REFERENCES

1. De Rosa, M. I, and C. D. Litton. Oxidative Thermal Degradation
of PVC-Derived, Fiberglass, Cotton, and Jute Brattices, and Other Mine
Materials. A Comparison of Toxic Gas and Liquid Concentrations and
Smoke-Particle Characterization, BuMines RI 9058, 1986, 13 pp.

2. ___. Determining the Relative Toxicity and Smoke Obscuration
of Combustion Products of Mine Combustibles. BuMines RI 9274, 1989,
11 pp.

3, ___.. Primary Gas Toxicities and Smoke Particle Characteristics

During Combustion of Mine Ventilation Ducts. Development of a Test
Parameter. BuMines RI 9284, 1989, 11 pp.

4. ___. Utilization of Smoke Properties for Predicting Smoke Tox-
icity. Paper in Recent Developments in Metal and Nonmetal Mine Fire
Protection. BuMines IC 9206, 1988, pp. 72-77.

5. __. Primary Gas Toxicities and Smoke Particle Characteristics
During a Two-Stage Combustion of Mine Conveyor Belts. Development
of a Test Parameter. BuMines RI 9250, 1989, 13 pp.

6. ___. Primary Gas Toxicities and Smoke Particle Characteristics
During Combustion of Mine Brattices. Development of a Test Parame-
ter. BuMines RI 9262, 1989, 13 pp.

7. ___. Embedded Hydrogen Chloride and Smoke Particle Charac-
teristics During Combustion of Polyvinyl Chloride and Chlorinated Mine
Materials. BuMines RI 9368, 1991, 13 pp.

8 ___. Hydrogen Cyanide and Smoke Particle Characteristics
During Combustion of Polyurethane Foams and Other Nitrogen-
Containing Materials. Development of a Test Parameter, BuMines
RI 9367, 1991, 15 pp.

Ye US.@P0: yee1—s11-oreunoes

9. Setchkin, N. P. A Method and Apparatus for Determining the
Ignition Characteristics of Plastic. J. Natl. Bur. Stand., v. 43, Res.
Pap. 2052, Dec. 1949, pp. 591-608.

10. Fristrom, R. M. Chemistry, Combustion and Flammability.
J. Fire & Flammability, v. $, Oct. 1974, pp. 289-320.

11. Hindersinn, R. Fire Retardancy in Encyclopedia of Polymer
Science and Technology. Wiley, Suppl. v. 2, 1977, pp. 270-339.

12, Morimoto, T., T. Mor, and S. Enomoto. Ignition Properties of
Polymer Evaluated From Ignition Temperature and Ignition Limiting
Oxygen Index. J. Appl. Polym. Sci, v. 22, 1978, pp. 1911-1918,

13, Fenimore, C. P., and F, J. Martin. Flammability of Polymers.
Combust. and Flame, v. 10, 1966, pp. 135-139.

44, Yeh, K, and R. H. Barker, Pyrolysis and Combustion of Cellu-
lose, Part IV. Thermochemistry of Cotton Cellulose Treated With
Selected Phosphorus-Containing Flame Retardants. Text. Res. J,,v. 41,
1971, p. 932.

15. Benisek, L., M. J. Palin, and K. Woollin. Fair and Realistic Flam-
mability Tests for Carpets. J. Fire Sci, v. 6, Jan.-Feb. 1988, pp. 25-41.

16. Bloczowski, W., R. Cole, and R. F. McAlery. An Investigation of
the Combustion Characteristics of Some Polymers Using the Diffusion
Flame Technique. Stevens Inst. Technol. (Hoboken, NJ), Tech. Rep.
ME-RT-11004, June 1971, pp. 130-135.

17. Steingiser, S. A Philosophy of Fire Testing. J, Fire & Flammabil-
ity, v. 3, July 1972, p. 238,

18, Litton, C. D., L. Grayhead, and M. Hertzberg. A Submicrometer
Particle Detector and Size Analyzer. Rev. Sci. Instrum., v. 50, No. 7,
1979, pp. 817-823.

