or gymnasiums
paint a realistic and balanced picture of the – Exhibition or exposition halls
club fatally injured 100 assembly property fire problem, so that it – Arenas or stadiums, including ball
employees and patrons, most can be provided with the urgency it de- parks, racetracks, or any other place
of them otherwise healthy serves without overreacting or acting pre- with grandstands
cipitously in the pursuit of fire safety. – Bowling alleys
young adults out for a night The following is an overview of what – Pool halls
of fun in West Warwick, qualifies as a public assembly property, us- – Amusement arcades
Rhode Island. This tragedy ing the categories and terminology of fire – Ice rinks or roller rinks
incident reporting. These categories have – Swimming pool facilities
was a reminder of the enor- been in existence for a quarter-century and – Playgrounds
mous potential for human describe individual facilities rather than • Libraries, museums, and courthouses
complexes. Some important types of more – Libraries
loss in high-occupancy prop-
recent vintage – such as convention cen- – Museums or art galleries
erties like those collectively ters – are therefore not explicitly shown. – Courthouses or legislative halls
described as public assem- • Eating and drinking places • Theaters and studios
– Restaurants, cafeterias, diners, lunch- – Legitimate or motion picture theaters
bly. (High-occupancy prop- rooms, snack bars, or drive-ins – Auditoriums or concert halls
erties would be any property – Nightclubs, bars, taverns, or dinner the- – Radio, television, or motion picture
with a large number of peo- aters studios
• Clubs • Passenger terminals
ple, whether the density is – Country club facilities, primarily club- – Airport passenger terminals, including
high or not, and could houses heliports
include stores, offices, and – City club facilities, primarily athletic – Rail terminals serving street-level, un-
clubs, such as YMCA derground, or elevated rail systems
residential properties other • Religious or funeral properties – Bus passenger terminals
than dwellings.) – Places of worship – churches, temples, – Marine passenger terminals

5 Fire Protection Engineering N UMBER 22

 Table 1. 20 Deadliest Single-Building or Complex
Fires and Explosions in U.S. History Half of the 20 deadliest fires in U.S. history that were
limited to a single building or complex (see Table 1) in-
Number of Deaths
volved public assembly properties, beginning with the
1. The World Trade Center 2,666 second deadliest (after the World Trade Center event of
New York City, New York
September 11, 2001
9/11/2001), which was the 1903 Iroquois Theater fire
where 602 people lost their lives. Others of historic size,
2. Iroquois Theater 602
Chicago, Illinois
listed in order of most deaths, were the 1942 Cocoanut
December 30, 1903 Grove night club fire (third deadliest, 492 deaths), the
3. Cocoanut Grove night club 492
1876 Conway’s Theater fire in Brooklyn (sixth, 285), the
Boston, Massachusetts 1940 Rhythm Club fire in Mississippi (seventh, 207), the
November 28, 1942 1908 Rhodes Opera House fire in Pennsylvania (ninth,
4. Ohio State Penitentiary 320 170), the 1944 circus fire in Hartford, Connecticut (tenth,
Columbus, Ohio 168), the 1977 Beverly Hills Supper Club fire (twelfth,
April 21, 1930 165), the 1811 Richmond Theater fire (thirteenth, 160), The
5. Consolidated School (gas explosion) 294 Station (eighteenth, 100), and the 1990 Happy Land Social
New London, Texas Club fire (twentieth, 87). In the last 45 years, the only fires
March 18, 1937 on this deadliest list have been assembly fires and terrorist
6. Conway’s Theater 285 attacks (World Trade Center in 2001 and Oklahoma City in
Brooklyn, New York 1991).
December 5, 1876
7. Rhythm Club 207
Natchez, Mississippi
April 23, 1940
Table 2. Fires in Eating and Drinking Establishments and
8. Lakeview Grammar School 175 Clubs Structure Fires Reported to U.S. Municipal Public
Collinwood, Ohio
March 4, 1908 Fire Departments
9. Rhodes Opera House 170
Boyertown, Pennsylvania Unclassified or Loss in all eating
January 12, 1908 unknown-type and drinking
Eating Drinking eating or places
10. Ringling Brothers Barnum and Bailey Circus 168 Year places places drinking places (Millions) Clubs
Hartford, Connecticut
July 6, 1944 1980 16,700 6,200 300 $188.4 3,000
11. Alfred P. Murrah Federal Building 168 1981 16,100 5,700 600 $176.1 2,500
Oklahoma City, Oklahoma
April 19, 199 1982 14,900 5,300 1,500 $211.6 2,100
12. Beverly Hills Supper Club 165 1983 12,400 4,600 1,200 $203.4 1,800
Southgate, Kentucky 1984 12,100 4,000 1,400 $193.4 1,600
May 28, 1977
1985 13,400 4,200 1,400 $210.0 1,900
13. Richmond Theater 160
Richmond, Virginia 1986 11,300 3,500 1,200 $126.0 1,600
December 26, 1811
1987 11,400 3,100 1,100 $129.3 1,500
14. Triangle Shirtwaist Company 146
New York, New York 1988 10,100 2,500 900 $178.2 1,300
March 25, 1911 1989 9,000 2,300 1,000 $145.5 1,200
15. Eddystone Ammunition Company plant explosion 133 1990 8,600 2,300 900 $172.5 1,100
Eddystone, Pennsylvania
April 10, 1917 1991 8,700 2,200 800 $174.2 1,100
16. Cleveland Clinic Hospital 125 1992 8,900 2,000 900 $191.7 1,100
Cleveland, Ohio 1993 8,400 1,900 900 $162.8 1,100
May 15, 1929
1994 8,900 1,700 1,000 $167.2 1,100
17. Winecoff Hotel 119
Atlanta, Georgia 1995 8,300 1,500 800 $129.3 900
December 7, 1946
1996 8,600 1,600 1,000 $171.0 1,100
18. The Station Nightclub 100
West Warwick, Rhode Island 1997 8,600 1,600 1,100 $172.5 900
February 20, 2003 1998 8,400 1,600 800 $175.6 1,700
19. Our Lady of the Angels School 95 1999 8,400 1,500 900 $199.7 1,200
Chicago, Illinois
December 1, 1958 Source: NFPA national estimates based on NFIRS and NFPA survey.
20. Happy Land Social Club 87
New York, New York
March 25, 1990
Source: NFPA archive files, 1984 Fire Almanac, and The Great International Disaster
Book, by James Cornell, Pocket Books, New York, 1976.

S PRING 2004 www.sfpe.org 6

 ■ Assembly Property Fires

However, these historic-sized major places outnumbered drinking places by largest share of public assembly struc-
fires are not typical of assembly prop- about eight to one. This reflects 192,000 ture fires occur in religious or funeral
erty fires, which tend to have a very full-service restaurants, 211,000 limited- properties. Very few of these fires in-
low risk of death in most years. And service eating places, 29,000 specialty volve funeral properties, and most
the assembly category contains as food services, and 51,000 drinking specifically involve churches, mosques,
many differences as similarities. In this places. (Source: U.S. Census Bureau, temples, or other places of worship. Al-
limited space, only the high points of Statistical Abstract of the United States: though confirming documentation is
trends and patterns can be addressed. 2002, Table 1244, establishments with thin, the deadliest single-building fire in
payroll.) world history is believed to be the 1863
EATING AND DRINKING PLACES Clubs other than nightclubs are fire at the Church of La Compaña, San-
AND CLUBS coded separately in U.S. fire statistics, tiago, Chile, where 2,500 people are re-
and Table 2 also shows the trends for ported to have died.
In a typical year, most public assem- structure fires in country clubs and city Table 3 indicates that structure fires in
bly structure fires and associated losses clubs. There is some ambiguity in cod- these properties declined by nearly half
involve eating or drinking places. Table ing between clubs and nightclubs. from 1980 to 1999. Special attention is
2 shows the trends in these fires since However, if the fires for drinking places given to intentional fires in Table 3. A
1980. Fires in eating places (e.g., comprise some or all of the fires associ- national furor erupted in 1996 around
restaurants, cafeterias) declined by ated with clubs, then drinking places allegations of sharp increases in church
roughly half from 1980 to 1999, while have a higher risk than determined arson, and specifically in fires set for
fires in drinking places (e.g., night- above for eating places. motives of religious or racial hatred. A
clubs, bars) declined by roughly three- National Church Arson Task Force was
fourths in the same period. As the Sta- RELIGIOUS OR FUNERAL formed in June of that year, and federal
tion fire illustrated, the deadliest fires in PROPERTIES agencies led by the Bureau of Alcohol,
these properties tend to be in drinking Tobacco, and Firearms (ATF) increased
places, but in a typical year, eating After eating and drinking places, the their support to local law enforcement,
places account for far more fires and
slightly more fire deaths than drinking
places. Table 2 also shows that assem-
bly fire property loss is consistently in
the nine-digit range but shows no con- Table 3. Total and Intentional Fires in Religious or Funeral Properties
sistent increase, whether or not one ad- Structure Fires Reported to U.S. Municipal Public Fire Departments
justs for inflation.
As part of references developed in Loss in
connection with the Station night club Intentional Intentional as Loss in all fires intentional fires
Year All fires fires percent of all fires (Millions) (Millions)
fire, NFPA posted on its Web site a list
of the 10 deadliest foreign nightclub 1980 3,500 1,300 38% $62.1 $39.9
fires since 1970 (see www.nfpa.org/Re- 1981 3,300 1,300 40% $79.2 $34.5
search). Five were in Asia, including a 1982 3,300 1,100 32% $43.3 $18.3
year 2000 disco fire in China where 309 1983 2,800 1,000 36% $114.0 $21.0
died. Four were in Europe, of which 1984 2,900 1,100 38% $50.4 $29.0
the 1998 Swedish disco fire in Gothen- 1985 3,000 1,000 34% $60.5 $28.4
burg was only the third deadliest. The
1986 2,800 900 32% $51.5 $29.0
tenth fire on the list was in South Amer-
1987 2,700 800 31% $51.7 $29.5
ica, specifically Venezuela. (Identifica-
tion and characterization of fire inci- 1988 2,400 700 30% $69.0 $25.0
dents is done using fire incident reports 1989 2,200 700 31% $59.0 $30.0
and reports from other responsible 1990 2,100 600 30% $62.1 $21.4
agencies, as contained in NFPA’s in- 1991 2,100 700 33% $56.9 $30.1
house databases on major fires of tech- 1992 2,200 600 29% $70.7 $33.2
nical interest. For some foreign inci- 1993 2,000 600 28% $57.7 $26.6
dents, the only details available are 1994 2,000 500 24% $60.7 $18.5
from news sources.) $52.1 $24.7
1995 1,900 500 24%
As for the comparison of eating
1996 2,200 600 26% $62.1 $19.5
places to drinking places, the risk per
1997 2,000 400 20% $43.6 $12.3
facility of fire is slightly higher in drink-
ing places, and the risk of death in a 1998 1,900 400 20% $68.4 $25.5
given fire is also higher in drinking 1999 2,000 400 20% $110.8 $32.1
places. In 1999, fires in eating places Source: NFPA national estimates based on NFIRS and NFPA survey.
outnumbered fires in drinking places
by roughly six to one. In 2000, eating

7 Fire Protection Engineering N UMBER 22

 ■ Assembly Property Fires

while also initiating a program of more Table 63, plus miscellaneous Web site AMUSEMENT PLACES
intensive and routine investigations of sources for estimates related to
fires at places of worship. mosques.) While there is substantial in- Amusement places range from large
Table 3 shows that 1996 did involve formation on numbers of facilities by arenas or stadiums, ballrooms or gym-
a jump in intentional fires in religious denominations, including the scores of nasiums, and exhibition halls, down to
or funeral properties but also a jump in distinct Christian denominations, the playgrounds, bowling alleys, pool halls,
unintentional fires in those properties. fire incident databases do not distin- ice rinks, and roller rinks. The diversity
However, 1996 proved to be a singular guish by denomination, and so it is not of design and function may be greater
anomaly. The 1996 jump was more possible to make fire risk comparisons than for any other class of properties,
than reversed in 1997, and the long- between denominations. and nearly half the amusement place
term trends have been down, not only Also, while worship are frequently structure fires in a typical year are re-
for numbers of intentional and total perceived as older buildings, many ported as unclassified or unknown-type
fires in these properties but also for the communities of worship, and even a fixed or variable amusement place.
intentional share of their fires, which number of whole religious denomina- Table 4 shows the trend for these fires,
has fallen by roughly half (from 38%- tions, are of comparatively recent vin- which declined by nearly two-thirds
40% to 20%). The ATF investigations of tage. It is not clear from readily avail- from 1980 to 1999.
fires in 1995-1999, meanwhile, found able statistics whether religious The deadliest amusement place fire
the same mix of motives, most of them properties are older on average than in U.S. history – the Connecticut circus
not involving any type of hate motive, other types of buildings. tent fire cited above – shares some
as are traditionally found in arson cases Table 3 also shows trends in property characteristics with the deadliest
for all types of properties. damage in total fires and intentional amusement place fires in recent world
There are roughly 310,000 places of fires for these properties. In a typical history. Most are not traditional build-
worship in the U.S., of which only year, the average loss per fire is higher ings. In 1995, a tent fire in India, re-
about 2,000 are mosques and only for religious or funeral properties than ported by news accounts as having
about 3,000 are Jewish temples. for other types of assembly properties only one exit for 1,500 occupants, was
(Source: U.S. Census Bureau, Statistical or for most other property use cate- the site of a fire that killed 538 people.
Abstract of the United States: 2002, gories generally. Better documented were the exiting
problems of the open-air Bradford, UK,
soccer stadium fire in 1985, where 56
Table 4. Fires in Other Public Assembly Properties people died. A second India tent fire,
Structure Fires Reported to U.S. Municipal Public Fire Departments this one in 1981 with 58 dead, and an-
other UK fire, this one intentionally set
Amusement
outside a London entertainment com-
Libraries, museums, Theaters and Passenger
Year places and courthouses studios terminals plex, resulting in 50 deaths, complete
the list of deadliest world fires in
1980 4,400 700 1,200 400
amusement places since 1970.
1981 4,100 600 1,100 400 The number of facilities varies widely
1982 3,800 600 800 400 by type of amusement place, and com-
1983 3,300 400 800 300 prehensive figures have proven elusive.
1984 3,300 600 800 300 There are roughly 1,300 stadiums, 600
1985 3,200 600 700 300 convention centers, 2,200 amusement
1986 2,800 600 600 300 arcades, 5,200 bowling centers, 23,000
1987 2,700 500 600 300
fitness and recreational centers (e.g.,
gymnasiums), and 4,500 spectator
1988 2,300 400 500 300
sports companies, including 900 race-
1989 2,000 500 500 200 tracks. (Source: U.S. Census Bureau,
1990 1,800 400 500 200 Statistical Abstract of the United States:
1991 1,900 500 400 300 2002, Table 1210, for establishments
1992 1,900 400 400 200 with payroll, except for the first two
1993 1,700 400 400 200 statistics, which were taken from mis-
1994 1,900 400 400 200 cellaneous Web site sources.)
This leads to perhaps the most sur-
1995 1,800 400 300 200
prising finding for this type of assembly
1996 1,900 400 300 200
property. Six of the seven costliest U.S.
1997 1,700 400 300 200 amusement place fires since 1970 –
1998 1,600 300 300 100 those involving $10 million in direct
1999 1,600 400 300 200 damage before adjusting for inflation –
Source: NFPA national estimates based on NFIRS and NFPA survey. were at racetracks, even though none of
the fires reported any damage to expen-

