REFERENCE

NBS

PUBLICATIONS

NAT'L INST. OF STAND & TECH

A 1 11 OH 0 3 1 b H 3

NBSIR 85-3139

Polyesters: A Review of the

Literature on Products of

Combustion and Toxicity

Emil Braun and Barbara C. Levin

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

January 1985

Issued June 1985

QC=

100

. U56

85-3139

1985

Sponsored in part by:

Consumer Product Safety Commission

Washington, DC

national bureau

OF STANDARDS

LIBRARY

NBSIR 85-3139

POLYESTERS: A REVIEW OF THE

LITERATURE ON PRODUCTS OF

COMBUSTION AND TOXICITY

Emil Braun and Barbara C. Levin

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

January 1985

Issued June 1985

Sponsored in part by:

Consumer Product Safety Commission

Washington, DC

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
"• : >.

' : r.

y

• • i-

-

; " • r

• '

• • -.-V • - . -

:• .'/Tr- . J
TABLE OF CONTENTS

Page

LIST OF TABLES iv

LIST OF FIGURES vii

Abstract 1

1. INTRODUCTION 2

2. CHEMICAL STRUCTURE AND THERMOPHYSICAL PROPERTIES 3

3. DECOMPOSITION 5

3. 1 Vacuum Pyrolysis 7

3.2 Inert Atmosphere Pyrolysis...

3.3 Combustion in Air 10

3.3.1 Tube Furnace Results 11

3.3.2 NBS Smoke Box 12

A. TOXICITY 15

A. 1 Laboratory-Scale Protocols 17

A. 1.1 DIN 53 A36 17

A. 1.2 FAA Toxicity Protocol 19

A. 1.3 NASA/USF Toxicity Protocol 20

A.l.A NBS Toxicity Protocol 22

A. 1.5 University of Pittsburgh 23

A. 1.6 Miscellaneous Protocols 25

5. LARGE-SCALE TESTS 30

6. CONCLUSION 33

7. REFERENCES 35

iii
LIST OF TABLES

Page

Table 1. Thermophysical Properties of Polyesters 41

Table 2. Thermal Degradation Products produced by Vacuum

Pyrolysis of Aliphatic, Aromatic, and Semiaromatic

Polyesters 42

Table 3. Decomposition Products of Inert Atmosphere Pyrolysis

of Polyester (450°-1200°C) as a function of

Temperature . 43

Table 4. Identified Combustion Products Resulting from the

Flash Pyrolysis of Untreated Polyester Fabric at

700°C and 900°C 44

Table 5. List of Specific Combustion Products Detected and

Concentrations Found During NBS Smoke Chamber Tests

of Materials Containing Polyester 45

Table 6. Comparison of Colorimetric Detector Tubes and

Instrumental Methods for Analyzing Gases Generated

from the Thermal Decomposition of Wool Pile,

Polyester-Backed Carpets in the NBS Smoke Chamber 46

Table 7. Concentration of Various Gas Species Produced by a Brominated Polyester in a Modified NBS Smoke Box 47

Table 8. Summary of Toxicity Protocols 48

Table 9. Results of Toxicity Tests of Untreated and Flame

Retardant Treated Unsaturated Polyester Resin and

Glass Fiber Structure 49

Table 10. Description of Polyester Materials Tested in FAA

Apparatus 50

Table 11. Tests Results of Materials Described in Table 10

from FAA Protocol 51

Table 12. Summary of Results for Polyester Fiber Batting 52

Table 13. Polyesters and Polyester Blends Tested in NASA/USF

Protocol 53
Table 14. Results of Gas Analysis During Thermal Decomposition

of Polyesters 54

Table 15. Results of Venting Tests on Two Polyester Materials 55

Table 16. Results of Non-Venting Tests on Two Polyester

Materials 56

Table 17. Carbon Monoxide Concentrations and Animal Incapacitation

Times 57

Table 18. Estimated LC 50 Values For Rats Exposed to Combustion

Products from Glass Reinforced Polyester 58

Table 19. LC 50 Values for Cotton and Cotton/Polyester Fabrics

Untreated and Treated with a Flame Retardant Finish 59

Table 20. Results of Gas Analysis from Large Scale Mattress Fire

Tests of Matresses with Rayon Ticking and Cotton Sheet.... 60

Table 21. Maximum Gas Concentrations Found by Burning Polyester

Curtains and Drapes in a Room 61

Table 22. Mortality During Room Corner Test of Three Fiberglass

Reinforced Polyester Resins 62

v
LIST OF FIGURES

Page

Figure 1. Chemical structure of polyesters 63

Figure 2. Comparison of the change in respiration rate during a 30 minute exposure to the combustion products of FR

treated and nontreated glass fiber reinforced polyester... 64
POLYESTERS: A REVIEW OF THE LITERATURE ON

PRODUCTS OF COMBUSTION AND TOXICITY

Emil Braun

Barbara C. Levin

Abstract

The available literature was reviewed to determine the nature and extent

of information available on the thermal decomposition products and the

toxicity of the combustion products of polyester materials used in consumer

applications such as textiles and building construction. This literature

review is limited to those publications printed in English through June, 1984.

The thermal decomposition products of polyesters are a function of

temperature and oxygen content of the atmosphere. In general, as the temperature increases, the quantity of heavier hydrocarbons decreases and the production of CO and CO2 increases. The presence of flame retardant additives, such

as bromine and chlorine-containing compounds, produce halogenated combustion

products. The use of phosphorus and bromine together in the same flame

retardant finish increases the concentration of low molecular weight

compounds.

Thirteen different test protocols have been used to evaluate the toxicity

of various types of polyester. Non-flame retarded polyesters give measured

LC^q values ranging from 30.5 mg/1 to 95.7 mg/1, while flame retarded

1
polyesters, have LC^q values ranging from 24.0 mg/1 to 38.0 mg/1. Several

exceptions, however, are noted. Toxicologists consider these differences to

be not significant. In general, the results from large-scale tests are

ambiguous because of the presence of other materials in addition to the

polyesters.

Keywords: Combustion products; flame retardants; literature reviews;

polyesters; pyrolysis; thermal decomposition; toxicity.

1. INTRODUCTION

It is generally agreecf~that the production of smoke and its toxicity play

an Important role in determining the likelihood of surviving a building fire.

Researchers over the past two decades have become increasingly concerned with

the measurement of toxic effects from burning materials under a great many

combustion conditions. Recently, many laboratories have attempted to develop

standard laboratory-scale toxicity protocols. In the wake of all of this

research and testing, much information has been scattered throughout the

technical literature on a great many materials. In an effort to collect,

compare, and systematize this information, the Fire Toxicology group within

the Center for Fire Research at the National Bureau of Standards conducted a

literature review on several classes of synthetic materials.

In this report, the literature on polyesters was reviewed to determine

the nature and extent of information available on these materials as they are

used in consumer applications such as textiles and building construction.

2
This review is limited to those publications in English through June 1984. A

total of 10 databases (Chemical Abstracts, Environmental Abstracts, Excerptica

Medica, FRIS Library, Medline, NTIS, RAPRA, RTECS, TRIS, Toxline) were

searched for pertinent publications.

The primary purpose of this review was to determine the possible products

of combustion that polyesters would yield under various fire conditions and to

evaluate the toxicity of these products of combustion. In general, fire

investigators, either combustion scientist or toxicologist, do not specifically identify the exact formulation of polyester used in their respective

studies. This severely limits the validity of any comparison of results

between different investigators. Differences in experimental procedures may

be overshadowed by the use of different polyesters. Nevertheless, a range of

values can be obtained that are descriptive of the class of materials called

polyesters. This includes thermophysical properties as well as products of

combustion and, therefore, toxicity.

2. CHEMICAL STRUCTURE AND THERMOPHYSICAL PROPERTIES

The term polyesters is applied to many different types of resins. Three

reactions are generally used for the synthesis of polyesters: (1) the

polyesterification of dicarboxylic acids with diols or their functional

derivatives; (2) self -polyesterification reactions of hydroxycarboxy lie acids

and their derivatives; (3) ring opening polymerization reactions of lactones

and cyclic esters. These hydrocarbon resins can be made in unsaturated and

saturated forms.

3
Unsaturated polyester resins are less flexible and less compatible with

aromatic cross-linking agents. These polyesters are primarily used in

composite structures where they can be reinforced with fillers such as glass

fibers. Polyester resins made by polyesterification of maleic and phthalic

anhydrides and propylene glycol increase resin flexibility. Unsaturated

glycols can be used to increase the rigidity of the cured resin by permitting

additional cross-linking.

Saturated polyester resins are most frequently used in the manufacture of

fibers and films. The most prevalent of these polyesters is poly(ethylene

terephthalate) . This is a linear polyester that is prepared by transesterification of the dimethylester of terephthalic acid and ethylene glycol [1,2]*.

The resulting polymer is chemically resistant to moisture, acids, and organic

solvents. Its chemical structure is shown in figure 1. Polyesters have a

relatively simple structure composed only of carbon, oxygen, and hydrogen

atoms in a benzene ring with CH2 attached via carbon-oxygen bonds. This

formula indicates that upon thermal decomposition the gaseous products would

be various hydrocarbon compounds and oxygenated hydrocarbons as well as CO,

CO

2

, and water. The addition of cross-linking agents, fillers, and flame

retardants would modify the nature of the combustion products.

The thermophysical properties of polyesters can vary depending on the

exact formulation and form of the material. Table 1 summarizes the range of

values found during this review. Polyester has a melting point that ranges

from approximately 250-300°C [2], while its self-ignition or autoignition

temperature has been found to be between 450-500°C [3,4,5]. Patten [3], using

^Numbers in brackets denote references listed at the end of this report

4
the piloted ignition test ASTM E136-58, reported a flash ignition temperature

of 400 °C.

Miller and Meiser [65] measured the flame temperature above burning

polymers. Their results showed that while polyester did not have the lowest

measured ignition temperature it did have the lowest flame temperature, 750°C,

among a group of polymers that included wood and nylon. This compares to a

stoichiometric flame temperature of 1977°C reported by Hilado [64] for an

unsaturated polyester. While these values do not appear to be correct

(stoichiometric polymer flame temperatures are approximately 1250°C), they are

included for the sake of completeness.

Goldfarb and McGuchian [6,7] determined that the thermal decomposition

activation energies of several aliphatic and aromatic polyesters ranged from

160-190 kJ/mole and that the activation energies of the aliphatic compounds

were slightly lower than that of the aromatic compounds. Throne and Griskey

[8] reported heats of combustion values of 25-30 MJ/kg for saturated and

unsaturated compounds.

Hilado [64] reports Oxygen Index values for various polyesters ranging

from 20 to 60. The higher values represent flame retarded compounds.

3. DECOMPOSITION PRODUCTS

A burning polymer undergoes thermal degradation by a complex series of

chemical reactions. These reactions occur either in the condensed phase or in

the gas phase above the polymer substrate. In general, the initial thermal

5
degradation of polyester appears to be due to random scission of the ester

linkage and pyrolysis of the simple esters produced. Newly formed end groups

decompose by secondary reactions [6,7,9].

Learmouth and Nesbit [10] have shown that polyester degradation follows a

two step reaction scheme that does not appear to be affected by the presence

of halogenated additives. The principal decomposition products (acetaldehyde,

water, carbon oxides, and the acid and anhydride end groups) and the kinetics

of degradation suggest a random chain scission [1]. The initial scission has

been found to occur at an alkyl-oxygen bond. Since the presence of oxygen

accelerates the decomposition of the polymer, a mechanism of radical formation

is required to explain the results [1]. The experimental work on thermal

reactions of this type has been done either in vacuum or in inert gas atmospheres. This research has been aimed at deducing the chemical mechanisms and

energies involved in each reaction step. Studies under normal atmospheric

conditions of 21% are limited to describing the nature of the combustion

products.

