A111D5 A*1A343 3SIR 81-2271

NBS

PUBLICATIONS Will the Second Item Ignite?

Vytenis Babrauskas

Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

May 1981

Final Report

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81-2271

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U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
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NBSIR 81-2271

WILL THE SECOND ITEM IGNITE?

Vytenis Babrauskas

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Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

May 1981

Final Report

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

TABLE OF CONTENTS

Page

LIST OF FIGURES iv

LIST OF TABLES iv

Abstract .......... 1

1 . INTRODUCTION 1

2. TESTING FOR FUEL/FUEL INTERACTIONS 2

3. IRRADIANCE MAPPING TESTS 4

4. IGNITION TESTS 7

5. RESULTS OF TESTS 11

6. ANALYSIS 21

7. CONCLUSIONS 25

8. ACKNOWLEDGEMENTS 29

9. REFERENCES 29
LIST OF FIGURES

Page

Figure 1. General view of irradiance mapping apparatus and

weighing platform 6

Figure 2. Wastebasket mass loss rates 8

Figure 3. View of ignition test apparatus 10

Figure 4. Storage unit Fll 14

Figure 5. Easy chair F16 15

Figure 6. Pedestal chair F17 16

Figure 7. Wicker couch F19 17

Figure 8. Stacking auditorium chairs F20 18

Figure 9. Irradiances for specimen F19, measured at 0.41 m

height 19

Figure 10. Irradiance distribution for specimen F19 at peak

burning time 20

Figure 11. Irradiance-time relationship for ignitability tests . 23

Figure 12. Dependence of maximum irradiance on peak mass loss

rate .......... 26

Figure 13. Relationship between peak mass loss rate and ignition

distance for various ignitability levels 27

LIST OF TABLES

Table 1. Specimens tested . 12

Table 2. Results of irradiance mapping tests 13

Table 3. Results of ignition tests 22
WILL THE SECOND ITEM IGNITE?

Vytenis Babrauskas

Abstract

The problems of characterizing the burning of

more than a single fuel item in a room fire are

considered, and one specific area is explored experimentally. The first step in describing multiple item

burning is to determine if, in fact, it will occur,

given the assumed ignition of the first item. This

question has been experimentally explored from two

aspects. (1) Irradiances have been measured at various

distances from burning objects, along with their mass

loss rates. (2) The ignitability of exposed objects

has been determined using a bench-scale uniform flux

ignitability test. It is then suggested that whether

the second item will ignite can best be determined

analytically from considering these two sets of results.

Key words: Burning rate, case goods, chairs, fire

tests, flammability, furniture fires, ignitability,

room fires, upholstered furniture.

1. INTRODUCTION

The burning rates of combustible items in building fires has been a matter of long-standing concern. The problem has typically been studied

from two approaches. On the one hand, room fire burning has often been

considered to be uniquely described by the fuel load (fire load) , with

the fuel load, expressed as the equivalent weight of wood fuel per unit

1
floor area, being the primary variable characterizing a fire. The fuel

load comprises both imovable ifurnishings and any combustible interior

finish and trim. Ingberg originally developed these concepts :in the

1920's [1]\ Ingberg' s basic intent was to determine the effect of the

burnout of all combustibles on fire penetration of barriers and on structural stability. More recently, interest has turned to the details

of the transient nature of fire growth in a room, and significant advances

have been made irn -measuring and describing the burning behavior of .a single,, isolated Ifuel item, commonly a piece of ffiimniture , 23 -. Missing, however, is -knowledge of .any interact ions. Two types of interactions in general ran be seen. First fuel/room interactions will occur

'Whenever the presence of a room fire around the fuel item modifies its

burning rate. This happens primarily in the later, post-f lashover stage

of a fire and involves two burning rate effects, augmentation due to

increased radiation, and diminution due to vitiation of the air from

combustion product contamination. Second, significant fuel/fuel interactions can occur whenever the first burning item can ignite a second

one. In this study we are concerned primarily with fuel/fuel interactions

where the fuel objects are pieces of furniture. A similar approach can

be taken for wall linings or other different types of combustibles. We

will assume that an initial item is on fire and will examine the possibilities for involvement of additional items. Burning of the initial and

any subsequent items will be assumed not to lead to significant fuel/room

interactions.