8 Fire Protection Engineering N UMBER 22

 ■ Assembly Property Fires

sive racehorses or other racing animals. the deadliest incidents, such as the ear- bly properties, but the numbers were
(The seventh was a jai alai fronton.) lier-cited India tent fire, the potential for already fairly low. Prior to 1999, this
There was also a Mexican racetrack fire catastrophe seems clear. category was also used for fires in his-
in this loss range during this period. These are not new concerns. The toric buildings, but that status is now
As with the deadliest amusement NFPA Life Safety Code®, for example, treated separately, as is more appropri-
place fires, racetracks are not traditional has detailed requirements for tents, ate. In a typical year, libraries account
buildings. None of these facilities have grandstands, and other features that for by far the largest share of these
the kind of compartmentation provi- characterize these unusual properties. fires, with museums and courthouses
sions associated with traditional build- The problem, as usual, is in achieving having comparable numbers.
ings, and it may be that all of their de- compliance. The properties in this category are
sign and usage choices – from the especially likely to have highly vulnera-
materials used in construction to the ma- LIBRARIES, MUSEUMS, AND ble contents, although managers may
terials used in contents and furnishings COURTHOUSES well overestimate the potential damage
to the absence of sprinklers – are such from water (e.g., sprinklers) relative to
as to support rapid fire development Table 4 shows that fires in libraries, the potential damage from fire. The
and spread, particularly given unlimited museums, courthouses, and like prop- properties in this category are also es-
access to fresh air to feed the fire. If this erties declined by one-third to one-half pecially likely to have cultural heritage
kind of fire potential is combined with from 1980 to 1999. This is a less dra- safety objectives, in addition to and
the exiting problems repeatedly cited in matic decline than for the other assem- possibly weighted more heavily than

Table 5. Characteristics of Fires in Selected Public Assembly Properties – Annual Averages of

1994-1998 Structure Fires Reported to U.S. Municipal Public Fire Departments

Eating Drinking Religious or Amusement Libraries, museums, Theaters and Passenger

Characteristic places places Clubs funeral properties places and courthouses studios terminals
Percent with indicated major cause
Cooking 47.7% 14.3% 10.9% 8.9% 7.0% 6.5% 15.5% 5.0%
Intentional 7.5% 28.3% 20.9% 22.1% 38.3% 25.1% 19.2% 18.7%
Electrical
distribution 12.1% 18.4% 11.5% 17.5% 13.4% 21.0% 21.2% 11.6%
Smoking 3.9% 8.5% 14.4% 2.3% 5.2% 4.3% 6.1% 23.7%
Heating 6.3% 6.2% 8.7% 11.6% 7.2% 8.9% 5.4% 3.0%
Open flame
(e.g., torch) 3.1% 4.6% 6.8% 7.4% 6.4% 8.8% 7.9% 11.5%
Natural causes 1.6% 1.1% 2.6% 5.4% 2.0% 3.9% 2.2% 1.0%
Percent with indicated active system present
Sprinkler present 32.6% 12.0% 35.8% 4.6% 16.7% 28.0% 34.6% 34.7%
Detector present 44.5% 26.6% 57.4% 39.1% 31.6% 67.1% 50.5% 47.1%
Percent with indicated type of construction
Fire-resistive 7.8% 4.2% 21.4% 6.9% 11.2% 18.9% 15.4% 42.7%
Noncombustible 13.8% 7.2% 12.8% 9.0% 17.6% 20.9% 27.0% 21.4%
Ordinary 46.1% 44.6% 33.1% 40.0% 33.7% 35.3% 38.6% 20.3%
Protected
wood frame 15.9% 16.4% 11.9% 18.3% 7.6% 7.5% 6.7% 2.1%
Unprotected
wood frame 13.8% 24.4% 17.2% 20.7% 20.2% 11.7% 7.4% 6.6%
Percent with indicated area of fire origin
Means of egress 1% 5% 4% 7% 5% 8% 13% 14%
Concealed space,
duct, shaft, chimney,
or elevator 11% 16% 11% 17% 12% 17% 10% 17%
External surface 9% 19% 9% 13% 10% 8% 10% 8%

Notes: Electrical distribution includes wiring, cords and plugs, switches and outlets, lighting fixtures, signs, and overcurrent protection devices. Ordinary and
noncombustible each include protected and non-protected construction.
Source: NFPA national estimates based on NFIRS and NFPA survey.

9 Fire Protection Engineering N UMBER 22

 ■ Assembly Property Fires

the traditional human and property loss victims in a balcony; in all, 57 people drinking places; libraries, museums,
objectives. These same heritage consid- died. The other three fires are not nec- and courthouses; and religious or fu-
erations may restrict fire protection op- essarily different, only undocumented. neral properties.
tions. Use of a standard tailored to Sprinklers (or other automatic sup-
these special properties is highly rec- PASSENGER TERMINALS pression equipment) were reported pre-
ommended, as is explicit engineering sent in one-fourth to one-third of re-
design, since each of these properties Table 4 shows terminal fires declined ported public assembly structure fires,
tends to have unique concerns. by one-half to three-fourths from 1980 except for amusement places (one-
There were roughly 4,000 museums to 1999. Roughly half these fires in a sixth), drinking places (one-eighth), and
and 32,900 libraries in the United States typical year involve airport terminals. religious or funeral properties (less than
in 2000. (Source: U.S. Census Bureau, The other half split roughly two to one one in 20). In some communities, the
Statistical Abstract of the United States: for rail vs. bus terminals. Constitutional separation of church and
2002, Tables 1210 and 1130, the former By contrast, there were 19,100 air- state has been invoked as a barrier to
counting establishments with payroll.) ports in 1999 compared to roughly the application of fire protection re-
2,900 rail stations and perhaps 2,000 quirements on places of worship. This
THEATERS AND STUDIOS bus stations. (Source: U.S. Census Bu- has not been an issue in the writing of
reau, Statistical Abstract of the United code requirements, but in some regions
Table 4 shows the number of struc- States: 2002, Table 1045, for airports; and communities, it has reportedly been
ture fires in theaters and studios has de- American Public Transportation Associ- an issue in achieving enforcement.
clined by about three-fourths, one of ation Web site for rail.) The largest bus Detectors are more in evidence in all
the largest declines among assembly carrier had 1,600 terminals and sales types of assembly properties. Fire de-
properties. In this case, that decline agencies, according to its Web site, and tectors were reported present in
may be partially driven by contraction no data were available for other carri- roughly one-half to two-thirds of re-
in the industry. For example, using ers. By any estimate, then, airport ter- ported public assembly structure fires,
comparable data, the number of mo- minals account for far more than half of except for amusement places and reli-
tion picture theaters declined from all passenger terminals. gious or funeral properties (one-third)
7,800 in 1987 to 5,900 in 2000. (Source: Most airport terminals are small ter- and drinking places (one-fourth).
U.S. Census Bureau, Statistical Abstract minals, serving corporate jets or other Fire-resistive construction is com-
of the United States: 2002, Table 1098, small planes, but even these are com- monplace in passenger terminals
and 1990, Table 1380, both establish- parable to a typical rail or bus terminal, (nearly half of reported fires) and not
ments with payroll.) There were 9,300 and the largest municipal airport termi- unusual in clubs (one in five). Unpro-
performing arts companies in 2000, but nals have no counterparts among other tected wood frame construction ac-
it is not clear how many theater facili- ground or air transportation. Marine counted for one-fifth to one-fourth of
ties they represented. (Source: U.S. passenger terminals account for very reported structure fires in drinking
Census Bureau, Statistical Abstract of few fires, and data were not available places, religious or funeral properties,
the United States: 2002, Table 1210.) on the number of such facilities. and amusement places. Drinking places
Theaters have also become smaller in and religious or funeral properties of-
size over the years, with the advent of CHARACTERISTICS OF ASSEMBLY ten combined an absence of sprinklers
suburban multiplexes as a more flexi- FIRES with the use of more vulnerable con-
ble delivery system for matching capac- struction materials.
ity to variable demand. Looking back in Cooking fires are, not surprisingly, Fires originating in means of egress
time, however, it is clear that the list of the leading cause of eating-place fires, can complicate safe escape. Such fires
the deadliest single-building fires is but it may be more surprising that the constituted a substantial share of fires
dominated by theater fires. Elsewhere second leading major cause is electrical in most assembly properties, particu-
in the world, high fire death tolls in distribution equipment. (See Table 5.) larly theaters and studios and terminals,
theaters are not yet a thing of the past. Intentional fires are a distant third, ac- where they accounted for one of every
Since 1970, seven theater fires have counting for one of every 14 eating- seven fires. Designers should provide
killed at least 50 people each. In Iran in place fires. for safety in assembly place fires for in-
1978, according to newspaper ac- Intentional fires are the leading cause stances when a major escape route is
counts, terrorists locked all doors be- in most other assembly property cut off by fire.
fore igniting a gasoline fire outside, groups, except for theaters and studios, Fires originating in concealed spaces
killing 422 people. In China in 1994, ac- where they rank second to electrical or outside the building can be outside
cording to newspaper accounts, seven distribution equipment fires, and pas- the effective range of sprinklers, detec-
of eight exits were locked and barred, senger terminals, where they rank sec- tors, and even compartmentation. A high
as 385 people were killed in that fire. ond to smoking-material fires. Inten- percentage of assembly property fires
In Italy in 1983, newspaper accounts tional fires represent a large share, originated in such locations, particularly
say 10 exit doors were locked as 64 however, only in amusement places, drinking places and religious or funeral
people died in a fire. In India in 1997, where they accounted for roughly two properties, where they accounted for
fire spread through air conditioning of every five fires. Intentional fires ac- one of every three fires. Designers
ducts and other routes, trapping most counted for about one-fourth of fires in should consider how safety would be

10 Fire Protection Engineering N UMBER 22

 ■ Assembly Property Fires

provided for instances when fire begins that comes automatically with high oc- (e.g., concealed spaces) and difficult to
outside the usual occupied spaces. cupancy. Assembly property fires have control through conventional fire pro-
involved even greater tragedies in tection methods, whether active or pas-
THE FUTURE many foreign countries, and these serve sive. Exiting provisions are especially
as a reminder of the importance of critical, and deficiencies in exiting pro-
Assembly properties account for maintaining, reinforcing, and extending visions, whether inadvertently or
about 15,000 to 20,000 reported struc- the controls that have been developed through hostile action, are a recurring
ture fires per year, but the numbers over the past century. part of the deadliest assembly fires.
have dropped substantially over the In the new world of performance- Many of the thousands of nonfatal
past two decades. Deaths are few in a based design, applications to assembly assembly fires each year are near
typical year, and most of the total properties need to be done with great misses that very easily could have been
deaths in assembly fires over the past care. Predictions of death tolls tend not major tragedies. Long periods of com-
two decades have occurred in a hand- to be robust, with huge variations pos- placency alternating with punctuated
ful of extremely serious fires, specifi- sible from small changes in assump- moments of national panic are no way
cally in nightclubs. Codes and stan- tions, because the predictions are ex- to make wise decisions about safety
dards have addressed the hazards that tremely sensitive to the timing of choices and their engineering conse-
led to the worst incidents of the past, occupant escape from threatened quences, but at the same time, it is not
but compliance is still less than perfect, spaces and of the development of life- unreasonable to assume, as the public
and the potential for a death toll in the threatening conditions in those spaces. tends to do, that any major tragedy that
hundreds still exists in thousands, if not Safety factors can be used to reduce could have been prevented should
tens of thousands, of facilities. this sensitivity to specific conditions have been prevented. The historical
Each type of assembly property has and assumptions, but the knowledge record is there to help. ▲
its own special problems and vulnera- required to set those safety factors is
bilities that justify continued close at- thin for many key phenomena. Large John Hall is with the National Fire
tention, because all assembly proper- shares of fires in these properties begin Protection Association.
ties share the high potential for life loss in places that are difficult to model

11 Fire Protection Engineering N UMBER 22

 FIRE ALARM SYSTEMS
Serving Assembly Occupancies:
Looking Beyond Assembly occupancies are character-
ized by a high concentration of people

Specifications resulting in relatively high occupant

loads in small and large buildings alike.
This high-density, high-occupant load
characteristic requires special fire safety
By Jorge Velasco & consideration such as egress design,
Edward L. Fixen, P.E. crowd management, human behavior,
and adequate fire protection, among

R ecent nightclub tragedies have highlighted the need to

revisit fire safety in nightclubs and other assembly occu-
pancies in general. Among the many factors affecting fire
safety in assembly occupancies, fire alarm systems play an
important role in protecting people.
other factors. Additional factors such as
security, special effects, and high ambi-
ent background noise levels are also
among the factors that must be consid-
ered in the design of fire alarm systems
serving various assembly uses.