In the next few sections of this report we will describe the gaseous

products that evolved during thermal decomposition in each of three environments - vacuum, inert atmospheres, and air. While it may not appear relevant

to the real fire situation to review work done under oxygen-free conditions,

it must be realized that studies such as these provide information about the

effect of well controlled conditions on the nature and amounts of volatile

products of thermal decomposition. As will be seen, some of these volatile

products survive the passage through the flame and appear ultimately as

products of incomplete combustion during atmospheric burning of the polymer.

6
3. 1 Vacuum Pyrolysis

Goldfarb and McGuchian [6,7] have done extensive work on the thermal

degradation of aliphatic, aromatic, and semiaromatic polyesters. They studied

eight aliphatic, three semiaromatic, and four aromatic polymers. Thermal

characterization of these polymers involved vacuum pyrolysis followed by

analysis of the volatiles by mass spectrometry (MS).

Table 2 is a tabulation of the gaseous combustion products detected

during vacuum pyrolysis of various polyester compounds [6,7,11]. The symbols

in the table give relative concentrations of these compounds. It should be

pointed out that not every polyester produced all the listed compounds. All

polyesters produce large quantities of CC>2 but only the aliphatic polyesters

produce large quantities of water. Aromatic and semiaromatic polyesters

produce moderate quantities of CO and small amounts of water. Aromatic polyesters produce fewer higher molecular weight hydrocarbons than aliphatic

polyesters and moderate amounts of benzene.

3.2 Inert Atmosphere Pyrolysis

Studies by Woolley and Fardell [12] at the British Fire Research Station

using a gas chromatograph/mass spectrometer (GC/MS) system and a tube furnace

showed that polyesters, like wood, decompose in nitrogen atmospheres into CO,

hydrocarbons, and oxygenated species. They also note that the same decomposition products are found when decomposition is carried out in air.

7
Madorsky [13] cites the work of Goodings who exposed poly (ethylene

terephthalate) to temperatures ranging from 283-306°C in nitrogen atmospheres.

Under isothermal conditions, this polymer slowly decomposes into low molecular

weight fragments such as C

2 H4 , 2-methyldioxolan, CH^, C^H^, and CH3

CHO in

addition to CO, CO2 , and H2O. The primary decomposition product was CH3CHO

representing 80 mole percent of the total gases.

Characterizing the pyrolysis products of a group of adhesives, Noble

et al. [14] decomposed polyester based adhesives in a nitrogen atmosphere in a

curie point pyrolyzer set to produce a 10 second "burn" at 610°C. The unsaturated polyester was copolymerized with a styrene monomer. A major feature of

the pyrograms was the strong presence of styrene.

Butt and Cotter [15] pyrolyzed a silicone rubber /poly (ethylene

terephthalate) cable insulation material in an inert atmosphere of helium at

800°C. The thermal decomposition products were identified by combined gas

chromatography - mass spectrometry (GC/MS). They detected the presence of CO,

CO2 , CH4 , ethylene, propylene, butadiene, benzene, and toluene, all of which

were attributed to the poly (ethylene terephthalate), and two cyclic compounds,

[(CH3 ) 2 SiO ]3 and [ (Cl^^SiO]^, which were attributed to the silicone rubber.

Using a micropyrolysis furnace and helium or nitrogen atmospheres,

Calcraft et al. [16] conducted experiments on three formulations of polyester

resin. Different alkyd resins were used in each formulation with styrene as

the cross-linking agent. Two formulations had added flame retardants, either

trichloroethylphosphate or antimony oxide. Varying the furnace temperature

from 150 to 800°C, they found that the yields of the lower boiling point

8
components (i.e., CO, CO2 , CH4 , ethylene, and acetylene) increased with

temperature. Chlorine-containing materials produced HC1. The maximum concentrations of the higher boiling point compounds of toluene and styrene appeared

between 600 and 700°C, while naphthalene was only detected above 700°C. When

the non-flame retardant polyesters were tested, the concentration of benzene

increased linearly with temperature and showed a peak around 700°C.

Green et al. [17] tested a set of polyester resins with the same formulations used by Calcraft. They used a quart microreactor and helium atmosphere

over a range of 450 to 1000°C. The results of Green tended to agree with

Calcraft for the low boiling components; however, the results for the higher

boiling point components showed that Green observed maximum yield of toluene

at a higher temperature, 1073°C, than Calcraft, 700°C. Styrene yield

increased with temperature in Calcraft's work while Green reports a maximum

yield at 873°C. Table 3 summarizes the results of Green and Calcraft in terms

of temperature effects on the production of decomposition products.

Using a flash pyrolysis/gas chromatography system, Bednas et al. [18]

investigated the products of pyrolysis of five commercial polyester fabrics,

four of which were treated with flame retardant additives. Tests were

conducted with the flash pyrolysis unit set at 700°C or 900°C and with helium

as the carrier gas. Approximately 28% of the mass of each fabric sample was

consumed at 700°C and an 86 % weight loss was observed at 900°C. This mass

loss was independent of the presence of a flame retardant. Results indicated

the presence of at least 43 compounds in the thermal decomposition products of

polyester. All of the compounds were identified except five of the higher

molecular weight compounds (Table 4). A greater number of compounds were

9
detected at 900°C than at 700 °C. Most notably, water was detected in trace

amounts at 900 °C, but not detected at all at 700 °C. Also, CO became the

principal product of pyrolysis at 900°C, while CO

2 was the principal pyrolysis

product at 700°C. Methane was produced in appreciable concentrations at the

higher temperature, but not observed at 700°C. On the other hand, the

observed concentration of acetaldehyde was lower at 900°C than at 700°C. This

work indicates that phosphorus-bromine-containing flame retardant systems

increase the concentration of the more volatile species as compared to the

untreated polyester. The phosphorus only flame retardant systems behaved very

similarly to the untreated polyester.

As an extension of the previous work. Day et al. [19] employed a similar

pyrolytic system to identify the products of thermal decomposition of Dacron

polyester before and after the application of either tris (2,3-dibromopropyl)

phosphate, tripropyl phosphate, or 2, 3-dibromopropanol. Considering only the

10 major products of combustion designated in the third column of table 4, Day

et al. observed that the addition of phosphorus-bromine flame retardants

greatly increase the concentrations of the low molecular weight nonaromatic

combustion products at the expense of the higher molecular weight aromatic

compounds.

3.3 Combustion in Air

Various methods exist for the thermal decomposition of materials in

oxygenated atmospheres. Two specific approaches have been applied to

polyesters - tube furnace and NBS smoke chamber (NFPA-258 [20] or a variant).

Tube furnace experiments are conducted under either isothermal conditions or

10
ramped heating with the rate of heating varying from 5 to 50°C/min. Tube

furnace experiments represent a dynamic flow system where combustion products

are carried away from the decomposing substrate by a flowing stream of gas, in

this case, air.

The NBS smoke chamber can be used to expose a material to purely radiant

energy or a combination of radiant and open flame heating. In either case,

the external thermal load is constant during exposures. Natural convection

within the chamber mixes the combustion products with the air already present.

3.3.1 Tube Furnace Results

Boettner et al. [21] determined the decomposition products from two gram

samples of polyester film placed in a tube furnace programmed to heat the

material 5 to 50°C/min over a temperature range of 100°C to 1000°C.

Quantitative measurements were not taken; however, the presence of CO, CO 2

,

methanol, and acetaldehyde were detected by infrared (IR) spectroscopy.

Methane, ethane, and benzene were identified by GC/MS. Active decomposition

was seen at 350°C and combustion was completed at 500°C.

Both Felger and Olsen [22] and Speitel et al. [23] evaluated polyester

materials at fixed tube furnace temperatures. Felger and Olsen conducted

their tests at 350°C and 450°C, while Speitel et al. used 600°C. Felger and

Olsen examined 0.5 gram samples of two types of polyester, a cast magnet wire

enamel film and a highly oriented poly (ethylene terephthalate ) film. GC and

IR analysis of the combustion products showed the presence of only small

quantities of aldehydes at 350°C. However, at 450°C, the concentration of

11
aldehydes were 50 times greater than that detected at the lower temperature.

Also, large quantities of CO for the cast enamel film and moderate amounts of

CO for the oriented film were found at 450°C. Only small quantities of

benzene were detected at the higher temperature.

Speitel et al. did not evaluate the combustion products of pure or simple

materials. They evaluated wool pile carpeting with a polyester backing and

latex back coating for the presence of specific gaseous products. They

detected large quantities of CO, HC1 and HCN with smaller amounts of t^S, S0£

and HCHO. The addition of a urethane foam pad did not substantially change

the amounts of low molecular weight gaseous combustion products. However,

because of the large quantity of wool present in the sample, none of the

detected compounds can be attributible solely to the polyester material. In a

similar vein, Hartstein and Forshey [24] evaluated several neoprene polymers

reinforced with polyester and found the same types of compounds as Speitel

et al.

3.3.2 NBS Smoke Chamber

The NBS Smoke Chamber is a well established method for measuring the

opacity of smoke produced when a material is burned. In addition, several

researchers have used this test apparatus to generate combustion products from

burning polyester prior to their identification.

One of the earliest attempts at characterizing combustion products

produced in the NBS Smoke Chamber was done by Gross et al. [25]. They used

colorimetric or gas detector tubes in an attempt to measure amounts of

12
specific low molecular weight compounds found in the chamber's atmosphere.

[See ASTM E 800-1 [26], Standard Guide for Measurement of Gases Present or

Generated During Fires for cautionary notes on the use of gas detector tubes.]

They tested a total of 141 aircraft interior materials, eleven of which

contained a polyester. A description of the polyester containing materials

and concentrations of resulting gases per mass of material tested are

presented in table 5. It is interesting to note that with two exceptions, HC1

was detected in all samples. This may be indicative of flame retardant

additives

.

In a similar set of experiments, Speitel et al. [23] decomposed materials

in the flaming mode in an NBS Smoke Chamber and determined the presence and

concentration of low molecular weight compounds in the combustion gases. They

compared colorimetric detector tubes with instrumental methods of analyses. A

wool pile, polyester backed carpet was tested with and without a urethane foam

pad. The results are reported in terms of mass of gas per mass of consumed

material (mg/g)( Table 6). It can be seen that, in general, colorimetric

detector tubes overestimate the gas concentrations of a particular species.

However, in one case, the instrumental methods detected the presence of H

2 S,

while the colorimetric detector tubes did not. In the case of HCHO, the

reverse was true.

A qualitative comparison can be made between the results of sample 17

(Table 5) of Gross et al. [25] and those of Speitel et al. [23] (Table 6). The

comparison can only be qualitative because Gross does not report mass consumed

nor can one expect the materials in both reports to be identical. Sample 17

under flaming conditions produced no measureable quantities of HC1 while the

13
wool carpet with a urethane foam pad tested by Speitel et al. produced large

quantities of HC1. Based on colorimetric detector tubes, there was nearly as

much HC1 produced as CO. The detection of HC1 in the latter material may be

indicative of the presence of a flame retardant additive. The quantities of

HC1 measured as compared to CO appear high. However, they should not be taken

as absolute values because of the large potential error associated with the

HC1 colorimetric detector tube in the presence of small amounts of [25].

Adams [27] studied the combustion gases produced by a brominated

polyester in a modified NBS Smoke Chamber. In this modification the sample

was mounted horizontally instead of vertically thereby preventing thermoplastic material from melting and flowing away from the source of heat. The

incident radiant flux was maintained at 2.5 W/cm . Adams used a mass spectrometer to measure the gas constituents collected in grab sample bulbs. Carbon

monoxide was monitored continuously with an infrared analyzer. Adams reports

his result in terms of mass of gaseous compound per mass of material consumed

(Table 7). Carbon dioxide and carbon monoxide were produced in the largest

amounts. As expected, bromide compounds were detected as well as styrene and

ethylbenzene both of which somehow survived the transition through the flame

zone.

