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NBSIR 84-2917

Environmental Cycling of

Cellulosic Thermal Insulation and

Its Influence on Fire Performance

J. Randall Lawson

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

August 1984

100

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84-2917

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Supported in part by:

Department of Energy

Washington, DC

NBSIR 84-2917

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ENVIRONMENTAL CYCLING OF

CELLULOSIC THERMAL INSULATION AND

ITS INFLUENCE ON FIRE PERFORMANCE

J. Randall Lawson

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

August 1984

Supported in part by:

Department of Energy

Washington, DC

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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TABLE OF CONTENTS

Page

List of Tables iv

List of Figures v

Abstract 1

1. INTRODUCTION 2

1 . 1 Background 2 1.2 Fire-Retardant Chemicals and Cellulosic Materials 5

2. CLIMATE SURVEY 7

3. ENVIRONMENTAL CYCLES 8

4. THERMAL INSULATION SPECIMENS 10

5. FIRE TEST PROCEDURES 10

6. INSULATION DENSITY MEASUREMENTS 12

6.1 Initial Density Determinations 12

6.2 Smolder "Break-Point" Density Determination 12

7. ENVIRONMENTAL CYCLING TEST RESULTS 13

7.1 Smoldering Combustion Test Results 13

7.2 Critical Radiant Flux Test Results 15

8. SUMMARY 16

9. CONCLUSIONS 17

10. ACKNOWLEDGEMENTS 19

11. REFERENCES 19

-ill-
LIST OF TABLES

Page

Table 1. Conditioning Cycle Specified in ASTM C739-77 33

Table 2. Evaluation of ASTM C739-77 Conditioning Method 34

Table 3. Cities Used in the Analysis of Climatic Conditions 35

Table 4. Environmental Cycles Used to Condition Specimens ......... 36

Table 5. Composition of Cellulosic Insulation Materials 37

Table 6. Blown and Settled Densities for Cellulosic Thermal

Insulation Samples 38

Table 7. Smoldering Combustion Test Results 39

Table 8. Critical Radiant Flux Test Results 40

-iv-
LIST OF FIGURES

Page

Figure 1. Relative humidity vs. dry bulb temperature for

Albuquerque, New Mexico, 1977-1978 21

Figure 2. Relative humidity vs. dry bulb temperature for

Billings, Montana, 1977-1978 22

Figure 3. Relative humidity vs. dry bulb temperature for

Boise, Idaho, 1977-1978 23

Figure 4. Relative humidity vs. dry bulb temperature for

Buffalo, New York, 1977-1978 24

Figure 5. Relative humidity vs. dry bulb temperature for

Chicago, Illinois, 1977-1978 25

Figure 6. Relative humidity vs. dry bulb temperature for

Duluth, Minnesota, 1977-1978 26

Figure 7. Relative humidity vs. dry bulb temperature for

New Orleans, Louisiana, 1977-1978 27

Figure 8. Relative humidity vs. dry bulb temperature for

Portland, Oregon, 1977-1978 28

Figure 9. Relative humidity vs. dry bulb temperature for

Richmond, Virginia, 1977-1978 29

Figure 10. Relative humidity vs. dry bulb temperature for

San Francisco, California, 1977-1978 30

Figure 11. Relative humidity vs. dry bulb temperature for

Tucson, Arizona, 1977-1978 31

Figure 12. Composite extreme climate data for eleven cities in the

United States 32

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ENVIRONMENTAL CYCLING OF CELLULOSIC THERMAL INSULATION

AND ITS INFLUENCE ON FIRE PERFORMANCE

J. Randall Lawson

Abstract

A study was conducted on climatological data for

eleven cities located throughout the United States.

Findings from this environmental study were used to

develop conditioning cycles for a research project on the

Influence of environments on the fire performance of

loose-fill cellulosic thermal insulation. Six cellulosic

insulation materials with different compositions of fire

retardant chemicals at an add-on level of 25 percent by

weight were specially manufactured for this study. These

materials were tested for fire performance using the

smoldering combustion test and the attic flooring radiant

panel test to establish a baseline.

After the materials were exposed to the various

environmental cycles, they were tested for fire performance. Results from these tests show that environmental

exposure can have a significant effect on the fire

performance of cellulosic insulation materials and

indicates that long term fire protection provided by fire

retardant compounds may be limited.

- 1 -
Key Words: climate; cellulose; environments; fire

performance; thermal insulation; fire retardants.

1 . INTRODUCTION

1 . 1 Background

Loose fill cellulosic thermal insulation has been used in housing for

many years in an attempt to reduce heating and cooling costs. With the rapid

rise in energy costs over the last decade, many home ovmers and ovmers of

commercial buildings have attempted to increase resistance to thermal losses

by Installing insulation or adding additional insulation to the structure. In

1977, a number of fire problems were identified with some cellulosic insulaA

tion products [1] . As a result, many questions were raised concerning the

fire properties of cellulosic insulation, job site installation practices for

the materials, standards for manufacturing, and standards for purchasing the

products. In addition to these questions, two other questions arose. One

question related to the peirmanence of fire retardant chemicals. The second

addressed the effect of various environmental conditions on fire performance.

The material standards generally used for specifying cellulosic thermal

insulation for buildings in 1977 were the American Society for Testing and

Materials (ASTM) Standard C 739 [2] and Federal Specification HH-I-515C [3].

The federal specification was based on the requirements stated in ASTM C 739.

This ASTM standard recognized the fact that cellulosic thermal insulation

\

Numbers in brackets indicate literature references at the end of this

report.

-2-
materials should be conditioned in some fashion before being submitted to fire

performance tests, but the conditioning procedure, as shown in the next paragraph, did not appropriately address the fire problems associated \d.th the

insulation. The ASTM C 739 conditioning procedure is presented in table 1.