INT.BU.OF MINES,PGH.,PA 29491


UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT

degree Celsius L/min _ liter per minute
centimeter min minute
square centimeter per pm micrometer
particle
p/cm? particle per cubic
gam centimeter
inch pet percent

liter s . second



RESULTS AND DISCUSSION

At 150° C set furnace temperature (unsustained smol-
dering stage of combustion), all materials soldered lightly
for a very short period of time, yielding small particle con-
centrations. The PVC brattice, the PVC belt, and the
wood samples, followed by the jute brattice and the SBR
belt samples, yielded the earliest onset time of smoke
Particles, ranging between the sixth minute for the PVC

materials and the wood, and the eighth minute for the
other materials (table 2 and figures 4 and 5). The coal
sample, followed by the fiberglass brattice and the neo-
prene belt samples, yielded the latest onset time, ranging
between the 11th minute for the coal and the 9th minute
for the fiberglass brattice and the neoprene belt.

Table 2.-Thermal decomposition data at set furnace temperatures of 150°, 250°, and 1,000° C.
(Furnace alrflow of 10-L/min for a 14-min duration),

Material?

Ar onset time of smoke panicles

Attia of maximum smoke particle generation

To Toft 10° dy, F temp, Tmax, = Ty, Tmax ny, dy Ftemp, Total
min p/em? om c min min 10° p/om? am Cc WL, 9
150° C
Conveyor belt:
PVC (Pt)... 6 0.01 0.002 190 7120 «6 0.4 = 0.2  0.004-0.009 190-170 0.0
Neoprene (N1) 9 26 003 183 112 3 3 + 4 004 008 179-170 0001
SBR(S1)... 8 13 001 187 9120 4 3 + 4 002 003 18317005
Brattice:
PVC (BI)... 6 01 012 190 TA2 «6 03 2 015 002 190-170 .05
Fiberglass (Fi) 9 o 559 213 10123 31 8 125-418 180-170 .0001
vute (Jt)... 8 47 001 187 12 4 20 = 25 001+ 001 187-170 05
Coal (C1) . " 1 022 195 2 01 05.007 176.0001
Wood (W1) 6 9 001 190 TAZ 6 10 -- 35 «008 .001_—*187-179 05
250°C
Conveyor Belk:
PVC (Pt)... 5 0.12 0.001 257 64 9 06 - 4 — 0.001-0.014 294.277 0.08
Neoprene (Ni) 8 2 474 304 om 6 3-11 004 001 304-277 02
SBR (81) . 7 18 005 304 B14 7 BT A704 003 304-277 «15
Brattice:
PVC (BI)... 5 14 776 172 6149 As 1 271 238 286-270 45
Fiberglass (F1) 8 a 014 310 94 6 5 018 .003 298-270 .001
vuteVt)... 7 at .003 294 a4 7 Bt 004-004 271-274 42
Coal (C1)... 10 a 022 272 W444 4 021-001 265-268 03
Wood (W1) . . 5 1 002 294 64 9 ot 010-012 271-286 32
1,000° C
Conveyor belt:
PVC (Pt)... 4 0.12 0.028 300 512 8 0.19-126 1.4 0.004 307-565 0.99
Neoprene (Nt) 7 10 .053 350 e147 (267 = 2 020-008 392565 99
SBR(S1)... 6 66 341 307 TAZ 6 140-190 060- 020 350-585 89
Brattice:
PVC (BI)... 4 10 284 228 510 6 «a7 Bt 053- 062 286-520 99
Fiberglass (Fi!) 7 40 001 355 a2 8 75-29 003 003 398-578 .09
dute(Wt)... 6 1.6 002 307 710 4 150-115 004.004 331-550 62
Coal (C1) ..... 9 a 016 374 10165 3-10 248 052 414-555 27
Wood (Wi).... 4 16 002 238 510 6 230-86 ~—004- .003 286-550 98
q ‘Smoke particles’ average diameter at time of smoke particle onset and at time of maximum smoke particle generation,
Ftemp Furnace temperature at time of smoke particle onset and at time of maximum smoke particle generation.
PVC Polyvinyl chloride,
SBR Styrene-butadiene rubber.
Ts Duration time of maximum smoke particle generation.
Tmax Time of maximum smoke particle generation.
Tmaxn, Smoke particle concentration at maximum generation time.
T, ‘Smoke particle onset time.
Ton, ‘Smoke particle concentration at onset time,
. Weight loss, “

14.9 sample.