Stauffer et al. [28] and Miller et al. [29,30] investigated the effects

of increasing levels of flame retardants on the smoke and toxic gases produced

by polyester resins decomposed in the NBS Smoke Chamber. Stauffer et al.

observed that as the brominated flame retardant increased, the production of

CO2 declined, while the production of CO, HBr, and total hydrocarbons

increased. The results of Miller et al. were identical. They also found

14
that, based on the amount of material decomposed, O

2 consumption also

decreased with increasing bromine concentration in the substrate.

While the exact products of decomposition depend on the specific

polyester, several generalizations can be made regarding the effects of atmosphere and temperature on the decomposition of these polymers. Data indicate

that vacuum and inert atmosphere pyrolysis result in polyesters decomposing

into a large number of high and low molecular weight fragments. Increasing

the temperature of pyrolysis increased the amount of low molecular weight

fragments at the expense of the higher molecular weight fragments.

The use of air as the decomposition atmosphere also resulted in the

decreasing production of high molecular weight fragments with increasing

temperature. An increase in the production of CO, CO2

, H2

O, and CH^ was

observed. At high temperatures, 450°-500°C, CH^ would also decompose to H 2 O

and C02 » The presence of flame retardant additives, such as bromine and

chlorine, produced halogenated combustion products. The use of phosphorus and

bromine in the same flame retardant finish increased the concentration of low

molecular weight compounds.

4. TOXICITY

At least 13 different toxicity protocols have been used to evaluate polyester materials. These protocols are briefly summarized in table 8. The

protocols are divided into three classes. The first class (no. 1-5) of

protocols represent widely recognized procedures for evaluating combustion

product toxicity. These procedures were developed for the purpose of

15
providing information on a broad range of materials. At least one has undergone interlaboratory evaluation (no. 4) and one is currently under consideration by the State of New York (no. 5) for use in developing a data bank on

material toxicity. With the exception of the U. S. Testing Company procedure

(no. 9), the second group of protocols (no. 6-11) were developed on an ad hoc

basis to evaluate the combustion product toxicity of selected materials. It

appears not to have been the intent of the researchers to design a general

purpose test protocol that could be used for material toxicity evaluations.

The U. S. Testing Company toxicity protocol does not precisely fit this

description. It appears to have been developed as a general purpose test

protocol. However, it has not received the same recognition as the first

group of protocols. It was designed to allow fire investigators to simulate

several different protocols in one apparatus.

The final group of protocols are those that employ a combustion system

from a standard test method, with the animal exposure system as an addendum to

the standard test apparatus. These represent exploratory uses of a standard

test method to generate combustion products for animal toxicity evaluation.

Those protocols marked with an asterisk in table 8 are described by

Kaplan et al. [31]. In addition to Kaplan et al. , citations will be provided

for a more complete description of each test protocol.

16
4. 1 Laboratory-Scale Protocols

4.1.1 DIN 53 436

The DIN 53 436 test method was developed in the Federal Republic of

Germany. It provides a steady output of combustion products and uses a horizontal moving tube furnace to decompose the sample in a flowing air stream

[ 3 2 J . The combustion air stream is diluted with room air and introduced into

an animal exposure chamber. The combustion products flow past the animals and

are exhausted out of the system. Material is introduced into the combustion

system based on equal specimen volume or weight per unit length.

Herpol and Minne [33] and Herpol [34] exposed three male and three female

rats per test to the combustion products generated by two glass fiber

reinforced polyester materials. One sample was flame retarded. All of the

tests were conducted for 30 minutes with combustion air flowing at 200 1/h.

When 10 grams of material were decomposed at a furnace temperature of 600°C,

the flame retarded polyester produced 100% mortality while the non-treated

polyester produced 0% mortality. The mean COHb for the dead animals was found

to be 72%, while surviving animals had a 30% COHb level in their blood. For

reference purposes, beechwood decomposed under the same conditions produced a

mortality rate of 54% and COHb levels of 33% and 62% for alive and dead

animals, respectively. However, the COHb values for live animals depends

largely on the time interval between the time of the end of exposure and the

time when the blood samples are taken. Doubling the amount of the untreated

glass fiber reinforced polyester to 20 grams resulted in 100% mortality and a

65% COHb level.

17
Herpol and Minne also conducted tests at 800°C with 10 grams of material.

No fatalities were seen with the untreated glass fiber reinforced polyester

and no attempt was made to determine an LC^q value. All samples exhibited

some flaming combustion. The animals were monitored for changes in respiration. The results were presented as the mean respiration frequency during the

experiment expressed as a percent of the mean normal value before the experiment. In general, the respiration rate of the surviving animals during the

test varied from 58% to 120% of normal, while for those dying during the test,

the respiration rate steadily declined. The respiration rates were higher at

the end of the 30 minute experiments than during the earlier part of the

exposure. Male rats exhibited a higher than normal respiration rate when

compared to females. These results are summarized in figure 2.

Hoffman and Sand [35] investigated the toxicity of an unsaturated

polyester resin with and without a flame retardant finish. Using the DIN 53

436 protocol, they varied the furnace temperature and dilution volume. Five

grams of material were placed in the furnace with the combustion air flowing

at 100 1/hr. They found that the toxicity increased with increasing decomposition temperatures and the flame retardant treated material was more toxic

than the untreated material (Table 9).

Kimmerle and Prager [36] also used the DIN 53 436 protocol, but they

determined LC^q values for a flame retardant glass fiber reinforced polyester

( 7 %-Sb203 ) and a polyester fiber specimen. They were decomposed under conditions of varying furnace temperatures, dilution volumes and exposure times.

The mass of material was fixed at approximately 36 grams or 0.12 g/cm, the

furnace flow rate was set at 100 1/h and rats were mounted in the head-only

18
configuration. Dilution values are reported as the total flow through the

animal exposure chamber. Their results on these two materials are listed

below. They report a critical degradation temperature, T(C), below which

death will not occur and a calculated temperature, TCLC^q), at which 50% of

the animals died with a 100 1/hr dilution. For the polyester fabric, TCLC^q)

is an extrapolation of the data. With the furnace temperature fixed at 600°C,

a critical dilution rate, DC^qq, above which deaths did not occur was determined. At the same furnace temperature, the dilution rate, D^qq, and mass

loading, LC^q

,

at which 50% of the animals died were also calculated.

Material T(C)

(°C)

T(LC50 ) (°C)

DC600

(1/hr)

°600

(1/hr)

LC50

(mg/1)

FR Glass Fiber Reinforced

Polyester

450-500 600 300-400 150 48

Polyester Fabric 500-600 650 200-300 100 72

4.1.2 FAA TOXICITY PROTOCOL

Crane et al. [37], at the Federal Aviation Administration (FAA), have

developed a small-animal inhalation toxicity system that uses a tube furnace

and provides recirculation of the system atmosphere from the tube furnace to

the animal exposure chamber and back again. Three albino rats are used in a

whole body exposure with time to incapacitation, as measured on an exercise

wheel, and time to death as the biological endpoints. The samples tested were

commercially available aircraft interior materials. The tube furnace was set

at 600°C and the animals were exposed for a maximum of 30 minutes. Sample

mass was fixed at 750 mg which is equivalent to a concentration of 60 rag/1 if

19
completely consumed. Crane et al. report three sets of time values. One set

was the actual time to effect, while the other two were normalized values

based on a 200 gram animal and sample weight of 1 gram, where sample weight

was either that charged to the system or that consumed during the test. Data

based on charged weight was called "standard" and that based on consumed

weight was called "loss." Of the 75 materials tested by Crane et al. , five

contained polyester, their descriptions are listed in table 10 and the test

results are presented in table 11. Sample 10, a glass fiber reinforced

polyester, appears more toxic than a wool pile carpet with a polyester

backing, 33 and 34. Normalizing the data does not change the toxic order of

the five materials.

4.1.3 NASA/USF TOXICITY PROTOCOL

The NASA/USF Toxicity Protocol was developed for the National Aeronautic

and Space Administration (NASA) and used extensively by Hilado at the

University of San Francisco (USF). This method exposes four Swiss-Webster

male mice to the combustion products developed in a horizontal tube furnace.

The animals are allowed to move freely about in a 4.2 liter animal exposure

chamber. The exposure chamber is connected to the furnace by a glass tube.

The furnace can be operated at fixed temperatures or ramped at a rate of

40°C/min. Movement of the combustion products is due to thermal expansion

except under flow-through conditions when a pump is used to move air through

the system at 3 1/min. Damant et al. [38] used this protocol to evaluate the

toxicity of several home furnishing materials. One was a resinated polyester

batting. With the tube furnace heating the sample at 40°C/min from 200 to

800°C, Damant et al. varied the sample weight and determined a lethal loading

20
value where 50% of the animals died (LL^g) at 85 mg for a 30 minute exposure

plus 14 days post exposure observation period. With a system volume of

approximately 4.2 1, an LC^q of 20 mg/1 was computed.

Hilado and his coworkers were concerned with the determination of time to

incapacitation (T^) and the time to death (Td ) as a function of sample heating

rate and mass charged to the furnace or mass consumed. Hilado [39,40,41]

evaluated the toxicity of three polyester fiber batting samples (Table 12).

varied from 8.0 to 15.7 minutes, while Td varied from 8.8 to 21.5

minutes. On a sample consumed bases, no appreciable differences in the time

to incapacitation or the time to death were observed for samples A and B when

the heating rate was increased from 40°C/min to 60°C/min. Sample C showed a

slight decrease in toxicity (i.e. increase in the and the T^) as the

heating rate was increased.

Hilado and Brauer [42] evaluated the toxicity of a polyester material at

a fixed temperature of 800°C, while Hilado [43] measured the toxicity of what

appears to be an identical material at a heating rate of 40°C/min. In both

cases, 1 gram of material was placed into the furnace. Td was reported to be

6.0 minutes for the fixed temperature tests and 19 minutes for the ramped

heating rate. In addition, the CO and CH4 concentrations were measured at the

end of the test and found to be:

Td CO CH4

Heating Mode (min) (ppm) (ppm)

800 °C 6.0 12,680 7,680

40°C/min 19.0 7,600 4,330

21
Table 13 summarizes Hilado's [39,44,41,43] results on polyester and

polyester blend fabrics. For polyester/cotton blends, reducing the polyester

fraction appears to reduce the toxicity of the blended fabric. Data are also

presented comparing toxicity results at a 60°C/min heating rate with the

chamber sealed as compared to an unsealed or flow-through chamber. Based on

mass consumed, the unsealed system appears less toxic because no animals died

during the exposure. The times to incapacitation were approximately the same

for the sealed and unsealed systems.

4.1.4 NBS TOXICITY PROTOCOL

The National Bureau of Standards (NBS) toxicity protocol has been

described in detail by Levin et al [45] and Kaplan et al. [31] . The sample

is introduced into a cup furnace set at 25°C above or below the sample's

autoignition temperature. It is a static system in that all of the combustion

products are contained in an exposure chamber that holds six male rats in a

head only exposure. The exposure lasts for 30 minutes at which time the

animals are withdrawn and survivors held for 14 days of observation. Sample

mass is varied in order to determine an LC5 Q value based on the amount of

material loaded in the furnace divided by the volume of the exposure chamber

(200 1). Levin et al. [4] found that a polyester fabric in the non-flaming

mode at 475°C had a 30 minute LC 50 of 39.0 mg/l» In the flaming mode at

525°C, the polyester had a 30 minute LC^q value of 37.5 mg/1. Similar tests

[46], using a polyester fiberfill material with an autoignition temperature of

525°C, resulted in a 30 minute LC^q of 28 mg/1 and 31 mg/1 for the nonflaming

and flaming modes, respectively. All values include deaths occurring during

the 30 minute exposure plus a 14 day post-exposure observation period.

