FHv" T GBT USn^EY

NATIONAL BUREAU OF STANDARDS REPORT

^-169

EXAMINATION OF THE GASEOUS COMBUSTION PRODUCTS

OF SEVERAL INTERIOR FINISHES

by

Alan Schriesheim

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
U. S. DEPARTMENT OF COMMERCE

Sinclair Weeks, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

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NATBONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1002-30-h-850 June 2b-, 1955 b-169

EXAMINATION OF THE GASEOUS COMBUSTION PRODUCTS

OF SEVERAL INTERIOR FINISHES

by

Alan Schrlesheim

Floor j Roof and Wall Covsrings Soction

Building Technology Division

for

Uo So Air Force Installations Representative

North Atlantic Region

Cross Servicing Order and Acceptance

No, CS0-92O-55-i+l

and subsequent amendments

<NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, rep

unless permission Isi 25,D,C. Such pern

cally prepared If th

Approved for public release by the "

Director of the National Institute of

ort has been speclfi- Standards and Technology (NIST)

on October 9, 2015.

f

TABLE OF CONTENTS

Page

1. INTRODUCTION 1

2. MATERIALS 2

3. METHODS 2

3.1 Combustion Method 2

3.1.1 Apparatus 2

3.1.2 Sample-Air Ratio 3

3.1.3 Combustion Procedure 4

3.1.^ Sample Size Variation with Temperature 4- 3.1.5 Collection of Combustion Products 6

3.2 Analytical Methods 7

3.2.1 Mass Spectrometer Determinations 7

3.2.2 Carbon Monoxide 7

3.2.3 Hydrogen Chloride Determinations 7

4. TOXIC HAZARDS 8

4.1 Carbon Dioxide 8

4.2 Carbon Monoxide ‘ 9

4.3 Hydrogen Chloride 10

4.4 Benzene 10

4.5 Toluene 11

4.6 Sulfur Dioxide 11

4.7 Other Gases 12

5. RESULTS OF THE COMBUSTION GAS ANALYSES 12

5.1 Chlorine-Containing Vs. Chlorine-Free

Interior Finishes 12

5.2 Plywood-Backed Vs. Unsupported Interior

Finishes 13

5.3 Application of Experimental Results to

Field Conditions l4

REFERENCES 15

FIGURES

EXAMINATION OF THE GASEOUS COMBUSTION PRODUCTS

OF SEVERAL INTERIOR FINISHES

by

Alan Schriesheim

ABSTRACT

An examination was made of the gaseous combustion products of several interior finishes at three temperatures. The

gases included many that were toxic. For each material, the

amount of gases varied depending upon the combustion temperature .

1. INTRODUCTION

An investigation was carried out on the gaseous combustion

products of several wall covering materials. It was anticipated

that some of the gases might be toxic and, in particular, that

those materials containing chlorine might give rise to hydrogen

chloride and phosgene.

The principal gases arising from the combustion of organic

materials in air are carbon monoxide and carbon dioxide. However, when elements other than carbon, hydrogen, and oxygen are

present, there is a possibility that the combustion will produce

several kinds of toxic gases. Thus, hydrogen chloride, ammonia,

cyanogen, and sulfur compounds have been found with materials

such as chlorinated hydrocarbons, wool, silk, and rubber, respectively (1-4) Generally

the toxic hazard of these gases is

small when compared to that of the carbon monoxide produced in

the combustion.

In order to study the gases that were produced upon combustion of some interior finishes, an apparatus was designed and

built in which the materials could be burned at various temperatures and in fixed amounts of air. Also, a series of chemical

1/

The numbers in parentheses indicate references at the end of

this paper.
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tests was devised whereby the gaseous combustion products could

be analyzed and any toxic gases present determined.

2. MATERIALS

The materials used and the methods of preparing the specimens are described on pages 1 to 5 of N.B.S, Report ^120,

"Evaluation of Flame Spread and Vapor Permeability Properties

of Interior Finishes" (5). These materials were received in

sheets approximately 1 ft, by 1 ft, and samples of appropriate

area were cut from these sheets with a hacksaw.

This cutting was done by slicing off the outer phenolic

bonded layer of the plywood. Then the required area was marked

off on this outer layer so as to give several strips 1/h in,

wide that fitted into the combustion boats.

The paint films were made by appling the paint to gummed

dextrin paper with a paint brush and the paint allowed to

dry. Strips of appropriate area were cut from these sheets

and placed in water so that the paint film floated free of the

paper. This film was then dried and used.

