c/EPA
United States
Environmental Protection
Agency
Office of
Toxic Substances
Washington DC 20460
June 1984
Asbestos-Containing Materials
in School Buildings
A Guidance Document
Part 2
-------
EPA-450/2-78-014^f .3-
(OAQPS No. 1.2-094)
SPRAYED ASBESTOS-CONTAINING
MATERIALS IN BUILDINGS:
A Guidance Document
aFOSROEVM
Wi&WIEffl COUfc
by
Robert N. Sawyer, M.D.
Preventive and Occupational Medicine
Yale Health Service
Yale U niversity
New H aven, Connecticut
and
Charles M. Spooner, Ph.D.
GCA/Technology Division
GCA Corporation
Bedford, Massachusetts
U.S. t
w MAR"»n LUuin
G»NCINNW. OHIO
L',BRA^
U.S. m CTL
26 W. MARTIN LUT ^ ^
Contract No. 68-02-2607
Work Assignment No. 4
EPA Task Officer: Carroll Specht
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
March 1978
US EPA-AWBERC LIBRARY
3 0701 1007 0533 1
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OAQPS GUIDELINE SERIES
The guideline series of reports is being issued by the Office of Air Quality
Planning and Standards (OAQPS) to provide information to state and local
air pollution control agencies; for example, to provide guidance on the
acquisition and processing of air quality data and on the planning and
analysis requisite for the maintenance of air quality. Reports published in
this series will be available - as supplies permit - from the Library Services
Office (MD-35), U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina 27711; or, for a nominal fee, from the National
Technical Information Service, 5285 Port Royal Road, Springfield, Virginia
22161.
This Guidance Document was furnished to the Environmental Protection
Agency by the GCA Corporation, GCA/Technology Division, Bedford,
Massachusetts 01730, in fulfillment of Contract No. 68-02-2607, Work
Assignment No. 4. The opinions, findings, and conclusions expressed
are those of the authors and not necessarily those of the Environmental
Protection Agency or the cooperating agencies. Mention of company
or product names is not to be considered as an endorsement by the
Environmental Protection Agency.
Publication No. EPA-450/2-78-014
(OAQPS Guideline No. 1.2-094)
ii
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ABSTRACT
The recognition of the potential health hazards from exposure to
asbestos fiber and the increasing use of this mineral in many products
over the past several decades has prompted the U.S. Environmental Pro-
tection Agency and other federal agencies to enact regulations for its
safe handling to protect the public, the environment and the worker. This
document is prepared for those involved in the use, removal, and disposal
of asbestos materials in the building trades.
Asbestos in all its forms is considered a serious respiratory hazard.
Individual fibers are invisible to the naked eye and their small size gives
them prolonged buoyancy even in still air. Unlike most chemical carcino-
gens, the mineral fibers persist in the environment almost indefinitely
and, when present in a building space open to its occupants, represent a
continuous source of exposure. From a toxicological perspective, the
latency period before onset of clinical signs is typically decades leading
to a difficulty in linking cause and effect. Since the beginning of the
century, asbestos has been used as a major constituent or an important
additive to many consumer products so that there are many sources of expo-
sure to the general public. In the past few tens of years several asbestos
products have been sprayed on structural steel for fireproofing or have been
sprayed as decorative coatings on ceilings.
iii
-------
With a view toward controlling exposures to the public, guidelines are
presented for the detection and monitoring, removal or encapsulation, and
disposal of asbestos-containing building materials. Measures available
to protect workers and building occupants are presented based on field
measurements and theoretical considerations. Sampling procedures are
discussed so that the user of this document can take an active role in
determining whether protective action is needed and, if so, how best to
protect himself, the public, and the environment.