When viewing table I, it should be noted that C 739 called for fire testing

the insulation immediately following the last 24 hour conditioning cycle. The

fact that fire testing of the materials occurred only 24 hours after being

exposed to a high relative humidity environment caused questions to be raised

concerning the conditioning methods validity.

An evaluation of this conditioning procedure was carried out at NBS

during 1978. The study was carried out using three commercially manufactured

cellulosic insulation materials. The fire retardant chemical compositions for

these materials were not supplied by the manufacturers, and no chemical

analyses were done to determine the constituents or amount of add-on. Two

different sets of specimens were taken from each of the three materials. One

set of specimens was conditioned using the C 739 method, and the second set of

control specimens was conditioned for two days in a 23 ± 3°C (73 ± 5°F) and

50 ± 5 percent relative humidity conditioning environment. For a period of

about one month before the samples v?ere conditioned, the materials were

stored, in their product bags, in an environmentally controlled laboratory

which had an environment similar to the 23°C and 50 percent relative humidity

condition mentioned above.

When the specimens were conditioned using the C 739 method, they were wet

upon completing the fourth cycle. This wet condition was not the result of

any error in carrying out the C 739 conditioning procedure but was the natural

- 3 -
end product of the conditioning method. Since the materials were wet, they

were not fire tested immediately, but were placed in the 23 ®C and 50 percent

relative humidity conditioning room for seven days before they were tested.

The fire tests conducted on the insulation materials measured surface

flammability and determined the propensity for smoldering. Test methods being

proposed by the General Services Administration (GSA) to replace the existing

ASTM E 84 fire test for surface burning characteristics of building materials

were used. The proposed test methods were the critical radiant flux test and

the smoldering combustion test [4]. These test procedures are outlined in

section 5 of this report. Test results using these procedures are shown in

table 2. The test results show that material ”A" improved significantly with

the smoldering combustion test after the C 739 environmental exposure, and

material ”B” showed a major improvement in critical radiant flux results.

Material "C" did not show a significant change for either fire test. In

general, variability in test results for all three specimens increased with

the C 739 environmental cycle when compared to the control specimen test

results. These findings as well as others associated with the ASTM E 84 fire

test procedure resulted in the GSA, which maintains standards for government

purchases, dropping the requirements for ASTM C 739 which included the conditioning method and the E 84 fire test and adopting a new standard.

The conditioning procedure in the new GSA standard HH-I-515D [4] required

that cellulosic Insulation materials be conditioned to equilibrium or for a

minimum of 48 hours, whichever is greater, at 21 ± 3°C (69.8 ± 5.4°F) and a

relative humidity of 50 ± 5 percent immediately prior to fire testing. This

conditioning procedure did not take into account any aspect of specimen aging

but attempted only to normalize the materials before testing.

-4-
In 1979, the Consumer Product Safety Commission published a standard for

cellulosic thermal insulation that was designed to reduce or eliminate an

unreasonable risk of injury to consumers from flammable or corrosive cellulose

insulation [5]. At that time, the consumer required Immediate action in

establishing a new standard because some unsafe products were being marketed.

The standard was published with no requirement for a fire retardant permanency

determination.

The purpose of this report is to provide information on environmental

conditions to which insulation materials are exposed that may influence fire

retardant permanency, and to show the sensitivity of the fire performance of

cellulosic thermal insulation materials to selected environmental exposure

conditions that are found in various parts of the continental United States.

1.2 Fire-Retardant Chemicals and Cellulosic Materials

Cellulosic thermal insulation materials are typically manufactured from

ground waste paper, wood pulp, or waste cotton. These materials are recognized to be easily ignited and to have a potential for fire growth. In order

to take advantage of the good insulating properties of these cellulosic

materials, manufacturers developed product formulations using known fireretardant chemicals. A study conducted at the Oak Ridge National Laboratory

[6] on 51 commercially produced loose-fill cellulosic insulations showed that

manufacturers used chemical fire-retardants with add-on levels that ranged

from 14 to 36 percent by weight.

-5 -
Some of the most common additives used as fire-retardants are borax,

boric acid, aluminum sulfate, ammonium sulfate, and ammonium phosphate. Borax

has been identified as the primary fire-retardant additive used to improve

flaming resistance [7]. The most common additive used to improve resistance

to smoldering combustion is boric acid, but compounds containing sulfur and

phosphorous are also used. Some chemical compounds, e.g., halides,

phosphates, and sulfates, are credited with inhibiting both flaming and

smoldering combustion in small scale tests with cellulosic fabrics [8].

The processes resulting in flaming or smoldering inhibition are not

clearly understood, but it has been suggested that the fire-retardant

chemicals serve as "chain-breakers" or "free radical scavengers" in the oxidation reactions [9]. This lack of understanding concerning the fire behavior

of the fire-retardant chemicals is compounded by the lack of knowledge

concerning the effects of environment on the chemicals. It is known that some

fire-retardant chemicals are water-soluble, e.g. boric acid and sodium borate,

and it is not uncommon for moisture to develop in wall cavities or in some

attic constructions as a result of variations in weather conditions or use of

the structure. Where moisture develops, these soluble fire-retardant

chemicals may be washed away from the insulation. A second area of interest

is associated with the fact that many of the cellulosic insulation materials

manufactured are produced by mixing dry granular or powdered chemicals with

the cellulose fibers. It has been noted that these dry chemicals have a

tendency to settle-out, as a result of vibrations and gravity, and collect at

the bottom of the structure containing the insulation. This leaves an insulation which is highly variable in its fire-resistance performance [10]. This

physical separation is not studied in this project. A third problem in ques6 -
tion is that boron containing compounds have an appreciable low vapor

pressure, and they have been found to sublimate as temperatures rise [6]. The

evaporation of the fire-retardant chemical also results in the possibility of

variable fire performance characteristics.