Table 1 lists the materials along with the specimen numbers, which are identical with those in N.B.S. Report hl20.

In addition to the materials listed in Report 4120, an additional surface finish, Saran, was included. This material is

listed in Table 1 as Specimen 42.

3. METHODS

3,1 Combustion Method

3.1.1 Apparatus

The experimental method used in this study involved the

building of an apparatus in which a given amount of sample

could be burned in a known volume of air.

2/ Figure J^'is a photograph of the entire apparatus which is

shown schematically in figures 1 and 2,

2/All Figures are grouped at the end of this report.


Table 1. Schedule of specimen assemblies for tests

Under the specimen number the letters of the alphabet are placed on fire or high humidity, b the next material, etc. The average coverage of

2.1 through 2,20 for descriptions of materials.

N. Specimen \ No.

Material

1 2 3 h y 6 8 9 10 11 12 13

SK (2 cts,330 ft^/gal ea)

Albi 99 (1 ct 200 ft2/gal)

Dex

Dp-y R

a

a a a a

PI

a

h

a

a a

Dxpr

A1

Crlx No, 1

Crlx No, 2

b b 0

b a b b

Crlx No. 3

PVA

Flkt (1 ct,250 ft2/gal)

Flpr (1 ct,250 ft2/gal)

Prlu (l ct,h60 ft^/gai;

Prph (1 ct,4h0 ft^/gal)

A1 Life-F (1 ct, 650-700

nUgaJj

A1 Life-V (1 ct , 4-kO- f t2/gal

)

A1 Life-P (1 ct,35 ft2/gal)

- SK UK ahnvp) h r* c. n Kerl 7 (2 cts,125 fi:;r/gal ea)

Ker^8 (2 cts,125 ftb/gal ea

)

BdrF (2 cts, ±2 5 it^-/gal ea

)

Fba.a 11 Qt. U2,_fJ.2 /^al)

Xply

Har

SK (as SK above)

a

a b b c c d d d b d

d

e

TESTS —Flamp .qp-ppa<i X X X X X X X X X X y Y Y

Jannr nermeabilitv X X X , X X X

- - -Decomnosition products X X X X X X

Flammabi i ity

*Tested with 2h hours air-dry curing j no accelerated curing.
line with the materials used; the letter a being the materia.', exposed to

material is given in parentheses after the name abbreviation. See Sections

14 15 16 17 00 19 20 21 22 2h 25 26

1 31 32 33 3^ 35 36 37 38 39 40 4l

a a

a

a

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a ah

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a

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a

b

a

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1 Lc

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a

a

a

c c

c e d c c c b

b b b b ef

b

b,

b

r,

c

d

X X X X X X -X- X V y X X y Y Y Y

X X X X X Tf X X Y X Y V Y

X X X X X X X X X X X X X

X
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The combustion furnace, figure 2, was constructed of pyrex

glass, except for the central combustion chamber extending down

its center. This chamber was a short length of silica combustion

tubing that had been sliced in half horizontally for half of its

length. The chamber was sealed to the walls of the reaction

vessel through a graded silica-pyrex seal.

A strip of mica, 3«5 in. by 1.2 in., was placed on top of

the open part of the silica tube, and twenty feet of 28 gauge,

B.S. platinum wire, coiled in 1/^ in. diameter spirals, was

wound around the silica tube and over the mica strip. This

arrangement allowed the sample to remain in the cool end of the

silica tube until the platinum coil reached the desired temperature. Inclining the combustion furnace caused the specimen

to slide down the silica tube into the hot platinum coil.

A thermocouple was Incorporated into the apparatus in

order to record the temperature. Both thermocouple and platinum lead-in wires entered the furnace through openings that

were sealed gas tight with woods metal.

The neck of the 2-1. furnace flask was replaced by a 55/50 ground glass female joint, and the open end of the pyrex

tube consisted of a 55/50 ground glass male joint. The two

halves of the apparatus were held together by the two springs

shown in figure 2.

The combustion furnace was attached to the vacuum manifold through the spiral, figure 1, and the ball joint. This

spiral was constructed of 7 innio pyrex tubing that had been

coiled into 5 circles each having a diameter of 6 inches.