22
4.1.5 University of Pittsburgh

This test protocol has been used by several researchers [47,48,49] to

evaluate combustion product toxicity. It is a dynamic flow-through system

that uses a Lindberg furnace and a programmed controller to heat the sample at

a fixed linear heating rate (20°C/min). Air and combustion products are

flushed through the furnace, diluted with cooled air, and passed through an

exposure chamber at a total airflow rate of 20 1/min. In each experiment,

four mice are exposed in the head-only mode. Typical endpoints are the LL^q,

the lethal loading that kills 50% of the animals during a fixed exposure time

(usually 30 minutes); the LT^q, the time needed to kill 50% of the animals

exposed to the LL^q; and the RD5 Q, the concentration that reduces respiration

rate of the animals to 50% of normal. In the University of Pittsburgh method

the concentration is denoted by the amount of material placed in the furnace.

In evaluating polyester batting, Alarie et al. [48] calculated a 30

minute LL^q of 28.0 ± 1.15 grams and an LT50 of 19.5 minutes. The LL50 can be

roughly converted to a volume base by using the total flew for a 30 minute

exposure. This yields 46.7 mg/1 for the 30 minute LC^q of polyester batting.

Fiber glass reinforced polyester was examined by Anderson and Alarie [49]

under similar conditions, and the LL^q and LT^q were found to be

67.5 ± 7.1 grams and approximately 20 minutes, respectively. Converting this

LL^q value to a volumetric base yields 112 mg/1. While there is a factor of

four difference between the two LC^q values, it should be pointed out that

both are based on the amount of material loaded in the furnace. In the case

of the reinforced polyester, a large portion of the mass of material was

fiberglass which does not contribute to the toxicity.

23
Alarie et al. [50] evaluated the toxicity of three polyester resins. One

was a commercially available acrylic modified unsaturated polyester resin,

another was an experimental version of the same polyester resin, and the third

was a styrenated, halogen modified polyester resin. The most toxic material

was the halogenated polyester resin, while the least toxic was the experimental resin.

Material

LL50

(g) A Ss?

Commercial Resin 34.8 58.0 119

Experimental Resin 57.4 95.7 121

Halogenated Resin 14.4 24.0 50

In all of these reports, the LL^q and LC^q values are based on a 30 minute

exposure plus a 10 minute recovery period.

Barrow et al. [47] measured RD^q values for a fiberglass reinforced

polyester using a slightly modified procedure. While he maintained a constant

linear heating rate of 20°C/min, he varied the total air flow from 10 1/min to

220 1/min and the sample weight from 5 mg to 200 mg. In addition, he varied

the duration of exposure from 3 to 7 minutes. Using various combinations of

these three test parameters, Barrow developed a dose-response curve by which

an RD50 value could be determined. He obtained an RD^q value of 0.14 mg/1

based on amount of material consumed.

24
4.1.6 Miscellaneous Protocols

Dufour [11] conducted a general literature review of combustion product

toxicity and the various means used for measuring a material's toxicity. He

cites the work of: Truesdail (1953); Snell, Corbett, and Gee (1957); and

Whitely (1958). Truesdail and Whitely used almost identical protocols to

evaluate the toxicity of polyester resins.

Truesdail used six albino rats placed on a mesh wire screen inside of a

14 inch diameter vertical glass cylinder. The glass cylinder had a one inch

square vent at the top. The material was burned in a horizontal section below

the animal location. Combustion products flowed from the combustion zone past

the animals (whole body exposure) and out the vent. Strips of selfextinguishing polyester resin reinforced with chopped glass fiber were burned.

After a two hour exposure, Truesdail observed no visible effects on the

behavior of the rats. Whitely used six white mice in a 10.5 inch diameter

glass cylinder (similar construction). After a 30 minute exposure, the mice

showed signs of nasal irritation, lachrimation, and unconsciousness, but all

recovered during the post-exposure observation period. The dose could not be

determined from the description of the test results.

Snell et al. exposed rats in a 4 cubic foot chamber that was ventilated

at the rate of six changes per hour. A mixing fan was used to prevent stratification of the combustion products produced by two stainless steel electrically heated plates in contact with the test material. All samples were

heated for five minutes. Some tests were conducted with a fixed area of

sample (22.5 in^), and varying exposure times (5, 10, 15, 30 minutes), while

25
other tests used fixed sample weights with a 30 minute exposure. For the

fixed area tests, at least a 15 minute exposure to the decomposition products

of a sample described as phthalic polyester was required before one death

occurred. A 30 minute animal exposure to the decomposition products from

22.7 grams of the phthalic polyester produced three post-exposure deaths but

none during exposure. A fire retarded polyester produced two exposure deaths

and one post-exposure death when 45.4 grams were thermally decomposed during a

30 minute animal exposure. Snell et al. measured the oxygen, nitrogen, CO 2

,

CO, and HC1 concentrations in the atmospheres produced when 22 grams of three

polyesters were thermally decomposed (Table 14).

Grand [51] used a system developed at the U. S. Testing Company. It

consisted of a 20 liter glass combustion chamber connected to a 40 liter

animal exposure chamber by 5/8" glass tubing. A rotating wheel (6 rpm) was

used to determine the incapacitation times of the exposed rats. Mortality was

also an endpoint. Two combustion modes were used in these tests. Non-flaming

combustion was achieved by an electrical radiant heater, while flaming combustion used four small butane burners. Exposures were vented (i.e., 8 1/min of

fresh air were mixed continuously with the combustion products to total a

circulation flow rate through both chambers of 16 1/min) or nonvented (only

the combustion products were recirculated). Non-flaming vented and non-vented

tests had animal exposure times of 15 and 30 minutes, respectively. Flaming

exposures were 20 minutes. Both fire retarded and non-fire retarded fiber

glass reinforced polyesters were tested. The results (Tables 15, 16, 17)

showed that the fire retarded material was more toxic based on the estimated

LC^q values (Table 18). In both the vented and non-vented tests, the toxicity

of the fire retarded polyester was similar to that of Douglas fir which was

greater than the non-fire retarded polyester.

26
Nunez et al. [52,53] compared toxicity results of the combustion products

from 100% cotton and 50/50% cotton/polyester fabrics some of which were

treated with flame retardant compounds. His system was composed of an 8.6 1

combustion chamber that had radiant glow bars heated by a gas burner connected

to a 449 1 exposure chamber holding 10 rats in a whole body exposure. The

test procedure resulted in flaming combustion of all samples. Air flow

through the combustion chamber was 10 1/min. Three minutes after ignition,

the burner was turned off and the entire system was sealed. Animal exposure

continued for 2 hours. The results of this work are shown in table 19. It

can be seen that the untreated materials had about the same LC^q value of

about 21.7 mg/1. The flame retardant materials showed an increase in

toxicity. The addition of polyester to the cotton did not increase the level

of toxicity.

Yamamoto [54] evaluated the toxicity of polyester fibers. A stainless

steel sample holder was placed on an electrically heated hot plate. The hot

plate was turned on to its maximum setting. Yamamoto reported that it took

about 20 minutes to reach its maximum temperature of about 500°C. The hot

plate was placed in a combustion chamber of about 45 1. This chamber was

connected by a flexible hose to a 13 1 exposure chamber. In each test, ten

grams of material were placed in the furnace holder and a single male rat

exposed. In 4 out of 5 tests, the polyester fiber burst into flames 7 minutes

after the furnace was turned on. Time to incapacitation was measured based on

observed animal activity. The maximum exposure time was 30 minutes. At the

time of incapacitation, the animal was withdrawn and %C0Hb measured. Only

flaming conditions produced incapacitation. The following data were obtained:

27
Sample Size (g): 10

Max. CO(ppm): 2900-5300

Min. 0

2 (%):

COHb (%): 20-30

15.6-19.1

Time to Incapacitation (min): 15-19

Yoshida et al. [55] used an airstream flowing at 2.5 1/min through a 2.18 1

stainless steel reaction vessel. With the sample in place, the furnace was

started at ambient temperature and allowed to heat as rapidly as possible to

550 °C. The entire flow was collected in a plastic bag. At the end of the

combustion experiment, the collection bag was connected to a 1.5 1 chamber

where three male mice were exposed in a whole body mode. The duration of the

exposure was one hour and was followed by a 7 day post-exposure period. The

polyester material began to decompose at 300 °C. Yoshida et al. determined a

60 minute plus 7 day LC^q value of 30.5 mg/1. Their gas analyzers detected

3000 ppm of CO, 1000 ppm of acetaldehyde and traces of benzene.

Keller et al. [56] and Moreci et al. [57] modified the NBS smoke chamber

(NFPA-258) to accommodate animal exposures to the combustion products produced

during sample decomposition. Moreci attached an animal exposure chamber to

one side of the NBS smoke chamber. The animal exposure system exposed the

whole bodies of four male mice and only the head of one mouse. They monitored

the behavior (i.e., level of activity) of the free moving mice, recorded

survival time, and the percent surviving. A 100% cotton and a 50/50 cotton/

o polyester fabric were exposed to a 2.5 W/cm radiant heat source and the

results were as follows:

28
Mass Pyrolyzed Survived Survival Time Peak CO

(g) (%) (min) (ppm)

100% Cotton Muslin 38.1 0 34 7000

50/50 Cotton/Polyester 29.8 60 33 6500

Keller et al. [56] placed 8 rats (4 male/4 female) into the NBS smoke

o chamber and set the radiant heat source at 5 W/cm . With the animals in the

smoke chamber, approximately five gram samples of untreated and fire retardant

treated polyester single knits were tested. A five minute sample burn was

followed by a 15 minute holding period for a total exposure time of 20

minutes. An additional 30 minute post-exposure period was used to determine

recovery. The biological endpoint was the time for each rat to leave a 25 cm

circle (exploration time). The materials tested contained three concentrations of fire retardants (1.2%, 5.6%, 15.9%). No appreciable differences were

noted between the untreated and the 1.2% and 5.6% fire retardant treated

polyester. Exploration times were approximately 5-6 seconds. However, addition of the 15.9% fire retardant showed a slightly longer exploration time,

13 seconds. In all cases, all animals survived and showed normal activity

throughout the 14 day observation period.

Pryor et al. [58] utilized the test described by ASTM E-84 [59] as a

combustion system to evaluate the toxicity of fiberglass reinforced polyester.

An exposure chamber was connected to the ASTM E-84 system by a one inch

pipe. The exposure chamber was approximately 295 1 and held 10 mouse cages.

Smoke was drawn from AS1M E-84 and trapped in the exposure chamber. The

29
animals were exposed to this atmosphere for 4 hours. One out of 10 animals

died during the exposure. The chamber was at 100°F and contained 1025 ppm of

CO. The concentration of CO was determined by colorimetric detector tubes.

Prior testing showed that exposure to 1500 ppm of CO for 4 hours is lethal.

5. LARGE-SCALE TESTS

Several researchers have combined large scale fire testing (i.e. , room

size or larger) of furnishings and/or finishing materials with animal exposures or with detailed analysis of combustion products. In most cases, polyester materials were tested in combination with other materials. This makes

it very difficult to assess the toxic contribution of one material as compared

to another since the toxicity is a result of the total combustion products.

However, comparisons between tests that differ in only one or two components

can be made.

Hafer and Yuill [60] and Yuill [61] conducted a series of room tests that

were designed to measure fire performance of an innerspring mattress with

various combinations of blankets and pillows after cigarette or match ignition. During all of these tests, they measured CO

2

, CO, and O

2 concentrations. The innerspring mattress had a rayon ticking and was covered with a

cotton sheet. A blanket (cotton, polyester, acrylic, or wool) or pillow

(feather or polyester) was added to each test. The maximum CO2 and CO concentration and minimum ©2 concentration as measured in the test chamber (12' x

14' x 8') along with the time of occurrence of the maximum CO value are

tabulated in table 20. The data appears to indicate the extent of burning

rather than any intrinsic property of the test materials.