12 Fire Protection Engineering N UMBER 22

 ■ Fire Alarm Systems

Table 1. Select Fire Alarm System Requirements for Assembly Occupancies

1 Positive alarm sequence is a manually initi-
8 ated delay in the operation of an automatic
Fire Alarm System NFPA Life Safety Code or International Building
alarm or voice alarm system for up to 180
Requirement NFPA 5000 Building Code7 Code6 seconds to permit investigation of the
alarm signal. The alarm will automatically
When Required Occupant Load > 300 Occupant load > 300 operate if the fire alarm system is not reset
prior to the end of the delay period.
Means of Initiation Manual or sprinkler operation Manual or sprinkler operation

Required when occupant load Required when occupant load 2 Access control egress door is an exit door
Emergency Voice Alarm that is locked by the access control system
> 300 > 1,000
on the nonegress side but automatically
Positive Alarm Sequence unlocks upon operation of a sensor, loss of
Permitted with approval of AHJ Permitted with approval of AHJ
(See Note 1) power, panic hardware, mechanical release
device, or activation of the building fire
Permitted on any egress door, Permitted on the main alarm system.
Access Control Egress Doors
except when the building is occu- entrance/exit door only, except
(See Note 2)
pied when the building is occupied
3 Delayed egress door is a locked exit door
Permitted in light and ordinary haz- that releases the locking mechanism within
ard uses at exit doors other than 15 seconds of operation of the door release
Delayed Egress Doors Not permitted in assembly device (typically panic hardware) or releas-
main entrance/exit when building is
(See Note 3) occupancies
fully sprinklered or provided with es without delay upon loss of power or
fire detection throughout activation of the building fire alarm system.

13 Fire Protection Engineering N UMBER 22

 A complete discussion of fire alarm dressed in this article include: BALANCING SECURITY WITH FIRE
systems serving assembly occupancies • Balancing Security with Fire Safety SAFETY
involves many complicated issues rang- • Special Effects
ing from systems design to human be- • Notification Effectiveness The locking of exit doors is always of
havior considerations to new detection • Systems Integration primary concern and is particularly criti-
and notification technologies. Many of Many other issues, such as preventing cal in assembly occupancies. While fire
these fire alarm system design issues nuisance/false alarms, for example, are alarm systems cannot directly prevent
and considerations are common to all important in the overall design process the inappropriate locking of exit doors,
occupancies and have been discussed and require special consideration, but well-designed integration of the security
in previous editions of Fire Protection are beyond the scope of this article. and fire alarm systems can help reduce
Engineering.1,2,3,4,5 This article specifically
focuses on the characteristics of assem-
bly occupancies that present significant
fire protection engineering challenges
to the design of fire alarm systems serv-
ing these occupancies. With these chal-
lenges in mind, this article is a high-
level overview of key considerations
and challenges involved in the design
of fire alarm systems serving assembly
occupancies.

BASIC FIRE ALARM SYSTEM

REQUIREMENTS FOR ASSEMBLY
OCCUPANCIES

Generally, the International Building

Code,6 NFPA 5000,7 and the NFPA Life
Safety Code8 require fire alarm systems
in assembly occupancies with 300 or
more occupants. The means of detec-
tion and notification differ slightly, but
these codes have similar overall protec-
tion philosophies. While specific fire
alarm system requirements must be in-
dividually evaluated based on the spe-
cifics of the project, Table 1 summarizes
select assembly occupancy fire alarm
system requirements based on each
code.
In all cases, the standard for the de-
sign and installation of fire alarm sys-
tems is the National Fire Alarm Code
(NFPA 72).9

DESIGN CHALLENGES

Within the assembly occupancy clas-

sification, there are numerous uses that
each has special considerations unique
to that use. Assembly uses include air-
ports, arenas, casinos, churches, cine-
mas, entertainment parks, exhibit halls,
nightclubs, restaurants, theaters, and
stadiums, to name a few. Similar to the
many assembly uses, the characteristics
and challenges related to design of fire
alarm systems serving these various as-
sembly occupancies are numerous.
Some of the more common issues ad-

S PRING 2004 www.sfpe.org 14

 ■ Fire Alarm Systems

the occurrence of locked exit doors by try. The concept is similar to the benefit useful design approach to reduce the
removing the need for owners/operators of providing automatic hold-open de- occurrence of illegally secured exit
to illegally lock exit doors. vices at fire doors in common circula- doors in many circumstances. Second-
The use of delayed egress doors at tion paths to prevent the doors from be- ary exits located in back-of-house
exit doors that are not part of the day- ing blocked open. While the use of and/or unsupervised locations are can-
to-day circulation can help to reduce delayed egress doors in assembly occu- didates for delayed egress doors to
the undesirable behavior of owners/op- pancies must be considered carefully to avoid unwanted locking of exit doors.
erators locking secondary exit doors in avoid potential crushing incidents or The use of delayed egress doors will re-
an attempt to prevent unauthorized en- undesirable crowd behavior, it can be a quire that the entire facility be provided
with an early warning fire detection sys-
tem throughout the building, in addi-
tion to other required fire protection
systems. The installation of an early
warning system throughout the building
should result in improved detection
time within the assembly occupancy
and more than offset the 15-second de-
lay associated with delayed egress
doors.
While design of security systems may
not be the responsibility of the fire
alarm system designer, coordination
with the security system and considera-
tion of fire alarm design approaches that
facilitate anticipated security measures
must be performed.

SPECIAL EFFECTS

The use of pyrotechnics, theatrical

smoke, and other special effects are
common in many assembly occupan-
cies, particularly theaters, nightclubs,
and concert venues. Besides the inher-
ent fire safety problems, special effects
create one of the greatest challenges to
the operation of fire alarm systems in
assembly occupancies that use special
effects. A fire alarm system is designed
to detect the same signatures created by
pyrotechnics and many special effects.
The use of special effects often leads to
fire alarm detection systems being tem-
porarily disabled to prevent nuisance
alarms. Should the fire detection system
be temporarily bypassed for the pur-
pose of special effects, the impairment
itself should be electrically supervised
to assure that the system is restored as
soon as possible and not inadvertently
left in the bypass mode. However, the
use of special effects not only inhibits
the detection system but may negatively
affect or impair visual notification sys-
tems as well.
The conflict between pyrotechnics/
special effects and early warning detec-
tion systems highlights the need to be
able to rely on fire sprinklers monitored

15 Fire Protection Engineering N UMBER 22

by the fire alarm system in assembly oc- an assembly occupancy. Similar to con- this, an emphasis must be placed on
cupancies using pyrotechnics and other siderations of potential security mea- both the intelligibility of voice alarm sys-
special effects. Fire sprinklers are not sures, the potential impact of special ef- tems and the content of emergency
prone to the nuisance alarms caused by fects and related operational behavior evacuation information given to assem-
special effects. The installation and should be anticipated and addressed by bly occupants.
monitoring of automatic sprinkler sys- the fire alarm system designer in assem- Places of assembly are often associ-
tems provide a more robust and reliable bly occupancies. ated with intermittent or constant high
means of detection in a special effects ambient background noise, particularly
environment. However, the lack of or NOTIFICATION EFFECTIVENESS in places such as nightclubs, concerts,
disabling of fire detection systems when and sporting events. The effectiveness
special effects are used potentially cre- Perhaps the most prevalent fire alarm of audible alarm systems for these uses
ates a conflict when delayed egress system design challenge common to requires special consideration in order
doors or other systems require early most, if not all, assembly occupancies to be intelligible. Fire alarm systems can
warning systems to initiate an auxiliary involves the design of an effective occu- shutdown building systems, but not a
function such as releasing delayed pant notification system. Even the most loud or cheering crowd. Therefore, the
egress door locks. This issue needs to effective fire detection system has little signal-to-noise ratio in these circum-
be carefully reviewed prior to reaching value if the notification system fails to stances must be adequate to overcome
a final design concept. evacuate occupants. In order for fire the high level of ambient noise.
Clearly, there is no simple answer to alarm notification systems serving as- However, just being louder than the
the best fire safety solution when pyro- sembly occupancies to be effective, two crowd is not enough. In fact, many
technics or special effects are involved. things must happen. First, the evacua- times it is because a system has been
It is suggested that there is a need for a tion information must be clearly under- designed to overcome high ambient
detailed fire safety evaluation that ad- stood. Second, the evacuation message noise levels without regard to distortion
dresses the design of the fire alarm sys- must provide meaningful information or reverberation that the signal becomes
tem and other critical fire safety consid- that will motivate the occupants to fol- unintelligible. Accordingly, the design of
erations when pyrotechnics are used in low evacuation directions. To achieve a notification system must address dis-

S PRING 2004 www.sfpe.org 16

 ■ Fire Alarm Systems

tortion and reverberation in addition to audibility to be intelligi- for implementing an effective voice alarm message. Voice alarm
ble. If any one of these three factors is not addressed ade- systems have been demonstrated to be significantly more effec-
quately, the intelligibility of the notification system will be un- tive than general alarm signals.10 Bryan has noted that, to be ef-
clear and insufficient to effectively evacuate occupants. These fective, a fire alarm system must direct an adaptive behavioral
factors require consideration of signal strength for sound pres- response by the occupants by providing essential definitive and
sure levels, speaker distribution at appropriate power settings directive information.5 Definitive and directive information con-
for clarity, and evaluating the acoustical nature of the protected sists of:10
space for potential reverberation. For further guidance and de-
tailed discussion on intelligibility as it relates to fire alarm sys- • What has happened.
tem design, refer to the Annex of the National Fire Alarm Code • What the occupants are to do.
(NFPA 72).9 • Why they should do it.
The issue of intelligible audibility is heightened in large as-
sembly buildings where high ambient background noise and While voice alarm systems have the capability to provide this
large spaces with high ceilings can require alarm audible levels information, there are several challenges to successfully imple-
often near the upper decibel limits of safe audibility. Often, this menting an effective voice alarm message. To be credible, the
situation is handled by installing speakers at the upper end of message must be nonambiguous about the occurrence and lo-
their power settings resulting in highly distorted and unintelligi- cation of the event. As important, the message must clearly
ble signals. Further complicating this situation, spaces with hard communicate what actions are to be taken and why it is impor-
surfaces/finishes can cause significant reverberation further re- tant that occupants follow those actions. Unfortunately, the im-
ducing intelligibility. In some cases, maximum sound levels es- portance of emergency voice communication and training of
tablished for safety reasons may not be adequate to overcome the operator are all-too-often-neglected aspects of the fire alarm
ambient noise levels. In these instances, supplemental visual system.
graphics interfaced with the voice evacuation message may be
advisable.
In addition to the intelligibility of the voice alarm system A detailed fire safety evaluation
needing to be addressed, the designer must develop a strategy
should be performed to determine
the numerous potential fire scenar-
ios and the most effective voice
message corresponding to the
appropriate fire response.

The general challenge in most assembly occupancies is that

the potential number and combination of fire locations and rec-
ommended exit paths are numerous. Prerecorded voice alarm
messages may be effective in high-rise buildings with typical
floor plans. However, a voice alarm message serving an assem-
bly occupancy where building areas are not typical and occu-
pants are likely to be unfamiliar with the building requires a dif-
ferent approach to implementing voice alarm messages. A
detailed fire safety evaluation should be performed to determine
the numerous potential fire scenarios and the most effective
voice message corresponding to the appropriate fire response.
As a final note on notification effectiveness, the use of posi-
tive alarm sequence, where the operation of the voice alarm sys-
tem may be delayed for up to 180 seconds while personnel in-
vestigate the alarm, is common in large assembly occupancies to
prevent unwanted nuisance alarms. Obviously, the evacuation
of thousands or even tens of thousands of occupants during a
major entertainment or sporting event as a result of a nuisance
alarm is highly undesirable. However, the use of positive alarm
sequence only increases the importance that should be placed
on designing an effective occupant notification system in assem-
bly occupancies. Unfortunately, the model codes leave accep-
tance of positive alarm sequence up to the AHJ and do not pro-
vide guidance as to when its use is or is not recommended.