INTRODUCTION

In 1984, the U.S, Bureau of Mines, within its mission to
create and maintain safety in the mines and, specifically, to
assess the hazard of mine materials during fire, initiated a
series of experiments to characterize smoke particles and
primary gas toxicities evolved during the combustion of
mine materials. It was found (1-8)? that the product (d,n,)
of smoke particles’ average diameter (d,) and particles’
average concentration (n,) varied with the main toxicities
evolved during the combustion of chlorine-containing
(hydrogen chloride and carbon monoxide) and nitrogen-
containing (hydrogen cyanide and carbon monoxide)
materials. The earlier and faster these types of materials

burnt, the earlier and faster the main toxicities evolved,
and the larger (nitrogen-containing materials) or smaller
(chlorine-containing materials) the dn, values were.

Could a simple test method be developed for the pre-
diction of materials’ most important fire parameter such as
materials’ ease of combustion? In the present study, the
Bureau carried out experiments to develop a simple test
method for the evaluation of these fire parameters by
studying the onset time of smoke particles (T,), and the_
time of maximum smoke particle generation (Tmax) and
its duration (T,).

BACKGROUND

The first line of defense of any material against fire is
its resistance to combustion. Many tests have been devel-
oped to examine materials’ fire parameters. These tests
determined the time at which temperatures shoot up
[Setchkin test (9)]; the time to ignition [Fristrom test (10)
and intermittent flame test (72)], the time to ignition by
gradually varying the oxygen concentration [limiting oxy-
gen index test (12) and American Standard Test Meth-
od (ASTM) D2863 (3)], the rates of heat release in a

controlled atmosphere [calorimetric method (14)], the
flame spread [2-ft-tunnel test (15)], and finally, the burning
rates [opposed flow diffusion flame test (16-17)].

The majority of these tests, however, allow for arbitrary
observations and conclusions; other tests allow extremely
small variances between the passing and failing ratings;
above all, numerous and complicated tests are needed for
the evaluation of a few selected fire parameters.

EXPERIMENTAL SYSTEM

The system (fig. 1) consists of an approximately 20-L
furnace whose temperature during experiments rises auto-
matically from-ambient (fig. 2) at a rate depending on the
set furnace temperature, which ranges from 100° to
1,200° C. The experimental temperatures are monitored
continuously with type K thermocouples connected to a
strip-chart recorder. A universal load cell, located under
the furnace floor and contacted by a sample-cup pedestal,
transmits voltages of sample mass weight loss via a bridge
amplifier to another strip-chart recorder. A vacuum pump
draws ambient air (10 L/min) continuously into the

furnace via an opening on the furnace door and sends the
resulting combustion air through a quartz tubing to the
submicrometer particle detector analyzer (SPDA) (18) and
the exhaust hood.

Flowmeters, installed between the pump outlet and the
SPDA, provide visual flow indication. Data of furnace
temperature, sample weight loss, and SPDA voltages, used
to compute n, and d,, are continuously acquired, mathe-
matically treated, logged, filed, displayed, and plotted by
means of a miniframe computer via a laboratory-based
real-time data acquisition system.

