EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET
Determination of Airborne Asbestos Concentrations Associated with Each Method
by,
John R. Kominsky and Ronald W. Freyberg
Environmental Quality Management, Inc.
Cincinnati, Ohio 45240
Kim A. Brackett
International Technology Corporation
Cincinnati, Ohio 45246
EPA Contract No.: 68-CO-0016
EPA Project Officer -- Marilyn Lehmkuhl
Water and Hazardous Waste Treatment Research Division
Risk Reduction Engineering Laboratory
Cincinnati, Ohio 45268
Technical Project Manager - William C. Cain
Water and Hazardous Waste Treatment Research Division
Risk Reduction Engineering Laboratory
Cincinnati, Ohio 45268
RISK REDUCTION ENGINEERING LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
^ .
DISCLAIMER
The information in this document has been funded wholly or in part by the United
States Environmental Protection Agency under Contract 68-CO-0016 to IT Environmental
Programs, Inc. (a wholly owned subsidiary of International Technology Corporation). It has
been subjected to the Agency's peer and administrative review, and it has been approved for
publication as an EPA document. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
11
-------
FOREWORD
Today's rapidly developing and changing technologies and industrial products and
practices frequently carry with them the increased generation of materials that, if improperly
dealt with, can threaten both public health and the environment. The U.S. Environmental
Protection Agency (EPA) is charged by Congress with protecting the Nation's land, air, and
water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities
and the ability of natural systems to support and nurture life. These laws direct the EPA to
perform research to define our environmental problems, to measure the impacts, and to
search for solutions/
The Risk Reduction Engineering Laboratory is responsible for planning, implement-
ing, and managing research, development, and demonstration programs to provide an
authoritative, defensible, engineering basis in support of the policies, programs, and
regulations of the EPA with respect to drinking water, wastewater, pesticides, toxic sub-
stances, solid and hazardous wastes, and Superfund-related activities. This publication is one
of the products of that research and provides a vital communication link between the
researcher and the user community.
This report provides information on the effectiveness of three cleaning methods to
remove asbestos structures from carpet and the airborne asbestos concentrations associated
with the use of each of these methods. Dry vacuuming using vacuum cleaners both with and
without a high-efficiency particulate air (HEPA) filter is compared to wet cleaning using a
hot-water extraction cleaner without a HEPA filter. This report recommends the use of wet
cleaning to remove asbestos from carpets.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
m
-------
ABSTRACT
This study was conducted to compare the effectiveness of three cleaning methods to
remove asbestos from contaminated carpet and to determine the airborne asbestos
concentrations associated with the use of each method. The carpet on which the methods
were tested was naturally contaminated over a period of approximately 15 to 20 years from
fallout of asbestos-containing material in ceiling tiles and fireproofing. Baseline
measurements showed an average concentration of 1.6 billion asbestos structures per square
foot of carpet. The effectiveness of dry vacuuming using vacuum cleaners with and without
a high-efficiency paniculate air filter was compared with that of wet cleaning using a hot-
water extraction cleaner. Overall, wet cleaning with a hot-water extraction cleaner reduced
the level of asbestos contamination in the carpet by approximately 60 percent. No significant
evidence was found to indicate either an increase or a decrease in carpet asbestos
concentration after dry vacuuming. Airborne asbestos concentrations were approximately 1.3
to 2 times greater during than before the carpet cleaning activities. The type of cleaner used
did not greatly affect the difference between the airborne asbestos concentration before and
during cleaning. Personal breathing zone concentrations did not exceed the Occupational
Health and Safety Administration (OSHA) action level of 0.1 fiber per cubic centimeter of
air. A reduction in the amount of asbestos in the carpet would suggest a possible reduction
in the potential exposure to custodial workers and building occupants.
International Technology Corporation submitted this document to the U.S.
Environmental Protection Agency's Office of Research and Development, Risk Reduction
Engineering Laboratory, in fulfillment of Contract No. 68-CO-0016. The report covers the
period from March 1991 to March 1992, and work was completed as of March 31, 1992.
IV
-------
CONTENTS
Disclaimer ii
Foreword • iii
Abstract iv
Figures vii
Tables viii
Acknowledgments ix
1. Introduction 1
Background 1
Objectives 2
2. Conclusions and Recommendations 3
Conclusions 3
Recommendations 4
3. Study Design 5
Description of test site 5
Experimental design 7
Sampling strategy 10
Sample size 11
4. Methods and Materials " 13
Carpet cleaning equipment 13
Carpet cleaning technique 14
Sampling methodology 15
Analytical methodology 16
Statistical analysis - 18
5. Quality assurance 19
Sample custody procedures 19
Sample analyses 20
6. Results and Discussion 25
Fiber Reentrainment 25
Effectiveness of Cleaning Methods 36
Structure Morphology and Length Distributions ' 42
References 54
-------
'V *&
CONTENTS (continued)
Appendices Page
A Sonication Procedure for Extraction of Asbestos Structures From 55
Carpet Samples
B Individual Airborne Asbestos Concentrations Before and During 57
Carpet Cleaning
C Average Airborne Asbestos Concentrations (Determined by TEM) 59
Before and During Carpet Cleaning
D Individual Personal Breathing Zone Concentrations During 60
Carpet Cleaning
E Average Personal Breathing Zone Concentrations (Determined by PCM) 62
During Carpet Cleaning
F Individual Airborne Asbestos Concentrations During Carpet Removal 63
G Individual Personal Breathing Zone Concentrations During Carpet - 64
Removal
II Individual Asbestos Concentrations in Carpet Before and After 65
Cleaning
I Average Asbestos Concentrations in the Carpet Before and After Cleaning 66
J Size Distributions of Asbestos Structures in Carpet and in Air 67
Plotted Using a Linear X-Axis Scale
VI
-------
FIGURES
Figure Page
1 Configuration of the Study Site 6
2 Order of Cleaning Experiments 9
3 Airborne Asbestos Concentrations Before and During Carpet Cleaning 28
4 Personal Breathing Zone Concentrations During Carpet Cleaning 31
5 Area Airborne Asbestos Concentrations During Carpet Removal 35
6 Asbestos Concentrations in the Carpet Before and After Cleaning 37
7 Particle Size Distribution in Carpet Before and After Dry Vacuuming 44
8 Particle Size Distribution in Carpet Before and After Wet Cleaning 45
9 Particle Size Distribution in Area Air Before and During Dry Vacuuming - 47
10 Particle Size Distribution in Area Air Before and During Wet Cleaning 48
11 Particle Size Distribution in Area Air Samples Before and During 51
Removal of Carpet in Furniture Storage Area
12 Particle Size Distribution in Area Air Samples Before and During 52
Removal of Cleaned Carpet
Vll
-------
TABLES
Table j^gg
1 Closed Field Blank Results for 0.8-^m MCE Filters Analyzed by PCM 21
2 Results of Replicate and Duplicate Sample Analyses 23
3 Interlaboratory Sample Results on 0.8-^m MCE Filters 24
4 Summary Statistics for Airborne Asbestos Concentrations Before 27
and During Cleaning
5 Analysis of Variance Table for Difference Between Asbestos 27
Concentrations Before and During Cleaning
6 Summary Statistics for Personal Breathing Zone Concentrations 29
(Analyzed by PCM) During Cleaning
7 Analysis of Variance Table for Difference Between Personal Breathing 30
Zone Concentrations During Cleaning
8 Comparison of TEM and PCM Concentrations Measured During Carpet 32
Cleaning Activity
9 Summary Statistics for Area Air Concentrations (Determined by TEM) 34
Before and During Carpet Removal
10 Summary Statistics for Personal Breathing Zone Concentrations 34
(Determined by PCM) During Carpet Removal
11 Summary Statistics for Asbestos Concentrations in Carpet Before 38
and After Cleaning
12 Analysis of Variance Table for Difference Between Asbestos 38
Concentrations in Carpet Before and After Cleaning
13 Estimated Asbestos Concentration in Carpet After Cleaning as 39
a Proportion of the Concentration Before Cleaning
viii
-------
TABLES (continued)
Tab!
14 Analysis of Variance Table for Difference Between Asbestos 40
Concentrations After the First and Second Cleanings
15 Estimated Asbestos Concentration in Carpet After Cleaning as 41
a Proportion of the Concentration Before Cleaning
16 Asbestos Structure Distributions From Carpet Samples Collected 42
Before and After Cleaning
%
17 Asbestos Structure Distributions From Area Air Samples Collected 46
Before and During Cleaning
18 Cumulative Size Distributions of Asbestos Structures in Work 49
Area Air Samples Collected Before and During Carpet Cleaning
19 Asbestos Structure Distributions From Area Air Samples 50
Collected During Carpet Removal
20 Cumulative Size Distributions of Asbestos Structures in Work 53
Area Air Samples Collected Before and During Carpet Removal
IX
-------
ACKNOWLEDGMENTS
This document was prepared for EPA's Office of Research and Development, Risk
Reduction Engineering Laboratory (RREL), in fulfillment of Contract No. 68-CO-0016.
William C. Cain served as the EPA Technical Project Monitor. The onsite technical
guidance and support provided by Bruce A. Hollett, CIH, of EPA's Office of Research and
Development are greatly appreciated. Special thanks are offered to Patrick J. Clark and the
staff of RREL's Transmission Electron Microscopy Laboratory for conducting the analyses
of the air samples. The administrative efforts of Roger C. Wilmoth and Bruce A. Hollett of
EPA's Office of Research and Development are also greatly appreciated.
Mr. John R. Dyer, Deputy Commissioner of Finance, Assessment, and Management,
Social Security Administration, authorized the use of the East High Rise Building cafeteria
area to conduct this research study. Ms. Betsy R. Bruce (Facility Asbestos Control
Manager) and Angela C. Danee (Industrial Hygienist) of the Social Security Administration
provided invaluable assistance in coordinating and overseeing the implementation of the
technical specifications for preparation of the cafeteria area for the study. They also
provided technical and administrative assistance during the course of the study, which
facilitated completing the study in a smooth and timely manner.