The combination of spiral and ball joint provided enough elasticity so that the combustion furnace could be inclined without snapping a glass part,

3.1.2 Sample-Air Ratio

Burning a specimen in the foregoing apparatus corresponded

to the burning of a surface finish in a closed room. In order

to duplicate service conditions, the volume of an unventilated

unit which was in use in the field was calculated. From a knowledge of this volume and the volume of the reaction vessel, a

sample size was determined that yielded the same area-volume

ratio as in field use.
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The ratio of sample to air used in this study was , 21.6 cm. /2 5 230 cm. 3 5 and was obtained by assuming that the

walls and ceiling were covered by the surface finish.

3.1.3 Combustion Procedure

The specimen^ of appropriate area^ was weighed into a

porcelain combustion boat and the boat placed in the silica

tube as far from the platinum coil as possible. Then the

2-1. glass bulb was placed in position^ the two springs

attached, and the current turned on.

The vessel was evacuated by opening the stopcock to

the vacuum manifold. This evacuation was necessary to remove any organic vapors that might be present which would

lead to spurious readings on the mass spectrometer. After

evacuation, the vacuum stopcock was closed and the draw-off

valve opened to the atmosphere. The latter valve was left

open until the combustion temperature was attained, as indicated by the thermocouple, and then closed.

After reaching the desired temperature, the combustion

chamber was inclined, as indicated in figure b, causing the

combustion boat containing the specimen to slide down the

silica tube into the platinum coil. Therefore, the specimen

was kept at, or near, room temperatures until the moment of

combustion, and the entire sample burned at a constant temperature. The pyrex flask was cooled by air jets shown in

figure 1.

Combustion was maintained for 12 min. , the current turned

off, and the apparatus allowed to cool to room temperature.

The gases were then collected as described in section 3,1, 5? and the boat taken out and weighed.

3.1.^ Sample Size Variation with Temperature

Under actual service conditions, a fire is initiated at

atmospheric pressure. This condition was duplicated in the

reaction vessel by allowing the draw-off tube to remain open

until combustion temperature was reached, and then closed.

- 5

The actual combustiorij however ^ was carried out under slightly

increased pressure because of the formation of gaseous products

in a closed systemo This pressure increase was recorded on the

manometer o A method that has been, used to allow the combustion gases

to expand utilizes a balloon into which the volatile materials

escape (l)o However® a balloon introduces errors arising from

(a) the difficulty o,f washing absorbed gases ^ as hydrogen

chloride, from the fabric; (b) the possible introduction of

organic vapors into the mass spectrometer; and (c) the diffusion of gases through the fabric®

Because combustion was carried out at three temperatures,

250°, ^00® and 550®C, different amounts of air were left in

the apparatus at the start of each combustion® Therefore, in

order to have a constant area-air ratio, ioS®, 21o6 cm® 2/2,230 cm,^

,

the volume of air at 2^®C was used as a reference standard and

the area of each specimen adjusted accordingly® This adjustment

was made using the following formulas

A2./A2

where

A]_ = Area of the sample at 25® C®

A2 = Area of the sample at combustion temperature®

= Pressure in the combustion furnace at 25®C®

P2 = Pressure in the combustion furnace at the combustion temperature®

Since A^ is known and and P2 can be measured, A2 is readily

calculated®

^ In practice, values of P2 were obtained before any combustions were made® This was done by allowing the combustion

temperature to be reached in the reaction vQjssel while it was

completely closed® The pressure at tnls temperature was recorded, and a graph made of pressure versus temperature® Values

of Pp to be put into equation 1 were read directly from this

graph which was linear over the range of temperatures, 250° C, ^00°C, and 550°C, used in this study* Thus, it was not
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necessary to measure P2 at the beginning of each run and the

draw-off tube was left open, as indicated previously, so as to

avoid any pressure buildup before a combustion.

3 . 1.5 Collection of Combustion Products

Several sample bulbs having volumes of 50 ml. and 2,000 ml.

were made. The 50 ml. bulb was used for the mass spectrometer,

figure 5, and the 2,000 ml. bulb was used for the carbon monoxide

analyses, figure 7, Before a run, each sample bulb was evacuated

by attaching it to the vacuum manifold.

After cooling the apparatus to room temperature, the

sample bulb was placed on the draw-off arm and the stopcock

from the furnace opened. In this manner, air that was in

the draw-off arm was mixed with combustion gases. The error

introduced by this air is negligible due to the small volume

of the draw-off tube compared to the volume of the furnace.

After the air and gases had mixed, the sample bulb stopcock

was opened and a sample of the gases sucked into the sampler.