EXPERIMENTAL PROCEDURE

Three sets of experiments (eight experiments in the set;
each experiment repeated three times) were performed at
set furnace temperatures of 150° (unsustained smoldering
stage of combustion), 250° (sustained smoldering stage of

Italic numbers in parentheses refer to items in the list of references
at the end of this report.

combustion), and 1,000° C (flaming stage of combustion)
(fig. 2) for a 14-min duration with 1-g samples of poly-
vinyl chloride (PVC) (P1), neoprene (N1), and styrene-
butadiene rubber (SBR) (S1) mine conveyor belts; PVC
(B1), fiberglass (F1), and jute (J1) mine brattices; coal
dust (C1); and wood shavings (W1). A list of the mate-
tials is reported in table 1. A 1-g sample was placed in a
2.5-cm-diameter sample cup, inserted in a quartz (70-cm)


PREDICTING MATERIALS’ EASE OF COMBUSTION:
DEVELOPMENT OF A SIMPLE TEST METHOD

By Maria |. De Rosa’ and Charles D. Litton?

ABSTRACT

The U.S. Bureau of Mines conducted experiments for predicting materials’ ease of combustion
(smoldering onset, smoldering, flaming, and decomposition rates) by means of submicrometer smoke
particle characteristics for the development of a simple test method. The experiments were carried out
in an approximately 20-L furnace, with a 10-L/min airflow through the furnace for a 14-min duration,
at set furnace temperatures of 150°, 250°, and 1,000° C.

The variables studied as a function of time were the onset time of smoke particles, time and duration
of maximum smoke particle generation, average concentration of smoke particles, and particles’ average
diameter, mass weight loss, and furnace temperatures. Results show that the onset time of smoke
particles is predictive of materials’ ease of smoldering, and the time of maximum smoke particle
generation and its duration, coupled with mass weight loss, are predictive of materials’ ease of
smoldering and flaming (depending on the experimental temperatures), and decomposition rates,

‘Industrial hygienist.
?Supervisory physical scientist.
Pittsburgh Research Center, U.S. Bureau of Mines, Pittsburgh, PA.


pedestal, and the furnace was set at the desired temper- where Ic = SPDA charged particle current,
ature with a 10-L/min airflow through the furnace for a
14-min duration. The resulting combustion air was di- and dn, + dy = n,.
rected (1.6 L/min) into the SPDA, and the remaining air
was directed under the exhaust hood. Under each set
furnace temperature, the variables studied were T, Table 1.—Materlals Investigated
(minutes), smoke particles of average concentration
(particles per cubic centimeter) and d, (centimeters Material Description Oh,
teported as micrometers), at onset time; Tmax (minutes) = oa pet
and T, (minutes), smoke particles of average concentration nveyor belt:
(Tmax n,) (particles per cubic centimenter) and d, (centi-. PY (P1) -.._ Polymer component is PVC with 23
meters reported as micrometers), at maximum generation Neoprene (N1) Polymer component is neoprene rubber 11
time. The data of n, and d,, calculated at 10-s intervals, with fillers,
were reported as average for each minute. Other variables ‘SBR (S1) ... _ Polystyrene-butadiene rubber treated 5
studied were the total mass weight loss (grams) and fur- for fire retardancy with chlorinated
, Fs . additives.
nace temperatures (degrees Celsius). The d, is obtained Brattice:
by calculating d,n, (particles per square centimeter) from PVC (B1) ... Polymer component is PVC with 28
the ratio of the SPDA experimental (with smoke) and ini- fillers.
tial (without smoke) current output (Ie/Io), following the Fiberglass (F1) Fiberglass (<90 pet) fibers treated for 5
relationships in equation 1 (see also figure 3). fro retarciency with chlorinated
(Kan) dute (J1) ... Jute fibers treated for fire retardancy 5
Te/Io = 1/(K dgn,) (1-exp ), (1) with chlorinated additives.
Coal (C1) ..... Coal dust (200 mesh), Pittsburgh 0
where K = charging constant (K 0.012, cm?/p). Seam.
. . . Wood (W1).... _ Pine wood shavings, untreated )
Once the dyn, is determined, d, can be obtained from PVC Polyvinyl chloride.
equation 2: ofan. -t SBR _Styrene-butadiene rubber.
dg = (exp) (te), 0)
1.0 TTT 4417 T1111 4777 1-1-1117
QF 4
et Te/Ip = 1/K dgng (1-expt-K dane) 4
7r a
6 4
-?
NS, 5 PF 4
°
-
467 4
Fr 4
2b 4
Ar 4
0 n peop itl n pe 1 a as |
Ol | 10 100

K dgno

Figure 3—Submicrometer particle detector analyzer (SPDA) current ratio (le/lo) as function of smoke particle diameter and

concentration product (dgng).