When the environmental variability of the chemical and physical

properties of fire-retardant additives are coupled with the fire properties of

loose fiber cellulosic materials, it is clear that fire-retardant permanence

is an important issue. As described above, environmental history may have a

significant influence on the behavior of cellulosic insulation materials if

they become exposed to an ignition source or a fire environment. In an

attempt to better define a range of environmental conditions that thermal

insulation may be exposed to, a climate survey was conducted.

2 . CLIMATE SURVEY

A survey of weather conditions for eleven cities located in the

continental United States was conducted to obtain information on the various

environments to which thermal insulation is exposed. The cities are listed in

table 3. These eleven cities were selected because their range of weather

conditions are representative of those found in the United States. Dry bulb

temperatures and relative humidities for these cities were analyzed using

climatological data for years 1977 and 1978. The data were obtained from the

National Oceanic and Atmospheric Administration (NOAA) , and the Koppen

Classification System for climatic types, as modified by Trewartha [11,12],

was used for analysis. For each of the eleven cities, average monthly dry

bulb temperature versus average monthly relative humidity was plotted.

-7 -
providing a range of temperature and humidity conditions for each city. These

plots can be seen in figures 1 through 11. These data were then combined into

one group, and the polygon in figure 12 shows the extreme conditions. The

aging cycles used in this study were developed by selecting significant high

temperature and extreme relative humidity conditions from the polygon.

3. ENVIRONMENTAL CYCLES

Three conditioning methods were used in this study to evaluate the

effects of environmental exposures on the fire performance of fire-retardant

treated cellulosic insulation materials. These three methods are presented in

table 4. The first environmental conditioning method was used to develop

baseline data on the insulation materials. The materials had been stored in a

well controlled air-conditioned laboratory for several months before they were

submitted to the baseline environmental exposure. The laboratory environment

over the storage period was almost identical to that used in the conditioning

chamber on the baseline exposure. All of the critical radiant flux test

specimens were blown into their metal specimen trays before they were conditioned, and all smoldering combustion test specimens were blown before being

hand loaded into their test containers prior to being conditioned.

Environmental cycles A and B shown in table 4 were designed to expose the

insulation materials to more extreme conditions than that used in the baseline

tests. However, the conditioning cycles had to be kept fairly short in order

to provide a procedure that may be used by industry for evaluating their

products. It was recognized that in a high production rate industry, like the

cellulosic insulation industry, lengthy conditioning cycles and testing

-8 -
periods create significant warehousing and marketing problems. These considerations resulted in the selection of the eight day environmental cycles.

These cycles were chosen with the knowledge that a longer conditioning procedure may be necessary to obtain a more reliable Indication of the effects of

environment on fire performance.

Because fire-retardant chemicals are likely to change or migrate at

higher temperatures, two elevated temperature climatic conditions were

selected for cycles A and B. The major differences between these two experimental environmental cycles are reflected in the percent relative humidity.

The conditions used in the first four days of cycle A are shown as extreme

environmental conditions in the climate polygon, figure 12. This temperature

and humidity condition is similar to that found in Tucson, Arizona during the

summer. See figure ll. The temperature for cycle A was increased from 37 °C

to 60°C in order to reproduce attic temperatures recorded in the western part

of the United States. The temperature for this cycle was also Increased to

remove free moisture from the insulation materials, and it was an attempt to

accelerate the aging process by thermally stressing the materials. The second

part of cycle A was used to normalize the insulation specimens for testing.

It is understood that more time may be needed for a specimen to completely

normalize after being exposed to an extreme environment. However, the four

day cycle at 23°C and 50 percent relative humidity was used to economize on

time and meet the requirement for a short cycling procedure as mentioned in

the paragraph above.

The first environmental condition shown in cycle B is also representative

of an extreme climatic condition identified in the climate survey. See the

-9 -
climate polygon in figure 12. This climatic condition exhibits a high relative humidity environment with a moderately high temperature. Figure 9 shows

that these conditions are similar to that experienced in Richmond, Virginia.

Again, the ambient temperature found in the climate survey was increased to

represent a higher temperature that may occur in an attic, and it was also

Increased so that the insulation materials would be stressed. The high relative humidity environment was selected because it would provide a moist condi

tlon which could result in the migration of soluble fire-retardant chemicals.

After the initial four days of exposure at the extreme conditions with cycle

B, the specimens were then exposed to the same normalizing moderate environment as used in cycle A.

4. THERMAL INSULATION SPECIMENS

The six cellulosic thermal insulation materials used in this study are

listed in table 5. Each specimen was prepared by a manufacturer that

possessed the equipment and working knowledge of the cellulosic insulation

manufacturing process. The specimens include fire retardant chemical composi

tions that have been identified in commercial insulation products.

5. FIRE TEST PROCEDURES

Two test methods were used to evaluate the thermal insulation materials

fire properties after they were exposed to the environmental conditions

described in section 3. One procedure, the Attic Flooring Radiant Panel test

[13], was used to measure changes in critical radiant flux. The second test

method, the Smoldering Combustion test [13], measured changes in smoldering

propensity.

- 10-
The radiant panel test apparatus exposes a 100 cm long specimen tray

filled with thermal insulation at its blown density to a radiant energy

source. The gas fired radiant panel produces a heat flux profile along the

O length of the specimen which ranges from l.l W/ cm at the specimen end nearest

the radiant panel to O.l W/ cm^ heat flux at the other end of the specimen. The

specimen is ignited by a small pilot flame at the end closest to the radiant

panel. If the specimen burns, flames move along the specimen away from the

radiant panel and then may stop at some point which is associated with the

chemical and thermophysical properties of the material. The flame will selfextinguish when thermal feed-back from the burning specimen and irradiance

from the radiant panel are insufficient to sustain flaming combustion. The

distance burned to flame extinguishment is converted to a measure of radiant

energy using a flux profile generated during test calibration, and the results

are reported as "critical radiant flux". A cellulosic thermal insulation

O material must have a critical radiant flux > 0.12 W/ cm to pass the test.