The sampler was allowed to remain in this position for five

minutes to insure proper mixing. Then both stopcocks were

closed and the sample bulb attached either to the mass spectrometer or to the carbon monoxide apparatus.

After cooling the reaction vessel, a vacuum was invariably

present within the apparatus. In those cases where hydrogen

chloride was suspected, the draw-off tube was attached to a beaker containing dilute (pH =10) sodium hydroxide. This

solution was sucked into the reaction vessel and allowed to

stand for 15 minutes. Due to the high affinity of hydrogen

chloride gas for water, any of this gas not absorbed upon the

vessel walls was expected to dissolve in the base. After 15

minutes, the springs were removed and the solution poured into

a beaker. The reaction vessel was then washed several times

with distilled water and these water washings combined and

analyzed by the method described in section 3.2.3«

- 7

- 3.2

Analytical Methods

3.2.1 Mass Spectrometer Determinations

The mass spectrometer sample bulb containing combustion

gases was placed on the inlet system of the mass spectrometer

(figure 6). An analysis was carried out for gases having a mass number of 1 to 100. The analytical results are recorded

in Table 6.

The mass spectrometer was a Consolidated Engineering type

21-103.

3.2.2 Carbon Monoxide

Carbon monoxide was determined by two methods. When

present in concentrations of 1,000 parts per million or less,

the mass spectrometer was not sensitive enough to give an

accurate analysis. It was, therefore, necessary to use the

indicator technique (6). The 2,000 ml. sample bulb (figure 7)

was filled with combustion gases and the pressure reading on

the manometer recorded. The bulb was attached to a source of

carbon monpxide free air under pressure, and air allowed to

enter the flask until the pressure was slightly above one

atmosphere. Then the flask was arranged as in figure 8. The

stopcock was opened and the gases passed through the indicator

at a constant rate as determined by the flowmeter. At the

end of a given time period, the color of the indicator was

compared with a color chart and the amount of carbon monoxide

in the sample flask determined.

The amount of carbon monoxide present before air was

admitted was calculated from a knowledge of the initial and

final pressures. Carbon monoxide present in the furnace was

calculated from a knowledge of the initial and final volumes.

3 .2.3 Hydrogen Chloride Determinations

Hydrogen chloride was absorbed upon the walls of the

reaction vessel along with any water produced during the

course of combustiono Because of this absorption, it was not

possible to determine hydrogen chloride by means of the mass

spectrometer, and the following analytical method was used.
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The water washings that were received from the procedure

outlined in section 3«1.5 were adjusted to a pH of 6. 0-7.0

and titrated with standard ,1N silver nitrate using fluorescein as an indicator (7)« The weight of hydrogen chloride

was converted into moles of gas and the gas percentage calculated from a knowledge of the volume of the flask and the

volume occupied by that number of moles of gas at room temperature .

k, TOXIC HAZARDS

h,l Carbon Dioxide

Combustion always produced carbon dioxide. This gas, in

itself, is not toxic, but production of large amounts was

usually associated with a decrease in the oxygen content.

Since the burning operation corresponded to a combustion in a

completely closed room, a decrease in oxygen might liave a deleterious effect upon the occupants.

The lack of oxygen causes asphyxiation in human beings.

There are four stages (8) of asphyxiation and each stage corresponds to a definite oxygen percentage.

First Stage : When the oxygen content of the air is decreased from

the normal 21^ to between 12 and l6^ , the ability to think

is diminished and muscular coordination is disturbed. This

percentage is somewhat less than the amount of oxygen present at which a candle is extinguished (17^).

Second Stage ; When the oxygen diminishes to values between 10 and 1^^,

the higher centers of the brain are affected. Consciousness

remains, but judgment becomes faulty and muscular efforts

lead to rapid fatigue.

- 9

-

Third Stage ; When the oxygen diminishes to between 6 and 10^, movement

ceases and loss of consciousness results.

Fourth Stage : When the oxygen is diminished below 6^, respiration soon

ceases and life is maintained for but a few minutes,

4-, 2 Carbon Monoxide

Carbon monoxide is not a physiologically inert gas like

carbon dioxide. Its action depends upon a chemical reaction

in which the carbon monoxide combines with the blood hemoglobin (9)o Therefore, the hemoglobin is not available for

combination with oxygen and asphyxia results. The following

table indicates the maximum dosages and the resultant

physiological effectss

Table 2, Physiological Effects of Carbon Monoxide (9)

Parts of Carbon

Monoxide Per Million

Parts of Air Physiological Effects

100 Shortness of breath on vigorous

muscular exertion.