IRI] 9398

Predicting Materials’ Ease of Combustion:
Development of a Simple Test Method

By Maria |. De Rosa and Charles D. Litton

UNITED STATES DEPARTMENT OF THE INTERIOR

BUREAU OF MINES


T TT T
Set furnace temp, 50° C

KEY
\ @Pl aFi
BBloci

T T T T
Set furnace temp, |,000° C

TTT
TTTTIT
SL

Liit

1
1

TOT TTTiny
fameentt|
Lt iiil

Ten

TT TTTITT
bt ditt

n

wet tail
T TT TTMy
Liviu

dg, pm
TTT

10°3 l | | i J n 1
4 6 8 1 (2 14
| T .
E Set furnace temp, 250° C TIME, min
lol E
102

TTT

10
4 6 8 1 2 14

TIME, min

Figure 5.—Average diameter of smoke particles (d,) versus time at set furnace temperatures of 150°, 250°,
and 1,000° C. (P1 = polyvinyl chloride belt, B1 = polyvinyl chloride brattice, F1 = fiberglass brattice, C1 = coal)


Also under the 150° C conditions, the PVC materials
and the wood, followed by the jute brattice and the SBR
belt samples, yielded the earliest time of maximum smoke
particle generation, ranging between the seventh minute
for the PVC materials and the wood, and the ninth minute
for the jute brattice and the SBR belt (table 2 and
figures 4 and 5), with a duration time of 6 min for the
PVC brattice, the PVC belt, and the wood, and 4 min for
the jute brattice and the SBR belt (table 2 and figure 4).
Small but observable weight loss were observed for these
materials, ranging between 5 pct for the brattices, the
wood and the SBR belt, and 1 pct for the PVC belt. The
coal, followed by the fiberglass brattice and the neoprene
belt, yielded the latest time of maximum smoke particle
generation, ranging between the 12th minute for the coal.
and the 10th minute for the fiberglass brattice and the
neoprene belt, and the shortest duration time, ranging
between 1 min for the coal and 3 min for the fiberglass

10" -——___, 3 10.00
F Set furnace temp, 150°C
| KEY J
@PlaFi
10° E-mBlocl y #100
10° q qo
2 108 Lg — |
&
> = 100
¢
10
I

4 6 8 O 2
TIME, min

14

Figure 4.—A\
atures of 150°,

brattice and the neoprene belt. Insignificant weight loss
(0.01 pct) were observed for these materials.

At 250° C set furnace temperature (sustained smol-
dering stage of combustion), the PVC materials and the
wood, followed by the jute brattice and the SBR belt,
yielded the earliest onset time, ranging between the fifth
minute for the PVC materials and the wood, and the sev-
enth minute for the jute brattice and the SBR belt. The
coal, followed by the fiberglass brattice and the neoprene
belt, yielded the latest onset time, ranging between the
10th minute for the coal, and the 8th minute for the brat-
tice and the belt (table 2 and figures 4 and 5).