2. TESTING FOR FUEL/FUEL INTERACTIONS

The interaction between two pieces of fuel becomes a moot question

if the items are placed one against the other, since then continuous

flame spread can occur. Ignition can also occur for slightly separated

items if the flames and hot gases from the first impinge directly on the

Numbers in brackets refer to the literature references listed at the

end of this report.

2
second., Conversely, if the second item is placed in the opposite corner of a room, far from the first ignited item, no involvement is expected

until room flashover (at f lashover the previously' unignited items are assumed to ignite nearly simultaneously) . For items that are nearby yet

not directly contiguous, however, it becomes appropriate to determine if

the second item can ignite by radiation from the first „ with the two

then burning as one "fuel packet." If this is, likely, we would then

want to predict this combined burning rate, which can be higher than

burning rates measured for the two, items separately. Such investigation

has not yet been made.

Since significant interaction is possible only if the second item

ignites from the first, it becomes of interest to determine this potential

for ignition. Given a set of n test specimens, one would wish to conduct

tests with each item paired with each other, with alternately the one or the other being viewed as the ignitor, and all done at various separation

2

distances. On the order of n tests at each separation distance would

be required. Additional tests may further be required to determine

repeatability. A program of this nature is unrealistic.

The problem can, however, be separated into its elements analytically. A given combustible item is presumed to be ignited and burning.

It is possible to determine first the irradiance, as a function of

distance, from this burning item No. 1, then to test some item No, 2 with different irradiances to determine the minimum for ignition. The

actual determination of ignition can then be done analytically, by

comparing the results. A testing program now becomes practical since

2 instead of n tests at several separation distances only n irradiance

mapping tests have to be run, the irradiances being measured at several

separation distances in a single test. Separately, 2n ignitability

tests can yield sufficient data on the ignitability item No. 2. In this

procedure, any separate combustible in a room can be item No. 1 or item

No. 2 — appropriate choices can only be made based on a plausible fire

scenario

.

3
Once the ignition or non-ignition of subsequent items is established,

the effects on burning rates would have to be considered. Once two or more items are burning their individual burning rates need no longer be

what they would have been for a sole item, but can be modified both by

radiation and by the convective flow fields. The magnitude of this

effect has not been studied.

3. IRRADIANCE MAPPING TESTS

In the present study experimental work was conducted to address one specific problem in the area of fuel interactions — will the second

item ignite by radiation? This was to be characterized by separate

tests for irradiance (radiant heat flux) and for ignitability

.

A very limited amount of irradiance mapping work has been reported

in the literature for common furnishings items. Theobald [3] burned

several types of common furniture in an open area, placing small targets

of cotton cloth, wood blocks and plywood sheet at various separation

distances. Maximum distances for target ignition were recorded. Fang

[4] and Klein [5] used heat flux gages to measure the irradiance at

different distances from burning upholstered chairs.

The present test series utilized the following set-up. A load

platform, 0.91 m by 1.88 m in size, was suspended from a water-cooled

load cell above. The load cell had a live load capacity of about 150 kg.

Load cell output was recorded with a digital data logger. The rms load

fluctuation level was measured as the equivalent of + 6 g under ambient

temperature conditions. The primary cause for fluctuations in experiments of this type, however, is not due to the limit of resolution

within the load cell itself, but rather due to the turbulence of the

fire. Fire turbulence manifests itself as buoyancy fluctuations acting

upon the load platform. These were not studied in detail but are in the

order of 100 or 200 g. The test load cell data were taken every 20 s and smoothed numerically with a 6 point averaging technique. In the

4
case of tall specimens, material loss from the platform was prevented by

erecting a wire mesh screen around the specimen. No significant losses

occurred from the platform in any test.

