NIST Technical Note 1757r1

Summary and Conclusions of a 

Workshop on “Quantifying the 

Contribution of Flaming Residential 

Upholstered Furniture to Fire Losses 

in the United States”

William M. Pitts
NIST Technical Note 1757r1

Summary and Conclusions of a 

Workshop on “Quantifying the 

Contribution of Flaming Residential 

Upholstered Furniture to Fire Losses 

in the United States”

William M. Pitts 

Engineering Laboratory 

Fire Research Division 

August 2013

U.S. Department of Commerce 

Penny Pritzker, Secretary

National Institute of Standards and Technology 

Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director 
Certain commercial entities, equipment, or materials may be identified in this

document in order to describe an experimental procedure or concept adequately.

Such identification is not intended to imply recommendation or endorsement by the

National Institute of Standards and Technology, nor is it intended to imply that the

entities, materials, or equipment are necessarily the best available for the purpose. 

National Institute of Standards and Technology Technical Note 1757r1

Natl. Inst. Stand. Technol. Tech. Note 1757r1, 135 pages (August 2013) 

CODEN: NTNOEF
iii

ABSTRACT

This report summarizes the presentations and discussions, lists major conclusions, and provides 

recommendations for specific next steps from a workshop entitled “Quantifying the Contribution of 

Flaming Residential Upholstered Furniture to Fire Losses in the United States” that was held at the 

National Institute of Standards of Technology on March 22-23, 2012. The workshop objective was “to 

identify approaches for quantifying the full contribution of flaming fires of modern residential 

upholstered furniture (RUF) to the Nation’s fire losses and, therefore, the potential for reducing these 

losses”. The workshop consisted of three sessions including 1) presentations by experts on RUF fire 

behavior and the collection and analysis of United States fire statistics (primarily the National Fire 

Incidence Reporting System (NFIRS)), 2) an open, wide-ranging participant discussion addressing several 

specific topics with the aid of facilitators, and 3) a closing session where conclusions were listed and 

recommendations developed for a series of actions designed to improve the quantification of fire losses 

due to flaming RUF with characterized levels of uncertainty. Major workshops findings included 1) fires 

involving flaming RUF have the potential to grow very rapidly to high release rate levels capable of 

threatening civilians, firefighters, and property, 2) fires involving RUF are a major factor in current fire 

losses in the United States, contributing at much greater levels than their numbers would indicate, and3) 

existing statistical analyses likely underestimate the full contribution of flaming RUF to fire losses. An 

approach based on a matrix analysis is recommended to improve estimates for the contribution of flaming 

RUF to fire losses in the short term. In addition, a series of longer-term steps designed to improve the 

accuracy of these estimates and reduce uncertainties in the values are suggested. These include1) surveys 

of NFIRS practitioners to better understand how specific items are coded in NFIRS,2) organize and carry 

out an NFIRS special study designed to provide targeted information concerning the role of flaming RUF 

in residential fires, and 3) perform probabilistic fire modeling to better understand the role of flaming 

RUF in fire growth and spread. Appendices to the report include the workshop announcement, attendees, 

agenda, and PowerPoint presentations; a copy of the NFIRS coding form; and a summary and conclusions 

from the first day presentations and discussion. Subsequent to the original release of this Technical Note 

in September, 2012, John Hall from the National Fire Protection Association forwarded the workshop 

organizer a letter report detailing the results of a study utilizing the matrix approach discussed above to 

estimate the losses associated with fires in which RUF was not the initial item ignited but for which the 

RUF was identified as the “item contributing most to flame spread.” The estimates for such fires 

corresponded to one-third additions to the fires, injuries and damages associated with fires beginning with 

ignition of upholstered furniture, as well as a one-quarter addition to the deaths. This letter report has 

been incorporated into this revised Technical Note as Appendix G.

Key Words: fire losses; fire statistics; flaming fires; NFIRS; residential fires, residential upholstered 

furniture; workshop
iv

Table of Contents

ABSTRACT...................................................................................................................................iii

Table of Contents........................................................................................................................... iv

1. Introduction ............................................................................................................................. 1

2. Background.............................................................................................................................. 1

3. Workshop Organization........................................................................................................... 2

4. Presentation Highlights............................................................................................................ 3

4.1. Anthony Hamins, NIST.................................................................................................... 3

4.2. William Pitts, NIST.......................................................................................................... 3

4.3. Thomas Fabian, UL.......................................................................................................... 4

4.4. Marc Janssens, SwRI........................................................................................................ 5

4.5. Bradley Pabody, USFA.................................................................................................... 7

4.6. John Hall, NFPA .............................................................................................................. 8

4.7. David Butry, NIST......................................................................................................... 11

5. Open Forum Discussion ........................................................................................................ 12

5.1. Would decreasing the rate of fire growth and heat release in an enclosure significantly 

reduce residential fire losses within the room of fire origin? (Facilitator: Jason Averill)........ 12

5.2. Would decreasing the rate of fire growth and heat release in an enclosure significantly 

reduce residential fire losses at locations substantially removed from the room of fire origin? 

(Facilitator: Richard Gann)...................................................................................................... 14

5.3. What are the relevant characteristics of residential fires involving flaming RUF 

contributing to fire losses? (Facilitator: Jason Averill)............................................................ 15

5.4. Is flaming RUF likely playing a significant role in residential fire losses? (Facilitator: 

Richard Gann)........................................................................................................................... 16

5.5. Is it appropriate to differentiate fire losses inside and exterior to the room of fire origin 

with regard to the role of RUF in Residential Fire Losses? (Facilitator: Jason Averill) .......... 16

5.6. Do existing fire statistics and related analyses effectively capture contribution of 

flaming RUF to residential fire losses?..................................................................................... 17

5.7. Can existing fire statistics and extended analyses better capture contributions of flaming 

RUF to residential fire losses? .................................................................................................. 17

6. Summary of Presentations and Discussions and Identification of Approaches and 

Participants for Estimating Role of Flaming RUF in Fire Losses................................................ 18

6.1. Summary of Major Findings.......................................................................................... 18

6.2. Recommendations.......................................................................................................... 19

7. Final Comments..................................................................................................................... 22

8. Analysis of Losses in Fires for which RUF is Identified as the Primary Contributor to Fire 

Spread but not as the First Item Ignited. ....................................................................................... 22

9. Acknowledgements ............................................................................................................... 23

10. References.......................................................................................................................... 23

APPENDIX A—Workshop Announcement................................................................................. 25

APPENDIX B—Workshop Attendees ......................................................................................... 28

APPENDIX C—Workshop Agenda ............................................................................................. 30

APPENDIX D—Presentations...................................................................................................... 33

APPENDIX D.1 Anthony Hamins, NIST................................................................................. 34

APPENDIX D.2 William M. Pitts, NIST ................................................................................. 41
v

APPENDIX D.3 Thomas Fabian, UL....................................................................................... 51

APPENDIX D.4 Marc Janssens, SwRI..................................................................................... 59

APPENDIX D.5 Bradley Pabody, USFA................................................................................. 75

APPENDIX D.6 John Hall, NFPA ........................................................................................... 84

APPENDIX D.7 David Butry, NIST...................................................................................... 101

APPENDIX E—NFIRS Coding Forms...................................................................................... 109

APPENDIX F—Summary of First-Day Presentations and Discussion...................................... 125

APPENDIX G—Acton Item Report: Fires with Upholstered Furniture as the Primary Item 

Contributing to Fire Spread by John Hall and Marty Ahrens (NFPA) and Bradley Pabody and 

Alexandra Furr (USFA).............................................................................................................. 127
1

1. Introduction

A workshop entitled “Quantifying the Contribution of Flaming Residential1 Upholstered Furniture to Fire 

Losses in the United States” was held at the National Institute of Standards and Technology (NIST) in 

Gaithersburg, MD on March 22-23, 2012. This report summarizes the presentations, discussions, 

conclusions, and outcomes of the workshop.

2. Background

The rationale for the workshop was discussed in the announcement. This document is included in

Appendix A.

Briefly, a large fraction of the residential upholstered furniture (RUF) found in existing homes is believed

to be capable of supporting rapidly growing flaming fires that can achieve sufficiently high heat release 

rates to ignite other nearby items and in some cases can induce flashover as a single burning item. 

Furthermore, this potential and the large size and mass of a typical RUF item mean that these items can be 

the principal contributors to the size and loss impact of the entire fire, even when a different item is the 

first item ignited. These diverse phenomena involve every aspect of RUF fire performance, except its 

susceptibility to smoldering ignition. For this reason, the term “flaming RUF” will be used throughout 

this report to refer to the propensity for RUF fires to grow rapidly to high peak intensities and thereby 

result in large, damaging fires.

Indications of the potential for RUF to contribute to fire losses is available in recent studies reported by 

NIST [1] and Underwriters Laboratories (UL) [2]. In the NIST study, fire growth was studied in rooms 

furnished with articles, including RUF, typically found in today’s living rooms in order to characterize 

smoke detector response time and its implications for fire losses. One of the parameters characterized

was the time to untenable conditions in the room. These times were compared with the results from a 

similar study carried out in the mid-1970s [3] and were found to have dropped from on the order of 

17 min to around 3 min. Changes in the materials used in RUF construction over this period were 

identified as a major, though not the only, factor in this dramatic decrease. The UL study included a 

comparison of fires in fully furnished rooms in which the only difference was the presence of RUF 

articles constructed from either materials commonly found in furniture today, (flexible polyurethane 

(FPUF) foam covered with polyester fabric), or so-called “legacy” materials (cotton fabric over cotton 

batting). This investigation found that the time to flashover in the room was reduced from just over 

30 min to around 4 min when the legacy RUF was replaced with RUF incorporating FPUF and the plastic 

fabric.

There are a number of modes in which RUF can participate in fires in residences. These include: 

(1) RUF is the first item ignited, and the fire begins and ends in smoldering mode. (2) RUF is the first 

item ignited, and the fire begins in flaming mode. (3) RUF is the first item ignited and the fire begins in 

smoldering mode, but transitions to flaming mode. (4) RUF is the first item ignited, but the RUF fire also 

serves as a flaming heat source to ignite other items. (5) RUF is the first item ignited, and the RUF fire is 

either the principal or only contributor to the room going to flashover. (6) RUF is not the first item 

ignited, but another item serves as a flaming heat source to ignite RUF.

 1 The National Fire Protection Association (NFPA) makes a distinction between “home” and “residential” 

fires. Homes include one- and two-family homes (including manufactured housing) and multi-family housing or 

apartments. Residential includes homes, but it also includes hotels and motels, dorms, residential board and care or 

assisted living, rooming houses, etc. Most of NFPA’s analyses, including analyses of upholstered furniture fires, 

refer to fires in homes and not all residential fires. Using these definitions, the workshop focus was home fires, even 

though the terms residential and home are used interchangeably in this report.
2

Statistics for the United States indicate that fires in which RUF is the item first ignited are responsible for 

a significant fraction of civilian fire losses (deaths, injuries, property). The most frequently cited ignition 

source for these fires is smoking materials, which typically ignite smoldering fires that can later transition 

to flaming. As a result, fire prevention efforts for RUF have focused on limiting smoldering ignition. 

The proposed Consumer Product Safety Commission’s (CPSC) draft standard 16 CFR Part 1634 [4] is the

prime example of this approach. Efforts to limit the fire growth and maximum heat release rates of 

flaming RUF have received far less attention. It should be noted that such standards aimed at flaming 

furniture have been developed for residential mattresses (16 CFR Part 1633 [5]) and commercial and 

institutional upholstered furniture (California Technical Bulletin 133 [6]).

The following three hypotheses listed in the workshop announcement, if true, suggest that significant 

reductions in fire losses would occur if the fire development rates and maximum heat release rates of 

RUF articles were substantially reduced. The hypotheses are:

• A decreased rate of fire development inside a residential room containing RUF increases the time 

available for response or escape and can result in decreased fire losses (both property and human) 

inside the room of fire origin.

• Flashover development in the room of fire origin increases production of toxic gases and smoke 

and the likelihood of fire spread to other areas of the residence. This increases the potential for 

fire losses at locations substantially removed from the room of fire origin.