17 Fire Protection Engineering N UMBER 22

SYSTEMS INTEGRATION insight into building and operating rela-
tively safe assembly occupancies. Inter-
Another aspect of fire alarm design estingly, the fire alarm systems serving
that must be addressed in assembly oc- these occupancies are not technically dif-
cupancies is the need for integration ferent from other assembly occupancies.
with other building systems. Security Instead, these industries set themselves
system integration discussed previously apart through employee training, crowd
is not the only building system that management, and fire prevention efforts.
should be carefully integrated with the This highlights the fact that a properly
fire alarm system. engineered fire alarm system must take
In most large assembly occupancies, into account many factors beyond tech-
the operation of the fire alarm notifica- nical specifications that contemplate an-
tion system must be integrated with the ticipated operational features, human be-
public address (PA) system. In some havior, and proper emergency
cases, the PA system is shut down by management/planning. ▲
operation of the notification system,
while in other cases notification utilizes Jorge Velasco and Ed Fixen are with
the PA system. Provided the PA system Schirmer Engineering Corporation.
meets the emergency power and quality
control standards of a voice alarm sys- REFERENCES
tem, there are many arguments in favor
of using the facility PA system. 1 Cohn, B.M., “Fire Protection and Security
A primary advantage of using the fa- Have Common Goals – How Do We Get
cility PA includes improved testing and There?” Society of Fire Protection
Engineers, Fire Protection Engineering, No.
maintenance. The normal use of the PA
20, Fall 2003.
system as part of the facility operations
will provide an economic incentive for 2. National Electric Manufacturers
the owner/operator to use and maintain Association, “Fire Alarm Testing Strategies
Can Improve Occupant Response and
the PA system more effectively than nor-
Reduce the Cry Wolf Syndrome,” Society
mal code-mandated testing/maintenance
of Fire Protection Engineers, Fire
requirements. Also, the audio capabili- Protection Engineering, No. 20, Fall 2003.
ties of state-of-the-art public address
systems are generally superior to fire 3. National Electric Manufacturers
Association, “Speech Intelligibility,”
alarm audio systems and are designed to
Society of Fire Protection Engineers, Fire
operate without distortion or reverbera- Protection Engineering, No. 16, Fall 2002.
tion in high ambient noise environ-
ments. Use of the PA system can elimi- 4. Tubbs, J.S., “Intelligent Fire Alarm
Systems,” Society of Fire Protection
nate many of the problems of
Engineers, Fire Protection Engineering,
intelligibility often associated with fire
No. 11, Summer 2001.
alarm notification systems in large,
acoustically challenging environments. 5. Bryan, J.L., “Psychological Variables That
Building management will also realize May Affect Fire Alarm Design,” Society of
Fire Protection Engineers, Fire Protection
cost savings by eliminating the need to
Engineering, No. 11, Summer 2001.
install and maintain a secondary system.
In addition to security and audio inte- 6. International Building Code, International
gration, in assembly occupancies such Code Council, Falls Church, VA, 2003.
as theaters where the lighting levels are 7. NFPA 5000, Building Construction and
allowed to be reduced during perfor- Safety Code, NFPA, Quincy, MA, 2003.
mances, the facility lighting system 8. NFPA 101, Life Safety Code, NFPA, Quincy,
should ideally be integrated with the fire MA, 2003.
alarm system to automatically raise exit
9. NFPA 72. National Fire Alarm Code,
illumination levels to a minimum of 1 NFPA, Quincy, MA, 2002.
footcandle (10 lux) upon activation of
the fire alarm system. 10. Proux, G., “The Impact of Voice
Communica- tion Messages During a
Related industries that have exemplary
Residential High-Rise Fire,” Human
records of fire safety and crowd manage-
Behavior in Fire: Proceedings of the First
ment can be looked to as models for as- International Symposium, Fire Sent
sembly occupancies. The entertainment Center, University of Ulster, 1998, 265-
and professional sports industries are 274.
two such industries that provide some

S PRING 2004 www.sfpe.org 18

 Fires in
Clean Rooms

The
Effects of
Downward
Air Flow on
Ceiling Jet
Flow
By Massimo Manganaro

T
he purpose of this article is
to provide a basic analysis
of the effects of downward
air flows in a clean room environ-
ment on fire protection system
operation. Clean rooms are specific types of occupancies which, especially over the
last few decades, have become more and more widespread in a large vari-
Other important aspects that are
ety of industrial fields, primarily semiconductors, electronics, and pharma-
typical of a clean room environ- ceuticals, but also food processing, biotechnology, healthcare, aerospace,
ment, such as plastic process equip- and automotive. The main characteristic which differentiates a clean room
environment from other industrial occupancies is the high level of cleanli-
ment and systems (wet benches, ness maintained inside and the extremely low contamination from outside
ductworks, etc.), furnaces, flamma- by any kind of particles.

ble liquids, pyrophoric

gases, and other process Table 1. Classification of Clean Room According to Federal Standard 209D
hazards, are beyond the Classification 1 10 100 1,000 10,000 100,000
scope of this analysis. N. of Particles/m ≥0.5µm
3 35 350 3,500 35,000 350,000 3,500,000

19 Fire Protection Engineering N UMBER 22

 ■ Fires in Clean Rooms

Table 2. General Guidelines on Air Flow Velocity and Clean Room Classification
Average Downward Air Flow Velocity
Class (m/s)
100,000 0.005 – 0.050
10,000 0.050 – 0.120
1,000 0.120 – 0.200
100 0.200 – 0.400
10 0.300 – 0.450
1 0.400 – 0.500

Figure 1. A Clean Room Air Handling System

MF MF
The main function of air To Scrubbers or Combustors
handling systems RAF
Ducted RAF Attic Return
is to reduce the amount Return Fume Exhaust Air Plenum
Option Ducts - FED Option
and the size HEPA/ULPA HEPA/ULPA
Filters Filters
of particles in the
environment.

Clean rooms are classified by their air H H

cleanliness level. The method most
largely known and applied is the one Perforated
suggested in Federal Standard 209, ver- Raised Floor POE POE Raised Floor
sion “D”, where clean room is classified
according to the number of particles
equal to and greater than 0.5 µm, pre-
Floor
sent in one cubic foot (0.028 m3) of air.
Table 1 is a simplified version of Federal
Standard 209D. Legend:
This type of classification is especially HEPA Filters = High-Efficiency Particulate Air Filters
applied to clean rooms in the semicon-
ULPA Filters = Ultrahigh Particulate Air Filters
ductor fabrication industry. Clean rooms
in pharmaceutical operations are com- MF = Makeup Air Fan (Fresh Air Inlet)
monly classified according to their Euro-
RAF = Recirculating Air Fan
pean Union designation, which consists
of a grading from A to D, where A and FED = Fume Exhaust Ducts with diameters of main ducts up to 800mm
B approximately correspond to class
H = Hood for exhausting fumes and gases towards scrubbers and/or combustors
100, grade C corresponds to class
10,000, and grade D corresponds to POE = Process Operation Equipment
class 100,000. Clean Air – Downward air flow from the ceiling to the floor
According to classification in Table 2,
each class is also characterized by a typ- Dirty Air – Upward air flow from side return air duct to outside and/or recirculating air fan
ical average downward air flow (veloc-
Exhausted process gases and fumes

20 Fire Protection Engineering N UMBER 22

ity) from the ceiling or, to be more pre- ity and cleanliness levels. AIR HANDLING SYSTEMS IN
cise, from the suspended ceiling to the The described differentiation among CLEAN ROOMS AND CLEAN
floor, and this downward air flow is several classes of cleanliness is ex- ROOM APPLICATIONS
what typically differentiates a clean tremely important for fire protection en-
room occupancy from other industrial gineering, because different downward Downward air flow in a clean room
occupancies. Table 2 provides general air flow velocities may affect smoke de- environment is provided by a dedicated
correspondence between air flow veloc- tector and sprinkler activation. air handling system, which can be con-

Table 3. Measured Temperatures from Experiment at Several Radial Locations from the Center of the
Fire Plume and at a Distance of 0.051 m Below the Test Room Ceiling
Average Measured Temperatures
Downward Heat Release Radial Distance from the Center of the
in the Experiment at 0.051 m below
Air Flow Rate Fire Plume as in the Experiment
Ceiling (Z = 0.929 m)

151 °C R = 0.12 m

96 °C R = 0.22 m
0.26 m/s 17.30 KW
57 °C R = 0.40 m

31 °C R = 0.70 m

S PRING 2004 www.sfpe.org 21

 ■ Fires in Clean Rooms

sidered the core system of a clean ity and effectiveness of process opera- flow). Class 1 and class 10 are found al-
room. The main function of air han- tions and to prevent products from con- most exclusively in semiconductor fab-
dling systems is to reduce the amount tamination. rication plants, where manufacturing of
and the size of particles in the environ- As far as typical industrial applica- circuits with dimensions in the order of
ment. Air handling systems provide the tions are concerned, class 1 and class microns and/or submicrons requires a
required degree of cleanliness mainly 10 clean rooms are generally quite diffi- very high level of air cleanliness.
through a combination of piping, cult to achieve and are characterized by In these applications, the air flow ve-
makeup air units, fans, and filtering a unidirectional, laminar air flow (typi- locity needed to guarantee such a level
media as needed to guarantee the qual- cally a unidirectional downward air of cleanliness inside can reach 0.45 –
0.50 m/s, often requiring a percentage
up to around 100% of ceiling coverage
with filtering systems (HEPA or ULPA
filters) which also require a very com-
plex air handling system layout. From a
fire protection standpoint, a very high
downward air flow velocity might hin-
der the quick operation of fire protec-
tion systems located on the ceiling.
Semiconductor plants can also em-
ploy clean rooms with lower level of
cleanliness, from a class 100 downward
(where, generally, airflow is no longer
unidirectional and is turbulent). In this
situation, the structure of the enclosure
and of the air handling system arrange-
ment may be less complex than for
class 1 and class 10 clean rooms.
Another industrial occupancy where
clean rooms or sterile zones are largely
used is pharmaceutical manufacturing.
Most of the process operations carried
out in pharmaceutical plants require an
extremely sterile work environment,
even if generally limited to clean areas
with a level of cleanliness from class
100 downward (however, pharmaceuti-
cal clean rooms are generally classified
according to European Union designa-
tion).
For a major analysis of structure and
characteristics, Figure 11 provides a typ-
ical clean room arrangement, with air
handling units, including fans, filters
(commonly known as HEPA/ULPA fil-
ters) located at ceiling level (suspended
ceiling), and also a prefiltering system,
where return and makeup air pass after
mixing and before entering the
HEPA/ULPA filters.

FIRE RISKS IN CLEAN ROOMS

AND POSSIBLE LOSSES

Major fire risks in clean rooms may

include flammable and combustible
liquids, which are largely used in man-
ufacturing processes, pyrophoric and
flammable gases, combustible process
equipment, and combustible sandwich

22 Fire Protection Engineering N UMBER 22

 ■ Fires in Clean Rooms

panels. Flammable and combustible liq- Figure 2. Ceiling jet temperatures for a 0.12 m grid size and downward
uids can be alcohols, or alcohol-based air flow source located 0.98 m above floor (at ceiling level)
mixtures, stored in glass or plastic con-
180.0
tainers. Process liquids, both flammable
and nonflammable, are often heated 160.0
using hot plates, electric immersion
140.0
heaters, or bonded heating systems.
Flammable and pyrophoric gases, such 120.0

Temperature (˚C)
as silane, arsine, diborane, and phos- 100.0
phine, are used in automated process
equipment such as diffusion furnaces. 80.0
Another large source of fire risk is 60.0
combustible furnishing materials,
40.0 R = 0.12 m
which may include work stations, wet R = 0.22 m
benches, suspended ceiling and raised 20.0 R = 0.40 m
R = 0.70 m
floor tiles, fume exhaust duct systems,
0.0
and sandwich panels, often made with
0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0
plastic based materials. Time (s)
A class 100 clean room may ap-
proach a value on the order of
$10,000/m2 of surface area, including
buildings, equipment, and stock inside, Figure 3. Ceiling jet temperatures for a 0.08 m grid size and downward
not including monetary losses due to air flow source located 0.98 m above floor (at ceiling level)
business interruption.
250.0
FIRE TESTS IN CLEAN ROOMS
200.0
In order to understand the response
of fire protection systems and their
Temperature (˚C)

performance in clean rooms, attention 150.0

has been focused on small-scale exper-
iments concerning flame spread and 100.0
heat detection, and experiments re-
garding fire behavior and smoke re- R = 0.12 m
50.0 R = 0.22 m
lease from furnishing materials used in
R = 0.40 m
clean rooms. R = 0.70 m
Based upon some of this data, it is 0.0
possible to consider the effectiveness 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0
of fire protection systems in clean Time (s)
room environments. To this end, the
applicability of NIST’s Fire Dynamics
Simulator (FDS) in clean room environ-
ments was judged by comparing ex- Figure 4. Ceiling jet temperatures for a 0.08 m grid size and downward
perimental data to model predictions air flow source located 0.50 m above floor
of ceiling jet flow temperatures in a fire 160.0
in a room with unidirectional down-
140.0
ward air flow.
Experiments were conducted in a 120.0
4.8 m x 6.0 m x 2.44 m (high) test
Temperature (˚C)

100.0
room.2 The clearance between the
ceiling and the floor was 0.98 m. The 80.0
fire source a circular methane gas
burner that was 0.23 m in diameter, 60.0
centered in the room and located a 40.0 R = 0.12 m
height of 0.17 m above floor. A suction R = 0.22 m
R = 0.40 m
blower was located inside the subfloor 20.0 R = 0.70 m
to produce a uniform flow of 0.26 m/s
0.0
from the ceiling to the floor. 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0
Temperatures at different elevations Time (s)

23 Fire Protection Engineering N UMBER 22

above the fire source and near the ceil-
ing were measured with thermocou-
ples. Table 3 shows experimental data
from one of these fire scenarios.
Another industrial occupancy where clean
rooms or sterile zones are largely used is
INFLUENCE OF DOWNWARD
AIR FLOW ON CEILING JET pharmaceutical manufacturing.
FLOW TEMPERATURES:
POSSIBLE IMPLICATIONS ON
QUICK OPERATION OF CEILING
FIRE PROTECTION SYSTEMS

Before running FDS simulations, to

understand how a clean room unidi-
rectional downward air flow could af-
fect fire plumes and ceiling jet temper-
atures, the data in Table 3 were
compared to calculations performed
assuming no downward air flow.
Considering the ceiling jet flow pro-
duced by a steady fire, it is possible to
predict the fire plume and ceiling jet
temperatures using correlations devel-
oped by Alpert.3 Predictions are made
at ceiling level, where temperatures
(because of the boundary layer cre-
ated by the ceiling) might be lower
than at a distance of 0.051 m below
the ceiling, which is location where
temperatures were measured in the
experiment.