The smoldering combustion test exposes a thermal insulation specimen at

its settled density, in an open-top 20 cm square stainless steel box which is

10 cm deep, to a smoldering non-filter tip cigarette. The lit cigarette is

inserted with the smoldering end up into an 8 mm diameter vertical hole which

is located in the center of the specimen. The cigarette and specimen are

allowed to burn until smoldering is no longer evident. After the specimen

holder has cooled, the specimen is reweighed. The material will pass the test

if the mass loss resulting from burning is _< 15 percent of the initial

specimen mass. Test results are reported on the basis of percent mass loss.

- 11 -
6. INSULATION DENSITY MEASUREMENTS

6.1 Initial Density Determinations

Since the smoldering combustion test can be influenced by specimen

density, the insulation sample densities were measured using the procedure

described in reference 13. Two different densities for each sample are shown

in table 6. The blown density represents the insulation density just after it

was blown through the cyclone apparatus specified in reference 13. This

density is similar to that expected from material blown into a building attic

space using a commercial insulation blower. The settled density reported in

Table 6 is the result after each material was shaken for a five minute period

on a 1.19 cm vertical displacement shaker. The settled density measurement is

designed to provide an estimate of a possible change in density that may occur

over a long period of time after a material has been blown into a structure.

6.2 Smolder "Break-Point” Density Determination

After the settled densities were determined, each insulation sample was

tested to determine if it would smolder at its settled density. The smoldering combustion test discussed in section 5 was used in the evalxiation. Each

test in this phase of the study was carried out after the specimens were

conditioned using the baseline environmental exposure shown in table 4. All

of the insulation materials passed the tests by exhibiting little or no

smolder propagation. Since all materials passed the test, no data are shown

in the test result tables.

- 12-
Upon completing the Initial smoldering combustion tests, a series of

experiments was conducted to determine the "break-point density" where each of

the different insulation materials would begin to smolder. This was done to

find a density that could be used to evaluate the effect of environmental

cycling on the smoldering propensity of each material. To accomplish this,

insulation specimen densities were gradually increased from their settled

densities, test by test, until smoldering combustion occurred. Compare

settled densities in table 6 with the selected test densities for the test

program in table 7. The densities for all of the samples except materials 3

and 4 were increased. It was found that only a very slight increase in

density would cause materials 3 and 4 to smolder. Therefore, the test

densities for these materials were maintained at their settled density.

Material 1 exhibited an unusual characteristic that is not shown in the test

result tables. This material showed smoldering tendency at a density of

O 88.0 kg/m , but it showed no indication of smoldering at a higher density of

96.0 kg/m^* This indicates that an upper density limit exists and that the

density range which supports smoldering combustion using this test method is

fairly narrow for this material. When the "break-point" densities were

selected, the materials were then ready for use in evaluating the effects of

environmental cycling.

7. ENVIRONMENTAL CYCLING TEST RESULTS

7.1 Smoldering Combustion Test Results

Smoldering combustion test results for each of the three environmental

exposures are presented in table 7. It should be noted that the values for

- 13-
mass prior to smoldering in exposure cycles A and B represent the specimen’s

mass after environmental cycling, and they reflect a relative gain or loss in

moisture when compared to the values of mass after the baseline environmental

exposure.

Three tests were conducted on samples of each of the six insulation

products after they were exposed to the various environmental cycles.

Additional tests using each of the specially manufactured insulation materials

were not possible since the supply was being depleted. However, the data

obtained from these limited test results do suggest basic trends that can be

seen in tables 7 and 8.

Two of the six materials, 2 and 5, do reflect significant changes in

smoldering behavior with changes in environmental exposure. All of the test

specimens for material 2 passed with exposure A, and all of the test specimens

failed with exposure B even though there was a marked increase in specimen

mass due to moisture gained during environmental cycling. Material 5

exhibited two failures after being exposed to environment A and had no

failures when exposed to environmental cycle B. Both of the above materials

contained similar fire retardant chemical additives, but they reacted

differently after experiencing the two different environmental cycles.

Environmental exposures A and B had little or no effect on the smoldering

behavior of materials 1, 3, and 4. The apparent change in smoldering seen for

material 6 should not be given too much emphasis since the values obtained for

the baseline condition were developed at a higher density of 88.0 kg/m^. The

O density for material 6 was lowered to 84.0 kg/m"^ for the remaining environ-

- 14-
mental exposures in an attempt to obtain better sensitivity at the smoldering

"break-point". Even with this change in density, the difference in smoldering

combustion characteristics for material 6 with exposures A and B do not appear

to be conclusive.

7.2 Critical Radiant Flux Test Results

Critical radiant flux tests using the attic flooring radiant panel test

apparatus were conducted on each of the six thermal insulation materials at

their blown densities. Data for materials before and after exposure to the

environmental conditions can be seen in table 8. Baseline data for the

materials showed that flame retardant performance on several of the sample

materials was not adequate. Material 4 and 5 had failures, values < 0.12

W/cm , on each test conducted for critical radiant flux. Also, it should be

noted that material 4 exhibited failures on all tests regardless of the

environmental conditions. This insulation material contained borax and

ammonium sulfate, which are both considered to be flame retardants, but these

test results indicate unacceptable performance. In addition to the failures

experienced with materials 4 and 5, material 2 had two failures and materials

1 and 3 had one clear failure each, with marginal results on the other two

tests

.

After the six materials were exposed to conditioning environment A,

material 1 showed an increase in flame spread with three failures as compared

to results from tests after the baseline environmental exposure. Material 6

exhibited one failure out of three tests after exposure A. This indicates

some loss in flame resistance. Material 2 had a slight improvement in test

- 15-
results after exposure A. and material 3 showed no change. Materials 4 and 5

failed all three critical radiant flux tests after the exposure to environment

A conditions.

When the materials were exposed to environmental cycle B, all specimens

except material 4 showed improvement in critical radiant flvix values.

Material 6, which exhibited one failure, showed a significant Improvement in

test results with the second and third tests in this set as compared to

results from the baseline environmental exposure and environmental exposure A.