Also under the 250° C conditions, the PVC materials
and the wood, followed by the jute brattice and the SBR
belt, yielded the carliest maximum generation time, rang-
ing between the sixth minute for the PVC materials and
the wood, and the eighth minute for the jute brattice and
the SBR belt. These materials also yielded the longest

10°

F Set fumace
| temp, 000°

TT

10" 100
10° 10

4 6 8
TIME, min

lo l2 14

a
oO
g
bE
x
9
w
=
n
7)
<
=
a
6
<4

j@ concentration of smoke particles (ng) and mass weight loss versus time at set furnace temper-
, and 1,000° C. Far right measurements taken at end of 14th minute. (P1 = polyvinyl chloride belt,

B1 = polyvinyl chloride brattice, F1 = fiberglass brattice, C1 = coal)



Exhaust

| |

Exhaust

1S
‘sampling &
port

Experimental furnace,

“Hood

Flow-

Infrared
gas analyzers

Exhaust

Q by 9 by 14 in Nalve Quartz tubing,
i
Thermo- 4 idiam by 3 ft long
couples yy U u I
Air — Gas i
sampling Sampling ports
port
‘Sample
Temperature
control Heating element
Load cell
and
accessory Brege (
amplifier Strip-chart recorders
Weight loss Temperature

FURNACE TEMP, °C

Figure 1.—Experimental system. (SPDA = submicrometer particle detector analyzer)

250

200

150

100

50
350
300
250
200
150
100

50

e
elt

pititit

°
Set furnace temp, 250°C

024 6810 12 14

TIME, min

r 700;>—+ ——1+—+
r 600 ef
1 e
I J 500 . 4
e e
e
L 4 400 J
e
f° | 300 ° 4
= 4 e
200
[ © Set furnace temp, 150°C Set fursaee comes
Pe ee ee ee 100 ha 2 1 1 4 1
o 2 6 8 0 2 14
eo TIME, min
e

eT

Figure 2.Furnace temperature versus time at set furnace temperatures of 150°, 250°, and 1,000° C.


CONTENTS

z

Abstract .....
Introduction
Background ..
Experimental system .
Experimental procedure
Results and discussion .
Conclusions . .
References ...

WOUNNNNHE

ILLUSTRATIONS.

1, Experimental system ............2005

2. Furnace temperature versus time at set furn: pers 1X

3. Submicrometer particle detector analyzer current ratio as function of smoke p particle diameter and
concentration product 1.0.6... cece cece cence ence eee e ence en ence nese teteeeteeeees 4

4, Average concentration of smoke particles and mass weight loss versus time at set furnace temperatures

ww

of 150°, 250°, and 1,000° C 6
5. Average diameter of smoke particles versus time 7
1. Materials investigated 4

2. Thermal decomposition data at set furnace temperature:
10-L/min for a 14-min duration) ......... 6... e ccc cee cece e ence ene eee eeneeeeeneeeaeee 5



Library of Congress Cataloging in Publication Data:

De Rosa, Maria I.
Predicting materials’ ease of combustion : development of a simple test method /
by Maria I. De Rosa and Charles D. Litton.

P- cm. — (Report of investigations; 9398)
Includes bibliographical references (p. 9).
1. Mining engineering—Materials—Thermal properties. 2, Mining engineer-
ing—Materials—Flammability. 3. Smoke~Measurement. I. Litton, C. D. (Charles

D.) IL Title. II. Series: Report of investigations (United States. Bureau of
Mines); 9398,

TN23.U43 [TN315] 622 s—dc20 [622’.82] 91-31202 CIP



Report of Investigations 9398

Predicting Materials’ Ease of Combustion:
Development of a Simple Test Method

By Maria I. De Rosa and Charles D. Litton

UNITED STATES DEPARTMENT OF THE INTERIOR
Manuel Lujan, Jr., Secretary

BUREAU OF MINES
TS Ary, Director


duration time of 9 min for the PVC materials and the
wood, and 7 min for the jute brattice and the SBR belt
(table 2 and figure 4). Large weight losses were observed
for these materials, ranging between ~45 pct for the
brattices, 32 pet for the wood, 15 pet for the SBR belt, and
8 pet for the PVC belt. The coal, followed by the fiber-
glass brattice and the neoprene belt, yielded the latest
maximum generation time, ranging between the 11th min-
ute for the coal, and the 9th minute for the brattice and
the belt. These materials also yielded the shortest dura-
tion time, ranging between 4 min for the coal, and 6 min
for the brattice and the belt. Small weight loss were
observed for these materials, ranging between 3 pct for the
coal, 2 pet for the belt, and 0.1 pct for the brattice.