• Reducing the fire growth rate on and limiting the maximum heat release rate of RUF to levels 

insufficient to generate flashover or ignite nearby furnishings would substantially reduce financial 

and human fire losses in the United States.

Even though the fire behavior of flaming RUF suggests that it likely makes a significant contribution to 

the nation’s fire losses, no authorative estimates of fire losses that include all and only the fires that we 

have here identified as “flaming RUF” are available. As a result, it is currently not possible to predict the 

potential for reducing fire losses by modifying RUF in such ways as to reduce its contribution to fire 

spread and growth in residences.

The workshop was organized specifically to evaluate the potential for estimating the contribution of 

flaming RUF to fire losses in the United States using currently available fire statistics and to identify 

future approaches for reducing uncertainties in such estimates.

The formal objective of the workshop was:

To identify approaches for quantifying the full contribution of flaming fires of modern RUF to the 

Nation’s fire losses and, therefore, the potential for reducing these losses.

3. Workshop Organization

The approach adopted for the workshop was to bring together experts familiar with the collection and 

utilization of fire statistics, primarily the National Fire Incident Reporting System (NFIRS), and the fire 

behavior of flaming RUF with a goal of creating a synergy that would contribute to meeting the workshop 

objective. The final list of attendees is included in Appendix B of this report.

In order to prepare a foundation for later discussion, a series of presentations were solicited dealing with 

the fire behavior of flaming RUF and the description and use of NFIRS. The presenters and their talk

titles are included as part of the workshop agenda provided in Appendix C. Note that due to a scheduling 

conflict, it was necessary for David Sheppard of the Bureau of Alcohol, Tobacco, Firearms and 
3

Explosives (ATF) to withdraw from the workshop, and this presentation was not presented. The allocated 

time for this presentation was absorbed into the other talks and discussion.

The afternoon session on the first day of the workshop was intended to provide a wide ranging discussion 

of the workshop topic involving all of the participants. A series of questions designed to satisfy the 

Workshop objective and address various aspects of the topic are listed in Appendix C. Facilitators aided 

in focusing the discussions and capturing the major thoughts and ideas discussed by the workshop 

participants.

The final half day session of the workshop was devoted to identifying approaches for meeting the 

workshop objective and suggesting a path forward. Even though the agenda indicates a series of stages to 

accomplish this, the workshop participants concurred that sufficient consensus had been achieved during

the first day that it was be possible to work together and lay out an appropriate strategy without further 

deliberation. John Hall of the National Fire Protection Association (NFPA) led the discussion.

4. Presentation Highlights

The slides presented by the speakers are included in Appendix D. Major points from the presentations 

and related questions and discussion are summarized below.

4.1. Anthony Hamins, NIST

Anthony Hamins, Chief of the Fire Research Division of NIST, welcomed the workshop participants and 

provided an overview of NIST and the Engineering Laboratory. He emphasized the Fire Research 

Division’s focus on measurement science and provided an indication of the breadth of the NIST research 

portfolio. The magnitude of the nation’s fire problem and its impact on society was made clear by citing 

statistics on direct fire losses, both human and property, as well as indirect costs such as fire departments 

and insurance. The fire research efforts at NIST were discussed both in terms of a long-range vision and 

its current programs.

The magnitude of continuing fire losses in the United States was provided by considering statistics from 

2008, which indicated that 2800 people died, 14,960 were injured, and direct property losses amounted to

16.6 billion dollars in structure fires. The importance of residential fires was emphasized, with 73 % of 

all reported structure fires, 92 % of civilian fire deaths, 86 % of civilian fire injuries, and 68 % of direct 

property losses due to such fires. The relative importance of residential upholstered furniture and 

mattresses to these losses was identified by noting that the numbers of deaths and injuries associated with 

fires when these items were reported as the item first ignited were substantially higher than when other 

items were identified as the first ignited.

4.2. William Pitts, NIST

William Pitts provided an overview of the workshop. As an example of the potential for RUF to be a 

serious fire problem, he showed heat release rate measurements and photographs from a NIST experiment 

in which a single sofa inside a small room (ISO 9705 [7]) was ignited with a small flame. For the initial 

100 s following ignition, the fire grew slowly and remained relatively small. This was followed by a 

period of more rapid fire growth. Starting around 180 s, the fire grew very rapidly, reaching a peak heat 

release rate of 2.5 MW around 300 s. The room became filled with flames and heavy smoke. The NIST 

Dunes 1 [1] and Dunes 2 [3] experiments and the recent UL studies of RUF flammability [2] discussed in 

the Background Section above were then summarized. It was noted that the roughly three to four minutes 

required for the development of untenable conditions and/or flashover in these studies were consistent 

with the time required for the single sofa to become fully involved in the NIST experiment. A short 

summary of previous research on RUF flammability was provided.
4

Some statistics from the CPSC Proposed Rule 16 CFR Part 1634, Standard for the Flammability of 

Residential Upholstered Furniture, were summarized [4]. These indicated that during the period 2002-

2004, 7800 reported residential fires, 540 civilian deaths, 870 civilian injuries, and $250 million in 

property loss per year were attributed to fires in which RUF was identified as the item first ignited. 

Utilizing NFPA statistics for fires from 2003 [8], it was revealed that these values represented 1.9 %, 

17 %, 6.2 %, and 4.1 %, respectively, of the totals for residential fires. The statistic which stands out is 

that the 1.9 % of total reported fires in which RUF was the item first ignited were responsible for 17 % of 

fire deaths in residences, but the values for injuries and property losses are also markedly higher than 

might be expected based simply on the percentage of fires involving RUF as the item first ignited. This 

provides an indication that fires involving RUF have the potential to be much more damaging than fires 

originating in other ways. In other words, the risks of civilian injury and death and property loss are

much higher when the item first ignited is RUF.

Statistics taken from a summary compiled by the NFPA for 2010 indicated that 92 % of civilian structural 

fire deaths occurred in residences, the 4 % of fires starting in a living room, family room, or den were 

responsible for 24 % of the total civilian fire deaths, and similar enhancements in deaths, injuries, and 

property losses were associated with fires starting in a bedroom. [9] While not directly linked, these 

statistics suggest that the presence of RUF and bedding contribute to more serious fires. Smoking

materials ignition of RUF or mattresses remained the leading cause of civilian fire deaths. Another 

interesting observation was obtained by normalizing fire losses by the number of reported fires per year 

and inspecting the trends over a period of time. This analysis revealed that even though the annual 

number of reported fires has dropped 55 % since 1980, the number of civilian fire deaths and injuries per 

reported fire has remained essentially constant. Over the same period the number of firefighter deaths 

and injuries per reported fire increased significantly, as did the average property loss per fire in 

normalized dollars.

The number of RUF articles in households was identified as an important parameter for understanding the 

role of RUF in fire losses. Statistics taken from the CPSC Proposed Rule 16 CFR Part 1634 indicate that 

an average residence contained four articles in the early 2000s [4]. This number is consistent with two, 

more recent, studies of flammable contents in residences carried out in Canada [10,11].

The purpose of the workshop, the hypotheses discussed earlier, and the workshop objective were then 

reviewed. The need to remain focused on the specific topic of the workshop was emphasized, since it was 

recognized that the general topic of RUF flammability is a wide-ranging topic of high current interest.

4.3. Thomas Fabian, UL

This presentation started with a review of fire statistics taken from a report by M. Ahrens of NFPA based 

on statistics from 2003-2008. [12] It was reported that 23 % of civilian fire deaths and 10 % of injuries 

were associated with the 4 % of reported fires that occurred in a living room, family room, or den. The 

percentage of reported fires and fire deaths agree well with those listed above. It was also noted that 

21 % of fire deaths occurred in fires where RUF was the item first ignited. This value is somewhat higher 

than the value of 17 % cited above based on the CPSC work. The similarity of these statistics to those for 

bedroom fires was noted.

A series of experiments was performed at UL in which RUF materials, mock-ups, and actual RUF were 

tested. A range of materials were used with a focus on the effectiveness of fire barriers. A single fabric, 

two flexible polyurethane foams (FPUFs), a single polyester wrap, and eleven barriers were used. Data 

were presented for mock ups and actual RUF that showed that the use of a barrier significantly slowed 

fire growth and reduced peak heat release rates (HRRs). Comparison of mock-ups and RUF constructed 

with either non-fire-retarded foam or FPUF meeting the California TB 117 standard [13] showed 
5

measurable reductions in peak HRRs for items containing foam meeting the standard, but the reductions

provided only a marginal improvement in fire performance. Cone calorimeter measurements were 

characterized as having the capability to distinguish the fire performance of individual materials or groups 

of materials, but did not necessarily correlate with large scale experiments.

In a second phase of the effort, specially constructed RUF was positioned inside a room containing other 

identical furnishings. Three types of RUF were considered: contemporary (non-fire-retarded foam with 

polyester fabric and polyester wrap), contemporary with added fire barrier, and legacy (cotton batting and 

cotton fabric). As mentioned above, when the contemporary furniture was ignited, flashover was 

observed in around 4 min. These times were comparable to those observed in the NIST experiment with 

used furniture. When the legacy furniture was tested, the time to flashover increased to about 34 min. 

Replacing the polyester wrap in contemporary furniture with a cotton-based barrier increased the required 

time for flashover to roughly 21 min.

In recently completed experiments, the effects of replacing contemporary RUF with contemporary RUF 

with an added fire barrier were investigated inside structures representing a one story ranch house and a 

two story colonial home with an open floor plan. The tenability at locations well removed from the fire 

room was considered. Using a measured temperature 1.5 m above the floor, i.e., face height, of 150 oC as 

a criteria, the time to untenability for an upstairs room in the two story structure was increased from 303 s 

to 1959 s when the fire barrier was added.

A participant asked whether there would have been similar changes in smoke detector response time

when the RUF was changed. The answer was that smoke detectors responded early in all fires, so that 

available escape times were significantly increased when the time to untenability increased.

The times quoted for the development of flashover and untenability led the audience to discuss the period

required for a fire department to reach a location following an alarm. For an urban fire department, Sean 

DeCrane, a Battalion Chief with the Cleveland Fire Department, indicated that the average time between 

the receipt of an emergency call and when firemen are prepared to enter a residence is 7 min to 9 min. 

This period includes response (4 min to 6 min) and scene deployment (3 min to 4 min) times. Times for 

rural departments will generally be longer. These response times have obvious implications given the 

rapid fire growth observed with the contemporary upholstered furniture.

There was some discussion of the effectiveness of various barrier types as well as the effectiveness of 

using high loft barrier materials to replace polyester wrap. Both advantages and drawbacks of this 

approach were mentioned.

4.4. Marc Janssens, SwRI

This presentation described an investigation funded by the Department of Justice that is aiming to 

improve and characterize uncertainties associated with different approaches for predicting the burning 

behavior of RUF during fire reconstructions. An important point was made that the information available 

describing the RUF can vary considerably from cases where duplicate articles of RUF are available for 

testing, to cases where only small samples of materials used to construct the article are available, to cases 

where little or no information is available concerning the RUF article. The modeling approaches adopted 

for these various cases may vary considerably. For instance, if a duplicate article or sufficient materials 

are available, the RUF can be tested at full scale either as a duplicate article or a partial mockup in order 

to directly determine its burning behavior. If only small material samples are available, they can be tested 

in small scale apparatuses, such as the cone calorimeter or microscale combustion calorimeter, with the 

results used as inputs for appropriate RUF fire models. If no information is available, models for generic 
6

RUF burning must be used. Uncertainties are expected to increase as the amount of information available 

concerning a RUF article decreases.

A number of existing models for flaming RUF were described. These included a model developed during 

the 1990s European project on Combustion Behavior of Upholstered Furniture (CBUF) [14], two simple 

models developed by Babrauskas during the 1980s [15], and the fire field model, known as the Fire 

Dynamics Simulator (FDS) [16], developed at NIST that has recently incorporated a fire spread and 

growth model.