To measure the irradiances at multiple locations in two dimensions

a movable trolley was constructed. Gardon-type gages were mounted at

0.41, 0.86, 1.32, and 1.78 m height above the platform. The trolley was moved along a track having detents at 0.05, 0.20, 0.50, 1.12, and 1.73 m

from the leading edge of the specimen (See Figure 1) . The convective

heat flux component from the fire was not desired since only the problem

of igniting objects at a distance is considered here. Therefore, the

gages were used with wide-angle (150°) Irtran 2* windows, which block

convective effects but transmit radiant energy over the desired wave length range of 0.8 to 13.0 ym. Fang's data [4] suggest that at short

distances from the source a convective component on the order of 10 to

20% of the radiant heat flux should be considered likely while in the

immediate vicinity of the source, convective heating can even dominate.

Conversely, away from the source plume region a modest convective cooling

effect can be found. The trolley was moved back one space at each data scan so that a complete record as a function of distance was obtained

every five scans.

The test rig was located in a large experimental area, with free

access to fresh air. The products of combustion were collected in a large hood overhead. The collection rate was sufficient to avoid the

backing down of combustion products into the experimental space.

Specimens were ignited by lighting off a small polyethylene waste

basket filled with 12 polyethylene-covered paper milk cartons. Six

cartons were placed upright in the waste basket, while six were torn

into small pieces and dropped inside. The total weight of a waste

basket was 285 g, while the 12 cartons together weighed 390 g, for a total weight of 675 g. The gross heat of combustion was measured to be

•k Trademark, Eastman Kodak Co. This identification does not constitute

a recommendation nor does it imply that other devices could not be used.

5
Figure 1. General view of irradiance mapping apparatus and weighing platform

6
46.32 kJ/g for the waste basket and 20.26 kj/g for the cartons, representing 21.10 MJ in all. Using an estimated correction, this gives a heat content of 19.7 MJ, based on the net heat of combustion. The waste

baskets and milk cartons were essentially identical to ones used in

tests at the University of California, Berkeley [6]. Figure 2 shows the mass loss rates for three specimens from the present series, along with

two from Berkeley. It is seen that there is no systematic difference

between the burning rates (one specimen from the present series, however,

showed a delayed early fire development). For purposes of characterizing

this ignition source, it seems appropriate to consider a constant mass

loss rate m = 1.8 g/s (equivalent to 52.5 kW based on the heat content

as determined above) for the first 200 s and negligible thereafter. At

the cessation of all burning an average of 61% of the initial mass is

consumed. If we define the active burning period to extend for the

first 200 s, then by subtraction, during the remaining 2200 s or so of

slower or smoldering type burning an additional 51 g of mass is lost.

(By actual measurement at 200 s an average of 66 g still remains to be

burnt.) In testing furniture items, the igniting waste basket was

placed flush against the side or back of the specimen in each case. Flux measurements were then taken at 90° away, to the front or side,

respectively. (Ignition is generally not possible without direct contact

of waste basket against the test specimen at a height of 0.41 m and

2 0.05 m away from the burning waste basket an irradiance of only 8 kW/m

was measured. This is appropriate since the waste basket is used only

to provide ignition of item No. 1 and should otherwise produce a small

f ire.

)

4. IGNITION TESTS

Ignition of furniture items has most commonly been tested with

small non-uniform flame sources, e.g. [7], This is intended to simulate

the actual ignition conditions of the first item. In the present case,

however, the ignition potential of the second item is of concern. In

such case, the second item receives an irradiance from the first item

7
Figure 2. Wastebasket mass loss rates

8
which is only slowly varying over its surfaces. Thus a test is needed

where a uniformly distributed irradiance rather than a concentrated

source is used. A piloted ignition condition is to be preferred for two

reasons: flying brands can be realistically expected, and piloted

ignition results typically show less scatter than autoignition. The

ignition testing was done in an apparatus adapted from a proposed International Organization for Standardization (ISO) test [8], The apparatus

was modified (Figure 3) primarily by substituting an electric spark

ignition (which is more repeatable and less affects specimen irradiance)

instead of the prescribed gas pilot, and by modifying the specimen

holder. All specimens are tested in the horizontal orientation in this

test. While there are differences in ignition characteristics that

depend on orientation, these were considered small compared to other sources of variability. The specimens were 150 x 150 mm in surface

area. The existing thickness, up to 50 mm was used. Samples were cut

from large, flat furniture areas, such as backs, seats, or side panels.