8 . SUMMARY

This report provides information on various environmental conditions

experienced in eleven different geographical locations in the continental

United States. Data on these climates provided basic information for the

selection of environmental conditions used in this study, and they provide a

collection of climatic data which may be used in further research on the

environmental cycling of thermal insulation materials.

Six cellulosic thermal Insulation materials containing chemical fire

retardants were exposed to different environmental conditions and were tested

for changes in fire performance. Each insulation material was tested for fire

performance using the smoldering combustion and the critical radiant flxix test

procedures [13]. Two of the materials showed improvements after being exposed

to a high temperature/high humidity environmental cycle and had poor results

after being exposed to a high temperature/ low humidity environment when tested

with the smoldering combustion test procedure. Another material experienced

- 16-
poor results from the high temperature/high humidity environmental cycle and

improved with the high temperature/ low humidity environmental cycle.

When the materials were tested for critical radiant flux, all except one

had failures with the basic environmental conditioning of four days at 23°C

and 50% relative humidity. This occurrence did not provide a good base for

observing differences in test results after the materials were exposed to the

two environmental cycles. However, a trend was suggested by the test results;

generally, critical radiant flux test results indicated that fire performance

of the materials became worse after they were exposed to a high temperature/

low humidity environment and it was improved by a high temperature/high humidity environment. The improvement noted may be attributed to increased moisture in the cellulosic insulation. This observation does not hold true when

comparing the smoldering combustion test results with the critical radiant

flux test results. Material 2 showed a reverse in this trend.

9. CONCLUSIONS

Test results from this research project are mixed, but provide insight

into the complex behavior of fire retardant chemicals on the fire performance

of cellulosic thermal insulation materials when they are exposed to various

environmental conditions. In spite of the mixed results, certain conclusions

can be made.

1. Test results show that environmental cycling can affect

the fire performance of cellulosic thermal insulation

materials

.

- 17 -
2. Cycling through either high temperature /high humidity or

high temperature/ low humidity environments can adversely

influence the protection provided by chemical fire

retardants in cellulosic thermal insulation.

3. These results indicate that fire performance behavior and

the effects of environmental exposure are markedly

affected by the composition and content of the chemical

fire retardants used.

4. Because of the mixed results from tests in this project

and the limited number of tests conducted, a simple

conditioning cycle cannot be recommended. In order to

properly design an acceptable environmental cycling

procedure for the permanency of fire retardant chemicals

and their effect on fire performance, a more comprehensive research project is required.

- 18-
1 0 . ACKNOWLEDGEMENTS

Appreciation is extended to Mr. David Klein for his assistance in

planning the project, developing the environmental data, and obtaining the

insulation materials. Mr. Newton Breese extracted the environmental data

presented in this report from computer tapes provided by the National Oceanic

and Atmospheric Administration. Special recognition is given to Mr. Eric

Mittlefehldt who spent many hours preparing test specimens, maintaining close

control over the environmental conditioning cycles, and conducting fire tests

on all of the materials discussed in this report. Appreciation is also

extended to Mr. Fred Gallagher (Mineral Research and Development Company) and

Mr. Robert Anderson for their assistance in obtaining the thermal insulation

materials. The Consumer Product Safety Commission Engineering Laboratory is

also recognized for their assistance in developing blown and settled density

test data on the six thermal insulation materials.

11. REFERENCES

[1] Gross, D., A Preliminary Study of the Fire Safety of Thermal Insulation

for Use in Attics or Enclosed Spaces in Residential Housing, National

Bureau of Standards (U.S.), NBSIR 78-1497 (1978).

[2] Standard Specification for Cellulosic Fiber (Wood-Base) Loose-Fill

Thermal Insulation, ASTM C739-77, American Society for Testing and

Materials, Philadelphia, PA (1977).

[3] Insulation Thermal (Loose Fill for Pneumatic or Poured Application):

Cellulosic or Wood Fiber, Federal Specification HH-I-515C

(April 13, 1976).

[4] Insulation Thermal (Loose Fill for Pneumatic or Poured Application):

Cellulose or Wood Fiber, Federal Specification HH-I-515D

(June 15, 1978).

[5] Interim Safety Standard for Cellulose Insulation, Consumer Product

Safety Commission, Federal Register, Vol. 44, No. 47, March 8, 1979.

- 19 -
[6] Yarbrough, D.W. , McElroy, D.L. and Harris, W.W., Properties and Testing

of Loose-Fill Cellulosic Insulation, ORNL/TM-6433, Oak Ridge National

Laboratory, Oak Ridge, TN (February 1982),

[7] Ohlemiller, T.J. and Rogers, F.E., Cellulosic Insulation Material II.

Effect of Additives on Some Smolder Characteristics, Combustion Science

and Technology, Vol. 24, pp. 139-152, 1980.

[8J McCarter, R.J., Combustion Inhibition of Cellulose By Powders:

Preliminary Data and Hypotheses, Fire and Materials, Vol. 5, No. 2,

66-72, (June 1981).

[9]

McCarter, R.J., "Smoldering Combustion of Cotton and Rayon, Proceedings,

Symposium on Textile Flammability, New Orleans, LA (April 20-21, 1977).

[10] Lawson, J.R., Interlaboratory Evaluation of the Attic Floor Radiant

Panel Test and Smoldering Combustion Test for Cellulose Thermal

Insulation, National Bureau of Standards (U.S.), NBSIR 79-1588 (1979).

[11] Trewartha, G.F., An Introduction to Weather and Climate, 2nd Edition,

McGraw-Hill, 1943.

[12] Wessel, C.J., Thom, H.C.S., "Climate and Deterioration", in

Greathouse, G.A. and Wessel, C.J., editors. Deterioration of Materials , Reinhold, 1954.

[13] Test Manual, Cellulosic Insulation, Part 1 - Radiant Panel and

Smoldering Combustion Test, U.S. Consumer Product Safety Commission,

Washington, DC.