A series of experiments were run to characterize the burning behavior of individual materials used in RUF 

as well as composites of these materials. Fire tests were run on small scale (cone calorimeter and 

microscale combustion calorimeter), intermediate scale (mock-ups), and full scale (RUF articles) in the 

open and inside a room. Material effects were investigated by considering two types of fabrics (non-fireretarded and fire-retarded cotton) and five types of fillings (low and high density untreated FPUF, foams 

meeting the Cal 117 [13] and BS 5852 (Ignition Source 5) [17] standards, and polyester fiber fill). Other 

parameters varied included the size of the flaming ignition source (gaseous fuel flames of match size or 

equivalent to several sheets of burning newsprint or pool fires involving on 50 mL or 100 mL of 

gasolene), the ignition location (seat, lower front, and rear), and the size of the RUF article (one, two, or 

three seats). A fractional factorial model was used to reduce the number of experiments required.

In addition, to supplement the controlled tests described above, a number of articles of used RUF were 

collected in sets of two or more items. This allowed the burning behavior of individual articles inside a 

room to be investigated, while materials taken from the same type of item were tested with appropriate 

small-scale fire tests.

Intense burning was observed during experiments involving mock ups and actual RUF. The primary 

effect of ignition fire size was to change the period required for a fire to fully involve an item. Due to the 

intense burning and relative independence from ignition source, it was noted that evidence of intense 

burning on upholstered furniture might be interpreted by an investigator as involving the use of 

accelerants when none were used.

A subset of the full-scale mockup tests was part of a fractional factorial experiment. Analysis of the data 

from these tests resulted in the following observations:

• The HRR time profiles of 3-seat sofas are sensitive to the ignition location on the top of the seat 

cushions where the ignition source is applied (e.g., side versus middle).

• The type of ignition source significantly affects the ignition delay, with smaller sources resulting 

in longer delays.

• Peak HRR is strongly affected by the padding material. As an example, the peak HRR was 

significantly lower for mockups containing CAL TB 117 foam as opposed to those with non-fireretarded foam.

• Ignition on the rear of upholstered furniture generally resulted in a shorter ignition delay, but a 

slower fire growth rate and lower peak HRR.

Note that the finding concerning non-fire-retarded and CAL TB 177 foams differs from the conclusion 

reached in the UL study, which indicated differences in fire development on items containing the two 

foam types were minor. The reason for the different conclusions remains unclear, even though it was 

suggested during discussion that the different volumes of the rooms used in the two studies could possibly 

provide an explanation.
7

Comparisons of model predictions for peak HRR with the experimental findings showed variable levels 

of agreement, depending on the model used. The overall best agreement was found with the simple 

model of Babrauskas [15]. The CBUF models also did a reasonable job, but predictions were somewhat 

poorer. Predictions using FDS tended to fall well below the measured values of peak HRR.

The study also evaluated the ability of two fire models (the zone model CFAST [18] and the field model 

FDS) to predict temperature distributions within a room given an experimental fire growth curve. Both 

models yielded results that agreed well with experiment.

During questioning, Janssens noted that single items of burning RUF were insufficient to induce flashover 

in the test room.

2

 This conclusion seemed to be at variance with the NIST and UL experiments described 

above. The larger size of the SwRI room (3.7 m × 4.9 m × 2.7 m) was identified as the most likely reason 

for the difference.

4.5. Bradley Pabody, USFA

The presenter is the Chief of the National Fire Data Center (NFDC), which has the responsibility for 

developing and maintaining NFIRS. NFDC is part of the United States Fire Administration (USFA) in 

the Department of Homeland Security.

The presentation included an overview of the NFIRS system and the type of data collected. The system is 

voluntary, but over 23,000 fire departments in all 50 states participate. During 2010, over 1 million fires 

were logged into the system. Data is collected locally by the fire departments, forwarded to state fire 

offices for compilation, and then collected and collated by NFDC. The USFA collates the results and 

makes them available to the public through its website. The raw data are also provided to various 

organizations to allow additional analysis. 

The system employs a standard form for inputting data. A copy of this form is included in Appendix E. 

NFIRS was started in 1975. Since then it has undergone five major revisions, and the current version is 

NFIRS 5.0 (there were 4.0 and 4.1 versions). NFIRS 5.0 has been in use since 1999. Preliminary 

planning is underway for the next version, NFIRS 6.0, but funding has not been approved, and no date for 

its introduction has been set. A number of initiatives are underway in the meantime to improve the 

handling and warehousing of data and improved web access and security.

NFIRS consist of 11 modules. The modules used vary with the type of incident. The modules are:

• The Basic Module (NFIRS–1) captures general information on every incident (or emergency call) 

to which the department responds.

• The Fire Module (NFIRS–2) is used to describe each fire incident to which the department 

responds. 

• The Structure Fire Module (NFIRS–3) is used to describe each structure fire to which the 

department responds. 

• The Civilian Fire Casualty Module (NFIRS–4) is used to report injuries or deaths to civilians or 

other emergency personnel (e.g., police officers, non-fire department/EMS personnel) that are 

related to a fire incident.

• The Fire Service Casualty Module (NFIRS–5) is used to report injuries and deaths of 

firefighters.

 2 Subsequent to the workshop, Marc Janssens reported that this conclusion was based on a criterion of flames 

extending from the doorway of the room. Later analysis utilizing different criteria for the onset of flashover 

indicated that flashover may actually have occurred in up to one third of their tests.
8

• The EMS Module (NFIRS–6) is completed by fire departments that provide emergency medical 

services.

• The Hazardous Materials Module (NFIRS–7) is completed to report spills or releases of 55 

gallons or more of hazardous materials or when special HazMat actions were taken.

• The Wildland Fire Module (NFIRS–8) is completed to report incidents that involve wildland or 

vegetation fires. The module is used in lieu of the Fire Module for wildland fire incidents.

• The Apparatus or Resources Module (NFIRS–9), a department-use module, is completed to 

report data specific to each piece of apparatus that responds to an incident. It includes information 

that can be used to calculate response time and time out of service.

• The Personnel Module (NFIRS–10), a department-use module, is completed to report the same 

information as on the Apparatus or Resources Module, but it also provides for tracking the 

personnel associated with that apparatus.

• The Arson Module (NFIRS–11) is completed to report additional information on fires that have 

been coded by the department as “intentionally set.”

Additional information can also be included on the Supplemental Form (NFIRS–1S).

Questions and comments during the presentation revealed the following additional information. There is 

no obvious correlation between the quality of reports and how often a fire department prepares a report. 

Several comments were made concerning how variable responses by different people or fire departments 

filling out the forms can affect data collected by NFIRS. It is difficult to modify the forms once they have 

been completed. Since more serious fires often involve additional investigation, some information can be 

lost if the NFIRS report is not revised to include the updated findings. The question was raised 

concerning whether there have been studies on how well the forms are filled out. The general answer was 

“no,” but it was noted that studies have shown that fires with sources coded as of “unknown source” 

provide data similar to fires coded as “known.” It was also noted that some fire departments advocate 

classifying fires as “unknown” if there is any doubt at all.

The question was asked whether new items will be included in NFIRS 6.0. The answer was that this is 

likely. The USFA will work with fire service stakeholders, including local and state fire organizations, 

other federal agencies and non-governmental organizations on this task. It was pointed out that the task 

involves a large group of both researchers and data providers (fire departments) that must be convinced of 

the need for change, and this generally takes a great deal of effort and time. Contracts are used for system 

enhancements, and these costs must be included in the budget.

4.6. John Hall, NFPA

John Hall began his presentation by noting that data from NFIRS is crucial to the fire statistics 

community. Without it, there would be little knowledge of the fire situation in America. He did note that 

NFIRS is not designed for representativeness or randomness, like a true statistically designed survey, 

although NFIRS captures such a large percentage of all fires that it can be treated as statistically valid for 

purposes of estimating the share of fires or losses having certain defined characteristics. NFPA performs 

a statistical survey of fire departments, which is combined with NFIRS data to provide an improved 

statistical picture of fire in the country.

Numerous choices must be considered by analysts when using NFIRS data. There are questions 

concerning how information is coded. Examples include residential structure versus home structure and 

how confined fires3 are treated. As indicated earlier, very large fire incidents often involve separate 

 3

Confined fires are those that do not spread beyond a non-combustible enclosure such as a cooking pot, chimney, or 

trash compactor.
9

investigations. Other types of data that might be used in conjunction with NFIRS include statistics related 

to insured fire losses and death certificates.

Certain data elements from NFIRS can be associated with particular fire characteristics. Elements which 

can be related to prevention of ignition and fire growth were considered during the presentation. A focus 

was information provided relative to RUF.

Six elements were identified that may be associated with an ignition. These include “cause of ignition”

(E1), “area of fire origin” (D1), “heat source” (D2), “equipment involved in ignition” (F1), “item first 

ignited” (D3), and “type of material first ignited” (D4) Note: Bolded indices in parentheses refer to items 

in the “Fire” module of NFIRS (NFIRS–2). Utilizing the “item first ignited” element coded with 

upholstered furniture for the 2006-2010 timeframe to obtain annual estimates revealed that 6700 structure 

fires (2 %) were responsible for 480 civilian deaths (19 %), 840 civilian injuries (7 %), and 427 million 

dollars in property losses (6 %). These values were adjusted statistically using the NFPA survey of fire 

departments. Values in parentheses are percentages of total losses in residences. These percentages are 

similar to those cited earlier based on CPSC analysis, with the exception that the percentage of property 

losses attributed to this type of fire is 50 % higher.

When “type of material first ignited” (NFIRS–2 (D4)) was considered, the code “fabric made of cotton, 

blend, rayon or wool” was cited in 72 % of fires and 76 % of fire deaths. An additional 14 % of fires and 

15 % of deaths were attributed to “unknown fabric”. The code “Plastic-coated fabric. Includes plastic 

upholstery fabric and other vinyl fabrics” was only chosen in 2 % of fires and was associated with 2 % of 

deaths. These results were questioned by a member of the audience since many upholstery fabrics 

contain large fractions of polyolefin or polyester thermoplastics. The answer provided was that 

firefighters filling out the form would be unlikely to be able to distinguish between the various types of 

upholstery fabrics.

The question of how upholstered furniture is being ignited was considered by combining the elements on 

“item first ignited” (NFIRS–2 (D3)) with “heat source” (NFIRS–2 (D2)). Statistics indicate that 28 % of 

these fires and 58 % of the associated deaths are attributed to lighted tobacco products. A wide range of 

other heat sources make up the remainder, with any given type representing a fraction of 10 % or less.

Primary elements related to fire growth are “item first ignited” (NFIRS–2 (D3)), which includes a check 

box for cases where spread “was confined to object of origin,” and “fire spread” (NFIRS–3 (J2)), which 

provides an indication of the farthest extent of fire spread. Recorded fires that were “confined to object of 

origin” represented 24 % of reported fires and were responsible for 6 % of deaths. Fires that were 

“confined to the room of origin,” but not to the “object of origin,” contributed 34 % of fires and 25 % of 

fire deaths. For fires in which fire spread (NFIRS–3 (J2)) extended beyond the room of origin (either 

coded as “confined to floor of origin,” “confined to building of origin,” or “beyond building of origin”), 

the corresponding values were 42 % and 69 %, respectively. Note that the latter type of fire is viewed as 

the best indictor that flashover took place during a fire. The important role of flashover is evident in that 

it occurred in less than one-half of the reported fires, but was responsible for over two-thirds of fire 

deaths.

The question of the contribution of RUF to fire growth was discussed in terms of the “item contributing 

most to flame spread” (NFIRS–3 (K1)), even though no specific values were provided. It was noted that 

fire growth and flame spread do not necessarily refer to the same fire behavior. It was concluded that 

while the “fire spread” element may not represent an adequate surrogate for cases where RUF is the 

primary second item burning, it is the best element available in NFIRS that can provide some information 

with regard to this important topic.
10

Cross referencing the elements for cases where RUF was the “item first ignited” (NFIRS–2 (D3)) with 

cases where fires extended beyond the room of origin (NFIRS–3 (J2)) showed that 60 % of these fires 

started on RUF and were responsible for 72 % of the deaths outside of the room. A wide range of items,

with none representing more than 6 % of the total, made up the remainder of the items first ignited.

There are a number of relevant properties concerning the burning behavior of RUF that cannot be 

estimated using only data collected by NFIRS. These include:

• Details of the type and composition of RUF present in residences.

• Location of ignition points on RUF.

• High-fidelity estimates of fires where RUF is the primary source of heat release, but is not the 

item first ignited.