John R. Kominsky, CIH, Ronald W. Freyberg, and Kim A. Brackett, Ph.D., of
International Technology Corporation (IT) were the principal authors. Marty Phillips of IT
performed the technical edit of the report.
-------
SECTION 1
INTRODUCTION
Asbestos-containing materials (ACM) may release asbestos fibers into, the building air
as a result of disturbance, damage, or deterioration over time. A concern is the extent to
which carpet and furnishings may be reservoirs of asbestos fibers and the release behavior of
these fibers when normal custodial cleaning operations are performed.
The Asbestos Hazard Emergency Response Act (AHERA) requires that all carpeting
in areas of school buildings in which friable ACM are present be cleaned with either a high-
efficiency paniculate air (HEPA)-filtered dry vacuum cleaner or a hot-water extraction
cleaner ("steam cleaner") without HEPA filtration. Little quantitative information is
available on how effectively these two vacuum cleaners remove asbestos fibers from carpet
or on the potential for airborne asbestos fibers to become reentrained during these carpet-
cleaning activities.
Background
In 1988, the Risk Reduction Engineering Laboratory (RREL) of the U.S.
Environmental Protection Agency (EPA) compared the effectiveness of dry vacuuming and
wet cleaning for the removal of asbestos fibers from artificially contaminated carpet.1 In
addition, airborne asbestos concentrations were measured during the carpet-cleaning
activities.' Artificially contaminating the carpet with known levels of asbestos resulted in a .
carefully controlled experiment with sufficient replication to demonstrate that the wet
1
-------
cleaning method removed significantly more asbestos material from the carpet than did the
dry cleaning method. Both the wet and dry cleaning methods resulted in a significant
increase in airborne asbestos concentrations.2
In 1990, EPA's RREL conducted a "real-world" study to determine whether the
experimental results obtained with artificially contaminated carpet would also apply to carpet
naturally contaminated via the release of asbestos fibers from in-place ACM. This study was
conducted to compare the effectiveness of three cleaning methods to remove asbestos from
naturally contaminated carpet and to determine the airborne asbestos concentrations
associated with the use of each of these methods. The carpet on which these methods were
tested was naturally contaminated over a period of approximately 15 to 20 years as a result
of asbestos-containing material in ceiling tiles and fireproofing on structural members above
the ceiling. The effectiveness of dry vacuuming using vacuum cleaners with and without a
high-efficiency paniculate air (HEPA) filter was compared with that of wet cleaning using a
hot-water extraction cleaner without HEPA filtration.
Objectives
The primary objectives of this study were 1) to determine the ability of three cleaning
methods to remove asbestos structures from carpet, 2) to determine airborne asbestos levels
during carpet cleaning by each of the three cleaning methods, and 3) to compare fiber
concentrations measured by phase contrast microscopy during each cleaning method with the
Occupational Safety and Health Administration (OSHA) action level of 0.1 fiber per cubic
centimeter.
-------
SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
The following are the principal conclusions reached during this study:
• The test results demonstrate that dry vacuuming alone is not an effective
method for removal of asbestos structures from carpet. The difference
between the effectiveness of wet cleaning and dry vacuuming in the removal of
•asbestos structures from carpet was significant. Wet cleaning reduced the
asbestos concentration in the carpet by approximately 60 percent, whereas
there was no significant evidence of either an increase or decrease in asbestos
concentrations after dry vacuuming.
• The type of cleaning method employed had no significant effect on the
difference between airborne asbestos concentrations before and during
cleaning. Both wet cleaning and dry vacuuming of carpet resulted in a
statistically significant increase in airborne asbestos concentrations in the work
area. Airborne asbestos concentrations were 1.3 to 2 times greater during than
before the carpet-cleaning"activities.
• The results of this study, which represents carpet with natural asbestos
contamination and wear characteristics, are comparable with results from a
controlled study under artificial, simulated conditions in both efficacy of the
carpet cleaning methods and reentrainment of asbestos structures during carpet-
cleaning activities.
• Removal of the carpet used in the cleaning experiments resulted in a
statistically significant increase in airborne asbestos concentrations in the work
area. Airborne asbestos concentrations were 1.7 to 4.3 times greater during
than before carpet-removal activities.
• Although the personal breathing zone samples analyzed by phase contrast
microscopy (PCM) were all below the OSHA action level of 6.1 fiber per
cubic centimeter of air, considerably higher exposures are indicated by the
personal breathing zone and work area samples analyzed by transmission
electron microscopy (TEM). The results of the two analytical techniques
3
-------
differ because PCM does not detect the smaller fibers (<5 A*m in length and
<0.25 /xm in width) measured by TEM. The structures observed by TEM
analyses were predominantly <5>m in length; that is, 99.6 and 97.1 percent
of the asbestos structures generated during dry and wet carpet-cleaning
activities, respectively, were <5 ^m in length; and 84 percent of those
generated during carpet-removal activities were <5 ^m in length.
Recommendations
The study conclusions led to the following recommendations:
• In buildings containing friable asbestos-containing materials (ACM),
vacuuming of carpets during routine custodial activities to remove general
surface debris should be conducted using dry vacuum cleaners equipped with a
high-efficiency paniculate air (HEPA) filter. Periodic cleaning of carpets
should be conducted to remove asbestos structures using wet cleaning methods
(e.g., a hot-water extraction cleaner). If ACM has been released onto a
carpeted area during an operations and maintenance (O&M) activity or from
.fallen surfacing material, the gross debris should be removed with a dry
vacuum cleaner equipped with a high-efficiency paniculate air (HEPA) filter
and then followed by wet cleaning of the carpet.
• Further research is needed to assess the release of asbestos structures from
carpet during carpet-removal activities in buildings containing friable ACM.
In addition, the research should be directed at evaluating paniculate
suppression techniques (e.g., spray-applied encapsulants) as well as the extent
and impact of residual levels of asbestos structures on the floor after carpet
removal.
-------
SECTION 3
STUDY DESIGN
Description of Test Site
This study was conducted in the cafeteria area of the East High Rise Building of the
Social Security Administration, Baltimore, Maryland. This area was unoccupied, awaiting
the removal of asbestos-containing acoustical ceiling tiles and fireproofing on structural
members above the ceiling. The acoustical ceiling tiles contained 1 to 5 percent chrysotile,
and the fireproofing contained 35 to 40 percent amosite.
The dining area was carpeted with a 0.25-inch cut pile carpet. The carpet was
naturally contaminated over a period of approximately 15 to 20 years from fallout of
asbestos-containing material in the ceiling tiles and fireproofing. The carpet was in good
condition, i.e., there were no torn or visibly worn areas. There was no record of any
asbestos abatement in the cafeteria area before the experiment was conducted.
Figure 1 shows the configuration of the study site. Approximately 3700 ft2 (58 ft x
I
64 ft) of the carpeted dining area was isolated as the test area. The perimeter containment
walls on the west and south sides were constructed of 2-inch by 4-inch lumber with studs
spaced on 24-inch centers. The east and north walls were the exterior walls of the building.
i
The west and south walls and the ceiling were covered with 6-mil polyethylene sheeting to
prevent any cross contamination of the area with asbestos. Within the test area, nine equally
dimensioned areas (19 ft 4 in. by 21 ft 4 in.), each with approximately 400 ft2 of carpet,
-------
LEGEND
H STATIONARY HEPA-FILTRATION UNIT
MOVABLE HEPA-FILTRATION UNIT
CAFETERIA
N
CONTAINMENT
WALL
i^ -
-------
were defined as experimental test cells. Each test cell was covered by a floor panel
19 ft 4 in. by 21 ft 4 in., which served as a protective barrier against cross contamination
during an experiment. The floor panel was removed for each experiment and replaced after
the experiment was completed. The floor panel frame was constructed of 2-in. by 4-in
lumber, and 6-mil-thick plastic sheeting was stretched across the top surface. An office
enclosure (approximately 24 ft by 27 ft) was constructed adjacent to the test area. Entry into
the test area was from the office area through a 5-ft by 13-ft decontamination facility. The
decontamination enclosure consisted of three equally dimensional chambers: equipment-
change room, shower room, and clean room.
Five HEPA filtration units were used to reduce the airborne asbestos concentrations to
background levels after each experiment (Figure 1). The units were operated during the
preparation phase of the experiment but not during the carpet-cleaning phase. Four of the
five HEPA units cleaned and recirculated the air, and the fifth unit discharged the air to the
outdoors via flexible ducting. Makeup air to the test area was obtained from outdoors
through the door at the decontamination facility.
Experimental Design
Three methods of carpet cleaning were evaluated: 1) dry vacuuming with a HEPA-
filtered vacuum cleaner, 2) dry vacuuming with a conventional vacuum cleaner (i.e., without
HEPA filtration), and 3) wet cleaning with a hot-water extraction cleaner without HEPA
filtration. Each method was tested three times to yield a total of nine experiments. Three
different HEPA-filtered vacuums (same model), three different conventional vacuum cleaners
-------
(same model), and three different hot-water extraction cleaners (same model) were used in
. this study so the results would not be influenced by the pecularities of a single unit.
The carpeted area was divided into nine equal areas, each having approximately
400 ft2 of carpet. Dividing the carpet into a large number of smaller areas would have made
the cleaning process less realistic and prevented collection of a sufficient volume of air for
the measurement of airborne asbestos levels. As a means of allowing for possible spatial
trends in the contamination level across the carpet, the three cleaning methods were applied
according to a 3 x 3 Latin square design. The carpet was divided by a grid of three rows
and three columns. Each cleaning method was applied once in each row and each column,
which provided three tests of each method (Figure 2).
*
A single experiment consisted of the following steps:
1) Collecting six baseline work-area air samples prior to the experiment.
2) Collecting six bulk carpet baseline samples from the test area.
3) ' Dry vacuuming or wet cleaning the carpet for 60 minutes while concurrently
collecting a second set of six work-area air samples and three personal
breathing zone samples.
4) Collecting a set of six postcleaning bulk carpet samples from the treated area.
5) Dry vacuuming or wet cleaning the carpet a second time for 60 minutes while
collecting a second set of three personal breathing zone samples.
6) Collecting a second set of final postcleaning bulk carpet samples from the
treated area.