-20-
TEMPERATURE

lO

rr>

Orr>

in

(M

O _

CM

m _ u

oa

U3 -

tn

I

0

1

t

O'—

Ooooooooooo attai— iouo’m’ene^^ Oo

IN3D^d ••• AilOn^nM SAJiyiBd

o

U-l

QJ3u

0)CL . E 00

dj

CTN JO I

I—

I

3

JO ON

x) Z

•HE ' 3 <U J3 3

cr > 0) •H o

4-1 cr

dJ 3

.-I M

d) I—

I

o' <

0)

)-> 3

QO

•rj u.

- 21 -

TEMPERATURE
TEMPERATURE

***

O - m

U3 .

(M

o _

(M

in u ^

o

to -

o

in _

I

O

O’-*oaoooooooo ataor^iDtowmeii^ Oe

lN33d3d ••• ALIGH^nH 3AI1V13M

- 22-

Figure

2.

Relative

humidity

vs.

dry

bulb

temperature

for

Billings,

Montana,

1977-1978.
TEMPERATURE

***

(n

o

tn

to

fM

O

(M

O

o

O

0

1

O'"*Oooaoaooooo o»aar'toiO'rcnM«-« Oo

lN33U3d *"• AiiaihOH 3Ali>rgu

- 23-

Figure

3.

Relative

humidity

vs.

dry

bulb

temperature

for

Boise,

Idaho,

1977-1978.
TEMPERATURE

***

to -

tn

o _

(n

to ~

(M

O _

(M

to - O

o _

o -

to _

I

I

o -

toM •-

I

o

ooaooooooo *-• enoor'cflin^cncsi'-* oa

iNSoysd -•* Aiioir'inM saiivtm

-24 -

Figure

4.

Relative

humidity

vs.

dry

bulb

temperature

for

Buffalo,

New

York,

1977-1978
TEMPERATURE

***

lOfO

o

tn

toM

O

(M

to u

o

o _

to

to

0

1

to

I

0

1

toM»

o

00

cCo

•H

-Co

(-1 o

(1) 3u

CO

(-1 <Ua

e

(U

3

rO

T3 W • > 00

<3^

I

r-. c^

(U cn > -r^ •H o w c

CO *H rH t-H d) rH

Oi I—

I

0) )13

00

IN3Dd3d xiiaiririM 3Aii\rGu

- 25 -
TEMPERATURE

***

O

W3 _

rr>

o _ m

to ~

(SI

o _

(SI

o

o

ID -

O

(SI

I

I lN33H3d AUOH^riM BAliVTSd

- 26 -

Figure

6.

Relative

humidity

vs.

dry

bulb

temperature

for

Duluth,

Minnesota,

1977-1978.
TEMPERATURE

***

lO - mo _

(T>

u>

_

(SJ o -

CM o Wd

cc

0) 1—I uo

OJ 2:do

0)dDUdu

0)ae

(U

!—I d

T)W 00 >

ON

>N >—1

4-1 I •HT3

•H ON E >—1 3

rd »• d

(1)

d > d

•H *H

4J

W

d ‘H rH 3 d O

Di hJ

<u3

00

•H - 27 -
TEMPERATURE

***

o —

lO<n

o

o o

O CD ofO oin Om CM O Oo

o

<n

U3N

O

CM

m

u —

o

o _

Ui

m

I

o

lO

I

0CM

1

to

CM

t iN3dU3d AilCl»NnH SAIIVISU

- 28 -

Figure

8.

Relative

humidity

vs.

dry

bulb

temperature

for

Portland,

Oregon,

1977-1978.
TEMPERATURE

***

1/3 (T)

O

fO

1/3

(VJ

o

IM

in

in

o

m

I

0

1

0

N1

inN

I

ooooiaar-wm^pncM*-' oooooooo oo

iN3DM3d ••• AilOlWnw 3AJIVT3M

- 29 -

Figure

9.

Relative

humidity

vs.

dry

bulb

temperature

for

Richmond,

Virginia,

1977-1978.
TEMPERATURE

***

119 - m

o -

rr>

m _

(SI

O -

(SI

u

o o

u> ~

o

m

I

lO

I

I OOOQOOQPO

lN30t£3d ••• AilOn^nM 3AiiV13tl

o •

o

o

w

•HO

cb

C

rt w

)-i o

y-(

<u

>-i 3

4J

rt

0)a

u

3

•3

• 00 w r>^ > o\

I w r~

•H r*^ -3 os

•1-1 I—

I

§ .

CO

•rl (u a

> M

•H O

4J M-4 CO *rt 3 CO

pcj O

3

3

00

•H

fi-i

-30-
TEMPERATURE

***

kO -

try

O _

(n

in _

(SJ

o _

CM

u

o

o -

in

I

o

in

I

(M

I

in

CM

I

oooooooooo o»aor~tOin'»cT)eM»^ Oo

iNSoysd ••• AiiOH^riM s/viivnsM

- 31 -

Figure

11.

Relative

humidity

vs.

dry

bulb

temperature

for

Tucson,

Arizona,

1977-1978.
TEMPERATURE

XNao^au AiiaiwnH aAiivian

m

<u 4J

ta +j COT30)

c

0) x:c

•H

CO<U U

•HO

(Ue

(1)

4JX

(U

•H

COO

ou

CM

(U3

00

•H

-32 -

TEMPERATURE

***°F
Table 1 Conditioning Cycle Specified in ASTM C 739-77

Cycle Condition

1 .

2 .

3.

A.

24 hrs. @ 180 ± 3°F (82.2 ± 1.7°C) and 96

24 hrs. @ 80 i 3°F (26.7 +_ 1.7°C) and 50 +

24 hrs. @ 180 3°F (82.2 _+ 1.7°C) and 96

24 hrs. @ 80 + 3°F (26.7 + 1.7°C) and 50 +

3% relative humidity

3% relative humidity

3% relative humidity

3% relative humidity

- 33-
Table

2.