Alpert’s correlations state:

16.9Q˙ 2 / 3
Tmax − T∞ = for R/H < 0.18
H 5/ 3

( )
2/3
5.38 Q˙ / R
T max − T∞ = for R/H > 0.18
H

Where:
Q̇ = heat release rate [kW]
H = distance from the base of the fire
to the ceiling [m]
R = radius [m]
Tmax = maximum ceiling jet tempera-
ture [°C]
T∞ = ambient temperature [°C]

Applying Alpert correlations, for

Q̇ = 17.3 kW, R = 0.12 m and 0.40 m,
H = 0.98 m - 0.17 m = 0.81 m, it follows:

For R = 0.12 m, Tmax = 161 + 27 = 188 °C

For R = 0.40 m, Tmax = 82 + 27 = 109 °C

S PRING 2004 www.sfpe.org 24

 ■ Fires in Clean Rooms

Table 4. Comparison of Average Experimental Temperatures and

FDS-Computed Outputs of Temperature

Average Temperatures
at 0.051 m
below Ceiling
Average Temperatures Average Temperatures (Z = 0.929 m)
Average Measured Average Predicted at 0.051 m at 0.051 m Simulation
Radial Distance from Temperatures in the Temperatures by below Ceiling below Ceiling 0.08 Grid Size
the Center of the Experiment at 0.051 m Alpert Correlation, with (Z = 0.929 m) (Z = 0.929 m) Downward Air Source
Fire Plume below Ceiling No Downward Air Flow, Simulation Simulation Locate 0.50 m
as in the Experiment) (Z = 0.929 m) at Ceiling Level 0.12 m Grid Size 0.08 m Grid Size Above Floor

R = 0.12 m 151 °C 188 °C 155 °C 165 °C 112 °C

R = 0.22 m 96 °C - 117 °C 120 °C 104 °C

R = 0.40 m 57 °C 109 °C 99 °C 104 °C 93 °C

R = 0.70 m 1 °C - 86 °C 90 °C 82 °C

Comparing this to the data in Table

3, the measured ceiling jet tempera-
tures at radial distances of 0.12 m and
0.40 m from the center of the fire
plume were respectively around 151 °C
and 57 °C. These measured tempera-
tures are considerably lower than tem-
peratures predicted in the absence of
a downward air flow. This result may
have implications on the performance
and quick operation of fire protection
systems located on the ceiling in a
clean room.

APPLICATION OF FDS TO
FIRES IN CLEAN ROOMS WITH
DOWNWARD AIR

Predictions made using FDS were

compared to the experimental data
from the 4.8 m x 6.0 m x 2.44 m (high)
clean room, with 0.26 m/s downward
air flow described earlier. Specifically,
measured temperatures at radial dis-
tances of 0.12 m, 0.22 m, 0.40 m, and
0.70 m, from the center of the fire
plume at distances 51 mm below the
ceiling were compared to predicted
values. Simulations were run for 180
seconds and average temperatures
were taken over the range of 80 - 180
seconds.

25 Fire Protection Engineering N UMBER 22

 One of the challenges in setting up Massimo Manganaro is with Zurich 2 Nam, S., “Numerical Simulation of Smoke
the FDS computation regarded how to Risk Engineering, Italy, as a loss preven- Movement in Clean Room Environments”
model the unidirectional downward tion engineer. Fire Safety Journal 34, 2000.
air flow. Several trials were conducted 3 Karlsson, B., and Quintiere, J., Enclosure
to choose the best location of the uni- REFERENCES Fire Dynamics, CRC Press, Boca Raton,
directional downward air flow source. FL, 2000.
Outputs differed with the choice of the 1 Clean rooms – Factory Mutual Global –
grid size adopted and location of the Property Loss Prevention Data Sheets – 2003.
unidirectional downward air flow
source. The modeling results showed
slight differences in ceiling jet temper-
atures among the different simulated
cases. The results of these simulations
can be seen in Figures 2 through 4.

CONCLUSIONS

This simple application of CFD sim-

ulation techniques to a small-scale fire
scenario in a clean room suggests that
predicting fire behavior in clean rooms
can be complex, especially as the dis-
tance from the center of the fire plume
increases. FDS can be sensitive to
some input parameters for simulation
of clean room fires. When simulating
ceiling jet flow, these include sizing of
grid cells and simulation of downward
air flow conditions. Improper selection
of these parameters can result in inac-
curate predictions of ceiling jet flow
temperatures which could affect pre-
dictions of fire protection system oper-
ation. For this reason, FDS should be
verified by experimental data in order
to get the most realistic outputs.
Moreover, this analysis of the influ-
ence of downward air flow on ceiling
jet temperatures suggests that the op-
eration of detectors and sprinklers
could be delayed in clean rooms, es-
pecially as the distance from the cen-
ter of the fire plume increases. Even
slight differences in temperatures
might have a harmful impact on possi-
ble losses in a clean room, since even
marginally longer exposures to smoke
in clean rooms can have a major im-
pact on losses due to the high suscep-
tibility of equipment. ▲

ACKNOWLEDGEMENTS

Sincere thanks for precious advice

and comments about this article are ex-
tended to Professor Jennifer Wen of
Kingston University, and to Mr. Giorgio
Franzini.

S PRING 2004 www.sfpe.org 26

 By Joseph B. Zicherman, Ph.D.
PLASTIC PIPE IN FIRE-RESISTIVE

A s the use of plastic piping (such as ABS, CPVC, PE, and CONSTRUCTION
PVC) in construction gained popularity, considerable How does the inclusion of plastic
testing and research took place to address issues relat- pipe in a room when a fire starts im-
ed to fire performance. Likewise, installation technologies and pact the life safety of its occupants?
building codes governing the use of plastic have evolved con- Plastic pipe is routinely installed behind
materials that form room “linings”
siderably as performance warranting its use was demonstrated which typically resist a growing fire for
for applications in more demanding building types and occu- 15 minutes or more.3 This feature pre-
pancies. Consistent with the preceding, that evolution can be vents direct flame impingement on the
majority of piping installations.
traced by comparing descriptions of early technology and reg-
Although a very small fraction of
ulations related to plastic pipe use1, 2 with the current state of plastic pipe used is exposed rather than
the art as reviewed here. installed behind room linings, does the

27 Fire Protection Engineering N UMBER 22

 ■ Plastic Pipe and Fire Safety

presence of small amounts of such exposed plastic pipe in-

crease the level of fire hazard? Five decades of U.S. fire inci-
dent data show no unique hazard or relationship linking plas-
tic piping to unusual fire ignition or fire spread.4 Consistent
with this, testing (both fire endurance testing and hose stream
tests) and post-fire evaluations of buildings constructed with
nonmetallic plumbing systems demonstrate that plastic piping
materials generally either burn away and char at wall lines, or
melt and drop in a wall cavity (see Figures 1 & 2).
The observed behavior is consistent with the low thermal
conductivity of plastic piping materials, which suggests that
ignition or the threat of fire spread due to temperature rise
(i.e., high temperatures developing) across fire separation
walls penetrated by plastic pipe is unlikely. Also, while tem-
peratures in wall cavities may exceed plastic-melting temper-
atures during the early stages of a structural fire, (as simu-
lated in the first half hour of ASTM E-119 testing), they are
still well below ignition temperatures of the pipe. This be-
havior is similar to the properties of approved plastic glazing
and ceiling inserts which are designed to fall to floors of af-
fected rooms before their ignition point is reached. Figure 3
illustrates the condition of an unburned segment of plastic
Figure 1. DWV stack with calcined wallboard
DWV pipe within a test wall cavity after a 30-minute ASTM E
removed, private residence, San Jose California.
119 fire exposure.

DESIGN SPECIFICATIONS

Design features requiring fail-safe fire-resistant detailing are

typically needed at locations where building services cross
floor-to-floor or unit-to-unit boundaries. Building subsystems
routinely found at such locations include plumbing, electrical,
and HVAC components.
Openings in fire-resistive walls – penetrations – for plastic
pipe must be addressed in design specifications. The term
“through penetration” refers to openings that transverse a fire-
resistive assembly while “membrane penetrations” contain
openings on one side only. The latter class of penetrations in-
cludes single-sided plumbing penetrations. Openings for all
such penetrations in both walls and floor/ceilings must be
protected to prevent unwanted fire spread and spread of
smoke and hot gases.
Flame spread performance is another property typically ad-
dressed by the codes. Regulations governing the use of plastic
pipe or any other combustible building product installed in air
handling spaces are found in both mechanical codes and
NFPA 90A.
The impact that combustion products from burning plastic
pipe installed in fire- resistive construction may create on life
safety deserves comment. A first consideration is the amount
of plastic piping used. Analysis demonstrates that this quantity
is relatively small – especially when compared with other
combustible construction materials and furnishings. In addi-
tion, combustion products created when plastic piping burns
do not evolve early in a fire due to how and where they are
installed. In addition, testing and field data indicate that result-
ing gases are no more toxic than other common building and Figure 2. Vent and DWV stacks post- fire. ABS remains in
furnishing materials.5 - 8 concealed spaces. Note charring of adjacent wood.

28 Fire Protection Engineering N UMBER 22

FIRESTOPPING

In the 1970s, initial testing of plastic piping installations in

fire-resistive assemblies was conducted with walls containing
both metal and wood stud structural elements.9-16 In both
cases, the use of the plastic plumbing pipes did not reduce
fire endurance provided penetrations were not oversized and
they were sealed properly. More recent test results conducted
under positive-pressure testing conditions assure that such in-
stallations will resist transmission of hot gases to unexposed
specimen surfaces.
Overall, fire endurance tests of cavity wall constructions
that include plastic pipe demonstrate that successful installa-
tions can be made using generic firestopping for smaller di-
ameters of pipe and approved penetration firestop systems
for larger diameters of pipe. In such test exposures, horizon-
tal through penetrations made with small-diameter plastic
pipe [1.5" (37.5 mm) or less] melted quickly and at the back,
unexposed wall surfaces, sealed off, and no flame passage
occurred. In the same tests, vertical drain and vent sections
melted and dropped within walls without flaming occurring
on unaffected back-face wall surfaces. By firestopping pene- Figure 3. Appearance of PVC DWV specimen following
trations with appropriate, approved materials and techniques, 30-minute E-119 fire exposure.
the fire-resistance properties of the penetration can be made
equal that of the original, unpenetrated assembly.

HISTORY OF PLASTIC PIPE REGULATIONS

In the 1960s and 1970s, building code regulations that de-

fined fire endurance requirements prescribed the ASTM E-119
method, which did not specifically address:
1) measurement of [allowable] temperatures on piping as-
semblies,
2) furnace pressure at which testing was to be conducted,
or
3) allowable penetrating element configurations.
These issues were relevant because, during a fire, pipe in-
stallations that were vented could be expected to behave dif-
ferently from unvented ones. In addition, metallic pipe and
plastic pipe systems could be expected to conduct heat
through affected assemblies differently. This performance at-
tribute was demonstrated during development of the ASTM E-
814 standard, in which the thermal response of metallic pene-
trating elements – such as pipes or sleeves – varied
significantly depending on the length of the sample – a direct
consequence of thermal conductivity and exposed pipe sur-
face area.17
As the volume of plastic pipe use has grown, marketplace
competition has been vigorous. The interested parties in-
cluded manufacturers of competing plumbing product mate-
rials (usually metallic pipe manufacturers) as well as unions
and cost-plus contractors who have seen their markets and
margins shrink. Regulators have been drawn into this contro-
versy as occasionally specious technical arguments have
been advanced to limit the expanded use of plastic pipe sys-
tems.18-20
In the late 1970s, partially in response to the growing con-

S PRING 2004 www.sfpe.org 29

 ■ Plastic Pipe and Fire Safety

troversy as to how best to test plastic

pipe installations in fire-resistive con-
struction, the ASTM E 05 committee
developed the ASTM E 814 Standard
(Standard Test Method for Fire Tests of
Through-Penetrations Fire Stops, also
known as UL 1479 and UBC Std 7-5),
first approved in 1983. This method
addressed shortcomings of the more
general ASTM E 119 method and clari-
fied testing criteria for through pene-
trations of fire-rated assemblies.
In the 1980s, code changes to ad-
dress use of plastic pipe, tube, and con-
duit in fire-resistive construction were
advanced in the model codes. Similar
activities by the Council of Building Of-
ficials – Board for the Coordination of
the Model Codes (CABO-BCMC) re-
sulted in the “Final Report on Protec-
tion Requirements for Vertical Penetra-
tions” in 1986.21 Almost a decade later,
in 1995, the BCMC guidelines were up- Chase wall including firestopping devices and PVC plumbing installation.
dated further with publication of the re-
port “Protection of Penetrations and
Joints in Building Wall, Floor, and Roof
Assemblies.” 22 mospheric are not uncommon in tall (Penetrations) address conditions and
One result of these activities has buildings due to stack effects. requirements for use of plastic piping
been a requirement for testing under Installation information for plastic materials in all building types, includ-
positive furnace pressures today. Such pipe in fire-rated construction was first ing those with noncombustible struc-
testing is conducted in the range of provided in an organized format in tural frames.
0.01" of water column (2.5 Pascal) to 1985.24 That document “Plastic Pipe in In the 1991, the NFPA 101 Life
simulate worst- case conditions found Fire-Resistive Construction” was the Safety Code recognized and addressed
in post-flashover fires. BCMC was the subject of a CABO National Evaluation the importance of protecting through
first group to adopt such a positive Report in 1992, and two later editions penetrations in fire-resistive construc-
pressure caveat in its guidelines. of this document have been pub- tion for piping as well as for non-
Unfortunately, positive pressure lished.25 metallic electrical raceway systems.
testing has also called into question Historically, the model code organi- That code utilizes the ASTM E 814 test
the results of early testing of pipe pen- zations also produce plumbing codes method and includes a table of perfor-
etrations in furnaces where a variety of which address performance of piping mance requirements for penetrations
pressures was used. While no field materials and systems. These generally with both metallic and nonmetallic
data suggesting shortcomings in the do not address fire safety issues. An ex- piping types. These provisions are
results or implications of those early ception to this has been the Uniform based upon the BCMC report22 and are
tests have been presented, the concept Plumbing Code 26 which before 1999 se- contained in an appendix note found
is important from a theoretical per- verely restricted use of plastic pipe in there.
spective in that structural fires do not fire-resistive buildings. That code was Initial ASTM E 119 and later E 814
show uniform pressures from floor to modified in 2000 to allow unlimited use fire testing of penetrations incorporat-
ceiling. Rather, maximum positive of plastic pipe in constructions of all ing plastic pipe has provided model
pressures are found in the top 1/3-1/2 types. code developers an improved under-
of affected rooms while pressures be- The International Building Code 27 standing of the characteristics and
low are typically negative and may ac- (IBC) includes comprehensive provi- properties of plastic pipe used in struc-
tually encourage an inflow of cooling sions for plastic piping system applica- tures as compared to what was avail-
air at through penetrations low on tions in fire-resistive construction. IBC able 25 years ago. Testing archives in-
walls where drains for sinks are lo- Sections 603 (Combustible Material in clude literally thousands of fire
cated.23 Likewise, pressures above at- Type I and II Construction) and 711 endurance test reports based on assem-