No attempt was made to test edges or small members. Two irradiance

2 values were used, 20 and 40 kW/m , as measured by a Gardon gage mounted

2 in place of the sample. The 20 kW/m value was chosen since it represents

a value near the minimum ignition flux for many common combustibles.

2 Those combustibles which require as much as 40 kW/m for ignition would

be considered dif f icult-to-ignite ; conversely, some data exist [9] to

show that for certain especially easily ignitable combinations of

2 materials, even 10 kW/m may be sufficient for ignition. The apparatus

was used in a draft shielded area. Power was turned on to the heater

and stabilized at the desired irradiance. The specimen in its specimen

holder was then quickly slid in and a stopwatch started. Ignition was considered to occur at the first evidence of flaming. An exception was

taken for melamine-laminate clad particle board type products. These

"exploded" at a certain point in heating when a violent delamination

took place. Further testing was not practical after such delamination

and this event was tabulated as tantamount to ignition.

9
Figure 3. View of ignition test apparatus

10
5. RESULTS OF TESTS

Tests were conducted on some eighteen types of specimens,

predominantly modern office furniture (Table 1). Exceptions included

F16 a traditional residential type easy chair, F19 a couch associated

with a fire in a local hospital sitting room, and F18 a prototype lowflammability prison chair. Illustrations of typical pieces are shown in

Figures 4 through 8. Irradiance mapping data for the fastest burning

upholstered specimen, wicker couch F19, are illustrated in Figures 9 and

10. From Figure 10 it can be seen that the burning item does not act as

2 a point source and that a 1/r flux representation would not be appropriate in the near region (far away, of course, there is no significant

hazard needing to be addressed) . A summary of the principal results is

given in Table 2.

Two specimens, F04 and Fll, were run in identical replicate tests.

Chair F04 burned very similarly in both tests. Storage cabinet Fll,

however, showed different fire development rates in the two tests. Most

major surfaces of this unit were covered with a melamine type plastic

laminate which is hard to ignite and does not readily spread fire.

Flame spread, and therefore, burning rate were consequently determined

by successive ignitions of the more ignition prone components, i.e.,

paper fuel, drawer insides, and shelf edges, all of this taking place

somewhat randomly. Even though Fll and a similar but smaller cabinet,

F10, showed substantial weight loss rates, neither of them indicated

much radiant heat flux. This is because the measurements were taken

from the side position; the only surfaces facing to the side in these

specimens were fully laminate covered and did not readily burn. The

side measurement position was considered preferable here since nearby

combustibles would more likely be found close to the sides, rather than

at the front.

Chair F17 was tested both from the sides and from the front. The

results confirmed earlier exploratory findings that with upholstered

11
TABLE 1

Specimens Tested

SPECIMEN TOTAL WEIGHT

(kg)

TYPE a

F01 27.8 Acoustical office screen, fiberglass padding,

nytril fabric (2 screens in corner)

F02 8.5 Molded frame "tulip" chair, cotton fabric

F03 13.2 Chrome frame armchair, vinyl cover F04 27.8 Oak armchair, vinyl cover

F05 45.9 Oak two-seater, vinyl cover F08 9.4 Chrome frame Breuer chair, nylon fabric

F09 43.4 Plywood /laminate desk

(1.21 x 0.44 x 0.78 m high)

F10 27.7 Plywood /laminate storage cabinet

(+ 7.7 added weight of paper load)

Fll 79.1 Large vertical plywood /laminate storage

cabinet (0.79 x 0.38 x 1.93 m high)

(+ 19.1 added weight of paper load)

F12 17.1 Chrome frame armchair, vinyl cover F13 7.3 Oak side chair, vinyl cover F14 6.1 Fiberglass molded chair, no padding

F15 18.5 Oak armchair, vinyl cover F16 23.4 Traditional style easy chair,

polypropylene fabric

F17 18.0 Molded polyethylene pedestal chair,

vinyl cover F18 35.6 Prototype prison chair, polyethylene frame,

neoprene foam, Nomex fabric

F19 19.9 Hospital couch, wicker frame polypropylene

fabric

F20 7.7 Padded stacking sidechair, vinyl cover

WB 0.675 Polyethylene waste basket, filled with

12 milk cartons

a - all upholstered furniture had polyurethane foam padding, unless otherwise

specified.