4-00 - 500 Shortness of breath on slight exertion;

occasionally slight headache.

600-700 Decided headache; easily fatigued.

1,000 - 2,000 Headache; collapse and fainting on

exertion.

1,500 - 2,000 Unconsciousness; respiratory failure

and death if exposure is continued.

4-, 000 and over Immediately fatal.

10 -

4o3 Hydrogen Chloride

On exposure to air, this gas forms dense white fumes from

the condensation of atmospheric moisture and the formation of

hydrochloric acid in minute droplets. Both the acid .droplets

and the gas are highly Irritating and make their presence

known in this manner (10).

The following table gives the physiological response of the

human body to various concentrations of the acid gas.

Table 3<> Physiological Response to Various

Concentrations of Hydrochloric Acid

Gas (10)

Parts of Hydrochloric

Acid Per Million Parts

of Air Physiological Action

10 Maximum concentration allowable

prolonged exposure.

for

10 - 50 Maximum concentration tolerable

few hours.

for a

oo

1

—

o 1 Maximum concentration tolerable

1 hour.

for

1,000 - 2,000 Dangerous for even short exposures.

Benzene

'Acute poisoning from benzene is generally due to its anesthetic action (11), Inhalation of high concentrations of benzene vapors may result in the rapid loss of consciousness,

followed in a short time by death from respiratory failure.

The following table lists the physiological responses of the

human body to various concentrations of benzene vapor.
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Table 4, Acute Physiological Response to Various

Concentrations of Benzene (11)

Parts of Benzene Vapor

Per Million Parts of Air Physiological Response

1,500 - 3,000 Slight symptoms after several hrs.

3,000 - 4-, 700 Maximum concentration that can be

inhaled for 1 hr.

7,500

19,000 and above

Dangerous to life in 1/2 to 1

Rapidly fatal.

hr.

5 Toluene

Toluene is generally similar in its physiological action

to benzene, and its toxic properties may be estimated from

table ho

4o6 Sulfur Dioxide

Sulfur dioxide is a colorless gas with an irritating

odor. In the presence of moisture, the dioxide is oxidized

and forms sulfuric acid. The following table lists its

physiological action.

Table Physiological Response to Various Concentrations of Sulfur Dioxide (12)

Parts of Sulfur Dioxide

Per Million Parts of Air Physiological Response

8 - 12 Causes throat irritation.

10 Maximum concentration for prolonged

exposure.

20 Immediate eye irritation and coughing.

50 - 100 Maximum concentration for short

exposure.

hOO - 500 Dangerous for short exposures.

12

h,7 Other Gases

The gases found in this study other than the ones previously mentioned were not present in amounts sufficient to

cause concern. Gases such as methane, ethane, and ethylene

act as anaesthetics and have to be present in amounts ranging from 30,000 to 50,000 p.p.m. to be harmful over long

exposure periods. For short exposures, much larger concentrations would have to be present to be toxic. There is no

information available on the toxic limit for short exposures.

Phosgene is decomposed by moisture into hydrochloric

acid and carbon dioxide. The reaction vessel was usually

coated by a thin moisture film after combustion, and no

phosgene was detected. Other investigators (1) have found

just detectable traces of phosgene upon burning chlorinated

plastics, but concluded that the toxic hazard represented

by this gas is negligible compared to that represented by

the hydrogen chloride and carbon monoxide.

The safe limit for methyl chloride and 1 ,2-dichloroethane is about 200,000 p.p.m. for short exposures (l4).

This concentration was never found for any of the materials examined.

5 . RESULTS OF THE COMBUSTION GAS ANALYSES

The materials used in this study, the temperatures at

which these materials were burned, and the analyses of the

gaseous combustion products are listed in tables 6, and 7.

5.1 Chlorine-Containing Vs, Chlorine-Free

Interior Finishes

Chlorinated (Specimens 5 ? 9 ? 17, 20, 21, 22, 35 > 39 and

42) and chlorine-free interior finishes were studied. The

principal gases produced from both types of finishes were

carbon dioxide and carbon monoxide. At the higher temperatures,

many different hydrocarbons were formed, usually including

methane, toluene, and benzene.


Table 6 I Concentration of Gases Evolved From Plywood Backed Interior Finishes

Materials Sped- Temp Concentration

men No

.