7) Covering the carpet with the protective floor panel.
8) Ventilating the entire experimental room with five HEPA-filtration units for 4
• hours.-
-------
LEGEND
EXPERIMENT NUMBER
CONVENTIONAL VACUUM
HEPA-FILTERED VACUUM
WET CLEANING
H I HEPA-FILTRATION UNIT
CAFETERIA
N
CONTAINMENT
WALL
FURNITURE
STORAGE
AREA
EXHAUST
AIR
OUTSIDE
MAKEUP AIR
Figure 2. Method & order of cleaning experiments.
M-830010-019-M2/91.2
-------
Independence was maintained between all experiments by covering the carpet with
nine protective floor panels. The area of carpet to be cleaned was uncovered for each
•
experiment and covered again after the experiment was completed. After each experiment,
the entire room was ventilated for 4 hours with five HEPA-filtration units to reduce the
airborne asbestos concentrations to baseline or background levels. The five air filtration
units were not operated during the baseline air monitoring or during the carpet-cleaning
phase of an experiment.
Sampling Strategy
Carpet Samples
Carpet samples were collected before and after cleaning to determine the effectiveness
of each cleaning method. Six bulk carpet samples were collected both before and after
cleaning by each cleaning method. After the carpet was cleaned a second time, six additional
bulk carpet samples were collected. Each test area was divided into approximately four '
hundred 1-ft2 areas (a 19-ft by 21-ft grid) by using a string grid system. The carpet was then
stratified into three pairs of equally sized sections. One bulk carpet sampling location was ;
selected at random within each of the six sections. This sampling strategy assured the
collection of representative samples from the entire piece of carpet. j
Air Samples \
Area air samples were collected before and during carpet cleaning to evaluate the
reentrainment of fibers into the air during carpet-cleaning activities. Six area air samples :
were collected before and six during the first carpet cleaning by each cleaning method. Area
air samples were not collected while the carpet was being cleaned the second time. Two
10
-------
SECTION 4
MATERIALS AND METHODS
Carpet Cleaning Equipment
Fourteen General Service Administration (GSA) field offices in 11 States were
surveyed to identify the most commonly used conventional vacuum cleaner. In 1988, a
similar survey of 14 GSA offices and six trade associations was conducted to identify the
HEPA-filtered dry vacuum cleaner and hot-water extraction cleaner that were evaluated in
4he 1988 EPA study.1-2
The HEPA-filtered vacuum cleaner used in this study was the same model that was
used in the 1988 EPA study. The HEPA-filtered hot-water extraction cleaner used in the
1988 EPA study is no longer being manufactured, and a different cleaner with a HEPA-
filtered power head could not be located. Therefore, a hot-water extraction cleaner without
HEPA-filtration manufactured by the same company that made the unit used in 1988 was
selected. The conventional dry vacuum cleaner selected for this study was the model most
frequently mentioned in the GSA survey.
Nilfisk Model GS-80
The HEPA-filtered vacuum cleaner selected for this study was the Nilfisk Model GS-
80 manufactured by Nilfisk of America, Inc.. The unit had an airflow capacity of 87 ftVmin
and 75 inches static water lift. (Water lift is the maximum amount of force a vacuum can
exert throughout the system if the end of the vacuum hose is completely closed off.) The
13
-------
unit was also equipped with a 16-inch carpet nozzle with a rotating brush. Three different
Nilfisk Model GS-80 vacuum cleaners were used in the study.
Advance AquaClean Model 262500
The hot-water extraction cleaner selected for this study was an AquaClean Model
262500 manufactured by the Advance Machine Company. The unit had an airflow capacity
of 95 fWmin and static water lift of 117 inches. The cleaner was equipped with a 3-in.-
diameter by 14-in.-long motorized agitator brush. This cleaner was not equipped with HEPA
filtration. The manufacturer has discontinued manufacturing the AquaClean Model equipped
with a HEPA filter.
Hoover Conquest Model U707J
The conventional vacuum cleaner selected in this study was a Hoover Conquest Model
U7071, manufactured by the Hoover Company. The unit had an airflow capacity of 110 ft3
per minute and static water lift of 20 inches. This cleaner was an upright model equipped
with a belt-driven agitator brush.
Carpet Cleaning Technique
The carpet in each experiment was methodically vacuumed or wet-cleaned for a
period of approximately 60 minutes to allow the collection of a sufficient air volume to
obtain an analytical sensitivity of 0.005 s/cm3. Each of the two cleaning periods consisted of
three passes over the carpet with each cleaner. Each pass of the cleaner was at a 90-degree
angle to the previous pass.
14
-------
Sampling Methodology
Carpet Samples
Bulk carpet samples were collected before and after cleaning with a 10-cm (4-in.)
square template and a utility razor knife. Each carpet sample was cut in half to provide a
duplicate sample for archiving. Each piece of carpet was placed in a separate labeled
container. Wide-mouth polyethylene jars with polypropylene screw caps were used to
contain the carpet samples. The template and utility razor were thoroughly cleaned between
each sample collection to reduce the possibility of cross-sample contamination.
Area Air Samples
The area air samples were collected on open-face, 25-mm-diameter, 0.45-^m-pore-
size, mixed cellulose ester (MCE) filters with a 5-^m-pore-size cellulose support pad
contained in a three-piece cassette. The filter cassettes were positioned on tripods
•»
approximately 5 ft above the floor with the filter face at a 45-degree angle toward the floor.
The filter assembly was attached to an electric-powered (110 VAC) 1/6-hp vacuum pump
operating at a flow rate of approximately 9 L/min. Air volumes ranged from 487 to 705 L.
At the end of the sampling period, the filters were turned upright before being disconnected
from the vacuum pump and then stored in this position.
The sampling pumps were calibrated with a precision rotameter (Manostat Model 36-
546-215) both before and after sampling. The precision rotameter is a secondary standard;
hence, it was calibrated with a primary airflow standard. The quality assurance procedures
and quality control checks specified in the AHERA Final Rule (52 CFR 41826, October 30,
15
-------
1987, pages 41871 through 41880) for sampling operations were adhered to during sample
system preparation, sampling, sample recovery, storage, and shipment.
Personal Air Samples
Personal breathing zone air samples were collected on the individual performing the
carpet cleaning during each experiment. This individual wore a personal sampling pump
with the filter assembly positioned in his/her breathing zone. The samples were collected on
open-face, 25-mm-diameter, 0,8-^m-pore-size MCE membrane filters and cellulose support
pad contained in a three-piece cassette with a 50-mm conductive cowl. The filter assembly
was attached to a constant-flow, battery-powered vacuum pump operating at a flow rate of
approximately 2 L/min. The sampling assembly was worn for the duration of the carpet-
cleaning activity. Air volumes ranged from 110 to 192 L.
The sampling pumps were calibrated with an electronic mass flowmeter both before
and after sampling. The mass flowmeter is a secondary airflow standard; hence:, it was
calibrated with a primary airflow standard.
Analytical Methodology
Carpet Samples
A'sonication procedure was used to extract asbestos structures from the bulk carpet
samples for subsequent analysis by TEM. Particles meeting the definition of a fiber length to
width aspect ratio >3:1 and having substantially parallel sides were classified as chrysotile
or arnphibole in accordance with definitions developed by Yamate.3 The sonication
procedure is presented in detail in Appendix A.
16
-------
Area Air Samples
The 0.45-/*m pore-size MCE filters used to collect the area samples were prepared
and analyzed by the EPA TEM laboratory, Cincinnati, Ohio, in accordance with a modified
nonmandatory TEM protocol as described in the AHERA Final Rule (40 CFR Part 763, p.
41870). The modifications to the AHERA protocol involve the use of the MCE collapsing
method of Burdett and Rood,4 the recording of the size of all asbestos-containing structures,
and the counting criteria as described here. Fibers were sized by measurement of length and
width. Bundles were sized by the length of the longest contained fiber and approximate
average width if the sides of the bundle were stepped. The aspect ratio of the bundle need
not be 5:1 if the fibers composing the bundle meet the 5:1 criterion. Clusters were measured
by recording the length and width of the longest asbestos structure within the cluster.
Matrices were sized by the length and width of the longest asbestos structure protruding from
the matrix. The protruding fiber or bundle was required to have a 5:1 aspect ratio, but the
total visible width of the structure was measured even if it was contained within the matrix
particle. A sufficient number of grid openings were analyzed to achieve an analytical
sensitivity of 0.005 s/cm3. The minimum area analyzed on high-volume, lightly loaded
samples was 0.057 mm2. Counting was terminated on heavily loaded samples upon finishing
the grid opening that contained the 100th asbestos structure.
Personal Air Samples
The 0.8-^m-pore-size MCE filters used to collect the personal breathing zone samples
were analyzed in accordance with NIOSH Method 7400 by using phase contrast microscopy
at the EPA TEM laboratory. The analytical sensitivity was approximately 0.01 f/cm3. A
17
-------
subset of these samples was also analyzed by TEM in accordance with the protocol described
for the area air samples.
Statistical Analysis
Carpet Samples
A single estimated concentration for each cleaning method and replicate combination
was obtained before and after cleaning by calculating the arithmetic mean of the three
individual estimates. This yielded nine pairs of concentrations, three for each cleaning
method. The relative change in asbestos concentration was measured by the ratio of the
concentration after cleaning to the concentration before cleaning. These ratios were
compared by taking the natural logarithm and comparing the averages by standard analysis of
variance techniques.
Area Air Samples
The statistical analysis of the area air concentrations was similar to that for the carpet
samples. A single estimated concentration for each cleaning method and replicate
combination was obtained before and during cleaning by calculating the arithmetic mean of
the three individual estimates. The relative change in asbestos concentration was measured
by the ratio of the concentration during cleaning to the concentration before cleaning. These
ratios were compared by taking the natural logarithm and comparing the averages by
standard analysis of variance techniques.
18
-------
SECTIONS
QUALITY ASSURANCE
The Quality Assurance Project Plan contains complete details of the quality assurance
procedures followed during this research project.5 The procedures used for this study are
summarized in the following subsections.