30
In a similar way, Moore [62] measured CO, C02> and O

2 levels produced

from burning curtains and drapes in a room ( 10 1 x 16' x 7 1/2') having one

doorway. He measured gas concentrations at the top of the doorway. The

results of the polyester curtain tests are listed in table 21. With the

drapes drawn back, higher levels of CO were produced than with the drapes

extended.

Woolley et al. [63] conducted a series of bedroom fire tests. One of the

mattress configurations used a polyester filled quilt with a cotton cover

fabric on a polyurethane core mattress covered with a layer of nylon fabric

and a PVC covering over the nylon fabric. Using an L-shaped facility with an

3 internal volume of 300 m and a ceiling height of 3 m, they ignited a wood

crib (Crib No. 7 as defined in Tests for the Ignitability of Upholstered

Seating British Standard Institution Draft for Development DD58:1978) placed

on one of 3 beds located in the bum room. Gas analyses were recorded from

within the burn room (1 m high) and adjacent simulated corridor (1 m high).

They monitored CO, (X^* and O

2 continuously and used colorimetric detector

tubes to measure HC£ and HCN. In the burn room, CO concentration did not

begin rising until after the fire involved the major part of the quilt and, in

all likelihood, had penetrated into the polyurethane core. CO reached a

maximum of 800 ppm, CO

2

reached 3%, and O

2 decreased to 18%. In the adjacent

corridor, CO

2 was 3-4% and O

2 was 18%. At both locations, HCN and HC£ concentrations were 5 and 17 ppm, respectively.

Alarie et al. [50] conducted room corner tests that included animal

exposures to the combustion products. Three grades of fiberglass reinforced

polyester were tested in the room comer test. A thirty pound wood crib was

31
used as the ignition mechanism. During each test, smoke was drawn from the

corner of the room and distributed via a manifold to four exposure chambers,

each holding four mice. Each exposure chamber received combustion gases

diluted to different concentrations. In this way, Alarie was able to develop

concentration-response relationships. His data is summarized in table 22. It

shows that an experimentally modified polyester resin was less toxic than the

commercially available resin. However, a halogenated polyester resin was more

toxic in comparison because it required a 40% dilution before it became nonlethal. A decrease in respiratory rate followed a similar pattern. Comparing

these results to Alarie's small-scale results previously cited (see section

4.15), one can see excellent agreement in the rank ordering of these three

materials

.

Alarie et al. [48] also used a similar approach in evaluating the

toxicity of combustion products produced by smoldering upholstery chairs in a

closed room. Chair number 5 was covered with a heavy cotton fabric and filled

entirely with polyester batting. The chair was placed on a load cell in a

closed room with dimensions of 3 x 3 x 2.4 m, A lighted non-filter cigarette

was placed into the crevice formed by the seat cushion and right sidearm. The

cigarette was covered by a piece of cotton sheeting. This assembly smoldered

during the entire test. Three groups of four mice each were exposed to the

combustion products at different times and dilution rates. The first group of

animals were exposed to the room atmosphere for the first 70 minutes of the

test. The second group was exposed from 73 minutes until 105 minutes and the

third group was exposed beginning at 113 minutes. The test continued until

180 minutes. Although respiratory depression was noted with the first two

groups of animals, no deaths were observed, even with undiluted air. From a

32
toxicological point of view, the third group of animals were exposed to the

highest concentrations of CO, CO 2

, and hydrocarbons. One death was observed

within this group at a 25% dilution level. No exposures were conducted at 0%

dilution. The oxygen concentration was approximately 17.5%. The CO 2 concentration was 5% and CO concentration was in excess of 3000 ppm.

6 . CONCLUSION

Pyrolysis products of a given polyester are a function of temperature and

atmosphere. As the temperature was increased, researchers observed a decrease

in the quantity of heavier hydrocarbons with an increase in the production of

CO and C02 » The presence of flame retardant additives, such as bromine and

chlorine, produced halogenated combustion products. The use of phosphorus and

bromine in the same flame retardant finish increased the concentration of low

molecular weight compounds.

Thirteen different protocols were found that evaluated the toxicity of

various types of polyester. In general, non-flame retarded polyesters were

found to be less toxic than flame retarded polyesters. LC^q values for nonflame retarded polyester ranged from 30.5 mg/1 [55] to 95.7 mg/1 [50]. This

variation could be due to differences in polyester formulations used by

various researchers as well as the effects of dyes and other finishing

compounds. Halogen compounds are usually employed to limit the thermal hazard

of polyester end-products, as defined by specified test methods. Flame

retarded polyesters had LC5 q values of 24.0 mg/1 [50] to 38.0 mg/1 [51]. Most

toxicologists consider less than an order of magnitude difference in LC 5 Q

not

to be significant. Therefore, the above differences do not necessarily

33
indicate that flame retarded polyesters represent a significantly more toxic

atmosphere than non-flame retarded polyesters.

The overall toxicity, as measured by an LC^q, of polyesters appear to be

within the range of many other commercially available materials. Douglas fir,

for example has been found to have an LC^q for 30 minute exposure of 21 mg/1

to 50 mg/1 [45]. Acrylonitrile butadiene styrene, polyphenylsulf one, and

polystyrene all have the same order of magnitude LC^q values [45] as the

polyesters. Several researchers, in fact, found some polyester materials to

be more toxic than materials known to produce toxic combustion products.

Crane et al. [37] found that fiberglass reinforced polyester was more toxic

than a wool carpet containing a polyester backing and a PVC/polyester fabric.

These results may, in part, relate to differences in polyester formulations.

More likely, they are indicative of the presence of flame retardant or other

additives in the fiber glass reinforced polyester. Hilado [39,40,41,42,43,44]

also found polyester to be more toxic than cotton and a flame retarded polyurethane foam.

In general, large-scale tests results were ambiguous because of the

presence of other materials. However, Alarie has shown that qualitative

results can be obtained from a comparison of large-scale and small-scale

tests.

34
REFERENCES

1. Cullis, C. F. , and Hirschler, M. M. , The Combustion of Organic Polymers.

Oxford Science Publications, Clarendon Press, Oxford, England (1981).

2. Moncrieff, R. W. , Man-Made Fibers. Fifth Edition, Heywood Books, London

(1970).

3. Patten, G. A., Ignition Temperatures of Plastics. Modern Plastics,

New York, Sept. (1961).

4. Levin, B. C. , Paabo, M. , Bailey, C. S. , and Harris, S. E. , Letter

Report to Sponsor-CPSC-Second Quarterly Report on Comparison of

Toxicity of Composite Materials Thermally Decomposed in the Cup

Furnace & Radiant Furnace. Center for Fire Research, National

Bureau of Standards, Gaithersburg, MD (1984).

5. Kasem, M. A., and Rouette, H. K. , Flammability and Flame Retardancy of

Fabrics: A Review. J. Fire Flam. 3^:310-325 (1972).

6. Goldfarb, I. J. , and McGuchan, R. , Thermal Degradation of Polyesters.

Part I. Aliphatic Polymers. Air Force Materials Laboratory,

Wright-Patterson Air Force Base, Ohio, Tech. Rpt. AFML-TR-68-182 , Part I,

October (1968).

7. Goldfarb, I. J. , and McGuchan, R. , Thermal Degradation of Polyesters.

Part II. Aromatic and Semiaromatic Polymers. Air Force Materials

Laboratory, Wright-Patterson Air Force Base, Ohio, Tech. Rpt.

AFML-TR-68-182, Part II, September (1969).

8. Throne, J. L. and Griskey, R. G. , Heating Values and Thermochemical

Properties of Plastics. Modern Plastics 49^:96-100, (1972).

9. Dollimore, D. , Gamlen, G. A., Jeffries, M. , and Taher, H. S. , The Use of

the Rising Temperature Technique to Establish the Kinetics of

Acetaldehyde Evolution During Atmospheric Polymerization of

Bis(hydroxyethyl) Terephthalate. Thermochimica Acta 61 : 97-106

(1983).

10. Learmonth, G. S. , and Nesbit, A., Flammability of Polymers. V. Thermal

Volatilization Analysis of Polyester Resin Compositions. Br. Polym. J.

<4:317-325 (1972)

11. Dufour, R. E. , Survey of Available Information on the Toxicity of the

Combustion and Thermal Decomposition Products of Certain Building

Materials Under Fire Conditions. Underwriter's Laboratories, Inc.,

Bulletin of Research, No. 53, (1963).

12. Woolley, W. D. , and Fardell, P. J. , Basic Aspects of Combustion

Toxicology. Fire Safety Journal 5:29-48 (1982).

35
13. Madorsky, S. L. , Thermal Degradation of Organic Polymers. John Wiley & Sons, Inc., New York (1964).

14. Noble, W. , Wheals, B. B. , and Whitehouse, M. J. , The Characterization of

Adhesives by Pyrolysis Gas Chromatography and Infrared Spectroscopy.

Forensic Sci. Lausanne, Switzerland 3^:163-174 (1974).

15. Butt, R. I., and Cotter, J. L. , Analysis of the Gaseous Products Arising

From Insulation Coatings on Aircraft Cabling at Elevated Temperatures.

Royal Aircraft Establishment, Tech. Rep. 77134 (1971).

16. Calcraft, A. M. , Green, R. J. S. , and McRoberts, T. S. , Burning of

Plastics: Part I, Smoke Formation. Plast. Polym. 42 : 200-207

(1974).

17. Green, R. J. S. , Hume, J. , and Kumar, S. , Burning Plastics: Mechanisms

of Smoke Formation. Fire Matls. 36-41 (1976).

18. Bednas, M. E. , Day, M. , Hop, K. , Sander, R. , and Wiles, D. M. , Combustion

and Pyrolysis of Poly (ethylene terephthalate) The Role of Flame

Retardants on Products of Pyrolysis. J. Appl. Polym. Sci. 26:277-289

(1981).

19. Day, M. , Parfenov, V., and Wiles, D. M. , Combustion and Pyrolysis of

Poly (ethylene Terephthalate). III. The Effect of Tris

(2,3-Dibromopropyl) Phosphate on the Products of Pyrolysis. J. Appl.

Polym. Sci. 27_: 575-589 (1982).

20. Standard Research Test Method for Determining Smoke Generation of Solid

Materials. NFPA 258-1982, National Fire Codes, Volume 10, National Fire

Protection Association (1983).

21. Boettner, E. A., Ball, G. L. , and Weiss, B. , Combustion Products From the

Incineration of Plastics. EPA-67012-73-049, July 1973.

22. Felger, M. M. and Olsen, R. S. , Analysis of Thermal Breakdown Products of

Electrical Insulation. Soc. Plast. Eng. Tech. 2^:289-291 (1975).

23. Speitel, L. C. , Feher, R. E. , and Spurgeon, J. C. , A Preliminary

Comparison of Thermal Decomposition Products of Aircraft Interior

Materials Using the National Bureau of Standards Smoke Chamber and the

Combustion Tube Furnace. Nat'l Aviation Facilities Experimental Center,

Atlantic City, NJ, Report No. FAA-NA-77-22; FAA-RD-77-123 (1978).

24. Hartstein, A., and Forshey, D. R. , Coal Mine Combustion Products:

Identification and Analysis. U.S. Dept, of Interior, Bur. of Mines, Rpt.

of Inves. RI 7872, (1974).

25. Gross, D. , Loftus, J. J. , Lee, T. G. , and Gray, V. E. , Smoke and Gases

Produced by Burning Aircraft Interior Materials. U. S. Nat. Bur. Stand.,

Gaithersburg, MD, Building Sciences Series 18, February (1969).

36
26. Standard Guide for Measurement of Gases Present or Generated During

Fires. ASTM E800-1, American Society for Testing and Materials,

Philadelphia, PA, 1984.