• Detailed scenarios that show when upholstered furniture is ignited and how important it is to the 

course of the fire.

Given the limitations of NFIRS data in providing as detailed picture of how RUF burns as desired, a 

number of potential approaches for increasing the amount of information available were considered. The 

first was to modify NFIRS to improve the depth of information relevant to RUF burning behavior 

collected. This approach was viewed as unrealistic due to the increased data collection burden and the 

lack of resources available for collecting such data. The use of other potential sources of data, such as 

detailed investigations and court cases, is limited because they are almost certainly non-representative and 

non-statistical.

In the past, the NFIRS Special Study option has been used locally when additional information was 

required about particular aspects of fires. In such studies, one or more fire departments voluntarily collect 

focused information over a finite time period. NFIRS 5.0 has additional special study fields, although no 

National studies have been conducted using this feature due to limitations of some commercial software 

programs that may not contain this feature. CPSC has conducted studies in the past by asking fire 

departments to alert their investigators anytime a fire occurred with a particular heat source, 

equipment involved in ignition, or item first ignited. The workshop participants viewed a special 

study as a viable approach to obtain statistically valid data concerning RUF fire behavior.

Another potentially useful option is to construct probabilistic models incorporating knowledge about the 

prevalence and types of RUF in residences combined with models of fire behavior. Such models could 

provide insights concerning the contribution of RUF to fire losses.

The following provides a summary of the implications of this presentation for the workshop topic.

• For fires that spread beyond the room of origin, RUF serving as a secondary fuel package 

appeared to increase the number of fires in which RUF played a critical role by 69 %, as 

compared to only considering cases in which RUF was identified as the item first ignited.

• The number of fire deaths was apparently increased by 39 % compared to cases where RUF was 

only considered as the item first ignited.

• The above does not consider unclassified furniture. If the majority of such cases actually

involved RUF, the increase in RUF contribution drops to 52 % for number of fires and 36 % for 

deaths.

• For fires with burning confined to the room but beyond the object of origin, secondary ignitions 

of RUF add 48 % to the number of fires and 31 % to deaths, not including unclassified furniture.

In more layman terms:

• Secondary ignitions of RUF add significantly to the number of fires and losses as compared to 

cases when RUF is recognized as the item first ignited.
11

• The quantitative increase in losses is currently subject to a fair degree of uncertainty.

• The uncertainty might be reduced through additional analysis and probabilistic modeling.

Several questions and comments were made in conjunction with this presentation. One participant

wondered for cases in which RUF was a major factor in a fire loss, but was not the “item first ignited,”

how likely was it to be identified as the “item contributing most to flame spread?” The speaker did not 

have an opinion. It was suggested that the cost of answering this question would likely be prohibitive.

The speaker was asked whether it was possible to determine the degree of human and property losses 

associated with fires that did not transition to flaming, e.g., ignition of a smoldering fire in RUF by a 

cigarette. The answer was that fire losses associated with this type of fire are very low percentages of the 

total losses. There was general agreement among the participants that this was the case. The implication 

of this conclusion is that fires that initiate as smoldering fires should be included in the totals of fires 

where flaming RUF plays an important role in fire losses.

The question concerning how well the fabrics identified as a “type of material first ignited” captured the 

actual type of fabrics involved was discussed further. The general consensus was that there is not likely 

to be useful information to identify the actual type of fabric (e.g., cellulosic, thermoplastic, leather, etc.) 

being coded.

A participant asked whether it is possible to identify whether a RUF item was only damaged or 

completely destroyed. The answer was that NFIRS does not provide this level of detail.

4.7. David Butry, NIST

This presentation discussed the use of NFIRS for performing economic analyses. A brief introduction to 

the economic theory of minimizing the sum of costs of protection and losses was provided. This analysis 

allows the most efficient amount of protection to be provided as long as the dependence of losses on the 

amount of protection is known. For any economic analysis dealing with fire, data on cost and losses are 

required.

The presenter provided a short introduction to the NFIRS system, before describing how such data can be 

used in economic analysis related to fire. NFIRS data can be used to measure the components of fire risk 

e.g., likelihood of fires, death, injuries and property losses, to understand factors related to ignition, e.g, 

item first ignited, and to understand factors related to losses, e.g., presence of smoke alarms. Information 

related to costs of fire protection and mitigation is more limited in NFIRS.

An example of a NIST economic analysis related to fire was provided. The goal was to describe the 

effectiveness of sprinklers in reducing fire deaths in single- and two-family homes and to convert the 

results to economic savings. A significant challenge was to isolate the effectiveness of sprinklers from 

confounders such as smoke alarm technology, distance to fire department, structure age, family income, 

family ages, etc. NFIRS fire incidence data was used to control for differences between sprinklered and 

non-sprinklered residences. It was demonstrated that sprinklers reduced fire deaths and associated 

property losses after confounding influences such as the presence or absence of smoke detectors and 

housing and family differences were accounted for.

The topic of RUF and NIFRS was considered next. The two items in the NFIRS fire module, “item first 

ignited” (NFIRS–2 (D3)) and “item contributing most to flame spread” (NFIRS–3 (K1)) refer directly to 

RUF. The second tracking item is considered only when the associated box indicating “check only if no 

flame spread OR if same material first ignited OR if unable to determine” is not checked. The “item first 

ignited” was reported 91 % of the time for reported non-confined residential fires during the 2002-2009 
12

time frame. During this period, RUF was listed as the “item first ignited” 2 % of the time. “Item 

contributing most to flame spread” is not a required field and was completed for only 28 % of reported 

fires. Even with these limitations, RUF was identified on this item for 1 % of reported fires. This would 

seem to suggest that, at a minimum, RUF as a second or later item ignited made a significant contribution 

to fire growth in roughly half as many fires as when it was the “item first ignited.” Data for individual 

years indicated that this ratio remained roughly constant over the 2002-2009 time period.

Several questions were raised concerning how to interpret the data supplied by NFIRS. These include:

• Do “Item First Ignited” and “Item Contributing Most to Flame Spread” account for all (most) of 

the fires involving RUF?

– Do other ways exist to identify fires involving RUF?

• Is it difficult to determine if RUF was involved?

– Is under-reporting likely?

• Are fires that spread beyond the room of origin ‘special’ or ‘different’ than those that don’t?

– Are there factors that affect both flame spread and the likelihood RUF is involved?

– Are ‘bad’ fires more likely to contain an “Item Contributing Most to Flame Spread”?

The potential for performing economic analyses related to fires involving RUF was considered. One 

approach would be to simply report the number of fires and losses (deaths, injuries, property) where RUF 

was identified as having a major role. This approach has the advantage that it is straightforward to 

accomplish, but ignores the potential for the confounding effects of other factors. A second approach 

would be to develop statistical approaches which could account for confounding effects, thus establishing

causal effects and providing a better understanding of RUF risks. Two downsides of this approach are

that a researcher would need to develop a baseline for comparison, and the outcome would not directly 

provide national estimates.

During the follow-up questions a member of the audience pointed out that the initial economic model 

discussed can be very sensitive as to how it is mathematically described. There was also a question 

concerning whether or not society generally seeks to balance sum of costs of protection and losses, or if 

other factors may come into play. The speaker agreed that both of these questions would have to be 

addressed in any future economic modeling.

5. Open Forum Discussion

An open forum discussion involving all workshop attendees took place during the afternoon of the first 

day of the workshop. The series of questions included in the agenda (see Appendix C) were used to 

provide a framework for the discussion. Facilitators led the discussions. The following summarizes the 

major topics discussed and conclusions and suggestions that were made during the open forum.

5.1. Would decreasing the rate of fire growth and heat release in an 

enclosure significantly reduce residential fire losses within the room of 

fire origin? (Facilitator: Jason Averill)

Dan Gottuk of Hughes Associates asked the question, “What is significant?” The general consensus was 

that the answer depends on the amount of fire losses associated with this type of fire. Various statistics 

described above suggest a large fraction of losses occur in fires which are confined to a single room. It 

seems reasonable to expect that reducing the rates of fire growth and heat release would reduce these 

losses in a meaningful way.

John Hall of NFPA noted that NFIRS contains very little information about fire spread and growth within 

the room of origin. The data element “Item First Ignited” (NFIRS–2 (D3)) indicates where initial fire 

development occurred, but there is little beyond this. The check box associated with “Type of material 
13

contributing most to flame spread” can provide an indication that a fire was localized to the item first 

ignited, but it can also mean that the item contributing the most to flame spread was the initial item 

ignited or that it was not possible to identify the material contributing most to flame spread. The next 

indication of fire spread and growth does not occur until the fire leaves the room of origin as identified in 

“Fire Spread” (NFIRS–3 (J2)). Reported property losses provide little additional detail about losses 

inside the room of origin. Additional information that might aid in assessing the answer to this question 

includes condition, activities, and proximity of people injured in such fires. Again, such information is 

unavailable. The lack of relevant information means that NFIRS provides little direct help in answering 

the posed question. It was suggested that engineering analysis combined with sensitivity analysis, of the 

type discussed during John Hall’s presentation, might provide some insight.

NFPA has released a report by Marty Ahrens entitled Home Fires that Began with Upholstered Furniture

[19] which summarizes much of the NFIRS data related to fires involving RUF based on data from 2005 

to 2009. Examples of information from this report include analyses indicating 18 % of the deaths 

involved people impaired by alcohol and/or drugs (Fig. 6 in report) and that around half of victims 

associated with fires started by smoking materials were found in the vicinity of the RUF (Fig. 14 in 

report). She noted that several types of information that could aid analyses of this type, such as at-risk 

populations, physical vulnerabilities of victims, and ignition behaviors of the RUF, are not available.

There was a wide ranging discussion of the effects of room characteristics on the recorded statistics. 

Recall that earlier experiments suggested that development of flashover with RUF burning seemed to 

depend on room size. Actual room sizes in residences can vary substantially. Think in terms of studio 

apartments compared with large living room and bedrooms in detached homes. No indication of such 

variations is available in NFIRS beyond type of residence. There are also uncertainties in how rooms 

may be coded. Many modern homes have large connected areas that can contain a kitchen, dining room, 

and living room, hallway, etc. These areas are essentially one single large room. Such areas are not 

distinguished from compartmented rooms.

The presence of medical oxygen was identified as another type of confounding variable. The role of 

oxygen in accelerating fires and contributing to losses is not generally captured in NFIRS. The consensus 

was that its contribution is likely underestimated and increasing over time.

It is clear that a great deal of information that could be useful in understanding fire spread and growth in a 

room containing RUF is not captured by NFIRS. One approach for obtaining this information would be 

through the special study option of NFIRS discussed earlier by John Hall. Marty Ahrens suggested that a 

one page check-box questionnaire that was carefully designed with five to ten simple questions would be 

appropriate. Sean DeCrane of the Cleveland Fire Department indicated that they frequently see fires 

involving RUF that are limited to a single room. Such fires had been responsible for several close calls 

during the past year. He believes that his department would be happy to participate in such a focused 

study. John Hall indicated that a study of this type could be performed over a period of roughly one year 

in cooperation with fire departments that were willing to participate. The selection of participating fire 

departments and the design of the research questions would need to be done carefully to ensure that the 

number of responses to a given question would be on the order of the hundreds required to provide 

meaningful statistics.

Several questions were raised above as to how specific NFIRS items are coded in the field. These 

questions included: What is coded as “Upholstered sofa, chair, vehicle seats” in “Item First Ignited”

(NFIRS–2 (D3)) and “Item Contributing Most to Flame Spread” (NFIRS–3 (K1))? What is coded as 

“Furniture, utensils, other” in “Item First Ignited” (NFIRS–2 (D3))? Are fires ignited on coverings or 

pillows coded as RUF or something else? How is “Area of fire origin” coded when there are multi-use 

areas connected together? What fabrics are really present when coded as “Fabric, fiber, cotton, blends, 
14

rayon, wool, finished goods. Includes yarn and canvas. Excludes fur and silk” or “Plastic-coated fabric. 

Includes plastic upholstery fabric and other vinyl fabrics.” in the “Type of material first ignited”

(NFIRS–2 (D4))? These questions introduce the possibility of uncertainties in the statistical values 

derived from the NFIRS database.