Sample Custody Procedures
Standard sample custody procedures were used to ensure sample traceability. Chain-
of-custody procedures document the identity of the sample and its handling from its first
existence as a sample until analysis and data reduction are completed. Custody records trace
a sample from its collection through all changes of custody until it is transferred to the
analytical laboratory. Internal laboratory records then document the custody of the sample
through its final disposition.
Each sample was issued a unique project identification number, which was recorded on a
sampling data form along with the other information specified on the form. After the
labeled sample cassettes were recovered from the sampling trains, the onsite industrial
hygienist completed (in ink) a request-for-analysis form and a sample chain-of-custody
record. The forms accompanied the samples, and each person having custody of the samples
noted receipt of same and completed an appropriate section of the form. Samples were
delivered,by overnight mail to the analytical laboratory. The laboratory's sample clerk
examined the shipping container and each filter cassette for any evidence of damage or
19
-------
tampering, noted any damage or indication of tampering on the accompanying chain-of-
custocly form, and then forwarded the form to the IT Project Manager.
Sample Analyses
Specific quality assurance procedures were used to ensure that the laboratory, tools,
equipment, sampling media, and reagents were clean and fiber-free. These procedures
included the use of filter lot blanks, open and closed field blanks, and laboratory blanks.
Quality control checks were also performed on a routine basis to verify that the
analysis system was in control. Routine quality control testing for asbestos focused on
precision checks, which involve a second count or multiple counts of a sample or a portion
of a sample (i.e., replicate and duplicate sample analyses). Selected samples were also
analyzed by a second laboratory.
Lot Blanks
Filter lot blanks, samples selected at random from the lot of filters used in this study,
were analyzed to determine background asbestos contamination on the filters. The
background asbestos contamination was determined on 5 percent of the total number of
0.45-/um pore-size MCE filters (2000 filters) from the filter lot used in this research study.
The filters were prepared and analyzed in accordance with the nonmandatory AHERA TEM
method. The TEM analysis of the 100 MCE filters showed a background contamination of 0
asbestos structures per 10 grid openings on each filter.
Field Blanks
Closed field blanks are filter cassettes that have been transported to the.sampling'site
and sent to the laboratory without being opened. Open field blanks are filter cassettes that
20
-------
have been transported to the sampling site, opened for a short time (<30 s) without any air
having passed through the filter, and then sent to the laboratory.
One open and two closed 0.45-pcm-pore-size MCE filter field blanks were collected
for each of Experiments 1 through 9 and analyzed by TEM. One open field blank was also
collected for Experiment 10. No asbestos structures were observed oil any of the 19 open
field blanks. One asbestos structure was observed on a single closed field blank. No
asbestos strucutres were observed on the other eight closed field blanks.
One closed 0.8-^m-pore-size MCE filter field blank was collected for each of
Experiments 1 through 11 and analyzed by PCM. Table 1 presents the results of the 11
closed field blank samples.
TABLE 1. CLOSED FIELD BLANKS RESULTS FOR 0.8-fjm MCE
FILTERS ANALYZED BY PCM
Experiment
1
2
3
4
5
6
7
8
9
10
Sample number
01P-01CB
02P-01CB
03P-01CB
04P-01CB
05P-01CB
06P-01CB
07P-01CB
08P-01CB
09P-01CB
10P-01CB
Total fibers
1
1
1
1
3
0
0
0
0
0.5
Laboratory Blanks
Laboratory blanks are unused filters that are prepared and analyzed in the same
manner as samples to verify that the reagents, tools, and equipment are fiber-free and that no
21
-------
TABLE 2. REPLICATE AND DUPLICATE TEM SAMPLE ANALYSES
~~~ ~~— ; 1
Concentration, s/cm3
Sample
04A-05B
07A-05D
09A-06D
11A-02B
01A-02B
1 1 A-02D
Original
0.049
0.044
<0.005
0.036
1.852
0.036
Replicate
0.073
0.073
<0.005
0.026
-
-
Duplicate
.
_
.
2.073
0.026
Duplicate Analysis
A duplicate sample analysis was also performed to assess the reproducibilty of the
TEM analysis and to quantify the analytical variability due to the filter preparation
procedure. A duplicate analysis is the analysis of a second TEM grid prepared from a
different area of the sample filter and performed by the same microscopist who performed
the original analysis. Two samples were randomly selected for duplicate analysis. The CV
associated with these four samples was determined as described for the replicate analyses.
The "CV for the duplicate sample analyses is 0.17. The results of the original and duplicate
analyses are given in Table 2.
Interlaboratory Analysis
Ten air samples were randomly selected and sent to an outside laboratory for quality
assurance analysis. The interlaboratory analysis is the preparation and analysis of a TEM
grid from a separate area of the sample filter and performed by the outside laboratory.
These samples served as. a quality control check on the primary laboratory's analysis of the -
23
-------
air samples. The original and second TEM analytical results for these interlaboratory
samples are given in Table 3. The coefficient of variation was determined as described for
*
the replicate analyses. The CV for the interlaboratory samples is 0.75. A'higher CV for the
interlaboratory samples compared with the replicate and duplicate samples is not unexpected
because this variability includes that resulting from a different preparation from the filter and
from interlaboratory variation.
TABLE 3. INTERLABORATORY TEM SAMPLE
ANALYSES ON 0.45-//m MCE FILTERS
Concentration, s/cm3
Sample
02A-06B
03A-03B
04A-06B
05A-04D
05A-05B
06A-02D
07A-03B
08A-04D
08A-06B
09A-04D
Original
0.121
0.045
0.045
0.067
0.064
0.062
0.035
0.054
0.026
0.047
Second laboratory
0.169
0.138
0.061
0.098
0.028
0.034
0.019
0.065
<0.005
0.024
24
-------
SECTION 6
RESULTS AND DISCUSSION
Fiber Reentrainment
Fixed-Station Area Air Samples
Air sampling results from Experiment 1 (conventional dry vacuum) showed that
average airborne asbestos concentrations decreased during the carpet-cleaning activity,
whereas all other experiments showed an increase in airborne asbestos levels during cleaning.
This anomaly occurred because prior to baseline monitoring in Experiments 2 through 9, the
room was ventilated for approximately 4 hours with the five HEPA-filtration units to reduce
the airborne asbestos contamination from the previous experiment. The HEPA-filtration
units were not operating immediately prior to the baseline monitoring in Experiment U
therefore, any activity in the room before baseline monitoring began may have contributed to
the airborne asbestos levels before the carpet was cleaned. Because the unusually high
baseline concentrations are believed to have obscured the effect on' airborne fiber
reentirainment due specifically to the carpet cleaning activity, the results from Experiment 1
were omitted from further data analysis. (The results of the statistical analysis of these data
were essentially unaffected by whether the results from Experiment 1 were or were not
included; nevertheless, these data were omitted because of their misleading effect on the
summary -statistics for the experiments evaluating the conventional vacuum cleaners.)
25
-------
Individual TEM air sampling results are presented in Appendix B. Table 4 presents
the summary statistics separately for concentrations measured before and during the first
cleaning stage. Three fixed-station area samples were collected before and during the first
cleaning stage in each experiment. This yielded a total of 54 area air samples. For each
experiment, a single estimated concentration was then obtained before and during cleaning by
taking the arithmetic mean of the three individual estimates. This yielded nine pairs of
concentrations, one for each experiment. These concentrations are presented in Appendix C.
Figure 3 illustrates the average airborne asbestos concentrations measured before and during
the carpet-cleaning activity with each of the three cleaners. An increase in average airborne
asbestos concentrations was observed during carpet cleaning with each of the three cleaners.
Results from the one-factor analysis of variance are summarized in Table 5. The type of
cleaning method had no statistically significant effect on the difference between airborne
asbestos concentrations before and during cleaning (p=0.3127); that is, the mean relative
increase in airborne asbestos concentration during carpet cleaning did not vary significantly
with the type of cleaner. The increase in airborne asbestos concentration during the carpet-
cleaning activity was statistically significant (p=0.004). Specifically, a 95 percent
confidence Interval for the mean airborne asbestos concentration during carpet cleaning as a
proportion of the baseline concentration before cleaning showed that the overall mean
airborne asbestos concentration was between 1.3 and 2 times greater during carpet cleaning.
26
-------
TABLE 4. SUMMARY STATISTICS FOR AREA AIRBORNE ASBESTOS
CONCENTRATIONS BEFORE AND DURING CLEANING
Number of
Cleaning method data pointsa-b
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
Before
2
3
3
During
3
3
3
Asbestos concentration, s/cm3
Mean
cleaning
0.034
0.079
0.046
cleaning
0.047
0.094
0.093
Minimum
0.053
0.025
0.040
0.030
0.043
0.066
Maximum
0.015
0.163
0.056
0.065
0.168
0.109
'Each data point represents the average of three work-area samples.
bResults from Experiment 1 are not included.
TABLE 5. ANALYSIS OF VARIANCE TABLE FOR DIFFERENCE
BETWEEN ASBESTOS CONCENTRATIONS BEFORE AND DURING CLEANING
Source of variation
Cleaning method
Average
Error
Degrees
of freedom
2
1
5
Sum of
squares
0.2311
1.9315
0.3903
F-value
1.48
1.93
p-value
0.3127
0.0042
These results are consistent with the 1988 EPA research study that evaluated the
efficacy of two cleaning methods (HEPA-filtered dry vacuum and HEPA-filtered hot-water -
extraction cleaner) and the airborne concentrations associated with the use of each cleaner on
27
-------
a
o
o
w
o
0)
(0
(0
.c
a.
0)
a
E
(0
CO
O)
c
D
Q
^
Q)
O
M-
CD
2
*•«
o
JD
Q)
c
0
'«
tt
o>
c
(0
(0
"5.
E
(0
CO
-------
carpet that was artificially contaminated with asbestos.1-2 The controlled study also showed
that the cleaning method had no significant effect on the relative increase in airborne asbestos
concentration during cleaning. That study further indicated an overall increase in asbestos
concentration that was 2 to 4 times greater during carpet-cleaning activities in comparison
with baseline measurements.