30 Fire Protection Engineering N UMBER 22

 ■ Plastic Pipe and Fire Safety

bly testing by accredited third-party ACCEPTANCE OF PLASTIC PIPE cealed piping. They cannot be used in
testing labs and research institutes. SYSTEMS IN FIRE-RESISTIVE dry pipe systems and must not be in-
CONSTRUCTION stalled with other types of plastic pip-
FIRE PERFORMANCE GUIDELINES ing materials, such as those used for
A 1978 survey of high-rise buildings supply or DWV piping. A comprehen-
It is extremely rare for a fire-resistive identified 108 high-rise or noncom- sive review of initial development ef-
assembly to be built exactly as found in bustible buildings in 28 states that had forts related to plastic-pipe-based sprin-
the generic form described in the tables been constructed using plastic piping kler systems was prepared by Wilging
of model building codes or the Gypsum for DWV systems.31 This survey was in 1988.35 ▲
Association Handbook.28 However, completed eight years before the first
thermoplastic piping materials tend to regulatory efforts to specifically ad- Joseph B. Zicherman, is with Fire
behave similarly on exposure to fire, dress use of plastic piping products in Cause Analysis
and certain “rules of thumb” can be such applications took place. To the
applied to evaluate and analyze perfor- author’s knowledge, all of these sys- REFERENCES
mance in various installations. In 1965, tems are still in use and none have suf-
Harmathy29 presented a seminal analy- fered fire-related problems. No other 1 Favro, P.C., and Sacco, J., “Fire Hazards
sis on the performance of fire-rated systematic data exist quantifying the of Plastic Pipe,” Report to the State of
assemblies which are of use to reason- use of plastic pipe in such complex California Commission on Housing and
ably predict the impact of design vari- structures in relation to fire perfor- Community Development (HCD), 1980.
ables in the field. Several of those rules, mance, although these materials are 2 Williamson, R.B., “Installing ABS and
paraphrased from the HUD Guidelines routinely used in fire-rated buildings in PVC Drain Waste & Vent Systems in Fire
for the fire performance of archaic many parts of the world today. Resistant Buildings,” Fire Journal, 1979,
building materials 30 are reviewed below In 1983, a draft Environmental Im- pp. 36-45.
in the context of plastic piping applica- pact Report32 was published in Califor- 3 Zicherman, J.B., “Performance of Plastic
tions. nia to address the expanded use of Plumbing and Electrical Products in Fire
plastic pipe and the lack of regulations Resistive Assemblies,” Fire Hazard and
Rule 1: Thicker assemblies (such as in that state. Based in part on the first Fire Risk Assessment, ASTM STP 1150, M.
walls and floor ceilings) will – with all draft of that study, Stanford Research Hirschler, Editor, 1992.
other factors being held constant – last Institute (SRI) issued a report in 198933 4 Hall, J., Personal communication, 1999.
longer than thinner walls of the same and the State of California, Department
5 Benjamin, I.A., “Toxic Hazards Analysis:
composition exposed to the same fire of Housing and Community Develop-
Electric Non-Metallic Tubing,” Journal of
conditions. ment, published a final report in 199834 Fire Sciences, 51, 1987, pp. 25-49.
endorsing use of plastic pipe in fire-re-
Rule 2: Fire-resistive assemblies con- sistive construction. 6 Clarke, F.B., “Toxicity of Combustion
taining hollow spaces tend to outper- Products: Current Knowledge,” Fire
Journal, 77(5), 1983, pp. 84-108.
form similar analogs composed of the PLASTIC PIPE AND SPRINKLER
same materials without hollow spaces. SYSTEMS 7 Clarke, F.B., and Steele, S., “How Do
Burning Products Affect Life Safety?” Fire
Rule 3: Insulated assemblies can be Journal, 84(6), 1990, pp. 48-55.
Plastic piping materials used in sprin-
expected to perform better than unin- kler systems have had a significant im- 8 Bukowski, R., et al. “Fire Risk Assessment
sulated ones. pact on fire safety and their use has Methods: Case Study-3 Concealed
grown significantly over the past 15 Combustibles in Hotels,” NISTIR 90-4245,
Rule 4: Smaller openings in walls years. Initially, fire protection and National Fire Protection Research
will lead to lesser diminution of fire en- Foundation, Quincy, Mass., 1990.
cost/benefits provided through use of
durance than larger openings. such systems substantially impacted 9 Williamson, R.B., “Fire Test of a Six-Inch
both fire safety levels in single-family Wood Stud One Hour Fire-Rated Wall
As such, if a fire-resistance-rated as- dwellings and in light hazard occupan- with a Polyvinylchloride DWV Plumbing
sembly is deeper or thicker than a System,” Fire Test Report 76-7, University
cies. Performance consistent with pro-
of California, Berkeley, 1985.
tested assembly, it will last longer visions of NFPA 13, as well as demon-
whether or not it includes piping. If in- strations that CPVC-based systems can 10 McGuire, J.H., “Penetration of Fire
sulation is present in a rated design be used in air-handling spaces – as reg- Partitions by Plastic DWV Pipe,” Fire
which was originally tested without in- ulated by the model mechanical codes Technology, 1973, Vol. 9, No.1.
sulation, whether or not it includes pip- and NFPA 90A – has assisted in this 11 McGuire, J.H., and Huot, P., “Fire Tests
ing, the insulated wall will last longer growth. Concerning the Penetration of Walls by
than the uninsulated version. If a wall At this point, plastic-pipe-based Horizontal Plastic DWV Pipes,” National
is tested with a given size of penetra- sprinkler systems can be used with Research Council of Canada, Technical
tion, the presence of a smaller penetra- Note No. 557, 1971.
both exposed piping (when fast re-
tion than the one originally tested will sponse sprinklers are used) and with 12 McGuire, J.H., “A Full-Scale Fire Test of
not reduce its fire endurance. standard- response sprinklers for con- a Wall Penetrated by Plumbing

31 Fire Protection Engineering N UMBER 22

 Facilities,” Building Research Note, 1997, 1997, Glen Ellyn, Illinois. Building Codes, Fire Test Work and a
National Research Council of Canada, Historical Perspective,” prepared for
25 Council of American Building Officials
1974. State of California Department of
“Plastic Pipe in Fire-Resistive
Housing and Community Development,
13 Parker, W.J., et al. “Fire Endurance of Construction,” National Evaluation
1978.
Gypsum Board Walls and Chase Report NER-370, 1992.
Containing Plastic and Metallic Drain, 32 SRI International, “Environmental Review
26 International Conference of Building
Waste and Vent Plumbing Systems,” NBS of Proposed Expanded Uses of Plastic
Officials. Uniform Building Code,
Building Series Report No. 72, National Plumbing Pipe,” SRI project No. HSH-
Walnut, California, 1997.
Bureau of Standards, Gaithersburg, 4910, 1983.
Maryland, 1975. 27 International Code Council Inc.,
33 Alger, R.S., “Technical Appendices D,” in
International Building Code 2000, Falls
14 Bletzacker, R.W., and Birle, J.G., Draft Environmental Impact Report:
Church, Virginia, 2000.
“Standard ASTM Fire Endurance Test on Plastic Plumbing Pipe; State of California
a Floor and Ceiling Assembly,” 28 Gypsum Association, “Fire Resistance Department of Housing and Community
Engineering Experiment Station Report Design Manual,” 16th Edition, Development, Sacramento, Calif., 1989.
Project 5539, Ohio State Univ., 1974. Washington D.C., 2000.
34 State of California Housing and
15 Bletzacker, R.W., “Standard ASTM Fire 29 Harmathy, T.Z., “Ten Rules of Fire Community Development, “Final
Endurance Test and Fire and Hose Endurance Rating,” Fire Technology, Environmental Impact Report for
Stream Test on Duplicate Load-Bearing 1965 1(2). Chlorinated Polyvinyl Chloride Pipe Use
PolyVinylChloride Plumbing Wall 30 U.S. Department of Housing and Urban for Potable Water Piping in Residential
Assemblies,” Engineering Experiment Development, “Guidelines on Fire Buildings,” California State Department
Station Report, Project 5561, Ohio State Ratings of Archaic Materials and of Housing, Sacramento, Calif., 1998.
Univ., 1984. Assemblies,” Rehabilitation Guidelines 35 Wilging, R.E., “Plastic Fire Sprinkler
16 Bletzacker, R.W., and Birle, J.G., Series, 2000. Piping 1967-1987,” BOCA Magazine,
“Standard ASTM Fire Endurance Test and 31 Plastic Piping and Fittings Association. July/August, 1988.
Fire and Hose Stream Test on Duplicate “Plastic Pipe and Fire Safety: The Model
Non-Load Bearing Acrylonitrile-
Butadiene-Styrene (ABS) Plumbing Wall
Assembly,” Engineering Experiment
Station Project Report No. 5473, Ohio
State Univ., 1973.
17 Priest, D., Personal Communication,
1999.
18 Flax, S., “Dubious War on Plastic Pipe,”
Fortune Magazine, 107(3), 1983, pp. 68-
71.
19 Zicherman, J.B., “Cost Benefit Studies of
PVC Pipe Tube and Conduit,” presenta-
tion to CSI-Construction Specifications
Institute Annual Meeting, San Diego,
Calif., 1990.
20 The Vinyl Institute. “Cost Benefit
Studies,” The Vinyl Institute News, July,
1990.
21 BCMC Public Hearings “Final Report on
Protection Requirements for Vertical
Penetrations,” Kansas City, Missouri,
1986.
22 BCMC Public Hearings “Protection of
Penetrations and Joints in Building Wall,
Floor and Roof Assemblies,” Orlando,
Florida, 1995.
23 Lee, B.T., “Standard Room Fire Test
Development at the National Bureau of
Standards,” In: Fire Safety: Science and
Engineering, ASTM STP 882, T.Z.
Harmathy, Ed., Philadelphia, Penn.,
1985, pp. 29-44.
24 Plastic Pipe and Fittings Association,
“Plastic Pipe in Fire-Resistive
Construction,” Editions 1-4, 1985, 1991,

S PRING 2004 www.sfpe.org 32

 Combining Emergency Voice
and Nonemergency
Paging Systems

T he use of voice mes-

sages to initiate evac-
uation or relocation
during fire and other emer-
gencies is increasing.
Figure 1. System Block Diagrams

Emergency Voice/Alarm
Communication System Music/Paging System
save costs and reduce
equipment installation?
Previous articles in this
series sponsored by the Na-
tional Electrical Manufac-
Building, fire, and life safety Pre-recorded Microphone turer’s Association (NEMA)
codes typically require Music have discussed voice system
Message Microphone or Paging
voice systems in large Module intelligibility, message con-
Module Sub-system
assembly occupancies, high- tent, and overall system reli-
rise buildings, and other ability. This article looks at
spaces where egress is com- the functional similarities
plex. In the wake of recent and differences of emer-
tragic nightclub incidents Pre-amp Pre-amp gency and nonemergency
and a devastating fire in the systems, and discusses how
Düsseldorf airport, experts and why the systems might
are reevaluating the need be combined.
for, and the application of, Figure 1 shows simplified
voice signaling. block diagrams for an EVAC
Amplifier Amplifier
Many occupancies that ei- system and for a general
ther require emergency paging/music system. To re-
voice alarm communication duce confusion, in this arti-
(EVAC) systems or that could cle one will be referred to
benefit from them regularly as the “EVAC” or “emer-
have and use systems for gency” system and the other
general, nonemergency simply as the “paging” or
voice paging, public ad- nonemergency system. The
dress, or background music. basic architecture of each
Is it necessary to have two system is similar, though
overlapping systems with their purposes are quite dif-
similar equipment? Can the ferent. Nevertheless, it ap-
systems be combined to pears that there is an oppor-

33 Fire Protection Engineering N UMBER 22

tunity to combine some or all of the
system components to eliminate dupli- Figure 2. Combination System
cate equipment and reduce the overall
costs to the owner. Emergency Voice/Alarm
Purpose: An emergency system is Communication System Music/Paging System
intended to initiate certain occupant re-
sponses – most often either evacuation Prerecorded Microphone
Music
or relocation. It does so by providing Message Microphone or Paging
Module
information: what has happened, what Module Subsystem
people should do, and why they
should do it. A paging system is used to
convey nonemergency information,
while a music system provides back-
ground noise for comfort, entertain- Preamp Fail-Safe Control/
ment, or to mask ambient noise. Disconnect
Use: An EVAC system is seldom used
– only during an emergency or once
per year when tested. Background mu-
sic systems are generally used when-
ever a building is occupied. Paging sys- Amplifier
tems may be used almost constantly,
such as in an airport or hospital; fre-
quently, such as in grocery stores; or
less frequently, such as in a commercial
office spaces. Emergency systems are
activated either automatically by a fire
detection and alarm system or manually
by staff or emergency forces, such as
fire department personnel. Because it is
seldom used, the emergency system
must be relatively easy to use by per-
sons with only a general familiarity
with such systems. In addition, it is in-
tended to be used during an emer-
gency, so its default mode is automatic generally require a higher level of intel- quirement exists for nonemergency
and its manual mode has defaults ligibility (not necessarily audibility) paging systems.
arranged to ensure that spoken mes- since a lower level of intelligibility that Despite the many differences in pur-
sages go to the affected areas without may be acceptable for an emergency pose, use, and characteristics, both
requiring much operator action – if system would result in listener fatigue emergency and nonemergency systems
any. Certainly, nonemergency paging for a system that is frequently used. The are intended to take input, process it,
systems must also be easy to use. How- sound quality of a music system or a and distribute it to listeners. Therefore,
ever, users have time to practice and paging system that is frequently used as shown in the simplified block dia-
become familiar with the systems. With needs to be comfortable to the listener grams of Figure 1, they have an overlap
the exception of hospital systems, if a – not a critical characteristic for an or redundancy of certain equipment. Is
user fails to immediately succeed in the emergency system. For some applica- it possible, and if so, is it permitted for
use of a paging system, there is little or tions, a music system needs to repro- the two systems to share components?
no downside risk compared to the duce the sound with fidelity, or true- The answers are yes and yes.
timely use of an emergency system. ness. For an emergency system, the
Characteristics: The differences in output does not need to faithfully re- COMBINATION SYSTEMS
purpose and use of emergency and produce the voice of the talker – it can
non-emergency paging systems lead to come out sounding like a computer NFPA 72, the National Fire Alarm
differences in function and in charac- synthesized voice, as long as it is intelli- Code, would refer to such a hybrid sys-
teristics of the systems. Both systems gible. One major difference in function tem as a combination system.1
must be intelligible, but a paging sys- is that certain components of emer-
tem must not be too intrusive or it will gency systems are required to be moni- 6.8.4 Combination Systems.
disrupt the general use and perfor- tored for integrity. Failure of these criti- 6.8.4.1* Fire alarm systems shall be
mance of the occupancy. An emer- cal components results in a trouble permitted to share components, equip-
gency system can, and should, be intru- signal to warn of the need for repair or ment, circuitry, and installation wiring
sive. Also, nonemergency systems maintenance of the system. No such re- with nonfire alarm systems.