An approach for reducing these uncertainties was discussed. It involved showing groups of fire 

investigators pictures of fire scenes and asking them to assign codes to specified questions based on what 

they observe. Such a survey might be done informally at assemblies of investigators by projecting the 

pictures and asking for a show of hands or more formally utilizing an internet survey. It was pointed out 

that such studies would not only provide important information for reducing uncertainties in fire statistics

related to RUF, but would also prove valuable to developers of the next generation of NFIRS

(Version 6.0).

5.2. Would decreasing the rate of fire growth and heat release in an 

enclosure significantly reduce residential fire losses at locations 

substantially removed from the room of fire origin? (Facilitator: Richard 

Gann)

It was pointed out that more than half of fire deaths and economic losses are associated with fires coded 

as extending beyond the room of origin in the “Fire spread” (NFIRS–3 (J2)) item.

Marty Ahrens noted that the earlier discussion concerning open areas is relevant for this question as well.

The point was raised that, as written, the subject question does not provide an indication of whether the 

extended space was sealed or not. This was viewed as having an important influence on the development 

of untenable conditions.

Dick Gann raised the question of whether or not it was possible to develop untenable conditions outside 

the room of origin without involvement of RUF in the fire. There was no consensus concerning an 

answer.

The current version of NFIRS provides little information on the relationship of victim proximity to a fire

and the likelihood of death or injury. Older data does provide some information.

The importance of fire growth rate was noted by Sean DeCrane. He noted that for a rapidly growing fire 

on the first floor of a multistory residence, very little time would be available for people on higher floors 

to escape. In this context, the findings of the most recent study at UL were reviewed. Tom Fabian 

reported that times to untenable conditions were increased from five minutes for fires involving 

contemporary furniture to 25 minutes when a fire barrier was added to the contemporary furniture. The 

importance of early detection in both scenarios was again noted.

John Hall noted that the discussion was pointing towards the value of scenario based modeling in 

understanding the role of RUF in fire losses. Marc Janssens added that appropriate modeling could 

greatly expand the database available for describing these types of fires.

Dick Gann suggested that a good data question for a special study would be aimed at determining how 

often firefighters find items of RUF still flaming when they arrive at residential fires.

Tom Fabian reiterated that the recent UL study completed in January considered tenability time at 

locations outside of the room and included soft furnishings in the fire loads.
15

Jason Averill briefly discussed a recent study on “Residential Fireground Field Experiments” which 

considered the effects of firefighter crew size on multiple measures of firefighter effectiveness. [20] This 

study found that 12 min to 13 min were required between the time of a 911 call and when water was 

applied to a fire. This time is comparable to the time for a slowly developing fire to reach flashover, but 

is much longer than the times reported above for RUF-fueled fires to develop untenable conditions. It 

should be mentioned that when rooms including upholstered furniture fires were burned as part of this

study, measured times to untenable conditions inside the fire room varied from roughly 150 s. to 250 s.

Sean DeCrane emphasized the need to consider the burning behavior of multiple items. He again pointed 

out the short amount of time available for firefighters to reach a residence before conditions become 

untenable outside the room of fire origin.

Tom Fabian returned to the subject of rapid fire development inside the enclosure by noting that only a 

small fraction of upholstered items have natural fiber fabrics. This implies that ignition by small open 

flames is relatively simple. Fast fire growth will follow.

The question was raised of whether or not the degree of ventilation plays a role in fire growth. The group 

was unable to answer the question. John Hall thought that it was possible. Dick Gann pointed out that no 

information on ventilation in real fires is available. He noted that the discussion was related to the earlier 

discussion on what defines a room.

John Hall summarized the discussion by noting that it provided additional justification of the need for a 

focused special study on the characteristics of flaming RUF fires.

5.3. What are the relevant characteristics of residential fires involving 

flaming RUF contributing to fire losses? (Facilitator: Jason Averill)

Jason Averill began the discussion by asking this question: Do people in a room of fire origin die from 

burns and people outside the room of fire origin die from smoke inhalation? John Hall replied that the 

statistics cannot be broken down this way. Some additional analysis, perhaps a special study would be 

needed to address this question.

This led to a discussion of smoldering versus flaming. Again, it appears to be impossible to differentiate 

with current information available in NFIRS. Dan Gottuk reiterated that the majority of fire losses are

associated with flaming fires.

At this point, John Hall suggested a change in terminology from “smoldering” versus “flaming” to 

“prevention” versus “mitigation.” The latter terms are based on current and possible future approaches 

for limiting fire losses. Current and proposed regulations for RUF are aimed primarily at preventing 

smoldering ignition. Future attempts to reduce the fire spread rate and maximum heat release rate of 

flaming RUF would be an example of mitigation once a fire was ignited.

Jason Averill pointed out that rapid fire development not only has implications for people in the 

residence, but also the firefighters who respond to the fire. Sean DeCrane seconded this by noting that the 

firefighters on the fire ground most often lose their lives as the result of cardiovascular problems or 

trauma associated with the fire. The probabilities of both types of event increase with fire size. He noted 

that a rapidly developing fire has ripple effects that increase the chances for firefighter losses.
16

5.4. Is flaming RUF likely playing a significant role in residential fire losses? 

(Facilitator: Richard Gann)

The discussion returned to the role of RUF in residential fire losses. Tom Fabian emphasized that RUF 

has always played a large role in fire losses and continues to do so. John Hall, based on his experience 

and discussions during the workshop, concluded that RUF as a second item ignited contributes to fire 

losses in meaningful way. Jason Averill questioned whether we are capturing its effect fully. The general 

answer was yes, but with caveats. Marty Ahrens noted that RUF is the most important “Item first 

ignited” in residential fire deaths. She feels that values currently derived from NFIRS may be 

underestimated.

5.5. Is it appropriate to differentiate fire losses inside and exterior to the 

room of fire origin with regard to the role of RUF in Residential Fire 

Losses? (Facilitator: Jason Averill)

Directly addressing the question posed, John Hall stated that it is possible to differentiate inside and 

outside the room of fire origin and that it is important to do so. He emphasized the point made earlier that 

it is more difficult to isolate the role of burning RUF inside a room due to the lack of data elements in 

NFIRS that capture fire behaviors between the ignition of “item first ignited” and fires which propagate 

beyond the room of origin. He once again noted that earlier versions of NFIRS included elements which 

could help address this limitation.

Marty Ahrens pointed out the need for the “Total square feet” (NFIRS–3 (I4)) to be filled out. It 

frequently is not. This value would be useful in determining the relative roles of fires inside and outside 

the room of origin on fire losses.

Dick Gann recommended that fire losses inside and outside the room of fire origin continue to be 

differentiated. John Hall agreed, but emphasized the need for different approaches to better understand 

what takes place inside the room of fire origin. An NFIRS special study is one example of such an 

approach.

Sean DeCrane emphasized the need to understand what is meant when a fire is coded as having moved

beyond the room of fire origin. He feels that there may be some ambiguity in NFIRS coding. The group 

recognized this as another question to be explored using the approach of polling NFIRS responders

discussed earlier.

Dick Gann pointed out that there is an extensive database of fire measurements inside rooms including 

such parameters as temperatures, toxic gas concentrations, and radiant heat fluxes. It should be possible 

to get a good idea of tenability criteria using these measurements. John Hall noted that the presence of 

people is crucial to such analyses. Once appropriate models are developed, their outputs can be compared 

with the existing statistics in order to determine how accurately they are capturing real-world 

observations.

Marc Janssens noted that the recent experimental series at SwRI had generated data for 85 room fires 

spanning heat release rates from 100 kW to 3 MW. These should provide an ideal database to serve as 

the basis for a study of the type suggested above. Dick Gann added that he did not think many people 

would be left inside a room by the time a fire had reached the 100 kW level.

John Hall asked what would be the technical feasibility of carrying out such a study and would it help 

improve the understanding of the role of RUF in fire losses. He answered his own question in the 

affirmative by noting the importance of the type of fires under discussion. He felt that the modeling 

approach provided a viable way forward.
17

5.6. Do existing fire statistics and related analyses effectively capture 

contribution of flaming RUF to residential fire losses?

John Hall started the discussion by indicating the answer to the question is “no.” Tom Fabian asked if it 

was possible to provide a positive answer using existing NFIRS data. The answer was yes, with a caveat. 

With the existing data it is necessary to integrate over the less severe fires that do not emerge from the 

origin of fire room.

The discussion at this point returned to prevention versus mitigation. Mitigation refers to actions that 

address fires that were not prevented. Characterizing fires in this way is consistent with the way the 

Center for Disease Control characterizes hazards.

Dan Gottuk reiterated that flaming combustion is primarily responsible for the hazard of residential fires. 

Significant fire losses due to a smoldering fire alone require extraordinary circumstances. John Hall 

raised the counterpoint that an extended smoldering period can cause a build-up of toxic products in the 

vicinity of the fire so that when the fire transitions to flaming, the time required for untenable conditions 

to develop, near or far from the fire, will be reduced. Tom Fabian also noted that higher levels of carbon 

monoxide and cyanide per unit mass loss are generated during smoldering combustion. Note that mass 

loss rates for smoldering fires are generally orders of magnitude lower than those for flaming fires.

5.7. Can existing fire statistics and extended analyses better capture 

contributions of flaming RUF to residential fire losses?

John Hall indicated that the answer to this question is “yes,” but with reservations. Teasing out the role of 

flaming combustion will require extended approaches for analyzing the existing NFIRS data and an 

improved understanding of what is actually being captured in the existing data. The type of study 

suggested earlier in which the personnel actually generating NFIRS data are polled to better understand 

how various items are being coded is an example of the latter.

At this point, John Hall suggested a specific approach for analyzing NFIRS data designed to isolate the 

contribution of flaming RUF to fire losses. He proposed that a series of 2 × 2 matrices be used to assess 

the contribution of RUF to the various types of fire loss (deaths (NFIRS–4 (C,H)), injuries (NFIRS–4 

(C,H)), and property (NFIRS–1, (G2)) for fires “confined to room of origin” and fires which spread 

beyond the room of origin, (NFIRS–3 (J2)). An example of such a matrix is shown below:

Nyy, Nyn, Nny, and Nnn represent the amounts of losses due to fires matching (y subscript) and not 
18

matching (n subscript) each cell’s criteria. The matrices isolate losses where both conditions were true 

(Nyy), one condition was true (Nyn and Nny) and neither condition was met (Nnn).

The total amount of losses where RUF was a primary contributor for a given type of fire loss will equal 

Nyy + Nyn + Nny, while the amount of losses in fires where RUF contributed most to flame spread but was 

not identified as the first item ignited will equal Nny. Summing together the results for fires isolated to 

and those spreading beyond the room of fire origin will provide the total losses associated with flaming 

RUF.

At this point, the discussion turned back to the potential for reducing fire losses once the actual 

contribution of flaming RUF to fire losses was quantified. The question was asked whether quantifying 

the contribution of RUF was sufficient along with the rhetorical question of whether it would not be better 

to just eliminate RUF as an issue. The answer was that in the absence of a realistic analysis of the actual 

contribution of RUF, it is not possible to estimate the effectiveness of various mitigation approaches for 

reducing fire losses.

Based on the presentations and discussions, the workshop participants agreed that limiting the 

development of flaming RUF fires provides the greatest opportunity for further reducing the nation’s fire 

losses. In addition to the current losses associated with RUF as the “item first ignited,” a significant 

fraction of current losses occur when RUF is the second (or higher) item ignited. For the particular case 

of residential fire deaths, participants estimated the annual numbers attributable to RUF as second item 

ignited would turn out to be in the 100s. Dan Gottuk asked how flaming RUF stacks up compared to 

mattresses, for which flaming behavior has now been regulated. John Hall answered that first- and 

second-item ignitions of RUF contribute to a comparable or larger fraction of fire losses as mattresses and 

bedding.

6. Summary of Presentations and Discussions and Identification of Approaches 

and Participants for Estimating Role of Flaming RUF in Fire Losses

The purpose of the final session of the workshop on the morning of the second day was to develop 

recommendations for estimating the total contribution of flaming RUF to fire losses and identifying 

potential organizations to perform the studies.