27. Adams, S. I., Analysis of Combustion Gases During Testing with the NBS

Smoke Chamber. J. Comb. Tox. 4^:360-375 (1977).

28. Stauffer, R. C. , Larsen, E. R. , Petrella, R. V., Manca, A., and Miller,

D.P., Dibroraoneopentyl Glycol - Its Effect on Smoke Evolution in

Unsaturated Polyester. J. Fire Retard. Chem. 3^:34-43 (1976).

29. Miller, D. P. , Petrella, R. V. , and Manca, A., An Evaluation of Some

Factors Affecting the Smoke and Toxic Gas Emission From burning

Unsaturated Polyester Resins. Proc. Ann. Conf., Reinf.

Plastic/Composite Institute, Soc. Plast. Ind. 3J_:20-c,l-8 (1976).

30. Miller, D..P., Petrella, R. V., and Manca, A., Smoke and Toxic Gas

Emission from Burning Unsaturated Polyester Resins. Modern Plastics,

53:96-103 (1976).

31. Kaplan, H. L. , Grand, A. F. , and Hartzell, G. E. , A Critical Review of

the State of the Art of Combustion Toxicology. Final Report 01-6862,

Southwest Research Institute, San Antonio, TX, June (1982).

32. Erzeugung Thermischer Zersetzungsprodukte von Werkstoffen unter

Luftzufuhr und ihre Toxikologische Purfang. Part 1, Zersetzungsgerat und

Bestimmung der Versuchstemperatur , Part 2, Verfahren zur Thermischen

Zersetzung, German Standards Insitute, DIN 53 436, draft, (1979).

33. Herpol, C. , and Minne, R. , Biological Evaluation of the Toxicity of Gases

produced Under Fire Conditions by Synthetic Materials. Part 2: Behavior

of Synthetic Materials in Definite Combustion Conditions as Compared to

the Behavior of Traditional Materials in Same Conditions. Com.

Sci. Tech. ^2:229-244 (1976).

34. Herpol, C. , Biological Evaluation of Toxicity Caused by Combustion of

Building Materials. Fire Matls. 4^: 127-143 (1980).

35. Hofmann, H. Th. , and Sand, H. , Further Investigations into the Relative

Toxicity of Decomposition Products Given Off From Smoldering Plastics.

J. Fire Flam./Comb. Tox. J_:250-257 (1974).

36. Kimmerle, G. , and Prager, F. K. , The Relative Toxicity of Pyrolysis

Products. Part 1. Plastics and Man-Made Fibers. J. Comb.

Tox. _7: 42-53 (1980).

37. Crane, C. R. , Sanders, D. C. , Endecott, B. R. , Abbott, J. K. , and Smith,

P. W. , Inhalation Toxicology: I. Design of a Small-Animal Test System

II. Determination of the Relative Toxic Hazards of 75 Aircraft Cabin

Materials. FAA Civil Aeromedical Institute, Oklahoma City, Oklahoma,

Report No. FAA-AM-77-9 (1977).

37
38. Damant, G. H. , Williams, S. S. , and Mikami , J. , Results of Some Toxicity

Studies. J. Comb. Tox. 8^77-88 (1974).

39. Hilado, C. J. , Furst, A., and Marcussen, W. H. , The Use of the NASA

Animal Exposure Chamber in Fire Toxicity Tests. Proc. West. Pharmacol.

Soc. JJh 397-400 (1976).

40. Hilado, C. J. , Relative toxicity of Pyrolysis Products of Some Loose

Fiber Materials: A Preliminary Study. J. Comb. Tox. 3^:151-156 (1976).

41. Hilado, C. J. , and Furst, A., Relative Toxicity of Pyrolysis Products of

Some Materials Used in Home Furnishings. J. Comb. Tox. 3^:425-464

(1976).

42. Hilado, C. J. , and Brauer, D. P. , Concentration-Time Data in Toxicity

Tests and Resulting Relationships. J. Comb. Tox. 6:136-149 (1979).

43. Hilado, C. J. , Carbon Monoxide as the Principal Toxicant in the Pyrolysis

Gases from Materials. J. Comb. Tox. 6^:177-184 (1979).

44. Hilado, C. J., Relative Toxicity of Pyrolysis Products of Some Foams and

Fabrics. J. Comb. Tox. _3: 32-60 (1976).

45. Levin, B. C. , Fowell, A. J. , Birky, M. M. , Paabo, M. , Stolte, A., and

Malek, D. , Further Development of a Test method for the Assessment of the

Acute Inhalation Toxicity of Combustion Products. U.S. Nat. Bur. Stand.

NBSIR 82-2532, Gaithersburg, MD (1982).

46. Levin, B. C. , Paabo, M. , Fultz, M. L. , Bailey, C. , Yin, W. , and Harris,

S. E. , An Acute Inhalation Toxicological Evaluation of Combustion

Products from Fire Retarded and Non-Fire Retarded Flexible Polyurethane

Foam and Polyester. U.S. Nat. Bur. Stand, NBSIR 83-2791, Gaithersburg,

MD (1983).

47. Barrow, C. S. , Alarie, Y. , and Stock, M. F. , Sensory Irritation and

Incapacitation Evoked by Thermal Decomposition Products of Polymers and

Comparisons with Known Sensory Irritants. Arch. Environ. Health

33:79-88 (1978).

48. Alarie, Y. , Stock, M. F. , Matijak-Schaper , M. , and Birky, M. M. , Toxicity

of Smoke During Chair Smoldering Tests and Small Scale Tests Using the

Same Materials. Fund. Appl. Tox. _3: 619-626 (1983).

49. Anderson, R. C. , and Alarie, Y. C. , Approaches to the Evaluation of the

Toxicity of Decomposition Products of Polymeric Materials Under Thermal

Stress. J. Comb. Tox. _5: 214-221 (1978).

50. Alarie, Y. , Anderson, R. C. , Stock, M. F. , Dombroske, R. L. , Keller,

L. W. , Hayduk, L. W. , and Park, R. E. , Toxicity of Thermal Composition

Products: An Attempt to Correlate Results Obtained in Small Scale with

Large Scale Tests. J. Comb. Tox. 8:58-68 (1981).

38
51. Grand, A. F. , Toxicity of Polymer Combustion Products, Impact on the

Construction Industry. Fire Retardant Chemicals Association, San

Francisco, California, Oct. 29 - Nov. 1 (1978).

52. Nunez, L. J. , Hung, G. W. , and Autian, J. , Toxicity of Fabric Combustion

Products. J. Comb. Tox. _3: 371-380 (1976).

53. Nunez, L. J. and Autian, J. , Toxicity Study of Fabric Combustion

Products, Correlation of Experimental Variables. 2nd International

Conference on Fire Safety, San Francisco University, pp. 532-560 Jan.

24-28 (1977).

54. Yamamoto, K. , Acute Toxicity of the Combustion Products from Various

Kinds of Fibers. Z. Rechtsmedizin, Springer-Verlag 76:11-26 (1975).

55. Yoshida, Y. , Kono, K. , Harada, A., Toyota, S. , Watanabe, M. , and Iwasaki,

K. , Toxicity of Pyrolysis Products of Thermal-Resistant Plastics

Including Polyamide and Polyester. Jap. J. of Hyg. _33: 450-458 (1978).

56. Keller, J. G. , Herrera, W. R. , and Johnston, B. E. , An Investigation of

Potential Inhalation Toxicity of Smoke From Rigid Polyurethane Foams and

Polyester Fabrics Containing Antiblaze 19 Flame Retardant Additive. J.

Comb. Tox. 3 : 296-304 (1976).

57. Moreci, A. P. , Parker, J. A., and Furst, A., A Study of the Effects on Mice of Smoke and Gases from Controlled Fires in Simulated Aircraft

Cabins. J. Fire and Flam. /Comb. Tox. 2_: 34-63 (1975).

58. Pryor, A. J. , Johnson, D. E. , and Jackson, N. N. , Hazards of Smoke and

Toxic Gases Produced in Urban Fires. Southwest Research Institute, SWRI

Proj. No. 03-2402 (1969).

59. Standard Test Method for Surface Burning Characteristics of Building

Materials, ASTM E84, American Society for Testing and Materials,

Philadelphia, PA (1980).

60. Hafer, C. A., and Yuill, C. H. , Characterization of Bedding and

Upholstery Fires. U.S. Nat. Bur. Stand., NBS-GCR 70-1, Gaithersburg, MD

(1970).

61. Yuill, C. H. , The Life Hazard of Bedding and Upholstery Fires. J. Fire

and Flam. 312-323 (1970).

62. Moore, L. D. , Full-Scale Burning Behavior of Curtains and Draperies.

U.S. Nat. Bur. Stand., NBSIR 78-1448, Gaithersburg, MD (1978).

63. Woolley, W. D. , Lant, M. G. , Smith, P. G. , and Fardell, P. J. , Fire Tests

of Beds and Bedding-Warlingham Park Hospital Fire. October, 1981, Fire

Saf. J. 6:81-95 (1983).

39
64. Hilado, C. J . , Flammability Handbook for Plastics. 3rd Edition,

Technomic Pub. Co. Inc., Westport, Conn. (1982).

65. Miller, B. , and Meiser, C. H. , Jr., Flame Temperature Measurements on Textile Systems. Proceedings of the Third Annual Meeting Information

Council on Fabric Flammability, New York City, pp. 116-125 Dec. 4 (1969).

40
Table 1

Thermophysical Properties of Polyester

Property Measured Value Reference

Melting point: 250-300°C 2 Heat of combustion: 25-30 Mj/kg 8

Activation energy 160-190 Kj/mole 6,7

Ignition temperature

flash ignition: ~ 400°C 3

self ignition: 450-500°C 3,4,5

Flame temperature: 750 °C 65

Stoichiometric

flame temperature: 1977 °C 64

Oxygen index: 20-60 64

41
Table 2 - Thermal Degradation Products Produced by

Vacuum Pyrolysis of Aliphatic, Aromatic, and

Semiaromatic Polyesters [6,7]

Compound Aliphatic Semiaromatic Aromatic

Acetaldehyde +++

Acetic Acid - Ace tone +

Acetylene +

Acrolein +

Allyl Alcohol +

Benzaldehyde - - Benzene +

Benzoic Acid - Butadiene +++ +

Butanaldehyde +

Butane +

Butene + +

co

2

+-H- -H-+- +++

CO ++ -H- Cyclobutanone +

Cyclohexadiene - - Cyclohexane +

Cyclohexanone +

Cyclohexene + ++

Cyclopentanone +++

Cyclopentene - Ethene + +

1,5 Hexadiene -H- Hydrogen - Methane +

Olefin +

1,3 Pentadiene +

1,4 Pentadiene +

Pentene + +

4-Pentene-l-ol +

Phenol - Propanaldehyde ++

Propene + +

Quinone +

Tetrahydrofuran + - Toluene - Water +++ + +

+++: more than 20% of total gaseous products

++: 10% to 20%

+: n to 10%

trace or minor amounts

42
Table 3

Decomposition Products of Inert Atmosphere Pyrolysis of

Polyesters (450 o -1200°C) as a Function of Temperature

Compound Temperature of Maximum Concentration

Calcraft [16] Green [17]

(°K) (°K)

CO + + CO

2

+ + ch

4

Ethylene & Acetylene + +/1073

Benzene +/800 t Toluene 700 1073

Styrene +/600 873

Naphthalene +/1073

Ethylbenzene & Xylene - + /873

Biphenyl - 1073

Fluorene - 873/1073

Phenanthrene & Authracene - 1073/1173

Methylanthracenes & Methyl fluorenes — 1073

Shows the general trend of compound

maximum detected before peak test

yield as a function of

temperature

.

temperature

' °K At least one sample had a maximum concentration before peak test

temperature

.

°K/°K Sample dependent maximums.