Personal Breathing Zone Air Samples
Results of the individual personal breathing zone air samples collected during carpet
cleaning are presented in Appendix D. All personal breathing zone samples were analyzed
by PCM. Table 6 presents the summary statistics for concentrations measured during carpet
cleaning.
TABLE 6. SUMMARY STATISTICS FOR PERSONAL BREATHING ZONE
CONCENTRATIONS (ANALYZED BY PCM) DURING CLEANING
Number of
Cleaning method data points'
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
During 1st
3
3
3
During 2nd
3
3
3
Concentration, f/cm3
Mean
cleaning
0.013
0.012
0.013
cleaning
0.011
0.012
0.016
Minimum
0.005
0.008
0.009
. 0.002
0.006
0.015
Maximum
0.021
0.018
0.018
0.022
0.018
0.019
"Each data point represents the average of three samples.
29
-------
Summary results are presented separately for each of the two cleaning stages. Three
personal breathing zone samples were collected during both cleaning stages in an experiment,
which yielded a total of 54 personal samples. For each experiment, a single estimated
concentration was obtained during the first cleaning and during the second cleaning by taking
the arithmetic mean of the three individual sample results from each cleaning. This yielded
nine pairs of arithmetic mean concentrations, one for each experiment. These arithmetic
mean concentrations are presented in Appendix E. All 54 individual samples showed
personal breathing zone concentrations below the OSHA action level of 0.1 f/cm3. The
maximum personal breathing zone concentration was 0.033 f/cm3. Figure 4 illustrates the
average personal breathing zone concentrations measured during the first and second carpet-
cleaninig stages with each of the three cleaners.
Results from the one-factor analysis of variance are summarized in Table 7. The type
of cleaning method had no statistically significant effect on the difference between personal
breathing zone concentrations during the'first and second cleaning (p=0.5716); that is, the
mean relative change in personal breathing zone concentration during the first and second
t
carpet cleanings did not vary significantly with the type of cleaner. No statistically
significant increase in personal breathing zone concentration occurred during the two carpet-
cleaning activities (p=0.8458).
TABLE 7. ANALYSIS OF VARIANCE TABLE FOR DIFFERENCE
BETWEEN PERSONAL BREATHING ZONE CONCENTRATIONS
DURING CLEANING
Source of variation
Cleaning method
Average
Error
Degrees
of freedom
2
1
6
Sum of
squares
0.2184
0.0073
1.0656
F-value
0.61
O.04
p- value
0.5716
0.8458
30
-------
T >
O)
C
a
E
03
CO
**-
O
0)
E
a
o
D)
C
'c
CO
0)
o
TJ
c
CM
^
O)
c
'c
cd
u.
31
-------
Thirteen of the 54 personal breathing zone samples were also analyzed by TEM.
These samples were selected to represent those with the highest fiber concentration measured
by PCM. The concentrations determined by both PCM and TEM are presented in Table 8.
Overall, the asbestos concentrations determined by TEM were consistently higher than the
total fiber concentrations determined by PCM, This result is not unexpected given the
inability of PCM to detect fibers less the 5 /*m in length and less than 0.25 /tm in width.
TEM analysis can measure structures 0.5 pm in length and 0.15 jtm in width. The majority
of structures observed by TEM analysis were less than 2 jtm in length. The Pearson
correlation coefficient associated with these measurements (r=0.03) indicates no significant
linear relationship between these TEM and PCM concentrations.
TAEJLE 8. COMPARISON OF PERSONAL BREATHING ZONE CONCENTRATIONS
MEASURED BY TEM AND PCM DURING CARPET CLEANING
Concentration
Sample number
01P-01D
02P-01D
02P-01RD
03P-03D
03P-01CB"
04P-03D
05P-03D
06P-03RD
08P-03D
09P-02RD
10P-01D
10P-01CB"
11P-04D
" PCM, f/cm3
0.016
• 0.017
0
0.021
0 fibers
0.013
0
0.015
0.005
0.024
0.033
0 fibers
0.061
TEM, s/cm3
0.640
0.124
0
0.117
0 structures
0.093
0.025
0.010
0.034
0.040
0.061
0 structures
0.050
"Closed field blank.
32
-------
1 y
Carpet Removal
After completing the nine designed experiments to determine the efficacy of the three
cleaning methods and the airborne asbestos concentrations associated with the use of each
method, the carpet was removed from the floor and rolled up for disposal. Two areas of
contaminated carpet were removed. The first area was located outside the contained test area
in the furniture storage area (Figure 1). The second area was the entire contained test area
(Figure 1).
Furniture Storage Area-Before the carpet was removed from the floor, six baseline,
fixed-station, area air samples were collected. During the actual removal of the carpet from
the floor, six fixed-station, area air samples and two personal breathing zone samples were
collected. All area air samples were analyzed by TEM; both personal breathing zone
samples were analyzed by PCM and one was also analyzed by TEM. The air monitoring
activity during the carpet removal in the furniture storage area is referred to as Experiment
10.
Contained Test Area-The carpeted area used during the first nine experiments (i.e.,
carpet-cleaning experiments) was also removed from the floor and rolled up. Before the
carpet was removed from the floor, six baseline, fixed-station, area air samples were
collected. During the actual removal of the carpet from the floor, six fixed-station, area air
samples and six personal breathing zone samples (three samples on each of two persons)
were collected. All area air samples were analyzed by TEM; all six personal breathing zone
samples were analyzed by PCM and one was also analyzed by TEM. The air monitoring
activity during the carpet removal in the contained test area is referred to as Experiment 11.
33
-------
Tables 9 and 10 present the summary statistics for the area and personal breathing
zone concentrations, respectively. Figure 5 presents the average airborne asbestos
concentrations during Experiments 10 and 11. The individual results for the area and
personal breathing zone samples are presented in Appendices F and G, respectively.
TABLE 9. SUMMARY STATISTICS FOR AREA AIR CONCENTRATIONS OF
ASBESTOS (DETERMINED BY TEM) BEFORE AND DURING CARPET REMOVAL
Concentration, s/cm3
Carpet location
Furniture storage area
Contained test area
Sample period
Baseline
During removal
Baseline
During removal
N
6
6
6
6 .
Mean
0.056
0.079
0.035
0.093
Minimum
0.030
0.051
0.015
0.073
Maximum
0.075
0.106
0.053
0.155
TABLE 10. SUMMARY STATISTICS FOR PERSONAL BREATHING ZONE
. CONCENTRATIONS OF TOTAL FIBERS (DETERMINED BY PCM) '
DURING CARPET REMOVAL
Concentration
Carpet location
Furniture storage area
Contained test area
N
2
6
Mean
0.046
0.069
Minimum
0.033
0.045
. f/cm3
Maximum
0.059
0.091
During the carpet-removal activities in the furniture storage area, the average airborne
asbestos concentration increased slightly; however, this increase was not statistically
significant (p=0.06)! The personal breathing zone concentrations were below the OSHA
action level, of 0.1 f/cm3.
34
-------
1 *
a
o
o
w
o
O)
c
i^"^
a
co
CO
"o
0
£
F
CO
^
O
£
0
O)
C
D
Q
H
0
c
CW^M
0
CO
CO
CQ
•
0
E
c
s
fl)
>i/
"ffl
o
«
ransmis
^
•°
TJ
O
N
«
(0
2
CD
«A
a
(0
CO
c
co
0)
E
,0
'•»3
CD
E
CO
C
g
*•»->
5
•*-•
0)
o
c
o
o
w >
Q.
O)
IO
CD
3
D)
LA.
euuo/s '
soiseqsy
35
-------
During the carpet-removal activities in the contained test area, a significant increase
occurred in the average airborne asbestos concentration (p=0.0004). Specifically, a 95
percent confidence interval for the mean airborne asbestos concentration during carpet-
removal activities as a proportion of the baseline concentration before removal showed that
the mean airborne asbestos concentration was between 1.7 and 4.3 times greater during'
removal activities.
Effectiveness of Cleaning Methods
Figure 6 illustrates the average (geometric mean) concentrations of asbestos structures
in the carpet before and after cleaning. T-he 95 percent confidence intervals for the
geometric mean concentrations are presented in Table 11. Individual results for the carpet
samples collected before and after cleaning are presented in Appendix H. For each
experiment, a single estimated concentration was obtained before cleaning, after the first
cleaning, and after the second cleaning by taking the arithmetic average of the three
individual" estimates. This yielded nine triplicates of concentrations, one for each
experiment. The average asbestos concentrations in the carpet before and after cleaning are
presented in Appendix I.
After 1st Cleaning
Results of the one-factor analysis of variance are summarized in Table 12. The type
of cleaning method had a statistically significant effect on the difference between asbestos
concentrations in the carpet before and after the first cleaning (p=0.0164); that is, the mean
«
relative change in asbestos concentration in the carpet after cleaning varied significantly with
the type of cleaner. The estimated asbestos concentration in the carpet after cleaning as a
proportion of the asbestos concentration before cleaning for each cleaning method and the
corresponding 95 percent confidence interval are presented.in Table 13.
36
-------
TJ
O
i
D)
C
"c
CO
JP.
O
0)
en
(0
a.
O)
c
'c
CC
JD
O
•D
C
CM
u_
(D
D)
C
c
CO
^ £
e 2
55 w
CD
CD
C
"CD
CD
O
0)
JC
C
CO
CD
O
CD
U)
W CJ)
C C
.2 c
•*± CO
CD »-
O Q>
C £
O *8
O TS
w c
O CO
W CD
CO
CD
3
g>
u_
UOJIIJLU 'uojiejjueouoo sojsaqsv
37
-------
TABLE 11. SUMMARY STATISTICS FOR ASBESTOS CONCENTRATIONS
IN CARPET BEFORE AND AFTER CLEANING
Number of
Cleaning method data points"
Asbestos concentration, billion s/ft2
Geometric mean
95% Clb
Baseline
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
3
3
3
1.6
1.1
2.0
(0.85, 3.1)
(0.28, 4.0)
(1.1,3.5)
After 1st cleaning
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot-water extraction
3
3
3
After
3 -.