12
Results

of

Irradiance

Mapping

Tests

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13
(a) Before test (b) Near peak burning

Figure 4. Storage unit Fll

14
Figure 5. Easy chair F16

15
(a) Before test (b) Near peak burning

Figure 6. Pedestal chair F17

16
Figure 7. Wicker couch F19

17
Figure 8. Stacking auditorium chairs F20

18
Figure 9. Irradiances for specimen F19, measured at 0.41 m height

19
Figure 10. Irradiance distribution for specimen F19 at peak burning time

20
chairs, the side and front positions tend to give quite similar results,

with slightly worse behavior being observed at the side position.

One specimen, F20, was an auditorium chair made to be stacked. Two

tests were conducted with this type chair, a single unit and three

stacked chairs. The single unit did not show significant burning; the

three stacked chairs, however, burned vigorously and showed peak fluxes

and mass loss rates some ten times that of the single chair.

Results of ignition tests are given in Table 3. All specimens

2 tested ignited at the higher, 40 kW/m irradiance with the exception of

* the prison chair F18. A number of specimens failed to ignite at the

2 lower,* 20 kW/m irradiance. Figure 11 suggests that if more than about

2 40 s is required for ignition at 40 kW/m irradiance, then ignition at

2 20 kW/m is unlikely. For homogeneous, thermally- thick materials, both

theory and experiments [10] indicate that the ignition time is expected

to vary inversely with the second power of the irradiance. The data in

Figure 11 show a dependence closer to the first power of irradiance.

The ignitability results can also be useful in evaluating certain

other fire possibilities, e.g., ignition from a fireplace rather than

from a burning furniture item if irradiances from such a source- are determined

.

6. ANALYSIS

The specimens tested here are seen to cover a broad spectrum of

burning behaviors, ranging from those which would not ignite from a wastebasket source at all, to ones which were readily ignitable and led

Testing at higher irradiances was not done in this program and a minimum value for this special prototype chair was not determined. It

is interesting to note, however, that results from other tests show

that a good readily available construction consisting of wool upholstery

fabric over neoprene foam requires approximately 65 kW/m2 for ignition.

21
TABLE 3

Results of Ignition Tests

SPECIMEN IGNITION TIME AT

20 kW/m2 IRRADIANCE

(s)

IGNITION TIME AT

40 kW/m2 IRRADIANCE

(s)

F01 43 24

F02 29 14

F03 25 14

F04 Seat 18 11

Back 31 9.3

F05 29 11

F08 OO 41

F09 oo 110

F10 oo 236

Fll oo 191

F12 24 11.4

F13 41 18.5

F14 oo 455

F15 22 15.3

F16 38 14.5

F17 Seat 20 12.0

Back 31 17.3

F18 OO OO F19 N.A. N.A. F20 Seat 32 12.4

Back 32 11. 3

oo N.A. Did not ignite

Not available

22
Figure 11. Irradiance-time relationship for ignitability tests

23
to large fires. A fiberglass molded chair, F14, and a highly retardant

treated prison chair, F18, failed to ignite and burn from a direct

contact wastebasket fire. Thus, they would not likely act as ignition

sources for other objects in a real fire. (Both specimens also did not

2 ignite at 40 kW/m in the ignition apparatus.) Several specimens burned

vigorously, producing maximum irradiances in the vicinity of 40-80

2 kW/m . These included F04 , an oak armchair; F05, a similar styled twoseater; F15, another oak armchair; F16, a traditional easy chair; F17, a molded polyethylene pedestal chair; and F19, a wicker couch. The

corresponding peak mass loss rates here were primarily in the range of

20-47 g/s. Assuming, very roughly, an effective heat of combustion of

21 kJ/g [11], suggests these to be fires in the range of 0.4 to 1.0 MW.