S PRING 2004 www.sfpe.org 34

 ■ Combining Emergency Voice and Nonemergency Paging Systems

6.8.4.2 If common wiring is used for dio equipment are installed or lo- tem to provide selective and all-call
combination systems, the equipment for cated with safeguards to prevent fire alarm evacuation voice messages
nonfire alarm systems shall be permit- tampering or misadjustment of and messages for occupants to relo-
ted to be connected to the common those components essential to in- cate to safe areas in a building.
wiring of the system. tended operation for fire.
2 The monitoring integrity require- The annex text says that the opposite
In a simplified way, such a combina- ments of 4.4.7 and 6.9.4.4 shall configuration is permitted. That is, a
tion system might be arranged as continue to be met while the sys- nonemergency system can be used for
shown in Figure 2. tem is used for nonemergency emergency messaging, but only as sup-
The combination system may have a purposes. plemental signaling. In NFPA 72, a sup-
single user interface (microphone, 3 It is permitted by the Authority plemental system is one that is not re-
switches, etc.) or it may have separate Having Jurisdiction. quired by NFPA 72 and designated as
interfaces for the general-use systems such by the Authority Having Jurisdic-
versus the emergency system. In some There may be several ways to inter- tion (AHJ). In a way, the annex text
configurations, the point of interface pret and apply these requirements. does not make any sense. If the non-
may occur after preamp processing or First, it appears that 6.8.4.5 permits an emergency system is used as supple-
even after amplification. Regardless of EVAC system (speakers used as alarm mental notification, there must still be a
how or where the interface occurs, a notification appliances on fire alarm required EVAC system with its own
key requirement of the code is that any systems) to be used for nonemergency speakers. The annex text was added by
failure or fault in the nonemergency part paging when the conditions of the first the committee into the 1999 edition of
of the system “shall not interfere with exception are met. The associated an- NFPA 72 and included the following
the monitoring for integrity of the fire nex text reads as follows: Committee Substantiation:
alarm system or prevent alarm, supervi-
sory, or fire safety control signal trans- A.6.8.4.5 In Exception No. 1, if the In many buildings, such as airports,
missions.” When paging is the only non- building paging system can be con- the building-wide all-call and selec-
emergency use, the simplest way to trolled by personnel at the fire com- tive paging system provide more-effi-
meet that requirement is for the entire mand center, and if permitted by the cient and more-reliable speaker sys-
system to be a listed and properly de- Authority Having Jurisdiction, the tems than those provided with an
signed EVAC system. True combination building paging system can be used emergency voice/alarm communica-
systems come into being when it is de- as a supplementary notification sys- tions system.
sired to add music or to add other user
interfaces such as the ability for users to
page using their telephones. A combina-
tion system may also be needed when it
is desired to have nonemergency paging Figure 3. Common Fire Alarm Design Practice
occur at lower sound levels than the
emergency messages. The system would Distribution of Sound Pressure Level in a Space
then have to be arranged to fail-safe to
the louder fire alarm system mode. Too Loud
Even though 6.8.4.1 of the 2002 Na-
tional Fire Alarm Code explicitly per-
mits combination systems, 6.8.4.5 im-
poses limitations on combination Minimum
paging systems: Required

6.8.4.5* Speakers used as alarm no-

tification appliances on fire alarm sys-
tems shall not be used for nonemer-
gency purposes.
Exception No. 1: If the fire command Figure 4. Even Distribution of Sound at Optimum Level
center is constantly attended by a
trained operator, selective paging
Distribution of Sound Pressure Level in a Space
shall be permitted as approved by the
Authority Having Jurisdiction.
Exception No. 2: Use for nonemer-
gency purposes shall be permitted
where all of the following conditions
are met:
1 The speakers and associated au-

35 Fire Protection Engineering N UMBER 22

 Another proposal submitted to the detriment of business and the invest- used daily will be familiar to operate in
committee attempted to explicitly spell ment made in the system. To reduce an emergency.
out in the body of the code (rather than the chances of tampering at the speak- • Combination voice systems that are
just the annex) that nonemergency sys- ers, a system needs to be properly bal- required to be tamper resistant are less
tems could be used for emergency pur- anced and more evenly distributed than likely to be degraded by vandalism or
poses. The submitter used the exact past fire alarm design practice. The use miss-adjustment.
same substantiation (above) that the of more speakers at a lower level is In many occupancies, emergency
committee wrote for its own proposal. best. The Notification Appliances Com- voice notification is not required. The
That proposal was rejected by the com- mittee of NFPA 72 changed the code to fire alarm may only be required to use
mittee with the following Committee remove a requirement for audible ap- tone signaling. By using a combination
Statement: pliances to produce a minimum of 75 system, the occupants and fire service
The committee feels that the existing dBA at 10 feet. This permits designs benefit by having a notification system
requirements are necessary to insure that have a more distributed sound that uses voice, which has been shown
reliability of voice communications. level as shown in Figure 4. to be more effective than tone-only sig-
This proposal could seriously degrade Still, the goals for the emergency and naling.2, 3 Voice systems are more easily
this reliability. the non-emergency use may require expanded than tone-only systems. That
Exception 2 provides a clearer path two differing sound levels – one for is, a circuit is not limited in the number
to the use of the emergency system for general use and a higher sound level of appliances in the same way as tone-
nonemergency purposes. Also, Excep- for emergency purposes. Automatic only systems. The limit is not based on
tion 2 permits the use for music as well level control at the front end amplifier available power supply current, only by
as general paging, unlike Exception 1 is one possible solution. It is also possi- wire size and amplifier capacity. Thus,
that addresses only paging. The annex ble to have level control at some or all systems can more easily be designed
text for Exception 2 discusses design speakers. One method uses speakers and installed to permit future expan-
and considers implementation with two voice coils. One coil is con- sion. Also, most speakers have multi-
strategies. nected to a monitored EVAC circuit ple power taps permitting greater flexi-
while the other is connected to a non- bility in making field adjustments to the
OTHER CONSIDERATIONS emergency paging circuit. Similarly, loudness of the system. The owner and
variable power taps controlled by the installer benefit by the greater flexibility
Whether the base system is an EVAC fire alarm system and arranged to fail- and expandability of voice signaling
system or a nonemergency sound rein- safe to the higher level are another pos- versus tone signaling systems. ▲
forcement system, the possibility exists sible solution.
that the system could be vandalized if Combination systems can result in REFERENCES
occupants are annoyed by a system’s significant cost savings for building
constant use as a music or paging sys- owners and can also improve the per- 1 NFPA 72, National Fire Alarm Code,
tem. System vandalism is site-specific formance and reliability of the emer- National Fire Protection Association,
and not the general case. The most gency communications system. The Quincy, MA, 2002.
common form of tampering is the cost savings for a combination system 2 Proulx, G., and Sime, J.D., “To Prevent
blocking of a speaker, which would not compared to a separate paging system ‘Panic’ in an Underground Emergency:
be found by monitoring the integrity of with a separate emergency voice sys- Why Not Tell People the Truth?,”
the circuits. One solution to reduce tem may be significant. However, the Proceedings of the Third International
possible tampering is the use of loud- savings depend on the chosen configu- Symposium on Fire Safety Science,
Elsevier, London, 1991.
speakers listed as vandal-resistant (an ration of the combined system, which
existing listing category). depends on the non-emergency pur- 3 Keating, J.P., and Loftus, E.F., “Logic of
Proper design, installation, and use pose and use. Fire Escape,” Washington Univ., Seattle,
of the combination system may also re- • Combining the building paging Psychology Today, 14-16, June 1981.
duce the likelihood of tampering. Stan- system and the emergency voice com-
dard fire alarm system design practice munications system into one not only
is to use fewer speakers than a non- eliminates the cost of duplication but
emergency system design for the same also provides other important benefits: Editor’s Note – About This Article
space. For a combination system, that • Combination voice systems that are
practice invites tampering because it re- used daily are more likely to be intelli- This is a continuing series of articles that is
sults in places close to the speaker gible in order to meet the day-to-day supported by the National Electrical
where the level is very loud in order to communications needs within a facility. Manufacturer’s Association (NEMA),
get the minimum level required for in- • Combination voice system that af- Signaling Protection and Communications
telligibility at a point farthest from the fect daily business needs are likely to Section, and is intended to provide fire alarm
speaker. See Figure 3. be well maintained (for example, de- industry-related information to members of
If a sound system annoys the staff, it fective speakers will likely be replaced
the fire protection engineering profession.
is reducing productivity and it is most well before required test intervals).
likely also annoying customers, to the • Combination voice systems that are

S PRING 2004 www.sfpe.org 36

 Resources
SFPE’s Annual Meeting and
Professional Development Conference

September 20-24, 2004

Palmer House Hilton, Chicago, Illinois

SEMINARS TO BE HELD ARE:

The SFPE fall meeting
■ New! Human Behavior in Fire
moves to Chicago! ■ New! An Enforcer’s Guide to Performance-Based Design Review
The 2004 Annual Meeting format ■ New! Dust Explosion – Hazard Recognition, Assessment, and
Management
will include a one-day compli- ■ Sprinkler Design for Engineers
mentary professional program ■ Principles of Fire Protection Engineering
addressing issues of concern for ■ Introduction to Fire Dynamics Simulator and Smokeview
■ Tenability Systems for Smoke Management
the practicing FPE and recent ■ How to Study for the FPE/P.E. Exam
technical advancements. This
OTHER CONFERENCE FEATURES:
will be followed by the traditional ■ 2-day symposium presenting the state of the art in flammable
Awards and Honors Banquet, and combustible liquids protection
and by four days of education ■ Expanded Engineering Technology Showcase with the latest fire
safety products and information
events, including 8 seminars, a ■ Complimentary Annual Meeting program with the latest informa-
Symposium on Flammable and tion on the fire protection engineering profession
■ Annual Awards and Honors Banquet
Combustible Liquids, and an ex-
■ Various networking events
panded Engineering Technology
Showcase. Non-member seminar attendees receive a
complimentary first-year membership in SFPE!

Visit www.sfpe.org to register or

contact SFPE at 301.718.2910.

37 Fire Protection Engineering N UMBER 22

 UPCOMING EVENTS
May 2-7, 2004 May 10-11, 2004 October 6-8, 2004
CIB World Building Congress 2004 Third Edition of the International Workshop – 5th International Conference on Performance-Based
Toronto, Ontario, Canada Structures in Fire Codes and Fire Safety Design Methods
Info: www.cibworld.nl Ottawa, Ontario, Canada Info: www.sfpe.org
Info: irc.nrc-cnrc.gc.ca
May 4-6, 2004 October 20, 2004
14th Annual Halon Options Technical May 23-26, 2004 Computational Simulation Models in Fire
Working Conference NFPA World Safety Conference and Expo Engineering and Research
Albuquerque, New Mexico Salt lake City, Utah Santander, Spain
Info: bfrl.nist.gov Info: www.nfpa.org Info: grupos.unican.es/gidai

May 9-14, 2004 July 5-7, 2004 December 6, 2004

5th International Scientific Conference – Interflam, 2004 Symposium on Firestopping
Wood & Fire Safety Edinburgh, UK Washington, DC
Slovak Republic Info: www.intercomm.dial.pipex.com Info: www.astm.org

The High Tatras

September 1-3, 2004
Info: uvt.tuzvo.sk/wfs/english/info/
g_info.htm Public Fire Safety – Professionals in Partnership
3rd International Symposium
Belfast, United Kingdom
Info: www.intercomm.dial.pipex.com/html/
events/hbif.htm

S PRING 2004 www.sfpe.org 38

 Products/Literature
Fire-Rated Lightning Protection System
Recessed Fixture The patented ERITECH® System 3000, a light-
ning protection system, recently won “best
The Firedome™ recessed new product” at the ELECTRIX 2003 exhibi-
downlight provides a ther- tion in Sydney. The system incorporates the
mally protected housing for fire protection in commercial facilities, mul- ERITECH® DYNASPHERE MKIV air terminal
tiple-family dwellings, and other fire-related construction. Designed for that provides a dissipation point for lightning
60-minute fire-rated floor-ceiling designs, Firedome™ features an inte- discharges that could otherwise strike an
gral intumescent lining. When exposed to high temperatures generated unprotected structure, its contents, or personnel. The design represents
by fire, the lining expands to create a stable fire-resistant insulating a number of design improvements over existing technologies and is
char. part of a complete lightning protection system.
www.dcolighting.com www.erico.com
—Capri Omega Lighting —ERICO®, Inc.