At 1,000° C set furnace temperature (flaming stage of
combustion), the PVC materials and the wood, followed by
the jute brattice and the SBR belt, yielded the earliest
onset time, ranging between the fourth minute for the
PVC materials and the wood, and the sixth minute for the
brattice and the belt. The coal, followed by the fiberglass
brattice and the neoprene belt, yielded the latest onset
time, ranging between the ninth minute for the coal, and
the seventh minute for the brattice and the belt (table 2
and figures 4 and 5).

Also under the 1,000° C conditions, the PVC materials
and the wood, followed by the jute brattice and the SBR
belt, yielded the earliest maximum generation time, rang-
ing between the fifth minute for the PVC materials and
the wood, and the seventh minute for the brattice and the
belt; with a duration time ranging between 6 min for the
PVC brattice, the wood, and the SBR belt (total weight
loss of 100 pct); 8 min for the PVC belt (total weight loss
of 100 pct); and 4 min for the jute brattice (total weight
loss of 100 pct). Evidently, the short duration time is due
to early, fast, and complete thermal decomposition of the
samples (table 2 and figure 4). The coal, followed by the
fiberglass brattice, yielded the latest maximum generation
time, ranging between the 10th minute for the coal, and
the 8th minute for the brattice; with a duration time of
5 min for the coal (total weight loss of <30 pet) and for
the brattice (total weight loss of <1 pct). The short
duration time for these latter materials is due, evidently, to
incomplete thermal decomposition (coal), and to extremely
low thermal decomposition (brattice). Surprisingly, the
neoprene belt, yielding a maximum generation time at the
eighth minute, with a duration of 7 min, underwent com-
plete thermal decomposition (total weight loss of 100 pct).

CONCLUSIONS

The PVC brattice, the PVC belt, and the wood shavings
samples, followed by the jute brattice and the SBR belt
samples, decompose much earlier and at faster rates than
the coal and the fiberglass brattice samples, at every set
furnace temperature tested. The neoprene belt sample de-
composes earlier, burning at faster rates, only at set
furnace temperatures of 1,000° C.

During the unsustained smoldering stage of combustion.
(~200° C), the PVC belt, the wood shavings, the jute
brattice, and the SBR belt samples yielded smoke particles
earlier and for longer periods of time, undergoing small
but measurable weight loss. On the contrary, the coal, fol-
lowed by the fiberglass brattice and the neoprene belt,
yielded smoke particles much later, for shorter periods of
time, undergoing insignificant weight loss.

During the sustained smoldering stage of combustion
(~300° C), the PVC materials and the wood, followed by
the jute brattice and the SBR belt, yielded smoke particles
earlier and for longer periods of time in large quantities,
undergoing significant weight loss. On the contrary, the

coal, followed by the fiberglass brattice and neoprene belt,
yielded smoke particles later and for shorter periods of
time in smaller quantities, undergoing small weight loss.

During the flaming stage of combustion (>400° C), the
PVC materials’, the wood, the jute brattice, and the SBR
belt samples, and surprisingly, the neoprene belt sample
yielded smoke particles at the earliest time, in extremely
large quantities, undergoing complete thermal decomposi-
tion in a very short time. On the contrary, the coal and
the fiberglass brattice yielded smoke particles later and for
shorter periods of time, undergoing small weight loss.

In conclusion, the onset time of smoke particles is
predictive of materials’ smoldering onset, and the time of
maximum smoke particle generation and its duration, cou-
pled with mass weight loss, are predictive of materials’
ease of smoldering and flaming (depending on the experi-
mental temperatures), and decomposition rates. This pre-
diction may allow the development of a simple, inexpen-
sive, and efficient test method for the evaluation of
materials’ most important fire hazard parameters.