For point of reference, such fire output can be expected to flash over

5/2

[11] rooms with ventilation factors A /h < 0.5 to 1.3 m , (where A = area of door/window, h = height) . This rule holds for rooms of moderate

wall area; additional considerations apply [11] for small-ventilation,

large wall area rooms. A common doorway size can yield a ventilation

5/2 factor -2.2m ; thus these specimens, burning alone, would not likely

be sufficient for room flashover if doorway flows are the ventilation

5/2 source. Windows, however, can commonly be found with A /h - 1.0 m , so flashover would be possible in that case.

Storage cabinets F10 and Fll represented a special case since they

showed mass loss rates in the same range as the fast-burning specimens

2 above, yet showed low irradiances to the side (6 to 8 kW/m ). Thus,

these would - short of flashover - not likely involve any additional

fuel items to the side, although they could readily involve items placed

in front or overhead and could also, given sufficiently small ventilation A /h, lead to flashover.

The remaining fuel items were all active fire sources but somewhat

2 less serious than the sources mentioned above. Since 20 kW/m is not

reached, second item involvement would not be expected with F01, F08 , or F20 (single) at any separation adequate to prevent direct flame contact.

Specimens F02, F03, F09, F12, F13, and F19 did exceed irradiances of 20

24
kW/m and thus might lead to ignition with an appropriate second item

placed close enough.

The majority of furniture pieces using fabric/polyurethane foam

2 constructions ignited within 45 s at an irradiance of 20 kW/m . This

length of time is short in comparison to peak burning durations, typically

several minutes (Figure 9); thus any No. 1 items showing irradiances >

2 20 kW/m would presumably ignite any of these No. 2 items. The pieces

2 that required 40 kW/m or more for ignition generally took a long time

to ignite. The analysis would then require an examination of the com- plete item No. 1 irradiance- time curve, which is probably not warranted.

While a detailed irradiance mapping, as in the present study, is a fairly time-consuming operation, a record of the mass loss rate is

likely to be available from most testing programs. Thus, it would be

useful if mass loss rate values could be used to approximately deduce

the expected maximum irradiance. Data from the present test series have

been plotted to seek this relationship in Figure 12. The irradiances are the maximum at 0.05 m away and at the heights as indicated in Table

2. There is no simple correlation to be seen, primarily because some of

the specimens burn in an open manner while others are — at least from some directions — self-shielded. For making conservative irradiance

estimates, then, it would be appropriate to use an envelope curve; such a curve has been indicated in Figure 12 and can be useful in making estimations.

One further rough simplification can be made. By combining those

points on the envelope curve in Figure 12 with the irradiance values

given in Table 2, a relationship between the mass loss rate for item No.

1 and distance-to-given- irradiance can be obtained. This is shown in

2 Figure 13 for 10, 20, and 40 kW/m levels and can be used to evaluate

candidate items No. 2.

25
Figure 12. Dependence of maximum irradiance on peak mass loss rate

26
IGNITION

DISTANCE

(m)

igure 13. Relationship between peak mass loss rate and ignition

distance for various ignitability levels
7. CONCLUSIONS

A method has been developed for assessing the likelihood of ignition

of additional, non-contiguous fuel objects when an initial object has

been set afire. The procedure involves making irradiance measurements

during the burning of the first item and conducting a bench-scale ignitability test on specimens of the second object.

2 Irradiances measured 0.05 m away range to near 80 kW/m for the

2 fastest burning specimens; however, 40 kW/m was not recorded farther

2 than 0.44 m away and 20 kW/m was not found beyond 0.88 m distant. The

implication is that common furnishings items, which normally require a

2 minimum irradiance approaching 20 kW/m for ignition, would stand little

hazard of fire involvement if placed at least 1 m away from the initial

source

.

The above conclusion is only applicable for fires short of flashover. Once flashover is reached, most combustibles can be presumed to

ignite and burn regardless of where they are in the room. Potential for

flashover can be evaluated using the techniques described in [11].

A modified version of the ISO ignitability test was found useful

for performing the required ignition tests. This method is superior to

most other common ignitability tests since, by virtue of a controlled

flux and one-dimensional heat conduction, it permits analytical use in

describing room fire behaviors. Greater use should be made of a test of

this type for systematic characterization of product performance.