43
Table 4

Identified Combustion Products Resulting from the Flash

Pyrolysis of Untreated Polyester Fabric

at 700°C and 900°C

Compound 700°C [18] 900°C [18] 900°C [19]

Carbon Monoxide + Methane + Carbon Dioxide +

Ethylene & Acetylene + Ethane

Water

Propylene + Acetaldehyde + Acetone +

Propenal + Ethanol + Benzene + Toluene + Ethylbenzene +

Styrene + p-Vinyl Toluene

Benzaldehyde

p-Ethyl Toluene

Acetophenone

Methyl Benzoate

Vinyl Benzoate + Ethyl Benzoate + p-Methyl Acetophenone + Benzoic Acid + p-Methyl Vinyl Benzoate + p-Vinyl Acetophenone

Propyl Benzoate

p-Ethyl Vinyl Benzoate + p-Vinyl Vinyl Benzoate + Biphenyl

1-Hydroxy Ethyl Benzoate + Diacetyl Benzene + p-Acetyl Vinyl Benzoate + Divinyl Terephthalate + Ethyl Vinyl Terephthalate + p-Acetyl Benzoic Acid + Methyl 1-Hydroxyethyl Terephthalate + Ethylene Dibenzoate +

+

++

++

+

+

++

++

+

++

++

+

++

+

+

+

++

+

++

+

+

++

+

+

++

+

+

+

+

++

+

+

+

+

+

+

+

44
Table 5

Specific Combustion Products Detected and Concentrations

Found During NBS Smoke Chamber Tests

of Materials Containing Polyester [25]

iple

l

Sample

Weight

(g)

Description

6 5.0 Polyester plasticizer

on cotton

7 12.2 Modacrylic/acrylic pile

w/ polyester back &

urethane foam pad

13 5.4 PVC & PVA base w/ABS

polyester film

17 15.2 Wool pile w/ polyester

back & urethane pad

20 13.0 PVA covered w/ polyester

on aluminum sheet

22 1.3 Polyester face & vinyl acetate, PVC

copolymer

30 12.3 Polyester coated glass

fabric paper honeycomb/

glass fabric

63 2.0 Modacrylic/ polyester

fabric

67 4.7 Polyester plastic filled

glass fiber fabric

75 3.9 Cotton/ nylon/ polyester

fabric

160 13.1 Styrene/ polyester

fiber glass panels

Gas Concentration (ppm/g)

Exposure CO HC1 HCN

F 70 40 0.6

N 80 60 0.4

F 41 7.4 1.6

N 10 2.5 2.5

F 37 56 0.6

N 11 50 0.4

F 21 0 1.0

N 20 0 3.9

F 22 7.7 0.2

N 1.5 6.2 0

F 69 54 0

N 7.7 23 0

F 23 3.7 0.6

F 140 75 23

N 40 50 20

F 49 4.3 0

N 6.4 1.7 0

F 46 0 1.3

N 31 0 1.3

F 38 15.3 0

N 9.5 11.5 0

F - Flaming exposure

N = Nonflaming exposure

PVC = Poly Vinyl Chloride

PVA = Poly Vinyl Alcohol

ABS * Acrylonitrile Butadiene Styrene

45
Table 6

Comparison of Colorimetric Detector Tubes and Instrumental Methods

for Analyzing Gases Generated from the Thermal Decomposition

of Wool Pile, Polyester-Backed Carpets in the

NBS Smoke Chamber [23]

Gas Concentration (mg/g)

Carpet Analysis

Method

CO HC1 HCN h2 s HCHO so2 no2

No Pad CDTa 32.3 17.5 3.2 ND 1.7 24.6 9.72

IMAb 27.2 7.1 3.0 3.0 ND 17.0 0.14

Pad CDT 38.0 31.8 2.6 ND 2.9 22.4 8.92

IMA 36.0 11.8 2.6 0.5 ND 15.8 0. 13

^Colorimetric detector tubes

“instrumental methods of analysis

ND: Not detected.

Pad: Urethane foam

46
Table 7

Concentration of Various Gas Species Produced by a Brominated

Polyester in a Modified NBS Smoke Box [27

]

Compound Gas Concentration

(mg/g)

CO

H~0

CO

2

ch

3oh

Styrene

Ethylbenzene

Methyl Bromide

Ethyl Bromide

Ethylene Bromide

Ethylene Bromohydrin

15.59

1.56

24.77

1.65

0.64

0.44

0.78

1.57

2.71

1.80

47
Table 8

Summary of Toxicity Protocols

No. Protocol Name An Iraal ExposureTime

(rain) Endpoint

Animal

Exposure

Combustion

System

Combustion

Flow System

1 * OIN rats 30 WBb/NOc tube furnace vented

2 * FAA* rats 30 1) Incapacitation

2) death

WB tube furnace recirculated

3 * NASA/US

F

mice 30 1) Incapacitation

2) death

WB tube furnace non- vented

4 * NBS rats 30 1) Incapacitation

2) death

Hl)d cup furnace non-vented

5 * Pittsburgh mice 30 1) Incapacitation

2) death

3) respiration

HD tube furnace vented

6 * Nunez rats 120 death WB radiant colls non-vented

7 Sne ll rats 5-30 death WB elect rlc hot plate

non-vented

8 Truesdall mice 30,120 behavior WB flaming vented

9 *U.S. Testing

Company

rats 15,20,30 1) Incapacitation

2) death

WB electric

heater

vented/ non- vented

10 * Yamamoto rats 30 incapacitation WB plate heater non-vented

ll Yoshlda mice 60 death WB preheated air non-vented

12 ASTM E-84 mice 240 death WB preheated air vented

13 NF PA 258 rats 20+ exploration time WB radiant non-vented

*

ab

c

d

Described by Kaplan et al. [31

J

Animals In an exercise wheel during

WB = whole body exposure

NO = nose only exposure

HO = head exposure

exposure

48
Table 9

Results of Toxicity Tests of Untreated and Flame Retardant Treated

Unsaturated Polyester Resin and Glass Fiber Structure [35]

Temp FR Dilution COHb Mortality

°C (cp:air) (%) (%)

300 - 1:

1

<15 0 + 1:1 <10 0

+ 1:4 <10 0 + 1:9 <10 0

400 — 1:

1

23 25

+ 1:1 28 100

+ 1:4 <10 100 + 1:9 <10 67

500 — 1:1 54 83 + 1:1 76 100 + 1:4 59 100

+ 1:9 22 100

600 — 1:1 63 8

+ 1:1 85 100 + 1:4 76 100

+ 1:9 58 100

All samples weighed 5 grams.

The combustion airflow was 100 liters per hour.

CP = Combustion products.

FR = Flame retardant.

49
Table 10

Description of Polyester Materials Tested in FAA Apparatus (37)

Sample

Number

Thickness

(mm)

Weight

(kg/m*) Description Use

10 0.99 1.91 Glassfiber Reinforced

Polyester

Cargo Liner

12 13.34 3.07 PVF/Polyester-Chopped

Glass/ Aramid Honeycomb

Polyester-chopped Glass

Panel

33 6.73 1.76 Wool Pile/Polyester

Backing/Latex Coating

Floor Cover

34 8.76 1.74 Wool Pile/Polyester

Backing/Latex Coating/

Urethane Pad

Floor Cover

97 0.46 0.39 PVC - Polyester Fabric

50
Table 11

Tests Results of Materials Described in Table 10 from FAA Protocol (37)

Sample

Number

Mean Response Time (min)

Measured Normalized Charged Normalized Consumed

T

i T

i T

d

10 5.09 7.89 3.99 6.20 3.6 5.59

12 7.57 - 5.85 - 3.6 -

33 7.07 15.80 5.26 11.73 4.95 11.07

34 7.35 20.43 5.53 15.35 5.13 14.26

97 9.23 13.59 6.97 10.28 6.51 9.60

T^ = Time to incapacitation.

T^ = Time to death.

~ = No responses during 30 minute exposure.

Measured = Mean of observed values.

Normalized Charged = Measured values normalized to a standard 200 g animal and

1 g material based on amount of material placed in

furnace

.

Normalized Consumed = Same as normalized charged except based on amount of

material consumed.

51
Summary

of

Results

for

Polyester

Fiber

Batting

[

39

, 40

, 41]

2

O' o •—4 ax O .—

t

ax O fH o o O Ox o ax o O CO *3 •3 CO Mf ^3 CO -3 <* CO <* *3 CO >3 CO >3 •3

d CM Ox >3 o OX CM CM in in NO ax o ao o 00 o in

xs H • • • • • • • • T3 a o CM ON CM <r o in o O Ox o v£> ax O in oo f-4 H

H V-/ ^4 ’“4 fH •H f-H CM CM

s d in co CM m o v£> o o> Ox »"H in o in CO co o co r-~- <0 T-l • • • • • • • • a On •—4 oo O —

h

00 CM oo 00 oo ax o 00 ax Ox oo CO in H H *“* fH

/-Nd

f-ia O o o o o O o o o o o o o o o o o o

O o o o o o o o o o o o o o o o O o

o fH »H iH F-* ^4 fH fH fH CO

'w' >«

>xU

•H

fH d

CO •H U a o o o o o o o o o o o o o o o o O in U o o o o o o o o o o o o o o o o CM Q o •—4 —

H

f-H 2 CM

v-/

a»s

u /—v

<D d

>

a in o in o o o o o o o o o o o o O O

CM xO -3 o o o o fH —4 fH

•—4

T3

0) in 00 S "bt> in 00 SO GO in in ax in 00 CM xO CO CM CM Ox ax 3 1 • • • L ®

'w' _H o o o o o o CM o CM o o CM O o

dou

u

x:

** b0 b0 o o o o o o o o o o O o o o o o o o

0) d • • • d • • • 3 •*-4 in CM fH in CM in CM fH -H in CM f-4 in CM in CM 6 .s O ro

o o O u Ui o O O

'O' 0> 0) •H *r4 v£> •H •H rH d <u fH d

g d d <** iH o •H *H R 0) 0) U CD • d CD

1) d o 0) in 0) a V 0)

i_) H cd U ~H T3 d f-J 4J

03 X

sO CDV

vO

r—t U CO x>

03 iH s

-0 o COin o S’ U •rJ sO d vO •M vO CM

a> 4J U

u 03 1 1 1 co

cq OJ 03 2 X < CQ o X < 0Q o

52

!

Value

not

recorded

Time

to

Incapacitation

Time

to

death
Table 13

Polyester and Polyester Blends Tested in NASA/USF Protocol

Material

Sample

Weight

(g)

Mass

Consumed

(g)

Tia (min)

Tdb

(min)

Ref

.