Evaluation

of

ASTM

C

Ti9-ll

Conditioning

Method

bO u

C 42 CO CM OS r- CO O' ON o O ro ^o o in 00 CM

•H bO CO • • • • • • • • • • • • • • • • • • c S^S o o o 00 sO in ro in sO ro o

o 0) hJ ro v£ v£> CO 00 CM CM CM CM 3

CO J-> *H

cb 'TS Q C

4J 0

CO

(U u H a^ 4= CO 00 in GO O' CM CM ON m in 00 00 o »o

ro bO CO • • • C •H o bO CM CO CM o CO o^ Ov ro CM 00 ON CO ro c^ o

o 0) ro ro CM 00 00 ro CM

CJ 3

CO 43 • • • 6 • > • > • >

O X o • Q o • U • O X • o X • o CO • CO • CO • bO o u o

C

*H

Ui0) iH XJ O (0 r*^ 00 CM CM 00 in CM 00 ON so ON in CO Os s pr] bC CO • • • • « • • • • • • • t • • • • • CO 2 6>S •H o CM in in CM O in o CM 00 Os f—

<

sO

0) tJ •*3* CM CM O sO vO VX> ro CM CM CM

ays 50% 3 a

CM u 4J o 4= CO CM 00 00 00 m m 00 00 ON CO SO 00 CM sO

ro bO CO • • • • • • • • • • • • • • • • • • CM •H o bO in o vD o CM in in in 00 m '4* o ro <r SO ro so

o; hJ CO 00 O CM so m m in 3

lA vo m CNJ <M CSJ CNJ I • • • • I o o o o

^

CM O Csl o o in

0) H

bc o d B m so Mf CO in in in o m o CO sO m m ON in 00 CM in CM ro o

c •H cd X CJ CM CM CM CM ro CM O <r so <r ro CM CM CM CM O o •H u •H o •

• • • • • • • • • • • • • • c •H •o 3 o O O o o O o 00 o o o o o o o o o O o O o in

0) 4J

«3 ^

Q CO

(0

ON C C O m <r o ON o in m ON CM in sO c o O m ro 00 r*N. m

ro u <0 B • • * • t » • • • • • • • • • • rv 3 4J o CM •—

4

CO in O o sO ON o ro o sD ro ro ON CM CM CM hs. CM in 00

03 Cfi w sD sO so sO m sO -3* CO in CM vO sO sO so

c

<d •H

(0 u

lio

Is

I—1 ^

« 4J CM O C 0

•r^ rt X y

4J -rt d

•H •« i-t 3 (-1 (d 'w' o Pi

• >

a *

• o CO • o

• > ^ o

CO • CJ

V V

• >

CO lx ®. o

C->

m sO 00 oo ON CM o- CO o o ro CO CO o o ON 00 CM ON SO sO

CM CM CM CM CM CM O o o o CM CM CM CM CM CM o CO

• • • • • • • • • • • • o O O O O O o vO o o o o o o o o o o O O O O o in

CM f

u

C /-V CM ro O ro 00 o O o Mf O 00 so sO O 00 00 00 ro so U cd e • • • • • • • • • • • 3 4J o ro O Os ON ON CM CO in O o OO sO 00 PN. p^ sO vO m 00

P3 0) >- so sO in in in in Os o o ON ON ON in m sO m so sO A /\

•u -H CtH CO CO CJ

<D C H 0) O

o

ro O

cn

c

flj 0)£

I \X

34

S.D.

-

standard

deviation

C.O.V.

-

coefficient

of

variation
Table 3. Cities Used in the Analysis of Climatic Conditions

1. Albuquerque, New Mexico

2. Billings, Montana

3. Boise, Idaho

4. Buffalo, New York

5. Chicago, Illinois

6. Duluth, Minnesota

7. New Orleans, Louisiana

8. Portland, Oregon

9. Richmond, Virginia

10. San Francisco, California

11. Tucson, Arizona

- 35 -
Table 4. Environmental Cycles Used to Condition Specimens

Baseline -

Cycle A -

Cycle B

-

4 days @ 23'’C and 50% relative humidity

4 days @ 60“C and 10% relative humidity, then

4 days @ 23“C and 50% relative humidity

4 days 0 35®C and 95% relative humidity, then

4 days 0 23 ®C and 50% relative humidity

- 36-
Table 5. Composition of Cellulosic Insulation Materials

Specimen Fire Retardant Chemical Additives

1 one part borax (5 mol) , two parts boric

acid; total chemical content, 25 percent

2 two parts borax, one part boric acid; total

chemical content, 25 percent

3 one part borax, one part boric acid, one part aluminum trlhydrate; total chemical

content, 25 percent

4 one part borax, four parts ammonium

sulfate; total chemical content, 25 percent

5 two parts borax, two parts boric acid, one part aluminum sulfate (alum); total

chemical content, 25 percent

6 two parts reacted boric acid/sodium sulfate

(e.g., Boron-10), one part boric acid;

total chemical content, 25 percent

- 37 -
Table 6. Blown and Settled Densities for Celluloslc Thermal Insulation Samples

Average Average

Blown Blown Settled Settled

Density Density Density Density

Material (kg/m^) (kg/m^) (kg/m^) (k«/oi3)

1 32.9 49.3

33.0 50.9

34.2 51.3

34.9 33.7 50.1 50.4

2 35.4 53.3

37.5 52.0

34.4 51.1

35.3 35.7 51.4 51.9

3 34.1 50.1

32.2 50.6

31.8 48.7

35.6 33.4 50.7 50.0

4 35.3 52.8

32.6 51.3

33.7 50.7

33.1 33.6 48.4 50.8

5 30.1 47.0

29.3 45.0

31.8 45.7

31.4 30.6 48.6 46.6

6 35.2 50.4

32.6 51.6

34.2 46.6

34.0 34.0 49.5 49.5

- 38-
•J

I- X

t X

* *

* * X O' X — —

X ir> ov- r' O'