6.1. Summary of Major Findings

The session was opened by William Pitts, who presented a short summary of major points that were 

identified from the presentations and discussions on the first day. The slides used for this summary are 

included in Appendix F. The following conclusions are based on these slides with some additional points

added:

• Recent studies confirm the potential for rapid flaming fire growth on RUF to cause significant 

fire losses in residences.

• Statistics show that fires involving RUF are many times more likely to result in property loss, 

injury, and particularly fatalities than expected based simply on their percentage of all fires.

• Times required for RUF-fueled fires to grow to dangerous levels are shorter than or on the same 

order as those required for fire departments to be notified and respond (implications for both 

human and property losses and fire fighter safety).

• Consensus that losses due to smoldering-only RUF fires are small and nearly negligible (losses 

occur following transition to flaming).

• Statistics suggest that flaming ignition of RUF occurs in a number of ways that in total represent 

a significant but not dominant source of fire losses involving RUF.

• Direct measures are not available describing RUF as a second (or higher) item ignited, but there 

may be approaches for estimating losses due to such burning.
19

• There is justification for breaking down statistics into losses inside the room of fire origin and 

outside the room of fire origin.

• Statistics describing the role of RUF inside the room of fire origin are somewhat limited due to a 

lack of information concerning fire growth within the room (events between ignition and fire 

leaving the room are not well captured by NFIRS).

• Statistics concerning the role of RUF on losses external to the room of fire origin appear to have a 

firm foundation.

• An analysis estimating the total contribution of RUF to fire losses utilizing the existing NFIRS 

database was suggested utilizing the matrix approach discussed on p. 16.

• Approaches for filling in some data gaps and uncertainties in NFIRS data were suggested.

• Informal questioning of people filling out NFIRS form to clarify how coding is being 

performed in the field.

• Targeted NFIRS special study using a one page data sheet.

• Probabilistic modeling of fire spread and growth in rooms based on fire experiments using 

existing fire models offers an approach for better understanding the role of RUF in fire losses.

• There is a continuing need for estimates of the numbers and characteristics (etc., fabric, 

polyurethane foam, fiber fill, barrier fabrics) of RUF items currently in residences.

• “Prevention” versus “mitigation” provides an alternate framework for discussing the contribution 

of RUF to fire losses.

6.2. Recommendations

As mentioned earlier, even though the workshop schedule (Appendix C) called for a systematic 

discussion building towards formulation of approaches for quantifying the full contribution of flaming 

fires of RUF to the nation’s fire losses, the participants felt that sufficient progress had been made during 

the first day such that only a shortened single discussion was necessary in order to formulate 

recommendations. John Hall of NFPA acted as the facilitator for this session.

The final recommendations of the workshop participants closely follow suggestions made during the 

presentations and open forum discussions.

1) Estimate fire losses (deaths, injuries, and property) utilizing the matrix approach discussed 

on p. 16.

The first recommendation is to use the NFIRS database to provide estimates for the annual fire deaths, 

injuries, and property losses in residential fires where flaming RUF played a crucial role as identified by 

its NFIRS coding as “Item first ignited” (NFIRS–2, (D3)) and/or “Item contributing most to flame spread” 

(NFIRS–3, (K1)). This analysis will be accomplished using the matrix approach described on p. 16. 

Careful attention will be paid to cases where the box in element K of NFIRS–3 is checked, since this 

element has the potential to introduce uncertainty into the analysis. The analysis will be repeated for 

various “Area of fire origin” (NFIRS–2, (D1)) and cases where fires are “Confined to room of origin” 

(NFIRS–3 (J2-2)) and where fires spread beyond the room of origin (NFIRS–3 (J2-3, 4, or 5)).

Summation over all of the elements will provide overall estimates for fire losses where flaming RUF

played a pivotal role. Considering individual classes will allow statistics to be broken out in terms of 

initial ignition condition (smoldering versus flaming), role of flashover (losses in room of origin versus 

losses outside of room) and location of the RUF.

Implementation of this recommendation was viewed by the practitioners as being relatively 

straightforward and as falling within their current duties. Researchers from NFPA and USFA committed 
20

to performing these analyses shortly after this report becomes available. Researchers at CPSC and NIST 

have expertise in this area and could effectively contribute to a joint effort.

From the presentations and discussions, it became evident that while completion of Recommendation 1) 

will provide much improved estimates for the contribution of flaming RUF to fire losses, the values will

still be subject to significant uncertainties due to questions as to how the relevant NFIRS items are being 

coded in the field and limitations based on the specific information that is collected by NFIRS.

Three approaches were recommended to reduce these uncertainties. The first is designed to address 

questions that arose as to how certain NFIRS items are coded by surveyors in the field.

2) Survey groups of people responsible for coding NFIRS forms to determine how items are 

coded when presented with pictures or descriptions of various conditions. 

This information will be utilized to better understand what the NFIRS responses of field practitioners 

actually represent. The surveys could range from questioning of groups at appropriate meetings to more 

formal internet surveys based on email lists of people known to fill out NFIRS forms and participants in 

training classes at the National Fire Academy.

A number of items and responses were suggested for examination. These include:

• How are large open areas encompassing multiple uses coded? (NFIRS–2 (D1), NFIRS–3 (I4))?

• What types of areas are coded as “function area, other” (Item 20)? (NFIRS–2 (D1), NFIRS–4 

(M5))?

• What range of items are identified as being “upholstered furniture” (Item 21)? (NFIRS–2 (D3), 

NFIRS–3 (K1))?

• What types of furniture are coded as “furniture, utensils, other” (Item 20)? (NFIRS–2 (D3), 

NFIRS–3 (K1))?

• How are upholstery fabrics being coded for a variety of types (Items 70 to 77)? (NFIRS–2 (D4), 

NFIRS–3 (K2))?

• What conditions result in the associated box for NFIRS–3 (K) being checked?

• Are fires where coverings/pillows are responsible for “Item first ignited” (NFIRS–2 (D3)) or 

“Item contributing most of flame spread” (NFIRS–3 (K1)) coded as “upholstered furniture 

(Item 21) or something else?

• What observations do coders use to determine that a fire has moved beyond the room of origin?

• Do respondents “observe” or “infer”?

• How often do respondents complete NFIRS forms?

Surveys of this type will not only serve to reduce uncertainties in estimates of fire losses due to RUF in 

residences, but will also provide valuable feedback to the NFIRS development team with regard to the 

current questionnaire (Version 5) as well as guidance for the development of Version 6.

Participants recognized that organizing a study of this type would represent a major undertaking requiring 

institutional support, significant time and financial resources, and cooperation among a variety of 

organizations. It was evident that such an undertaking requires additional planning and coordination 

between potential participating organizations. It is recommended that planning for a study of this type be 

started as soon as possible. Potential participants include NIST, NFPA, USFA, and CPSC, as well as 

organizations that can aid in identifying and obtaining cooperation of NFIRS coders to participate in the 

survey.

3) Organize an NFIRS Special Study Focused on RUF Fire Behavior in Room of Fire Origin
21

The second approach for reducing uncertainties in fire loss estimates is to utilize the NFIRS provision for 

special studies designed to address specific questions concerning fires recorded by the survey. The 

participants recommended that such a special study be designed and carried out to better understand the 

role of flaming RUF in the room of fire origin. As discussed earlier, the existing NFIRS database

provides few insights concerning fire behavior between the time an item is ignited inside a room and the 

fire spreads beyond the room of origin.

It was suggested that a single page containing five to ten carefully formulated questions be developed for 

incorporation into the NFIRS questionnaire. This additional page would ask for observations aimed at 

developing a better understanding of flaming RUF behavior during residential fires. Potential points that 

could be addressed by the special study include:

• Specific details concerning RUF, e.g., pillow and coverings, type of upholstery fabric, size, 

general configuration.

• Did flaming RUF occur?

• Area of RUF burning when fire department arrived.

• Area of RUF burned when fire was extinguished.

• Where was RUF ignited?

• Were there signs of flashover in the room?

• What were the ventilation conditions in the room of origin?

• If fires were fatal, were deaths due to burns or smoke inhalation (broken out by inside and outside 

of room of fire origin)?

The participants felt that a one-year period would be sufficient for the study, assuming the active 

participation of a sufficient number of fire departments to ensure statistically meaningful samples.

The development and performance of an NFIRS Special Study is a major undertaking. As for the more 

informal survey discussed above, a great deal of planning and cooperation between multiple organizations 

would be required. The questionnaire must be developed carefully and tested prior to the study. Due to 

the extra burden and training associated with a Special Study, a premium is placed on identifying fire 

departments willing to participate in the study. The workshop participants recognized the large 

commitment of organizational resources would be required to make such an effort successful. 

Nonetheless, the participants strongly recommended that a Special Study be organized because of the 

unique opportunity it offers to advance the understanding of the role of flaming RUF in fire losses. 

Participants noted that CPSC has extensive experience in organizing NFIRS Special Studies. Additonal

organizations that could make invaluable contributions include USFA, NFPA, NIST, the International 

Association of Fire Fighters, and the International Association of Fire Chiefs.

4) Probabilistic Modeling of RUF Room Fires Incorporating Experimental Observations

The third approach identified for limiting uncertainties associated with estimates of fire losses due to 

flaming RUF is to combine existing model(s) of fire behavior with experimental results for the burning 

behaviors of RUF to investigate the role of RUF in fire spread and growth and the development of 

untenable conditions. This approach is designed to better understand the burning behavior of RUF inside 

a room of fire origin as well as the likelihood of fire spread beyond the room of origin.

Using this modeling approach, it would be possible to study the importance of key parameters over a wide 

range. These parameters include such intrinsic RUF properties as fire growth rate and maximum heat 

release rate. Properties related to the room of fire origin such as dimensions, volume, other contents, and 

ventilation conditions will also be varied parametrically. Some fire models include the capability to ignite 
22

nearby items, thus it will be possible to investigate the role of RUF in igniting nearby items as well as fire 

spread to RUF from nearby burning items.

This type of modeling requires an extensive database of flaming RUF to serve as inputs. The recent 

studies from UL, SwRI, and NIST described in this report along with earlier published studies can serve

as the basis for such a database. All three organizations are committed to making their experimental 

findings available to the research community.

The modeling effort necessary to understand the behavior of RUF in residential fires is likely to require 

an extended period and involve strong interactions between experimentalist and modelers. Prior to the 

workshop, NIST researchers had in place a plan for a scoping study designed to investigate the potential 

of the CFAST software [18] to provide a better understanding of the contribution of RUF to fire losses. 

This study will be carried out during the next few months. It should provide a good indication of what 

progress can be expected using this approach.

7. Final Comments

The objective of the workshop, to identify approaches for quantifying the full contribution of flaming 

fires of modern RUF to the nation’s fire losses, was met. When the approach outlined above is fully 

implemented, it will provide a vastly improved quantification of the role of RUF in residential fire losses. 

The data generated by the study would also provide valuable input to the developers of NFIRS.

Research discussed during the workshop reinforced the widely held perception that the potential for rapid 

flaming fire spread and growth on RUF is likely playing a large role in current fire losses in residences

and is likely the largest single factor for fire fatalities. Statistics showing the unusually high number of 

fire deaths associated with fires starting in rooms typically containing RUF and the high losses in fires 

where RUF is cited as the “Initial item ignited” and/or the “Item contributing most to flame spread,” when 

combined with experiments showing the rapid fire spread and growth possible on contemporary RUF 

provide strong evidence for the important role of RUF. The implications for civilian and firefighters 

losses are evident.

8. Analysis of Losses in Fires for which RUF is Identified as the Primary 

Contributor to Fire Spread but not as the First Item Ignited

Subsequent to and in direct response to this Workshop, John Hall of the National Fire Protection 

Association performed an analysis based on the approach outlined as Recommendation 1) in Section 6.2. 

The results of this analysis were communicated to the workshop organizer in the form of a written action 

item report on September 12, 2012. This report is incorporated into this revised workshop proceedings as 

Appendix G.

The author found that losses associated with fires in which RUF was identified in NFIRS as the “item 

contributing most to flame spread” but not as the item first ignited resulted in a “one-third addition to 

the fires, injuries and damages associated with fires beginning with ignition of upholstered 

furniture, as well as a one-quarter addition to the deaths.”