3
3
2.1
1.3
0.85
2nd cleaning
1.3
1.4
0.88
(1.2, 3.7)
(0.39, 4.3)
(0.32, 2.3)
(0.23, 7.3)
(0.82, 2.4)
(0.24, 3.3)
"Each data point represents the average of three work-area samples.
b95 percent confidence interval for the geometric mean.
TABLE 12. ANALYSIS OF VARIANCE TABLE FOR DIFFERENCE BETWEEN
ASBESTOS CONCENTRATIONS IN CARPET BEFORE AND AFTER CLEANING
Source of variation
Cleaning method
Error
Degrees
of freedom
2
6
Sum of
squares
2.2432
0.7643
F-value
8.80
p-value
0.0164
38
-------
TABLE 13. ESTIMATED ASBESTOS CONCENTRATION IN CARPET AFTER
CLEANING AS A PROPORTION OF THE CONCENTRATION
BEFORE CLEANING
Cleaning method
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot water extraction cleaner
Pa
1.3
1.2
0.43
95 percent confidence interval
(0.75,2.1)
(0.74, 2.0)
(0.26, 0.72)
•Asbestos concentration in the carpet after cleaning as a proportion of the
concentration before cleaning.
The asbestos concentration after wet cleaning was approximately 0.4 of the asbestos
concentration before cleaning (i.e., a 60% reduction in the concentration). The upper 95
percent confidence limit for this proportion (Table 13) is less than 1, which indicates this is a
statistically significant reduction.
The asbestos concentration in the carpet after dry vacuuming with a conventional and
a HEPA-filtered dry vacuum cleaner was 1.3 and 1.2 times the concentration before
cleaning, respectively (Table 13). The 95 percent confidence intervals for both estimates
include the number 1, which indicates the data do not provide statistically significant
evidence of either an increase or a decrease in asbestos concentration after dry vacuuming .
with either a conventional or a HEPA-filtered vacuum cleaner.
These results are consistent with the findings from the 1988 EPA controlled research
study,, which evaluated the efficacy of HEPA-filtered dry vacuum and HEPA-filtered hot-
water extraction cleaners on carpet that was artificially contaminated with asbestos.1-2 The
controlled study similarly showed that the efficacy of wet cleaning was significantly greater
than that of dry vacuuming. The study showed an approximately 70 percent reduction in
39
-------
carpet contamination levels after wet cleaning, compared with an approximately 60 percent
reduction in this study. The 1988 study, likewise did not show statistically significant
evidence of either.an increase or a decrease in asbestos concentration after dry vacuuming.
After 2nd Cleaning
The carpet was dry-vacuumed or wet cleaned a second time to determine the effect of
repeat vacuuming or cleaning. The type of cleaning method had no statistically significant
effect on the difference between asbestos concentrations in the carpet after the first and
second cleanings (p=0.5314). Results from the one-factor analysis of variance are
summarized in Table 14. The estimated asbestos concentration in the carpet after the second
cleaning as a proportion of the asbestos concentration after the first cleaning is given in
Table 15 for each cleaning method, together with a 95 percent confidence. The 95 percent
confidence intervals for these estimates include the number 1, which indicates the data do not
provide statistically significant evidence of either an increase or a decrease in asbestos
concentration after cleaning the carpet a second time.
TABLE 14. ANALYSIS OF VARIANCE TABLE FOR DIFFERENCE
BETWEEN ASBESTOS CONCENTRATIONS AFTER THE FIRST AND
SECOND CLEANINGS
Source of variation
Cleaning method
Error
Degrees
of freedom
2
6
Sum of
squares
0.5522
0.2761
F-value
0.70
p-value
0.5314
40
-------
TABLE 15. ESTIMATED ASBESTOS CONCENTRATION IN CARPET AFTER
CLEANING AS A PROPORTION OF THE CONCENTRATION
BEFORE CLEANING
Cleaning method
Conventional dry vacuum
HEPA-filtered dry vacuum
Hot water extraction cleaner
P*
0.63
1.1
1.0
95 percent confidence
(0.26, 1.5)
(0.45, 2.6}
(0.43, 2.5)
interval
"Asbestos concentration in the carpet after the second cleaning as a proportion of
the concentration after the first cleaning.
Comparison With 1988 Controlled Carpet Study
A controlled carpet-cleaning study was performed in 1988 with new carpet that had
been sprayed with an aerosol containing known concentrations of chrysotile asbestos.
suspended in water.1-2 After the carpet had dried, it was rolled with a 200-pound steel roller
to simulate the effects of normal foot traffic in working the asbestos into the carpet. The
results of the present study, which represent a real-world carpet with unknown contaminants,
similar asbestos contamination levels (1.6 billion s/ft2 average), and wear characteristics, are
quite comparable with the results of the high concentration (1 billion s/ft?) controlled
experiment in terms of the reentrainment of asbestos during cleaning procedures; i.e., the
airborne asbestos concentrations measured in the present study were 1.3 to 2 times greater
4
during carpet cleaning versus 2 to 4 times greater as measured in the 1988 study. The
results of'the present study are also comparable regarding the effectiveness of the cleaning -
methods to remove asbestos structures from carpet; i.e., the present study showed a 60
percent reduction in asbestos concentrations in the carpet after wet-cleaning compared with a
41
-------
70 percent reduction in the 1988 study. Both studies showed that dry vacuuming did not
significantly change the asbestos concentration in the carpet.
•
Structure Morphology and Length Distributions
Carpet Samples
Table 16 presents the asbestos structure morphology and length distributions for the
carpet samples collected before and after cleaning. Overall, the asbestos structures were
primarily fibers and matrices, and to a lesser extent, bundles and clusters. Chrysotile and
amosite represented approximately 96 and 4 percent, respectively, of the asbestos structures
present in 18 baseline carpet samples. The distribution of chrysotile and amosite in the
carpet was unaffected by cleaning; i.e., the data suggest that an equal percentage of
chrysotile and amosite structures were removed or entrained into the air as a result of
cleaning.
TABLE 16. ASBESTOS STRUCTURE DISTRIBUTIONS FROM
CARPET SAMPLES COLLECTED BEFORE AND AFTER CLEANING '
% Structures*
Sample
Baseline
After 1st cleaning
After 2nd cleaning
Chryso-
tile
96.3
96.1
95.7
Amosite Fibers
Dry
3.7
3.9
4.3
vacuuming
55.8
56.1
61.9
Bundles
9.8
12.4
7.5
Clusters
2.4
2.4
2.8
Matrices
31.9
29.2
27.8
Wet cleaning
Baseline
After ,1st cleaning
After 2nd cleaning
96.5
96.8
96.7
3.5
3.2
3.3
68.0
71.1
70.0
7.3
7.0
5.0
1.5
0.2
2.0
23.2
21.6
23.0
' Total percentage may exceed 100% because of rounding.
42
-------
Fibers
Matrices
Bundles
J Clusters
Fibers
Matrices
Bundles
Clusters
Structure length, micrometers
Figure 7. Asbestos particle distribution in carpet before (top) and
after (bottom) dry vacuuming, as measured by TEM.
44
-------
Fibers
Matrices
Bundles
G3 Clusters
Fibers
Matrices
Bundles
Clusters
-s»~ -a-^ «o»
Structure length, micrometers
Figure 8. Asbestos particle size distribution in carpet before (top) and
after (bottom) wet cleaning, as measured by TEM.
45
-------
TABLE 17. ASBESTOS STRUCTURE DISTRIBUTIONS FROM
AREA AIR SAMPLES COLLECTED BEFORE AND DURING CLEANING
% Structures'
Sample
Chryso-
tile
Amosite Fibers
Bundles
Clusters
Matrices
Dry vacuuming
Baseline
During cleaning
Baseline
During cleaning
100
99.8
97.6
98.2
0
0.2
Wet
2.4
1.8
98
98
cleaning
96.3
75.4
0.4
0.2
0
2.9
0
0.2
1.2
0.6
1.6
1.7
2.4
21.1
a Total percentage may exceed 100% because of rounding.
The distribution of structure morphology was not greatly altered by dry vacuuming
(Table 17). Wet cleaning, however, produced a substantially larger number of asbestos
matrices than did dry vacuuming. Approximately 21 percent" of the asbestos structures
observed during wet cleaning were matrices compared with 1.7 percent and 2.4 percent for
dry vacuuming and baseline measurements, respectively. There is no apparent reason why wet
cleaning produced a substantially larger number of asbestos matrices than did dry vacuuming.
Figures 9 and 10 illustrate the size distributions of asbestos structures found in the air
before and during cleaning. These same data are also presented by using a linear scale X-axis
(Appendix J). Table 18 presents the cumulative size distributions of asbestos structures found
in air both before and after carpet cleaning. The data presented in Figure 9 show a small
decrease in the size and complexity of structures in the air during dry vacuuming, whereas "
Figure 10 shows a small increase in the size and complexity of structures during wet cleaning.
Approximately 75 percent of the asbestos structures observed during wet cleaning were less
46
-------
Fibers
Matrices
Bundles
D Clusters
Fibers
Matrices
Bundles
Clusters
^--a*"-*^ ^ ^-P-
Structure length, micrometers
Figure 9. Asbestos particle size distribution in area air before (top)
and during (bottom) dry vacuuming, as measured by TEM.
47
-------
Fibers
Matrices
Bundles
Fibers
Matrices
Bundles
Clusters
Structure length, micrometers
Figure 10. Asbestos particle size distribution in area air before (top) and
during (bottom) wet cleaning, as measured by TEM.
48
-------
than 2 /*m in length compared with 97 percent for dry vacuuming (Table 18). Hence, the wet
cleaning of carpet results in larger asbestos structures becoming airborne as opposed to dry
vacuuming.