°C Carbon

Dioxide

Carbon

Monoxide

Oxygen Nitrogen Methane Methyl

Chloride

Har 1

250

400

550

8,400

194.000

171.000

Eoo ~

14.000

36.000

199,^00

27.000

28.000

783.000

742 . 000

719.000

14,000

9,800

Xply 2

-250—

400

550

437W

174.000

166.000

4 , 000

1,400

64,000

162,000

46,000

_ .19.700.

771.000

747.000

. 719,000 14^100

XplyjSK 3

246

400

550

12,000

110,000

168,000

6,000

3,600

47,000

196.000

112.000

26,700

781.000

744.000

:Z35.^ooo_..

2,800

8 ,i00 1

Xply;

Albi 99 4

250

400

550

12 , 400

12,900

180,000

4,000

10,000

32,000

200,000

168,000

23,300

771.000

799.000

746.000 6.100 II Xply;SK;

Dex 5

250

400

770

^~IE ,900

163.000

171.000

3,000

44.000

41.000

187,000

29,000

20,400

782.000

740.000

722 , 000 . 15,500

19,000 1,700 i

Xply ;Dexpr

i

Dex R;

Albi 99

9

250

400

440

20,000

62 , 000

141,000

600

12,000

86,000

198.000

142.000

23.400

769.000

740.000

697.000 16,000

1,500 1

3.900

3.900 ..i

Har ; Flpr

;

Flkt 16

240

400

550

13,000

161.000

174.000

3,000

14,000

60,200

218,000

71,000

2,700

744.000

740.000

704.000 1,300

i har ; Prph;

Prlu 17

240

400

440

28,000

140,000

,.172.500^

1,200

3,900

^ 8>+,300_|

184,400

70,000

24,700

772,200

768,000

687,300 13,600 400 j Xply ; Flpr

;

Flkt ; Pva;

Albi 99

18

240

400

440

12,300

ii4o,ooo

il77.,000

1,200

12,000

13,v000

200,000

40,000

28^000^

772.000

777.000

, 75.6 ,

,

000 .. 774.000

777.000

737.000

9^800 200

Xply; Prph;

Prlu;

Albi 99

19

240

400

1 10,400

100,000

184,000

600

10,000

43.000

203.000

103.000

16,100 ..5.30a 400

Xply;SK;

Crlx No. 1 20

240

400

440

u, 8 oo

176,200

147,000

1,200

600

132,000

200^800

27.000

26.000

772.000

773,100

641.000

7,300

19,000

4,300

4,300

j Xply;SK;

1 Crlx No. 2

1

i

! 21

i

240

400

440

2,800

!140,000

| 144,100

2.400

6.400

110,000-

184,400

46,000

2 4 , 100..

777,200

742 . 000

674.000 14.700 ... .30 . Xply;SK;

Crlx No. 3

)

1 22

240

400

440

! 7,400

112 7,200

il 42 . 000

1,200

400

104,000

202,000

23,000

. 26 , 900..

780.000

369.000

682.000

5,300

1,650.

2,900 1 2,400

! Fban

1

i

! 24

j

240

400

440

3,000

109.000

199.000

900

3,400

24,000

167,000

9,400

22,700

793.000

776.000

740.000

2,400

2. 500

Maximum Permissab]_e Concentrations

1

; Safe for Long Periods a 100 a 30,coc-40,coo b 1 Safe for -§--1 hr a 400-400 a b b

' Dangerous for Short a 1,500- a b b

1 Period (j-l hr) l^QDQ

aSee Section ^. 1 ; b see Section 4 , 7'.; where no results are reported, no
)ecomposed in Air by Heat

)f Gases. PoPoM» ^Loss

on

combustioi

. , 2 -Dichloroethane

Ethane Ethylene

Propylene

1 , 3~Buta^

diene

Benzene

Toluene Hydrogen

Chloride

Hydrogen

2b, 000 boo 70 100 Trace

10

b8

61

1,700 1.800 ItOO . 100 Trace 2.900

9

b 9

7b

1,800 im Trace

9

50

79

1.500 100 lAoo

8

b8

71

5,000 1,300 600 500

Trace

600

200

Trace

100

100

16,000

27,500

10,000 1.200

b

51

56

5,100 1„600 2 . 100 500

200

boo

80

_ _1D0

19,700

30,000

39.500 b.200

16

75

66

1,200 300 600 b.OOO

6

59

71

900 2,300 30 200 70

1,000

l,b00

3.500

2

5b

70

900 2,000 boo '