When combined with the losses associated with direct flaming ignition of RUF, these findings suggest 

that flaming ignition of RUF (as either the first or subsequent item ignited) is responsible for roughly one 

half of the of fire losses attributed to direct smoldering ignition. Utilizing this finding along with the 

conclusion of the workshop participants that the vast majority of fire losses associated with RUF fires 

ignited by smoldering sources take place after the smoldering fires transition to flaming, emphasizes the 

dominant role that flaming RUF plays in the losses in fires in which RUF plays an important role.
23

9. Acknowledgements

The success of the workshop was the direct result of the active participation and contributions of all of the

attendees. The organizers wish to thank everyone for their hard work and dedication. We recognize that 

every person and organization in attendance invested time and money to spend a day and a half at NIST. 

It is our hope that you found the workshop as useful and informative as it was for us. We look forward to 

working together with you and your organizations as we move forward to implement the 

recommendations generated formulated by the workshop participants.

10.References

[1] R. W. Bukowski, R. D. Peacock, J. D. Averill, T. G. Cleary, N. P. Bryner, W. D. Walton, P. A. 

Reneke, E. D. Kuligowski, Performance of Home Smoke Alarms Analysis of the Response of Several 

Available Technologies in Residential Fire Settings, National Institute of Standards and Technology 

Technical Note 1455-1, Gaithersburg, MD, December 2007 Revision, 396 pp.

[2] Upholstered Furniture Flammability, World Wide Web Summary of Project, 

http://www.ul.com/global/eng/pages/offerings/industries/buildingmaterials/fire/fireservice/upholstere

d/, Underwriters Laboratories, Northbrook, IL.

[3] R. W. Bukowski, T. E. Waterman, and W. J. Christian, Detector Sensitivity and Siting Requirement

for Dwellings. Final Technical Report, National Bureau of Standards Government Contractors Report 

GCR 75-51, Gaithersburg, MD, 1975, 337 p.

[4] Standard for the Flammability of Residential Upholstered Furniture; Proposed Rule, 16 CFR Part 

1634, Consumer Product Safety Commission, Federal Register 71 (50), 13471-13523 (March 4, 

2008).

[5] Standard for the Flammability (Open Flame) of Mattress Sets; Final Rule, 16 CFR Part 1633, 

Consumer Product Safety Commission, Federal Register 73 (43), 11701-11752 (March 15, 2006).

[6] Flammability Test Procedure for Seating Furniture for Use in Public Occupancies, State of California, 

Department of Consumer Affairs, Bureau of Home Furnishings and Thermal Insulation, Technical 

Bulletin 133, North Highlands, CA, January 1991, 29 pp.

[7] Fire tests - Full-scale room test for surface products, International Organization for Standardization 

ISO 9705: 1993(E), Geneva, Switzerland, 1996.

[8] M. J. Karter, Jr., United States fire loss for 2003, NFPA Journal, 66-71 (November/December 2004). 

[9] The U. S. Fire Problem, National Fire Protection Association, Quincy, MA, 

http://www.nfpa.org/itemDetail.asp?categoryID=953&itemID=23071&URL=Research%20&%20Re

ports/Fire%20statistics/The%20U.S.%20fire%20problem.

[10] A. C. Bwalya, An extended survey of combustible contents in Canadian residential living rooms, 

National Research Council Canada Research Report No. 176, Ottawa, Ontario, November, 2004, 

30 pp.

[11] A. C. Bwalya, G. D. Lougheed, A. Kashef, and H. H. Saber, Survey results of combustible contents 

and floor areas in Canadian multi-family dwellings, National Research Council Canada Report

NRCC-50593, Ottawa, Ontario, January 2010, 21 pp.

[12] M. Ahrens, Home structure fires, National Fire Protection Association, Quincy, MA, March 2010.

[13] Requirements, test procedure and apparatus for testing the flame retardance of resilient filling 

materials used in upholstered furniture, Bureau of Home Furnishings and Thermal Insulation, 

Technical Bulletin 117, North Highlands, CA, January 1991, 8 pp.

[14] B. Sunström, ed., CBUF—Fire safety of upholstered furniture-the final report on the CBUF research 

programme, European Commission Measurements and Testing Report EUR 16477 EN, Interscience 

Communications Limited, London (1995).

[15] V. Babrauskas, Upholstered furniture heat release rates–measurements and estimation, 

Journal of Fire Sciences 1, 9–32 (1983).
24

[16] K. B. McGrattan, S. Hostikka, J. E. Floyd, H. R. Baum, R. G. Rehm, Fire Dynamics Simulator 

(Version 5) Technical Reference Guide, National Institute of Standards and Technology Special 

Publication SP 1018, Gaithersburg, MD, October 2007, 100 pp.

[17] Methods of Test for Assessment of the Ignitability of Upholstered Seating by Smouldering and 

Flaming Ignition Sources, British Standards Institution, BS 5852:2006, London, England, March 

2006.

[18] W. W. Jones, R. D. Peacock, G. P. Forney, P. A. Reneke, CFAST: Consolidated Model of Fire

Growth and Smoke Transport (Version 6). Technical Reference Guide, SP-1026, National Institute 

of Standards and Technology, Gaithersburg, MD, April 2009 revision, 117 pp.

[19] M. Ahrens, Home fires that began with upholstered furniture, National Fire Protection Association, 

Quincy, MA, August 2011, 94 pp.

[20] J. D. Averill, L. Moore-Merrell, A. Barowy, R. Santos, R. Peacock, K. A. Notarianni, and D. 

Wissoker, Report on Residential Fireground Field Experiments, National Institute of Standards and 

Technology Technical Note 1661, Gaithersburg, MD, April 2010, 104 pp.
25

APPENDIX A—Workshop Announcement
26

Workshop on Quantifying the Contribution of Flaming Residential Upholstered Furniture to Fire 

Losses in the United States

Background. Modern residential upholstered furniture (RUF) and particularly the flexible polyurethane 

foam (FPUF) most often used as cushioning material are frequently cited as playing a dominant role in 

fire growth in residences. Fire tests have shown that modern RUF can be responsible for rapid fire 

growth to intense levels, especially due to the prevalence of FPUF in the cushioning. NIST showed that 

the burning of modern RUF led to untenable conditions in about 3 minutes. Underwriters Laboratories 

found similar flashover times of about 4 minutes.

Appropriately, the regulatory focus on RUF in the United States has been on scenarios that are prevalent 

in the compiled fire loss statistics as tracked by the National Fire Incident Reporting System 

(NFIRS). Since these statistics have indicated that the largest cause of fire deaths is from cigarette 

ignition of soft furnishings (RUF and beds), much effort has been focused on limiting smoldering 

ignition.

There has been less focus on and less success in limiting the consequences of flaming RUF. There are 

similar products whose contributions to fire hazard are regulated: 16 CFR Part 1633 caps the allowable 

heat release rate from residential mattresses. California TB 133 caps the allowable heat release rate from 

upholstered furniture for public occupancies.

A principal impediment to limiting the consequences of flaming RUF is the absence of authoritative 

estimates of the losses from these fires. This, despite RUF having been shown to be capable of being the 

principal contributor to rapid fire growth and spread in rooms, even if it is not the first item ignited. Such 

quantification is crucial in order to understand the potential benefits of developing and implementing 

approaches that effectively slow fire growth on and limit the maximum heat release rates from RUF.

This workshop is designed to identify approaches for and to stimulate efforts to develop this 

quantification. The results of this workshop will guide NIST research efforts and also serve to nurture 

cooperative efforts with members of the wider research community.

Hypotheses. The following hypotheses are provided as means for investigating and guiding efforts to 

quantify the contribution of RUF to residential fire losses:

• A decreased rate of fire development inside a residential room containing modern RUF increases 

the time available for response or escape and can result in decreased fire losses (both property 

and human) inside the room of fire origin.

• Flashover development in the room of fire origin increases production of toxic gases and smoke 

and the likelihood of fire spread to other areas of the residence. This increases the potential for 

fire losses at locations substantially removed from the room of fire origin.

• Reducing the fire growth rate on and limiting the maximum heat release rate of RUF to levels 

insufficient to generate flashover or ignite nearby furnishings would substantially reduce financial 

and human fire losses in the United States.

Workshop Objective. The purpose of the workshop is to identify approaches for quantifying the full 

contribution of flaming fires of modern RUF to the Nation’s fire losses and, therefore, the potential for 

reducing these losses. The small group of invited participants will consist of experts in fire statistics and 

building fire dynamics. The program for this one-and-one-half day workshop will consist of:

a. Short introductory presentations on fire statistics, RUF characteristics in modern American 

residences (including a brief overview of materials, sources, and industry practices), RUF fire 
27

behavior, relevant structure fire dynamics, and current efforts to reduce the contribution of RUF 

(and mattresses) to flaming fire development.

b. Identification of approaches for estimating the contribution of RUF flaming fire behavior to fire 

losses utilizing existing fire incidence data. 

c. Identification of modest additions to fire incident reports that would improve the quality of these 

estimates in future years.

d. Development of an action plan for quantifying the contribution of modern RUF to the existing 

fire problem in the United States. 

Workshop Details.

The workshop will take place over one and a half days on March 22-23, 2012 at the National Institute of 

Standards and Technology campus in Gaithersburg, MD. The first session will start at 8:30 a.m. on 

Thursday morning and we will wrap up by 4:30 p.m. A la carte lunches at your own expense will be 

available in the NIST cafeteria. An informal dinner will be arranged Thursday evening for those wishing 

to join the group. On Friday, we will once again begin at 8:30 a.m. and conclude the workshop by noon.

NIST is closed to the general public at this time. In order to attend the workshop it is necessary to preregister. Preregistering is easy. Please email your full name and affiliation to the Fire Research Division 

Secretary, Wanda Duffin-Ricks (wanda.duffin-ricks@nist.gov, 301-975-6863) by Friday, March 16th

and indicate you will be attending the Residential Upholstered Furniture workshop.

On the day of the workshop, badges can be picked up at the visitor center located at the NIST main gate at 

W. Diamond Ave. and Bureau Drive. Photo identification must be presented to receive your badge. 

Directions to NIST, site maps, and additional information are available on the WEB at www.nist.gov.

The workshop will be held in the Fire Research Division Conference Room, which is Room B245 in 

Building 224. To reach Building 224 from the visitor center, after passing through the guard’s station you 

will come to a “T.” Turn right onto North Drive. Take your first left onto West Drive You will see the 

new NIST “Net-Zero Energy Home” on your left. Building 224 is the second general purpose laboratory 

building on your left after you pass the house. Ample parking is available in the lots in front of the 

building. Building 224 is secured and requires an employee badge for entry. You should be met at the 

door in the morning if you arrive on time. If you arrive and no one is present, there is a phone in the 

lobby which you can use to call x6863 or x6859. Someone will come to escort you in.