'— 'C f*' lT'

lT' lt>

O' ^ —

= ^

S X

X u o . I c X =d rv. O<

CS fM <•

cs; rvi {Ni CM CNi :m

l^^l iX X

CM f'J CSi CM CM CM

r' r~ X

CM CM CM

X

X I

t X I

X — X

5^

X '— V

X c -z tc ^ c ~ X

c iX —

CM c^ r~

cr< —

< x

<r CM

lT X c^

c" X X X r-. C CM

iT'. in in m rn c^^ CM rsl CM

CM CM CM CM CM CM X

CM X X

nj

X

CM

CM X X

CM CM

CM CM X C

* *

< * X

c o U i- > X

X

^

i: 2 ;

u

X ^ w X c -3 to U c

S- c=5 •

os tn X

X C LT ^ 3 o <r rsi cs X

ir> CM CM fsl CM CM CM — — sC

CM CM CM CM CM CM

'C

CM CM CM

CM CM CM

•1C * -KX

lT

>» ~ J « ^ X -C.! 5l^

X

X

X

in

-c- X

- 39 -

*

Thosi*

li'sts

w«T»‘

ooiuluc

I

i*(l

ill

.1

(liMiHlty

()l

HH.O

kjp/in

**

Tfbt

t.illurrs,

ptTCiMit

nuisH

Iohh

>

IS

prrc'«*nl.
fH * * •K * « *

CO vO 00 nO sf 00 00 >a- CM <-4 CO sf

PQ

O c X CM CN CM ^4 CN CN

•H CO 3 B

ure

•H fH

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

'w'

VV

V

V

VV

V

COoaXu

V

B

O

m vO o «n 00 CO •o ON CM

mm iri fs NO

m CO CO 00

rH 3 c c

CO

B Li CO E CO ON sf ON CO o o ON CO CO CO

m CO CN CO

O 4J H 3 4-1 u o rsi vO NO rs vO NO o o O ON 00 o ON nO nO C X PQ CO

(U CO 1-( e S Q co

Li •H> M c C (1) vO vO SJ- CM 00 00 CN 00 o sf o m CO NO

O NO NO

u •g

B vO -am >a- sf «a- < sf CO NO UO NO NO 00 sf CO CO

•H CO •—4 f-H ^4 ^4 e-4 ^4 ^4 ^4 ^4 ^4

CO

H 'w' fH * « * K IC •K •K •K <te * * K

CO fH3 4J ^4 ^4 CO CO ^4 CN CM ^4 ^4 ^4 ^4 ^4 ^4 ^4 fs

CJ 3 X CNJ ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4

iH •H 3 3 E

CO < •H iH

y o o o o o o o o o o o o o o o o o o •W 'a Pm

(U Li *5 3 VV

V

VV

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CO

00 o

0)

a

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X 3 X B CJ 3 3 3 /-N o ON UO rs. o rs CO -a- NO in

m

m in in in CO ON CO

fH

B Ll 3 B • • • • • • • • « • • • • • • • • • iH CO •H 3 4J o CN CO rs NO CO •a- ON o CO CO CO CO CO CO NO r-l CM

Pm

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4J <0 s Q C 6 CO 3

•H

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CO

U •H

B CN ON 00 ^4 Sf CN NO UO CN

m fs o o o o CM NO

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B •H 3 fs NO 00 NO

m rsm fs o NO

m fs 00 ON 00 rs

m 00

O 3 H ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 CN ^4 ^4 ^4 ^4 ^4 ^4 *-4 ^ •H

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0)

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fH

CO

O 3 X CM ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 •4 ^4 «-4 pH 44 ^4

•H 3 3 B

CO 4.J •H iH

y o o o o o o o o o o o o o o o o o o H •H •3 (I4 w Ll o 3 IS V V V V V V V V V V

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B3 3 3

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m

m

m

m o m ON

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m CM 'a- ^4 uo rs ON CO CO CO CO CO CO pH rs

m

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CQ •H ^4 ^4 ^4 ^4 >c £ Q U33

•H

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CO3

PQ

bO3

•H 3B y-N CO sf ON ON NO CN CO ON 00

m o fs ON ON ON ON

B •H 3 o 00 00 CJN o ON oo rs ^4 o rs o 1-4 •3- >o <»

CO

r-4 Pm

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CNJ ro

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-AOTest

failures
NBS-114A iREv. 2-aci U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See i nstructions)

1. PUBLICATION OR

REPORT NO. NBSIR 84-2917

2. Performing Organ. Report No, 3. Publication Date

August 1984

4. TITLE AND SUBTITLE

Environmental Cycling of Cellulosic Thermal Insulation and

Its Influence on Fire Performance

5. AUTHOR(S)

J. Randall Lawson

6. PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s) 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)

Department of Energy

Washington, D.C.

10. SUPPLEMENTARY NOTES

I [ 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

bibliography or literature survey, mention it here) A Study was conducted on climatological data for eleven cities located

throughout the United States. Findings from this environmental study were

used to develop conditioning cycles for a research project on the influence

of environments on the fire performance of loose-fill cellulosic thermal

insulation. Six cellulosic insulation materials containing 25 percent by

weight of fire retardant chemical add-on of different compositions were

specially manufactured for this study. These materials were tested to

establish a baseline.

After the materials were exposed to the various environmental cycles, they

were tested for fire performance. Results from these tests show that

environmental exposure can have a significant effect on the fire performance

of cellulosic insulation materials and indicates that long term fire protection provided by fire retardant compounds may be limited.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key

Climate; cellulose; environments; fire performance; fire retardants;

insulation.

words by semicolon S/ thermal

13. AVAILABILITY 14. NO. OF

1 Unlimited

1 1 For Official Distribution. Do Not Release to NTIS

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46

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