100

Trace

Trace

100

Trace

Trace

5

b3

71

2 , 300 100

1,000

1,450

3.600

1

b5

63

2,300

7,100 300

i

300

189

200

L ,000

189

200

boo

7 , 2

^

17,300

38,200 6 „ 900

19

35

2

bl

1.800 11.000 1.100 bio 700 200 50

1,7§0

2,270

.. . 5 , 5. 90 . 3...900

1,500

5. ‘too b .900

100

700

200

200

5,300

20,500

12 . 100 6.200

6

62

59 .

boo 100 _5go

ib

bl

57

of Toxic Gases: P.PoM. _

b

b

' b —30,000-50,000----

b b b

b b b

b

b

b

1,500-3,000

3,000-b,700

7,500

10

50-100

1,000-

2.000

gas was detectedo

£i. I

i

i.

I

'

,v
Table 7

Concentration of Gases Evolved From Unsupported Interior Finishes

^feterials Specimen No.

Temp

°C

Gnn_ceji±rati on 1 Carbon

Dioxide

Carbon

Monoxide

Oxygen Nitrogen Methane Methyl

Chloridi

Dex 35

250

400

550

6,800

111,000

101,000

1,000

6,000

58,000

177,000

64,000

3,200

790.000

812.000

777.000 10,000 800 1

SK 36

250

400

550

9,400

18,800

36,000

600

30

200,300

193.000

182.000

773.000

774.000

772

.

000

1

Albi 99 37

250

400

550

8,000

16.000

33.000

192.000

201.000

188,000

779.000

767.000

770.000

1

Flkt ;Flpr 38

250

400

550

9,200

13,500

27,000

60

209.000

198.000

198,000

772 . 000

778.000

767.000

j

Prph; Prlu 39

250

400

550

32,900

27,200

41,000

100

100

60

176.000

189.000

170.000

780,000

779.000

778.000

Saran 42

250

400

550

23,000

8,200

4,400

187.000

219.000

170,070

782.000

762.000

814,450

i

Maximum Permissable Concentrations

Safe for Long Periods a 100 a 30,000- b

Safe for i-1 hr a 400-500 a

50,000

b b

Dangerous for Short a 1,500- a b b

Period (i-1 hr) 2,000

aSee Section ^. 1 ; b see Section ^. 7 ; where no results are reported, no |

1

I

II

I

I
I

I'ecomposed in Air by Heat

If Gases, ^P.M. ^Loss

i.,2-DichlO'- Ethane Ethyl- Propyl- 1 , 3-Buta- Ben- Toluem Hydro- Sulfur on

1 oe thane ene ene diene zene gen Diox- ComChloride .. Ide bustior

23,700 16

33,200 40

1 400 4,800 1,200 500 300 70 *+ 7,300 53

1

16

1 24

1 44

12

67

i 90 100 66

1 2

I Trace Trace 400 11

800 4o

1

-- Trace Trace 1,080 700 9

Trace Trace 1,510 500 60

1

100 100 3,950 100 70

1 5,750' 19

8,300 55

1

40 40 11,000 79

f Toxic Gases;

1 ^

-- 30 , 000 - 50,000 b u> 00

.1— -3,000 10 10

b b b b b 3,000 -4,700 50-100 50-100

I b b b b b 7 ,500 1,000- 400-500

2,000

^as was detected.,

II

I

I

- 13 -

From the chlorinated interior finishes, considerable amounts

of hydrogen chloride were evolved, even at the lowest temperature

used (250°C). At higher temperatures, these chlorinated materials gave rise to a host of chlorine-containing hydrocarbons.

In general, the chlorinated interior finishes produced amounts

of carbon monoxide and hydrogen chloride which were above the

safe limits for short exposures. In a similar study, other investigators (1) found that chlorinated plastics, upon combustion

in air, produced toxic amounts of the above gases.

In the combustion of chlorine-free materials, carbon monoxide represented the greatest toxic hazard. Specimen 38 also

produced hazardous amounts of sulfur dioxide. With few exceptions, the concentration of carbon monoxide increased with

temperature until, at 550° C, observed values were 10 to 50

times the safe amount for short exposures.

5.2 Plywood Backed Vs. Unsupported Interior Finishes

The smallest volume of gases was evolved from the paint

films (Specimens 38 , 37, 38, 39 and ^2); this was due to

their low weight per unit area. A plywood specimen having

the same area as an unsupported specimen weighed approximately

50 times as much.

Table 7« lists the combustion gases produced when the

materials were burned without a plywood backing. Specimens

36 and 37 produced the smallest amounts of hazardous gases.