False Fire Alarm Stopper Smoke Detector Alarm Control

The Stopper II is a pull station cover that
®
The new version of this company’s single-unit
mounts directly to the wall over an exist- beam smoke detector, Fireray Reflective, makes
ing pull station. When the cover is lifted, routine testing simpler and faster. An optional
a self-contained alarm sound draws imme- low-level controller allows authorized personnel to
diate attention to the area. Someone carry out alarm tests from a convenient location,
pulling a false alarm will run or be without the lengthy and potentially expensive
caught, helping to prevent a false fire process of accessing detectors installed at height.
alarm. The cover does not restrict legiti- Correct alarm function can be checked using a
mate fire alarms from being activated. key switch on the controller. Also includes a serial port for use with a
www.sti-usa.com laptop and may be hooked up to a datalogger.
—Safety Technology International, Inc. www.ffeuk.com
—Fire Fighting Enterprises Ltd.

Open-Path Gas-Detection System Video CD

The Model OPECL Gas Detection System A new 11-minute video shows in
delivers open-path infrared combustible gas precise detail the different benefits in
detection for protection of oil/gas and oth- fire protection provided by automatic
er industrial facilities. With a sensing path sprinkler systems and FM-200®
of up to 60 meters, the OPECL system Waterless Fire Protection systems.
offers features including stainless steel con- The video shows the effectiveness
struction, redundant xenon flashlamp tech- and value of both types of fire pro-
nology, multiple communication protocols, tection, but highlights differences in speed of activation, fire size, and
ease of installation and alignment, and a secondary damage for critical facilities. Videos are free upon request.
standard three-year warranty. www.fm-200.com
www.detronics.com —Great Lakes Chemical Corporation
—Detector Electronics Corp.

New Notification Devices Improved Pipe-Grooving Tools

The new SpectrAlert® Dual Strobe series Victaulic is improving its pipe-grooving tools
of notification devices was developed by continually adding new features and
for use where two-stage visual notifica- enhancements. The complete line is designed
tion is required for life safety and other for preparing standard or lightwall carbon steel
applications for two-stage visual notifi- pipe, stainless steel, aluminum, PVC, copper,
cation. Examples include security, torna- and other materials in various applications.
do alert, preaction alarms, and evacuation. The series is UL 1638 listed Keyless lower rolls and main drive shafts are
and can be customized. Housings are available in red or white with available on several of the company’s roll
strobes available in a variety of colors including red, amber, blue, groovers. The lower rolls also contain features to work with both the
green, and clear. keyless and keyed-style main shafts.
www.systemsensor.com www.victaulic.com
—System Sensor —Victaulic Company of America

39 Fire Protection Engineering N UMBER 22

 Products/Literature
Control Panel Protector Updated Product Literature
This new, super-tough, see-through As part of its continuing update program,
polycarbonate enclosure offers excellent Victaulic issues new and revised literature
protection and immediate access for fire on significant fire protection products that
alarm control panels installed external- they manufacture. Each product submittal
ly. The STI Clear & Accessible Control sheet provides specific details about the
Panel Protector guards against vandal- company’s most recent product develop-
ism, dirt, dust, and grime. Two models ments. The sheets are used to replace old
are available: the STI-7521 is secured with a thumb lock, and the STI- sheets in the customer’s current Victaulic
7520 is secured with a key lock. Fire Protection binder.
www.sti-usa.com www.victaulic.com
—Safety Technology International, Inc. —Victaulic Company of America

Retrofit Ball Valve Supervisory Switch Free Courses Online

This retrofit ball valve supervisory switch Wheelock, Inc., provides a self-paced
(RBVS), designed specifically for the fire sprin- online training program offering a
kler industry, detects the fully open position of comprehensive course curriculum
quarter-turn ball valves. It provides the opportu- that serves designers, installers, speci-
nity to have the ball valves supplied as compo- fiers, contractors, end-users, and other professionals involved in the fire
nent parts of back-flow devices brought into full alarm, security, and facility communications industries. Courses include
compliance with the requirements stipulated by a wide range of topics covering technical, applications, and sales
NFPA 72. Additionally, the ball valves installed in approaches. The programs carry CEU credits. The free courses may be
alarm lines on wet, dry, and pre-action systems accessed at www.wheelocku.com.
may now be brought into full NFPA compliance. www.wheelockinc.com
www.pottersignal.com —Wheelock, Inc.
—Potter Electric Signal Co.

Smoke Detectors Product Catalog

The F220 Series of smoke detec- Tyco’s 68-page, full-color Fire Protection
tors is self-testing. Other features Products catalog contains detailed infor-
include compatibility with 12 mation about the company’s automatic
VDC or 24 VDC systems; drift sprinklers, system valves and devices,
compensation of the detector and piping and electrical products.
chamber; sensitivity readout Sprinkler specification charts are also
through an onboard LED; patent- provided. The catalog includes photos,
pending, time-saving way to clean the chamber; “needs to be cleaned” specification information, examples of
signal; and wide range of available bases. applications, and more.
www.boschsecurity.us www.Tyco-Fire.com
—Bosch —Tyco Fire & Building Products

Factory-Built Grease Duct COIN™ Quick Response Space Sprinkler

Metal-Fab G Series™ Grease Duct Systems This new COIN™ quick response combustible
are factory-built in a controlled environment interstitial space sprinkler sprinkler from Viking
to ensure quality fabrication. They are Corporation has been tested and listed for use in
assembled with a liquid-tight connection specific light hazard combustible and non-com-
system. No welding is required to connect bustible concealed horizontal spaces requiring
components, ensuring that no leaks contami- sprinkler protection per installation standards. In
nate insulation, compromise fire integrity, or some cases, it can allow the use of any listed
cause health hazards. The systems have a CPVC piping system within concealed spaces
12-year warranty. requiring sprinkler protection.
www.metal-fabinc.com www.vikingcorp.com
—Metal-Fab, Inc. —Viking Corporation

40 Fire Protection Engineering N UMBER 22

 FIRE PROTECTION

B R A I N T E A S E R
Sales
Offices
HEADQUARTERS
TERRY TANKER Publisher
1300 East 9th Street
An examination is being taken by a student who is not prepared. The Cleveland, OH 44114-1503
exam consists of 80 multiple choice problems, each problem having four 216.696.7000, ext. 9721
fax 216.696.3432
possible choices. Assuming that each problem has only one correct answer ttanker@penton.com
and the student needs at least 20 correct answers to obtain a passing score,
NORTHEAST
what is the probability that, if the student guesses at each problem, the stu-
TOM CORCORAN District Manager
dent would receive a passing score?
929 Copes Lane
West Chestor, PA 19380
610.429.9848
fax 610.429.1120
Solution to last issue’s brainteaser tomcorcoran@penton.com
Four people of different ages told each other how old they were. One of them said, “If I NORTH CENTRAL
multiply my age by any of your ages, the product is a permutation of the digits of the two JOE DAHLHEIMER District Manager
ages.” How old is everyone?
1300 East 9th Street
Cleveland, OH 44114-1503
First, assume one person’s age is one digit and another’s is two digits. Call the ages s and
216.696.7000, ext. 9279
[tu], where s, t, and u are single digits. (Here, the brackets mean that the digits are not mul- fax 216.696.3432
tiplied.) Then, s times [tu] is a permutation of s, t, and u. In the case of [uts], u times s = jdahlheimer@penton.com
[ns], and t times s = [u(t-n)], where n is an integer.
CENTRAL / WEST
For n = 0, u times s = s, and t times s = [ut]. Either u = 1 or u =5, and s is odd. If u = 1, AMY COLLINS District Manager
two solutions are (s,t)={(3,5),(6,2)}. The solutions are 6 & 21 and 3 & 51. If u = 5, there are 3240 Shadyview Lane North
no solutions. Plymouth, MN 55447
763.404.3829
For n>0, there are no solutions. No other permutations have solutions. fax 763.404.3830
acollins@penton.com
Now, assume the ages being multiplied are both two digits. Call the ages [rs] and [tu].
[rs] times [tu] = some permutation of r, s, t, and u. From above, one of the two numbers SOUTHEAST
must end in 1 or 5. The permutation [utrs] gives solutions 21 & 60 and 51 & 30. The per- DEBBIE ISGRO District Manager
mutation [stru] gives the solution 21 & 87, and the permutation [ruts] gives the solutions 15 707 Whitlock Avenue SW
& 93 and 27 & 81. Suite B-24
Marietta, GA 30064
The ages are therefore 6, 21, 60, and 87. 770.218.9958
fax 770.218.8966
disgro@penton.com

3M (Fire Protection Fluid). ...........................Page 35 NOTIFIER Fire Systems.................................Page 57

Index of AGF Manufacturing, Inc. ...............................Page 59 OCV Control Valves ......................................Page 25
Advertisers Ansul Incorporated........................................Page 21 Potter Electric Signal Co................................Page 29
Anvil International, Inc. ................................Page 53 Prescolite........................................................Page 15
Bermad, Inc. ..................................................Page 37 Reliable Automatic Sprinkler ........................Page 41
BlazeMaster® Fire Sprinkler Systems/ Rockbestos .....................................................Page 23
NOVEON ..................................................Page 45 Rolf Jensen & Associates, Inc......Inside Front Cover
Chemguard.....................................................Page 13 Safe Fire Detection, Inc. ................................Page 55
Clarke Fire Protection Products, Inc. ...........Page 34 Safety Technology International, Inc. ..........Page 27
DACS Inc........................................................Page 26 Siemens Building Technologies, Inc.
Detection Systems .........................................Page 11 Faraday Division ........................................Page 7
Edwards Systems Technology .................Page 30-31 Siemens Building Technologies, Inc.
Fike Corporation ...........................................Page 24 Fire Safety Division..................................Page 17
Fire Control Instruments .................................Page 4 SimplexGrinnell ...............................................Page 2
Gast Manufacturing .......................................Page 43 Tyco Fire & Building Products................Back Cover
Grice Engineering..........................................Page 39 University of Maryland..................................Page 22
Honeywell Fire Systems................................Page 33 Victaulic Company of America.....................Page 47
Knox Company..............................................Page 38 Wheelock, Inc................................................Page 19
Koffel Associates, Inc....................Inside Back Cover Worcester Polytechnic Institute ....................Page 18

41 Fire Protection Engineering N UMBER 22

 from the technical director

What it Means to be a Professional Engineer

I n the United States, engineers who

are licensed to offer engineering
services directly to the public earn
the title “Professional Engineer,” or
“P.E.” for short. Licensure as a profes-
Each time that the fire protection engi-
neering exam is graded, SFPE assembles
a diverse group of licensed engineers to
define “minimally competent” and how
it corresponds to the questions on the
sional engineer requires a combination P.E. exam. Examples of the standards of
of education and experience. The typi- minimal competence include “a thor-
cal requirement includes graduation ough understanding of fundamental
from an engineering school, successful systems and practices as they pertain to
completion of the fundamentals of life safety and to fire prevention, detec-
engineering, or “EIT” exam, a mini- tion, control and extinguishment. This
mum of four years experience and suc- includes the ability to apply this under-
cessful completion of the principles standing in conjunction with commonly
and practices of engineering, or “P.E.” used fire protection standards.”2
exam. Given that licensure is adminis- No exam could determine whether an
Morgan J. Hurley, P.E. tered on a state basis, the specific engineer has all of the knowledge that
Technical Director requirements may vary slightly from they would need for to solve any prob-
Society of Fire Protection Engineers state to state, and some states allow the lem that might arise. Indeed, in some
substitution of additional experience engineering subjects, the standards of
above the minimum requirement in minimal competence uses words like
lieu of some of the other requirements. “awareness” or “basic understanding.”
Professional engineering examinations Licensure as a professional engineer
are available in a number of engineering means more than having a certain
disciplines, such as mechanical, electri- amount of experience and having passed
cal, civil and fire protection. The Society a few examinations – it also means that
of Fire Protection Engineers is responsi- an engineer can be held responsible if
ble for developing the fire protection they fail to protect public health, safety
engineering exam. Approximately 55% and welfare through their practice of en-
of all SFPE members are licensed as gineering.
professional engineers.1 Licensure as a professional engineer is
Anecdotally, there seems to be a wide an achievement for which any engineer
range of views about the meaning of should be proud. However, licensure in
licensure as a professional engineer. itself should never be interpreted as
These views range from opinions that meaning that the engineer is all knowing
licensure does not mean anything to and above reproach. Similarly, lack of a
opinions that licensed engineers are professional engineer’s license in itself
capable of anything within the field (or does not mean that an engineer is not at
at least think that they are). Of course, least “minimally competent;” it simply
the correct meaning lies somewhere in means that the engineer has not met the
between these extremes. criteria associated with obtaining a pro-
In the Unites States, the National fessional engineering license.
Council of Examiners for Engineering
and Surveying sets the bar for licensure REFERENCES
in any engineering discipline as “mini-
mally competent” within the licensee’s 1 Society of Fire Protection Engineers, “2003
field of engineering. “Minimally compe- Profile of the Fire Protection Engineer,”
tent” is defined as possessing at least the Bethesda, MD, 2003.
minimum amount of engineering exper- 2 Lataille, J. “The Discipline of Fire
tise to protect public health, safety and Protection Engineering,” Fire Protection
welfare in the practice of engineering. Engineering, 3, Summer 1999, pp. 40-42.

60 Fire Protection Engineering N UMBER 22