Heating Rate = 40°C/min Sealed System

Polyester 1 0.7 7.4 9.4 40

Polyester 1 0.8 - 19.0 43

Polyester/ acetate , 65/35 1 - 7.8 10.6 41

Polyester/cotton, 70/30 5 - 8.0 9.6 39

Polyester/ cotton , 50/50 5 - 9.5 9.6 44

Polyester/cotton, 30/70 5 1.3 10.5 11.1 44

Heating Rate = 60°C/min Sealed System

Polyester/cotton, 50/50 5 3.0 10.0 11.0 44

Unsealed System

Polyester/cotton, 30/70 10.4 6.3 9.5 10.2 44

Polyester/cotton, 50/50 4.8 2.8 10.9 - 44

Polyester/cotton, 50/50 9.8 4.7 9.5 ‘ 44

a

-)'Time to incapacitation

b 'Time to death

53
Results

of

Gas

Analysis

During

Thermal

Decomposition

of

Polyesters

[11]

<r o CM

33

B

CL

Ou I

s

n. o CL

cj ^

m

as

<TCM

I I CM

c

o

(0Ljd

0)o

d

6

CM o

o

3^

lti r-^ <t lo

• • * • CM —l —l 1-^ N h

il • • I I O ifl cm >—i O O • • • • CM —I CM —

I

03

cO O

CM Z ^

o o • • • co

• ON 00 00

• • ON OS

ON 1 CM oo oo 1 1 00

• • • OS 00 00

r»

co o CM

• • • • 00 O' LP) O' O *—fl 0 fl 9 •

c—

H

CM

CM o N-/

0 1 CM Os O' on

•-H r—

H

B ON

1 lO

• © • • oo oo oo On

bOd -o

•H o

fH *H c 3? 3? oCM

CL U H is is | B 03

flj Qli e

V-/

v£> V3

/“sc

o

•H

4_> cn Li

CO 03 c co CM 4-1 bO os OS CO •H s—

'

03 CO to

03 Lt L4 1—

I

d Q 03 03 O

•H 4-1 4J 04

Li CO co CD

03 — 03 03 CJ

4-1 Li >> to •w

eg O i—

1

i—

1

f—

4

S C O o CO

4-1 Cl 04 J3 a 4J < oi 03 JC

Cij CL 04

Oco

I co

CM

TJ

03 tJO

<u

4-1 0) •a

03e

a;bo

cnO

x:cluo

u

o

r-H J3O

£

03

4-1 O

z

54
Table 15

Results of Venting Tests on Twa Polyester Materials [51]

Glass

Reinforced

Polyester

Non-Flaming

NFR 9.5 6.1 64 13.3-14.5 0/6 1/5* —

10.0 7.3 73 11.8-14.7 0/6 1/5* —

11.5 8.3 72 6. 3-8.

3

6/6 — 71

12.3 8.8 72 9.5-10.0 6/6 — 70

FR 5.6 4.2 75 10.0-14.0 0/6 1/5* —

5.7 4.2 74 11.7-14.7 0/6 2/5* —

6.1 4.6 76 7. 9-9.3 4/6 0/2 66

6.1 4.6 75 8.5-10.0 6/6 — 67

6.7 4.9 73 7. 2-9.

3

5/6 0/1 69

Flaming

NFR 4.8 3.7 77 7.3-9.

2

1/6 0/5 67

FR 4.1 3.0 73 8.3-10.2 4/6 1/2 67

4.1 3.1 76 7.7-10.4 2/6 0/4 80

*COHb from dead animals only. averages given when two or more values obtained

*One animal sacrificed.

NFR: Not fire- retarded.

FR: Fire-retarded.

Mass

Tested

(g)

Mass

Loss

(g) (%)

Time to

Incapacitation

(min)

Number Died

Number Tested COHb

Within Post

Exp. Exp. (%)

1

55
Table 16

Results of Non-Venting Tests on Two Polyester Materials [51]

Glass Mass

Reinforced Tested

Polyester (g)

Mass

Loss

(g) (%)

Time to

Incapacitation

(min)

Number Died

Number Tested COHb*

Within Post

Exp. Exp. (%)

3.6 2.0 56 — 0/6 2/6 * —

4.7 3.1 66 19.8-23.7 0/6 0/5 —

6.3 3.5 56 16.3 1/6 1/5 56

5.6 3.8 68 14.3-17.2 3/6 0/3 76

7.2 4.0 56 12.7-16.7 5/6 0/1 66

2.3 1.5 63 — 0/6 0/5* —

2.4 1.5 64 — 0/6 2/5 —

3.6 2.0 56 — 0/6 °/6 —

3.1 2.2 72 14.0-16.2 2/6 1/3 66

3.2 2.3 70 13.3-14.1 6/6 — 67

3.6 2.3 62 — 0/6 1/6 —

3.6 2.3 64 17.4-18.0 3/6 0/6. 84

3.7 2.3 62 16.3-19.5 2/6 3/3 58

3.8 2.3 60 16.3-27.0 4/6 1/2 57

4.1 2.7 66 13.0-14.8 5/6 0/1 60

^COHb from dead animals only, averages given when two or more values obtained.

One animal sacrificed.

NFR: Not fire-retarded.

FR: Fire- retarded.

56
Table 17

Carbon Monoxide Concentrations and Animal Incapacitation Times [51]

Glass Time to

Reinforced Incapacitation CO x Tia CO x Mean Ti

Polyester Mass Loss Mean (ppm-min (ppm-min

Sample (g) (min) (min) x 10 3

) x 10 3

)

Non-Venting

FR 2.7 13.0-14.8 13.7 39.5-48.7 43.0

2.3 13.3-14.1 13.6 41 .0-44.5 42.0

2.3 16.3-27.1 19.3 32.3-64.8 42.0

NFR 4.0 12.7-16.7 14.2 30.5-48.6 37.6

Venting

FR 4.9 7. 2-9.

5

8.1 35.4-54.7 43.7

4.6 7. 9-9.

3

8.6 32.1-44.4 38.3

4.6 8.5-10.0 9.7 29.0-41.4 38.5

NFR 8.3 6. 3-8 .3 7.3 22.8-45.4 34.1

Flaming

FR 3.0 8.3-10.2 9.1 32.5-40.4 35.8

NFR 3.7 7. 3-9.

2

8.2 25.5-32.8 29.2

aIncapacitation time

.

FR: Fire retarded.

NFR: Not fire retarded.

57
Table 18

Estimated LC^q Values ^ For Rats Exposed to

Combustion Products from Glass Reinforced Polyester

Fire Retardant Conditions (mg^?)

+

Vented2 122-138

Non-vented 63

Vented 76

Non-vented 38

i Results estimated from data of Grand assuming a 60 liter combustion and

exposure system [51].

2

See text for description.

58
Table 19

LC^q Values for Cotton and Cotton/Polyester Fabrics Untreated

and Treated with a Flame Retardant Finish [52,53]

Sample Description

If ^51

(mg /

Cotton Twill, untreated 9.49 ± 0.61 20.7

Cotton Twill, THPOH/NH

3 1.02 ± 0.05 2.2

Cotton Twill, THPOH/NH

3 & Topped 3.62 ± 0.30 7.9

Cotton Flannel, untreated 10.40 ± 0.60 22.7

Cotton Flannel, THPOH/NH

3 3.80 ± 0.27 8.3

Cotton Flannel, THPOH/NH

3 & Topped 1.22 ± 0.12 2.7

Cotton/Polyester, Untreated 9.89 ± 0.83 21.6

Cotton/Polyester, THPOH/NH

3 2.39 ± 0.14 5.2

Cotton/Polyester, THPOH/NH

3 & Topped 2.87 ± 0.41 6.3

Topped = topping agent was trimethylomelamine

THPOH = Tetrakis (Hydroxymethyl) Phosphoniura Ifydroxide

59
O

cjX

CT3 C <r <T o —

J

-o- x ^ Ti <r O n —•* <r X)

04w

05

cu we

Ol 04 —

H

<uu H

AJaj 04 XX ~—4 O ^

c M CN CN| <r _ •H

sO • • • • • •

<4-4 0k H W vD CO 00 00 O

o o r —

*

—4 ^4 04 —

H

x>

05 •—

»

4-1 CO0)

00

4-1 04 o m o n n cn lO H

0)

0)

0) -C X

X W

to £

LO

in

r-* CM

co

co 04

Ut

-^4 to

u, c

o

05 AJ

05

05 AJo o ^ o o o o O 0 Li CJ r~i o in m m AJ x s: —

c O' ao CSI r-* AJ

03 T5C

ro <r ci CM ~o

3! X

u ao 04 04 0) —4 c c AJ AJ AJ X -H o AJ AJ AJ a a«i i-4 0) 04 04 co cj AJ u u jj -C u J=

1 *r4 -a 05 CO u CJ CT3 CJ 0) H C TJ ao ao AJ AJ ao AJ M ao o -*«4 *rJ X X i-4 X u c •-1 x u CJ X 2: CJ X

JS o

:o

CO 4J

U-t 0i 04 3

o -X AJ 5

x: 4-1 C 04 3‘ i—H

05 AJ 04 CO ad O •—4 AJ *H X 1—1 c AJ —4 i-4

i—

4

3 c 33 X 04 —4 CL 3 ^4 t0 r—

4

-X i-4 CO cQ *-h 1—4 l. CD c a. U

<u C SJ S3 0) X 04 ad O T-l AJ CJ 1—4 Li 4J •H tj C X i-4 33 04 X

05 aj 0) o 04 —

4

SI 04 3 •H AJ AJ 50 >> —4 4J >>

CJ -o X 4J f-4 U O X •-H T3 Z o o CJ O 04 0

<c CJ CL < 3 Ct, CL u

01 J3e3 o —H CM CO —j 04 Z —H —4 04 04

AJ

cn<v H

60
Table 21

Maximum Gas Concentrations Found by Burning Polyester Curtains and

Drapes in a Room [62]

Test Position

Number

CO CO

2 02

(ppm) (%) (%)

S 14

S7

Extended

Retracted

500 2.73 18.34

800 2.65 18.09

Weight: 3.17 oz/yd^

Size : 48" x 84" per panel

61
Table 22

Mortality During Room Corner Test of Three Fiberglass

Reinforced Polyester Resins [50]

Material Dilution Time to

(%) Death

(min)

# Deaths

// Exposed

Commercial 0 9.6-12.0 4/4

18.5 0 0/4

31.5 0 0/4

42.0 0 0/4

Experimental 0 0 0/4

18.5 0 0/4

31.5 0 0/4

42.0 0 0/4

Halogenated 0 7. 0-8.0 4/4

18.5 8. 4-8.

5

4/4

31.5 11-11.3 3/4

42.5 0 0/4

62
Polyester

Poly(ethylene terephthalate)

Figure 1. Chemical Structure of Polyesters

63
0.5 10 15 20 25 30 35

Tim© (min)

Figure 2. Comparison of the change in

respiration rate during a 30 minute

exposure to the combustion products

of FR treated and nontreated glass

fiber reinforced polyester

64
U.S. DEPT. OF COMM. 1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publ ication Date BIBLIOGRAPHIC DATA

SHEET (See instructions) NBSIR-85/3139 June 1985

4 . TITLE AND SUBTITLE

Polyesters: A Review of the Literature on Products of Combustion and Toxicity

5. AUTHOR(S)

Emil Braun and Barbara C. Levin

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions) 7. Contract/Grant No.

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City. State, ZIP)

Consumer Product Safety Commission

Washington, DC 20207

10.

SUPPLEMENTARY NOTES

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

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bliography or literature survey, mention it here)

The available literature was reviewed to determine the nature and extent of information

available on the thermal decomposition products and the toxicity of the combustion

products of polyester materials used in consumer applications such as textiles and

construction. This literature review is limited to those publications printed in

English through June, 1984.

The'thermal decomposition products of polyesters are a function of temperature and

oxygen content of the atmosphere. In general, as the temperature increases, the

quantity of heavier hydrocarbons decreases and the production of CO and CO„ increases.

The presence of flame retarded additives, such as bromine and chlorine containing

compounds, product halogenated combustion products. The use of phosphorus and bromine

together in the same flame retardant finish increases the concentration of low

molecular weight compounds.

Thirteen different test protocols have been used to evaluate the toxicity of various

types of polyester. Non-flame retarded polyesters are less toxic, with LC_„ values

ranging from 30.5 mg/1 to 95.7 mg/1, than flame retarded polyesters, whose LC.- n values

ranged from 24.0 mg/1 to 38.0 mg/1. Several exceptions, however, are noted. 'In

general, the results from large-scale tests are ambiguous because of the presence of

other materials in addition to the pol yp.p.fprs

.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by se~ co o-s Combustion products; flame retardants; literature reviews; polyesters; pyrolysis;

thermal decomposition; toxicity.

13.

availability 14. NO. OF

PRINTED PAGES

nq Unlimited

| | For Official Distribution. Do Not Release to NTIS ~i Order From Superintendent of Documents, U.S. Government Printing Office, Washington. D.C. 20402.

[ X Order From National Technical Information Service (NTIS), Springfield, VA. 22161

71

15. Pr.ce

$ 10 .

• 04 •