An empirical relationship between peak mass loss rate and limiting

maximum irradiance has been obtained. Also, a similar relationship was derived relating critical distances for ignition to peak mass loss

rates. These relationships could be refined with additional test data

and with more detailed considerations of shielded fires.

28
2 2 Peak irradiances of 40 kW/m and 57 kW/m measured at 0.05 m from

2 the burning No. 1 item produce irradiances 20 kW/m at up to 0.20 m

and 0.50 m away, respectively, from the item. Additional values could

usefully be derived from further studies.

8 . ACKNOWLEDGEMENTS

This work was partly funded by the Veterans Administration;

Christine Pappamihiel assisted in specimen procurement. David Swanson

and Robin Breese assisted in constructing equipment, conducting tests,

and reducing data. The problem was first suggested by Sanford Davis.

9 . REFERENCES

[1] S. H. Ingberg, Tests of the Severity of Building Fires,

Q. National Fire Prot. Assn. 22 , 43-61 (July 1928)

.

[2] V. Babrauskas, Full-scale Burning Behavior of Upholstered Chairs,

Nat. Bur. Stand. (U. S.), Tech. Note 1103 (1979).

[3] C. R. Theobald, The Critical Distance for Ignition from Some Items

of Furniture (Fire Research Note 736). Fire Research Station,

Borehamwood (1968)

.

[4] J. B. Fang, Measurements of the Behavior of Incidental Fires in a Compartment, Nat. Bur. Stand. (U. S.), NBSIR 75-679 (1975).

[5] D. P. Klein, Characteristics of Incidental Fires in the Living

Room of a Mobile Home, Nat. Bur. Stand. (U. S.), NBSIR 78-1522

(1978)

.

29
[6] P. S. Klitgaard, R. B. Williamson, The Impact of Contents on Building Fires, J. of Fire and Flammability /Consumer Products

Flammability Supplement . 2_ , 84-113 (March 1975) .

[7] Tests for the Ignitability of Upholstered Seating (DD58: 1978),

British Standards Institution, London (1978)

.

[8] Draft Proposal of DP 5657, Fire Test—Reaction to Fire

Ignitability of Building Materials. International Organization

for Standardization (June 1977)

.

[9] A. W. Moulen, S. Grubits, Fire Properties of Some Commonly Used

Upholstery Materials (Technical Record TR 44/153/412). Department

of Works, Commonwealth Experimental Building Station, North Ryde,

Australia (1973).

[10] J. R. Hallman, Ignition Characteristics of Plastics and Rubber,

Ph.D. Dissertation. University of Oklahoma, Norman (1971).

[11] V. Babrauskas, Estimating Room Flashover Potential, Fire

Technology . 16 , 94-104 (May 1980)

.

30
NBS-114A (REV. 9-7 8)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 81-2271

2, Gov't. Accession No. 3. Recipient's Accession No.

4. TITLE AND SUBTITLE

Will the Second Item Ignite?

5. Publication Date May 1981

6. Performing Organization Code

7. AUTHOR(S)

Vytenis Babrauskas

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

10. Project/Task/Work Unit No.

\ * IS :

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, state, ZIP) 13. Type of Report & Period Covered

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less factual summary of most s i gni ficant information. If document includes a significant bibliography or

literature survey, mention it here.) The burning of more than a single fuel item in a room fire has not been

well characterized. The first step in describing multiple item burning

is to determine if, in fact, it will occur. This question has been

experimentally explored from two aspects. (l) The radiant heat fluxes

from burning first-to-ignite objects have been measured, along with

their mass loss rates. (2) The ignitability of exposed objects has

been determined using a bench-scale uniform flux ignitability test. It

is then suggested that whether the second item will ignite can best be

determined analytically from considering these two sets of results.

17. KEY WORDS (six to twelve entries ; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Burning rate, case goods, chairs, furniture fires, ignitability, room fires

upholstered furniture.

18. AVAILABILITY QUnlimited

| | For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003- m Order From National Technical Information Service (NTIS), Springfield, VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF

PRINTED PAGES

34

22. Price

$6.50

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