TABLE 18. CUMULATIVE SIZE DISTRIBUTIONS OF ASBESTOS
STRUCTURES IN WORK-AREA AIR SAMPLES COLLECTED BEFORE
AND DURING CARPET CLEANING
Sample
% Structures
<1 <2 <3
and lengths,
<4
//m
<5
Dry vacuuming
Baseline
During cleaning
82.2 98.7 100
74.3 97.2 99.3
100
99.4
100
99.6
100
99.8
Wet cleaning
Baseline
During cleaning
72.0 95.1 97.6
50.9 74.9 87.1
98.8
93.0
98.8
97.1
98.8
98.8
Area Air Samples During Carpet Removal
Table 19 presents the asbestos structure morphology and length distributions for the
area air samples collected during carpet removal (Experiments 10 and 11). As during carpet
cleaning (Tables 16 and 17), chrysotile was the predominant form of asbestos found in the
baseline air samples collected before cleaning. A larger proportion of amosite asbestos
structures, however, were observed in samples collected during removal than in samples
collected during cleaning or in baseline samples collected before removal. Approximately 11
and 26 percent of the asbestos structures observed in Experiments 10 and 11, respectively, •
were amosite, compared with less than 2 percent during cleaning with either method. The
49
-------
distribution of structure morphology was similar to that for wet cleaning; i.e., the asbestos
structures were primarily fibers and matrices, and to a lesser extent, bundles and clusters.
TABLE 19. ASBESTOS STRUCTURE DISTRIBUTIONS FROM
AREA AIR SAMPLES COLLECTED DURING CARPET REMOVAL
% Structures8
Sample
Chryso-
tile
Amosite Fibers
Bundles
Clusters
Matrices
Experiment 10
Baseline
During removal
97.1
88.7
2.9 81.2
11.3 67.0
4.3
4.1
4.3
5:2
10.1
23.7
Experiment 1 1
Baseline
During removal
100
73.6
0 100
26.4 66
0
2.8
0
3.8
0
27.4
8 Total percentages may exceed 100% because of rounding.
Figures 11 and 12 illustrate the size distributions of asbestos structures found in the air
before and during carpet removal. These same data are also presented by using a linear X--
axis scale (Appendix J). Comparison of the data presented in Figures 11 and 12 shows a
notable decrease in size and increase in complexity of asbestos structures in the air during the
removal of carpet compared with baseline measurements. During Experiment 11 (removal of
the carpet that had been cleaned in Experiments 1 through 9), approximately 37 percent of the
observed asbestos structures were less than 1 ^m in length compared with approximately 83
percent for the baseline measurements (Table 20). None of the baseline measurements for
50
-------
Fibers
Matrices
Bundles
CD Clusters
%
-4-O
3O
2O
1O
O
Fibers
Matrices
H Bundles
E3 Clusters
Structure length, micrometers
Figure 11. Particle size distribution in area air samples before (Top)
and during (bottom) removal of cleaned carpet.
-------
Fibers
Matrices
Bundles
Q Clusters
1 O
%
3O
2O
1O
Fibers
Matrices
€ Bundles
E3 Clusters
Structure length, micrometers
Figure 12. Asbestos particle size distribution in area air samples before (top)
and during (bottom) removal of cleaned carpet.
52
-------
Experiment 11 showed structures greater than 10 /urn in length, whereas 10 percent of the
structures observed during carpet removal were greater than 10 pm in length. Hence, carpet-
removal activities are more likely to release large asbestos structures into the air.
TABLE 20. CUMULATIVE SIZE DISTRIBUTIONS OF ASBESTOS
STRUCTURES IN WORK AREA AIR SAMPLES COLLECTED BEFORE
AND DURING CARPET REMOVAL
Sample
% Structures and lengths, //m
<1
<2
<3
<4
<5
Experiment 10
Baseline
During cleaning
71
45.4
92.8
75,3
97.1
82.5
97.1
86.6
97.1
89;7
100
95.9
Experiment 11
Baseline.
During cleaning
82.9
36.8
95.1
64.2
97.6
73.6
97.6
79.2
100
84.0
100
90.6
53
-------
REFERENCES
1. Kominsky, J. R., et al. Evaluation of Two Cleaning Methods for Removal of Asbestos
Fibers From Carpet. Am. Ind. Hyg. Assoc. J. 51(9): 500-504 (1990).
2. Kominsky, J. R,, and R. W. Freyberg. Asbestos Fiber Reentrainment During Dry
- Vacuuming and Wet Cleaning of Asbestos-Contaminated Carpet. U. S. Environmental
Protection Agency, Risk Reduction Engineering Laboratory, Cincinnati, Ohio,
EPA/600/52-91/004. May 1991.
3. Yamate, G., S. C. Agarwal, and R. D. Gibbons. Methodology for the Measurement
of Airborne Asbestos by Electron Microscopy. Draft Report. U.S. Environmental
Protection Agency, Office of Toxic Substances, Washington, D.C. EPA Contract No.
68-02-3266. 1984.
4. Burdett, G. J., and A. P. Rood. Membrane Filter, Direct Transfer Technique for the
Analysis of Asbestos Fibers or Other Inorganic Particles by TEM. Environmental
Science & Technology 17(11): 643-648. 1983.
5.- PEI Associates, Inc., Chesson Consulting. Quality Assurance Project Plan: Evaluation
of Three Cleaning Methods for Removal of Asbestos Fibers from Carpet and -
• Associated Airborne Concentrations. Volume 1: Field Procedures. U.S.
Environmental Protection Agency, Risk Reduction Engineering Laboratory. October
18, 1990.
54
-------
APPENDIX A
SONICATION PROCEDURE FOR EXTRACTION
OF ASBESTOS STRUCTURES FROM CARPET SAMPLES
Analytical Method:
A sonication procedure will be used to extract asbestos particles from the carpet swatch
samples for subsequent analysis by TEM.
Sample preparation: A 5-cm x 5-cm area of carpet is placed carpet-side down into a
1000-mL polypropylene disposable beaker containing 100 mL of a 0.1 percent solution (by
volume) of Aerosol OT made with distilled water. The beaker and its contents are placed in
an ultrasonic bath and sonicated three times, 10 minutes each time. After each sonication, the
solution is drained into a 500-mL polyethylene screw-cap container and another 100 mL of
fresh Aerosol OT solution is added for the next sonication. The carpet is then removed from
the beaker and the beaker is rinsed with 100 mL of distilled water. -
The rinse from the beaker is added to the sample container. The resultant suspension
is shaken vigorously to achieve a "homogeneous suspension of fibers" and then allowed to sit
for 2 minutes. Aliquots of 1-, 5-, 25-, and 125-ml volume are extracted with, a disposable
graduated pipette. (These four measured aliquots of different volumes should'be sufficient to
attain an acceptable fiber loading.) Each aliquot is then poured through an approximately
100-mesh stainless steel screen into the top of a filtration apparatus (Millipore Corporation
Cat. No. XX10 025 00). A new glass funnel is used for each carpet sample as well as for
each laboratory blank. (The purpose of "the coarse-mesh screen is to remove large nonasbestos
structures from the sample solution before filtration.) The filtration apparatus contains a
0.22-Aim pore size, 25-mm-diameter mixed cellulose ester (MCE) filter (having an effective
area of 230 mm2) backed by a 0.8- to 5-^m pore size, 25-mm MCE filter.
When filtration is complete, the 0.22-/*m mixed cellulose ester filter is carefully
removed from the funnel assembly and placed in a Gelman "Analyslide" dish or equivalent.
The filter is dried before proceeding with the preparation procedure.
Filter Preparation and TEM Analysis: Portions of the 0.22-/
-------
APPENDIX A (continued)
Duplicate Analysis
A duplicate analysis is the analysis of a second TEM grid prepared from a different
area of the sample filter and analyzed by the same microscopist as the original analysis.
Sample Blank
A sample blank is a sample prepared in a manner identical to that used for the carpet
swatch samples, but no carpet sample is used. These blanks serve as a Quality Control check
on contamination from solutions, glassware, filters, and handling procedures. One sample
blank will be prepared for every 15 samples analyzed.