The closest major hotel to NIST is the Holiday Inn, Gaithersburg, located at 2 Montgomery Village Ave

on the corner of North Frederick Ave and Montgomery Village Ave 1.5 miles from NIST. We have 

arranged a special rate of $119/night with the Holiday Inn. Reservations may be made by calling the 

Hotel directly at 301/948-8900. In order to receive the special rate, you must identify your group 

affiliation, “NIST/Upholstered Furniture Fire Loss,” at the time of the reservation. Reservations must be 

received by Wednesday, March 7, 2012. Any reservations received after the cut-off date will be 

accepted on a space and rate availability basis. The Holiday Inn Gaithersburg participates in the “Smoke 

Free” program. Smoking is not permitted in any guest rooms, restaurants, lounges, meeting rooms and 

public space. Should this program be violated, the Hotel reserves the right to charge a $250.00 recovery 

fee. A shuttle is available to and from NIST with times to be determined.
28

APPENDIX B—Workshop Attendees
29

First Name Last Name Sponsor/Company E-mail addresses Telephone Number

Thomas Fabian UL thomas.fabian@us.ul.com 847-417-5646

John Hall NFPA jhall@nfpa.org 617-984-7460

Marc Janssens SwRI mjanssens@swri.org 210-522-6655

Bradley Pabody USFA brad.pabody@dhs.gov 301-447-1340

James Heeschen USFA jim.heeschen@dhs.gov 301-447-1180

Marty Ahrens NFPA mahrens@nfpa.org 617-984-7463

Bob Luedeka PFA rluedeka@pfa.org 865-657-9840

David Miller CPSC dmiller@cpsc.gov 301-504-7323

Douglas Thomas NIST douglas.thomas@nist.gov 301-975-4918

Anthony Hamins NIST anthony.hamins@nist.gov 301-875-6598

Rick Davis NIST rick.davis@nist.gov 301-975-5901

Jason Averill NIST averill@nist.gov 301-975-2585

Dick Gann NIST rggann@nist.gov 301-975-6866

Bill Pitts NIST william.pitts@nist.gov 301-975-6486

David Butry NIST david.butry@nist.gov 301-975-6138

William Grosshandler NIST william.grosshandler@nist.gov 301-975-6850

Chuck Smith CPSC clsmith@cpsc.gov 301-504-7701

Rik Khanna CPSC rkhanna@cpsc.gov 301-987-5208

Shivani Mehta CPSC smehta@cpsc.gov 301-987-2025

Linda Fansler CPSC lfansler@cpsc.gov 301-987-2059

Andrew Lock CPSC alock@cpsc.gov 301-987-2099

Lisa Scott CPSC lscott@cpsc.gov 301-987-2064

Dan Gottuk Hughes Associates, Inc. dgottuk@haifire.com 410-737-8677

Sean DeCrane Cleveland Div. of Fire rovloc93@aol.com 216-224-6150

Michael Hawthorne Chicago Tribune mhawthorne@tribune.com 312-222-3315

Kathy Butler NIST kathryn.butler@nist.gov 301-975-6673

Amanda Robbins NIST amanda.robbins@nist.gov 301-975-6551

Tony Putorti NIST anthony.putorti@nist.gov 301-975-8615

Nathan Marsh NIST nathan.marsh@nist.gov 301-975-5441

Rick Peacock NIST richard.peacock@nist.gov 301-975-6664

Bob Chapman NIST robert.chapman@nist.gov 301-975-2723

Jonathan Kent CPSC jkent@cpsc.gov 301-987-2485

George Robbins Fairfax Cty. Fire & Rescue george.robbins@fairfaxcounty.gov 703-246-4741
30

APPENDIX C—Workshop Agenda
31

AGENDA

Workshop on Quantifying the Contribution of Flaming Residential Upholstered Furniture 

to Fire Losses in the United States

NIST

Building 224/Room B245

March 22-23, 2012

Thursday Morning, March 22, 2012

Background Presentations and Discussion

8:30Anthony Hamins, Welcome

8:45William M. Pitts, “Introduction and Background to Workshop Topic”

9:15Tom Fabian, “Residential Upholstered Furniture Flammability”

9:45 Marc Janssens, “Reducing the Uncertainty of Quantifying the Burning Rate of

Upholstered Furniture in Fire Investigations”

10:15Break

10:30 David Sheppard, “An Investigator’s View of the Role of Upholstered Furniture in Fire 

Scene Investigations”

11:00Brad Pabody, “NFIRS Overview”

11:30 John Hall, “How NFPA Measures Fire Problems and Safety Strategies with Special 

Attention to Upholstered Furniture”

12:00 David Butry, “The Use of NFIRS in Economic Analysis”

12:30Lunch

Thursday Afternoon, March 22, 2012

Open Forum Discussions

1:30 Would decreasing the rate of fire growth and heat release in an enclosure significantly 

reduce residential fire losses within the room of fire origin? (Leader: Jason Averill)

1:55 Would decreasing the rate of fire growth and heat release in an enclosure significantly 

reduce residential fire losses at locations substantially removed from the room of fire 

origin? (Leader: Richard Gann)

2:20 What are the relevant characteristics of residential fires involving flaming RUF 

contributing to fire losses? (Leader: Rick Davis)

2:45 Is flaming RUF likely playing a significant role in residential fire losses? (Leader: 

Richard Gann)

3:10 Break

3:30 Is it appropriate to differentiate fire losses inside and exterior to the room of fire origin 

with regard to the role of RUF in Residential Fire Losses? (Leader: Jason Averill)

3:55 Do existing fire statistics and related analyses effectively capture contribution of flaming 

RUF to residential fire losses? (Leader Rick Davis)

4:20 Can existing fire statistics and extended analyses better capture contributions of flaming 

RUF to residential fire losses? (Leader Richard Gann)

4:45 Summary of Presentations and Forum Discussions (William M. Pitts)
32

5:00 Adjourn

6:15 Dinner at Buca di Beppo Italian Restaurant, 122 Kentlands Boulevard, Gaithersburg MD 

20878

Friday Morning, March 23, 2012

Identify Approaches and Participants for Estimating Role of Flaming RUF in Fire Losses

8:30 Brief Recap and Introduction to Session (William M. Pitts)

8:45 Identify Approaches for Estimating Contribution of Flaming RUF to Fire Losses within 

the Room of Fire Origin Using Available Fire Statistics (Leader: Jason Averill)

9:30 Identify Approaches for Estimating Contribution of Flaming RUF to Fire Losses at 

Locations Removed from the Room of Fire Origin Using Available Fire Statistics 

(Leader: Richard Gann)

10:15 Break

10:45 Identify Limitations in Existing Fire Statistics and Provide Suggestions for Improvement 

(Leader: Rick Davis)

11:30 Gauge Interest and Develop Working Group to Improve the Quantification of the 

Contribution of Flaming RUF to Residential Fire Losses (Discussion Leader: William 

M. Pitts)

12:15 Wrap-up and Final Comments (William M. Pitts)

12:30 Adjourn
33

APPENDIX D—Presentations
34

APPENDIX D.1 Anthony Hamins, NIST

Welcome
35
36
37
38
39
40
41

APPENDIX D.2 William M. Pitts, NIST

Introduction and Background to Workshop Topic
42
43
44
45
46
47
48
49
50
51

APPENDIX D.3 Thomas Fabian, UL

Residential Upholstered Furniture Flammability
52
53
54
55
56
57
58
59

APPENDIX D.4 Marc Janssens, SwRI

Reducing the Uncertainty of Quantifying the Burning

Rate of Upholstered Furniture in Fire Investigations
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75

APPENDIX D.5 Bradley Pabody, USFA

NFIRS Overview
76
77
78
79
80
81
82
83
84

APPENDIX D.6 John Hall, NFPA

How NFPA Measures Fire Problems and Safety Strategies with

Special Attention to Upholstered Furniture
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101

APPENDIX D.7 David Butry, NIST

The Use of NFIRS in Economic Analysis
102
103
104
105
106
107
108
109

APPENDIX E—NFIRS Coding Forms
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125

APPENDIX F—Summary of First-Day Presentations and Discussion
126
127

APPENDIX G—Acton Item Report: Fires with Upholstered Furniture as the 

Primary Item Contributing to Fire Spread as communicated by John Hall from 

NFPA on September 12, 2012
128

This memorandum executes the approach identified at the NIST workshop on flaming residential 

upholstered furniture. The goal was to develop estimates of home fires and associated losses where 

upholstered furniture was the primary fuel package but not the initial fuel package. The assignment was 

accepted by John Hall and Marty Ahrens from NFPA and Brad Pabody and Alex Furr from USFA. Marty, 

Alex, and Brad, as well as NFPA’s Ben Evarts, reviewed my original draft and provided helpful comments, 

and all concur with this final version of the analysis.

“Residential” is here understood to mean homes – one- and two-family dwellings, manufactured homes, 

and multi-family housing (apartments) – but not hotels, motels, barracks, dorms, boarding and lodging 

homes, and the like.

Fires With Upholstered Furniture as Item First Ignited and a Flaming Heat Source

In 2006-2010, these were the average numbers per year of reported home structure fires and associated 

losses when upholstered furniture was the item first ignited:

 6,712 fires 

 480 civilian deaths

 844 civilian injuries

 $427 million in direct property damage

Shown below are the average numbers when the heat source is specified as an open flame, including 

matches, lighters, candles, warning or road flares, flames or torches used for lighting.4

 The statistics also 

include proportional shares of fires with unknown heat source and smoking material or open flame fires 

with heat source unknown between the two:

 1,475 fires

 63 civilian deaths

 224 civilian injuries 

 $73 million in direct property damage

These flaming upholstered furniture fires are far outnumbered by the ignitions with an extended initial 

smoldering phase, and the difference is greatly expanded if some fires started by intentional acts – possibly 

including cases of playing with fire – are excluded as non-addressable.

Fires With Upholstered Furniture as Primary Contributor to Fire or Flame Spread But NOT as Item 

First Ignited

In 2006-2010, these were the average numbers per year of reported home structure fires and associated 

losses when upholstered furniture was NOT the item first ignited:

 364,961 fires 

 2,105 civilian deaths

 12,064 civilian injuries

 $6,767 million in direct property damage

The data element that is used to report the item principally contributing to fire spread has some 

characteristics that affect the approaches that can be used to analyze it.

 4 These are all the open flame options identified in NFIRS under Heat Source. Flares and torches would not fit the 

definition of “small open flame”, but they constitute a very small share of the total. The shares of the 1,475 fires per 

year for the five types of open flame are as follows: candle (44%), lighter (36%), match (16%), flame or torch used 

for lighting (4%), and warning or road flare (0%).
129

 When reporting the extent of flame damage, the term “fire spread” is used, but when reporting the 

item contributing most, the term “flame spread” is used. It is possible that the term “flame spread” 

will provide a subtle push toward surfaces (room linings) that flame may spread along rather than 

major fuel packages that will support fire growth leading to fire spread. This may tend to 

understate the contributions of major fuel packages like upholstered furniture and overstate the 

contributions of room linings like ceiling and wall coverings.

 When the data element on item contributing most to flame spread is left blank, under NFIRS rules, 

it can be for any or all of four reasons:

 There was no “significant” fire/flame spread.

 It was not possible to determine whether there was fire/flame spread

 The item contributing most to flame spread was the same as the item first ignited

 The type of item contributing most to flame spread was unknown; this may also be indicated by 

the code “undetermined”, which should not be used for the three other conditions.

We can address these by: 

a) analyzing upholstered furniture as principal item contributing to fire/flame spread separately for 

each value of fire spread; 

b) proportionally allocating blank or undetermined item contributing most to fire/flame spread, as we 

normally do for any data element, but only when there is high confidence that fire/flame spread 

occurred; and 

c) analyzing only fires where upholstered furniture was not the item first ignited. 

Here are the percentages of fires where item contributing most to fire/flame spread was blank or 

undetermined, for each fire size:

 Confined fires – 98% blank; 0% undetermined

 Confined to object of origin – 95% blank; 0% undetermined

 Beyond object of origin but confined to room of origin – 61% blank; 1% undetermined

 Beyond room of origin but confined to floor of origin – 56% blank; 2% undetermined

 Beyond floor of origin but confined to building of origin – 57% blank; 3% undetermined

 Beyond building of origin – 56% blank; 4% undetermined

Almost by definition, there is no fire/flame spread for confined fires or for fires confined to object of origin. 

Almost by definition, there is significant fire/flame spread for fires with flame damage beyond the room of 

origin. 

The principal question has to do with fires with flame damage beyond the object of origin but confined to 

room of origin. However, the blank and undetermined percentages for these fires are essentially the same 

as for the larger fires. It seems reasonable to treat them the same as the larger fires.

Therefore, this calculation proportionally allocates all the blank- and undetermined-item fires for the four 

largest fire spread categories and does not proportionally allocate any blank- or undetermined-item fires for 

the two smallest fire spread categories. Here are the results.
130

Fire spread Fires Civilian Deaths Civilian Injuries Direct Damage(in 

Millions)

Confined fire 6 0 1 $0

Confined to object of 

origin 11 0 2 $0

Confined to room of 

origin 944 41 101 $28

Confined to floor of 

origin 369 17 41 $23

Confined to building of 

origin 808 64 109 $74

Beyond building of 

origin 85 8 21 $14

Total 2,223 130 276 $138

To provide some context, these fires represent a one-third addition to the fires, injuries and damages 

associated with fires beginning with ignition of upholstered furniture, as well as a one-quarter addition to 

the deaths.

Alternatively, these numbers are larger (by as much as 2-to-1) than the numbers of fires and losses 

associated with fires beginning with flaming ignition of upholstered furniture.