Specimens 38 , 37? 38 and Fireban showed the least tendency

to increase the hazardous gases produced by specimens 1 and

2. Specimen numbers of the respective built-up interior

finishes are 3? ^5 I 8 and 31 • However, specimens I 8 and I 8

were built up of materials that gave rise to sulfur dioxide

(specimens 38 and 39) « Sulfur dioxide was not detected in

the built-up specimens and it is believed that this was due

to the oxidation of the sulfur dioxide to sulfuric acid by

the water formed when the plywood was burned. Sulfuric acid

in water solution would be absorbed upon the walls of the

reaction chamber and might not be detected by the mass

spectrometer. Specimens I 6 and I 8 therefore might represent

a toxic hazard due to the sulfur dioxide which, although not

detected, was probably present as sulfuric acid.
111

i-I

I. ) M
- l4 -

5.3 Application of Experimental Results to

Field Conditions

In interpreting the results, caution should be exercised

in extrapolating them to those that would be obtained in

practice. As indicated in section 3ol»2, in this investigation samples were burned in a completely closed chamber; in

a ventilated room, decomposition products might not accumulate to such a hazardous extent. Criticism might also be

leveled at the fact that forced heating sometimes took place

under conditions of insufficient oxygen to cause combustion,,

and the combustion products might not represent those produced in actual service. However, Kingman et„ al. (15 J

j

have

found that the oxygen content of ventilated rooms drops to

as low as IjOOO p.p.m. after 15 minutes of burning. Thus,

as pertains to the oxygen content, the results appear to be

in accord with experiments carried out under conditions in

which the rooms were ventilated.

Ac knowl ed gment

The author of this report wishes to acknoli‘7ledge the help

of the following employees of the National Bureau of Standards

Mr, S. Schumann and Mr, F. Elder of the Gas Chemistry Section

for performing the mass spectrometer analyses; Miss S. Gunther

of the Gas Chemistry Section for interpreting the mass spectrometer results and for performing the carbon monixide determinations; and Mr. J. Loftus of the Fire Protection Section

for performing the hydrogen chloride determinations.
f

I

I

II-\y

!

I

I.

.Iv

Vv'

% *, V

. • -

' ;ii^

I A.

-5

(

:!
- 15 -

( 1 )

( 2 )

(3)

(4)

(5)

(6)

(7)

( 8 )

(9)

( 10 )

( 11 )

( 12 )

(13)

( 1^)

(15)

REFERENCES

Eo H. Coleman and C. H. Thomas, J. App. Chem, , p. 379,

(195^).

J. C, Olsen, G. E. Ferguson, and L. Scheflan, Ind. Eng,

Chem., p, 599, (1933).

L. B, Berger, H. A, Schrenk, J. A, Gale, Rn W. Stewart,

and L. E. Sieffert, U. S. Bureau of Mines Report R.I.

413^, Oct. 19^7.

Fire Eng., 99. p. l48, (19^6).

J, V. Ryan, E, W. Bender, W. C. Cullen, and D. Gross,

National Bureau of Standards Report 4120, May 25, 1955o

M. Shepherd, Anal. Chem., ]^, p, 77, (1947).

I, M. Kolthoff and E, B. Sandell, "Textbook of Quantitative Inorganic Analyses", The Macmillan Co.

,

New York,

N. Y., 1949, PP. 475, 572.

Y, Henderson and H„ W. Haggard, "Noxious Gases and the

Principles of Respiration Influencing Their Action",

Reinhold Publishing Co,, New York, N, Y, , pp, l44-l46,

(1943).

ibid., p. 168.

ibid., pp. 126-127.

ibid., p. 213.

ibid., p. 215.

ibid. , p. 131.

ibid., p. 202.

F.E.T, Kingman, E. H. Coleman, and D. J, Rasbash, H;. .App.

Chem., p. 4b3 , (1953).

o

FIG. I

COMBUSTION

APPARATUS

<

rO Ph

FIGURE

4.

FIGURE

5.

COMBUSTION

FURNACE

IN

HORIZONTAL

POSITION

COMBUSTION

FURNACE

IN

INCLINED

POSITION

HQM PQ • O

pq

W o

gsg o so. M O S Q ^

K02 O

FIGURE

8.

FIGURE

9.

MASS

SPECTRO^IETER

INLET

WITH

SAMPLER

CARBON

MONOXIDE

APPARATUS

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