56
-------
APPENDIX B
Individual Airborne Asbestos Concentrations
Before and During Carpet Cleaning, as Determined Using TEM
(Page 1 of 2)
Experiment Cleaning, Method
01
01
01
01
01
01
01
02
02
02
02
02
02
02
03
03
03
03
03
03
03
04
04
04
04
04
04
04
05
05
05
05
05
05
05
06
06
06
06
06
06
07
07
07
07
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HOT-WATER EXTRACTION
HOT- WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
• HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT- WATER EXTRACTION
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED -DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
>. HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
Sample Type
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
Sample Concentration,
Number s/cm^
01A-01D ,
01A-02D
01A-06D
01A-01B
01A-02B
01A-05B
01P-01D
02A-01D
02A-03D
02A-05D
02A-02B
02A-03B
02A-06B
02P-01D
03A-01D
03A-05D
03A-06D
03A-01B
03A-03B
03A-06B
03P-03D -
04A-02D
04A-03D
04A-04D
04A-02B
04A-05B
04A-06B
04P-03D
05A-02D
05A-04D
05A-06D
05A-03B
05A-05B
05A-06B
05P-03D
06A-01D
06A-02D
06A-05D
06A-02B
06A-03B
06A-05B
07A-02D
07A-03D
07A-05D
07A-01B
0.671
0.885
0.685
0.656
1.852
0.864
0.640
0.146
0.207
0.152
0.274
0.093
0.121
0.124
0.146
0.060
0.120
0.088
0.044
0.035
0.117
0.089
0.072
0.152
0.025
0.049
0.045
0.093
0.054
0.067
0.073
0.039
0.064
0.056
0.025
0.095
0.062
0.055
0.034
0.045
0.068
0.054
0.031
0.044
0.025
57
-------
Appendix B
(-Page 2 of 2)
Experiment Cleaning Method
Sample Type
Sample
Number
Concentration,
07 HEPA-FILTERED DRY VACUUM
07 HEPA-FILTERED DRV VACUUM
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
07A-03B
07A-05B
08A-01D
08A-03D
08A-04D
08A-02B
08A-05B
08A-06B
08P-03D
09A-01D
09A-04D
09A-06D
09A-02B
09A-04B
09A-05B
0.035
0.014
0.056
0.089
0.054
0.044
0.056
0.026
0.034
0.042
0.047
0.000
0.025
0.015
0.005
58
-------
Appendix C
Average Airborne Asbestos Concentrations (Determined
by TEM) Before and During Carpet Cleaning
Cleaning Method
Experiment
Average Concentration, a/cm3
Baseline During cleaning
CONVENTIONAL DRY VACUUM
HEPA-FILTERED DRY VACUUM
HOT WATER EXTRACTION
1
5
7
2
6
7
3
4
8
1.12
0.053
0.015
0.163
0.049
0.025
0.056
0.040
0.042
0.747
0.065
0.030
0.168
0.071
0.043
0.109
0.071
0.066
59
-------
Appendix D
Individual Personal Breathing Zone
Concentrations (Determined by PCM) During Carpet Cleaning
Experiment
01
01
01
01
01
01
02
02
02
02
02
02
03
03
03
03
03
03
04
04
04
04
04-
04
05
05
05
05
05
05
06
06
06
06
06
06
07
07
07
07
07
07
08
08
08
Cleaning Method
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY " VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY .VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT- WATER EXTRACTION
HOT- WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
CONVENTIONAL DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
• •HEPA-FILTERED DRY VACUUM
HEPA-FILTERED DRY VACUUM
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
HOT-WATER EXTRACTION
Sample Concentration,
Number f/cm^
01P-01D
01P-01RD
01P-02D
01P-02RD
01P-03D
01P-03RD
02P-01D
02P-01RD
02P-02D
02P-02RD
02P-03D
02P-03RD
03P-01D
03P-01RD
03P-02D
03P-02RD
03P-03D
03P-03RD
04P-01D
04P-01RD
04P-02D
04P-02RD
04P-03D
04P-03RD
05P-01D
05P-01RD
05P-02D
05P-02RD
05P-03D
05P-03RD
06P-01D
06P-01RD
06P-02D
06P-02RD
06P-03D
06P-03RD
07P-01D
07P-01RD
07P-02D
07P-02RD
07P-03D
07P-03RD
08P-01D
08P-01RD
08P-02D
0.016
0.001
0.015
0.006
0.007
0.019
0.017
0.000
0.011
0.004
0.008
0.013
0.014
0.020
0.018
0.020
0.021
0.016
"o.oos
0.020
0.007
0.010
0.012
0.014
0.011
0.000
0.003
0.000
0.000
0.000
0.020
0.015
0.021
0.024
0.012
0.015
0.011
0.014 - -
0.006
0.016
0.006
0.010
0.015
0.016 ;
0.015
60
-------
Appendix D
(Page 2 of 2)
Experiment Cleaning Method
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
08 HOT-WATER EXTRACTION
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
09 CONVENTIONAL DRY VACUUM
Sample Concentration,
Number f/cm^
08P-02RD
08P-03D
08P-03RD
09P-01D
09P-01RD
09P-02D
09P-02RD
09P-03D
09P-03RD
0.022
0.005
0.006
0.033
0.019
0.012
0.024
0.018
0.023
61
-------
Appendix E
Average Personal Breathing Zone Concentrations
(Determined by PCM) During Carpet Cleaning
Average Concentration, f/cnv*
Cleaning Method
Experiment
During 1st
cleaning
During 2nd
cleaning
CONVENTIONAL DRY VACUUM
HEPA-FILTERED DRY VACUUM
HOT WATER EXTRACTION
1
5
7
2
6
7
3
4
8
0.013
0.005
0.021
0.012
0.018
0.008
0.018
0.009
0.012
0.009
0
0.022
0.006
0.018
0.013
0.019
0.015
0.015
62
-------
Appendix F
Individual Airborne Asbestos Concentrations
(Determined by TEM) During Carpet Removal
Experiment Cleaning Method
10
10
10.
10
10
10
10
10
10
10
10
10
11
11
11
11
11
11
11
11
11
11
11
11
11
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
Sample Type
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
BASELINE
BASELINE
BASELINE
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
DURING CLEANING
BASELINE
BASELINE
BASELINE
BASELINE
" BASELINE
BASELINE
DURING CLEANING
Sample Concentration,
Number s/crn^
10A-01D
10A-02D
10A-03D
10A-04D
10A-05D
10A-06D
10A-01B
10A-02B
10A-03B
10A-04B
10A-05B
10A-06B
11A-01D
11A-02D
11A-03D
11A-04D
11A-05D
11A-06D
11A-01B
11A-02B
11A-03B
11A-04B
11A-05B
11A-06B
11P-04D
0.051
0.106
0.052
0.103
0.097
0.064
0.030
0.061
0.054
0.066
0.075
0.052
0.082
0.073
0.082
0.075
0.155
0.090
0.034
0.036
0.041
O.O15
0.052
0.034
0.050
63
-------
Appendix G
Individual Personal Breathing Zone Concentrations
(Determined by PCM) During Carpet Removal
Experiment Cleaning Method
Sample
Number
Concentration,
10
10
11
11
11
11
11
11
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
CARPET REMOVAL
10P-01D
10P-02D
UPrOlD
11P-02D
11P-03D
11P-04D
11P-05D
11P-06D
0.033
0.059
0.045
0.090
Oi.091
0.061
0.081
0.047
64
-------
•C
0)
0)
Q
!•<
85
o "1
X JJ
•^ 10
•a u
c v
'f-i^«j'r-voin
O IN CN »* •* O»
ON in oo *cf co \o
t-i in en o vo m
VO
inrocoinr-ot»ovnmrHCNCM.-ir«.
ovoino«Nf»r~voo,oovocNcor-
in CN O CO vO f) CN fl CN vO ^J1 vO O f*' fO
t-ICNf-l^r-ICNCOOvOvOO
i** O ON ^3* rH r^ r*»
CN in r-» «a- CN ON n
ON 00 in CN *3* CTN vO
rH CN CN rH CN
in rH vo T n co ON
ro vO f~ ro O 00 O
vO <» CN 00 n f VO
c-i.HO'JCN'H
in vo rH in ON co CN
O CN ON m CN rn n
^3* ro ^" f^> C3 vO ON
CN i-t ^
co
ssssssss
pppDDDDD
DDDDDDDD
DDDDDODD
88588588^^33^^
I5^g^^|§^
>>>>>>oooooo
a «
X X
a a
QQQQQQQQ
| g £ g S g S S S
QQDQQOQQQ
ooo
M M M
S 8 t? S
ggggggggg
§§
M M
W W
o o
O CJ
< < < . .
§§§§§
W rH M M 1-1
EH h H EH H
z z z z z
S£r-!r-!t1r'H'->'-''->>-i'->^'Jw3
•^4 »*4
gg
W Ed
U U
> > .
z z z
U W
z
o o o o o o
CJ O O 0 O O
rH rH rH in in ON
65
-------
X
£
>* ft
c
*o "g
•H ^
V4
® 1.J
4J " jj*
(J) '••
Q M-4
M g*
x o Jg
•n jj
c a
££
_»
CN
4J
~i.
in
•H
^J
m
jj
c
0)
0
c
o
u
m
0)
^
•O
C O^
CN C
^
V4 C
oi a
-P 0)
< u
4J
01 D<
rH C
Vi C
01 «
4J 01
VW rH
sC u
0)
c
]_l
0)
10
(0
m
c
0)
£
R
X
H
.
^4
«
p
ij
^
z
0
M
H
Z
^
2
0
0
CN O <»
CO ro ^*
ro ro O
VO i-l •*
O cn vO
ro CN i-l
•H 00 CN
r~ •-! co
»H ro f-
•H i-l iH
00 O CN
rH in vo
O O vo
O CN in
00 CN O
O 00 <*
r~ en rH
co ro vo
r- ro O
•-I CN
CO CO i-l
r» vo o
in ^- r-
CN 00 f
co en in
en rH ro
en in VD
r~ r>..cn
rt
CN vo r-
S
D
D
O
^
X
«
Q
Q
/v]
Oi
W
E^
M
PL,
1
rfj
o,
X
VO vo CN
•3* en r^
^j. ro en
r^ vo rH
f» vO ro
sr co en
rH VO i-l
(T> vo ro
•* ro O
rH fH
o o cr»
C— VO rH
r- in en
vo co ro
vo ro f
en t- •<*
m ro vo
CN vo en
CN in co
«.
i-i
CN r-- r-
co r- in
r** o en
•* rH i-l
en r** ro
m CM en
CN Cn rH
in en in
r» vo in
rH rH CN
ro <* co
gj
O
tH
gH
O
K
£H
^
w
K
W
EH
J2
F-l
o
ac
66
-------
APPENDIX J
SIZE DISTRIBUTIONS OF ASBESTOS STRUCTURES
IN CARPET AND IN AIR PLOTTED BY USING A
LINEAR X-AXIS SCALE
67
-------
35
30
25
20
15
1 O
5
O
Fibers
Matrices
Bundles
Clusters
CSS
so
25
2O
1 5
1 O
5
O
Fibers
Matrices
Bundles
Clusters
Structure length, micrometers
Figure J-1. Particle size distribution in carpet before (top) and after
(bottom) dry vacuuming.
68
-------
Fibers
Matrices
Bundles
Clusters
Fibers
Matrices
Bundles
Clusters
Structure length, micrometers
Figure J-2. Particle size distribution in carpet before (top) and
after (bottom) wet cleaning.
69
-------
9O
SO
TO
SO
50
4O
SO
2O
1O
O
Fibers
Matrices
Bundles
Clusters
Fibers
Matrices
Bundles
Clusters
Structure length, micrometers
Figure J-3. Particle size distribution in area air before
(top) and during (bottom) dry vacuuming.
70
-------
Fibers
Matrices
Bundles
D Clusters
H Fibers
81 Matrices
B Bundles
E3 Clusters
-
Structure length, micrometers
Figure J-4. Particle size distribution in area air before (top) and during
(bottom) wet cleaning.
71
-------
QO
SO
7O
©o
50
30
2O
1 O
o
05
so
©o
so
-4O
30
20
1O
O
Fibers
Matrices
S Bundles
O Clusters
Structure length, micrometers
Rgure J-6. Particle size distribution in area air before (top) and
during removal of uncleaned carpet.
BM5»1
• Fibers
H Matrices
• Bundles
£D Clusters
73
------- |