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CONTENTS
Page
Abstract iii
List of Figures viii
List of Tables ix
PART I
ASBESTOS: BACKGROUND, ENVIRONMENTAL CONTAMINATION,
STANDARDS, AND ANALYSIS
Sections
1 Introduction 1-1-1
1.1 Nature of Asbestos 1-1-1
1.2 Spray Application of Asbestos 1-1-2
1.3 Potential for Environmental Contamination 1-1-4
2 Asbestos Contamination of the Environment 1-2-1
2.1 Asbestos Fiber Size and Ambient Community Contamination 1-2-1
2.2 Asbestos Fiber Aerodynamics 1-2-3
2.3 Asbestos Contamination in Buildings 1-2-5
2.4 Asbestos-Related Diseases 1-2-11
3 Existing Standards 1-3-1
4 Analytical Techniques 1-4-1
4.1 Bulk Samples Asbestos Analysis 1-4-2
4.2 Airborne Asbestos Analysis 1-4-3
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CONTENTS (continued)
Sections Page
PART II
THE CONTROL OF EXPOSURES TO SPRAYED ASBESTOS
1 Determining Asbestos Exposure Levels II-l-l
1.1 Introduction II-l-l
1.2 Factors to Consider 11 — 1 — 2
1.3 Asbestos Analysis 11 — 1—4
2 Asbestos Control Measures II—2—1
2.1 Temporary Control Measures II-2-1
2.2 Long-Term Control Measures II-2-2
2.3 Asbestos Emission Control and Personnel Protection II-2-4
3 Asbestos Containment II-3-1
3.1 Enclosure Systems II—3—1
3.2 Encapsulation With Sealants II-3-2
4 Asbestos Removal II-4 II-4-1
4.1 Dry Removal II-4-1
4.2 Wet Removal II-4-2
5 Regulations and Compliance by Contractors II-5-1
Appendixes
A References A-l
B Aerodynamic Behavior of Airborne Fibers B-l
C Asbestos Sample Collection C-l
D Recommended Decontamination Procedure D-l
E Stripping Sequence for Wet and Amended Water Methods E-l
vi
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CONTENTS (continued)
Appendixes Page
F Suggested Specifications for Asbestos Removal F-l
G U.S. Environmental Protection Agency Regulations
Pertaining to Asbestos G-l
H Occupational Safety and Health Administration Regulations
Pertaining to Asbestos H-l
I U.S. Environmental Protection Agency and Occupational
Safety and Health Administration — Regional Offices 1-1
J Commercial Sources of Materials, and Equipment for
Asbestos Removal Operations J-l
vii
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FIGURES
No. Page
1-1-1 Friable Asbestos-Containing Material Hanging From
Damaged Ceilings 1-1-5
1-2-1 Asbestos Size Comparison With Other Particles and
Measurement Techniques 1-2-2
1-2-2 Theoretical Settling Velocities -of Fibers 1-2-4
1-2-3 Modes and Rates of Fiber Dispersal 1-2-6
1-4-1 Commercially Available Aerosol Monitoring Kit 1-4-4
B-l Fiber Settling Velocities as a Function of Fiber Length B-5
E-l Removal of Asbestos-Containing Ceiling Material. Note
Use of Headgear, Coveralls and Respiratory Protection E-3
E-2 Drums With 6-mil Plastic Liner to Contain Removed
Debris E-4
F-l Sequence of Steps in an Asbestos Removal Operation F-8
viii
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TABLES
No. Page
1-2-1 Airborne Asbestos in Buildings 1-2-9
I-4-1 A Comparison of Asbestos Analysis Techniques Available 1-4-9
II-2-1 Custodial Asbestos Exposures and Effect of Wet Methods I1—2—2
II-2-2 Alternatives for Reduction/Elimination of Contamination
From Sprayed Asbestos II-2-3
11-4-1 Commercially Available Wetting Agents for Wet Removal of
Asbestos in Buildings II-4-4
ix
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PART I
ASBESTOS: BACKGROUND, ENVIRONMENTAL CONTAMINATION,
STANDARDS, AND ANALYSIS
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1. INTRODUCTION
1.1 NATURE OF ASBESTOS
In recent years, there has been an increasing awareness of the impor-
tance of environmental factors in carcinogenesis. Asbestos has become a
widespread environmental contaminant for large segments of our society, and
has caused fibrosis and malignancies of the lung and other organs.
The mineral fibers resist degradation, and persist in the environ-
ment. Because of fibrous form and small size they possess the aerodynamic
capability of prolonged suspension in air and repeated cycles of reentrain-
ment. Asbestos fibers, even in low concentration, may have carcinogenic
potential, and a biologic activity that may persist for the lifetime of an
exposed host.
Asbestos is a generic term applied to a wide chemical variety of
naturally occurring mineral silicates which are separable into fibers. The
six major recognized species of asbestos minerals are chrysotile of the
serpentine group ("white asbestos"); and cummingtonite-grunerite asbestos
(also amosite or "brown asbestos"), crocidolite ("blue"), anthophyllite
asbestos, treiiiolite asbestos, and actinolite asbestos of the amphibole
group. Specific attributes and characteristics vary with the different
types, but the commercially valuable asbestos minerals, in general, form
fibers which are incombustible, possess high tensile strength, good
1-1-1
-------
thermal and electrical insulating properties, and moderate to good
chemical resistance. They may be packed, woven, or sprayed. These char-
acteristics of durability, flexibility, strength, and resistance to wear
make asbestos well-suited for an estimated 3,000 separate commercial,
public, and industrial applications.1 These include roofing and flooring
products; fireproofing textiles; friction products; reinforcing material
in cement, pipes, sheets, and coating materials; and thermal and acoustical
insulations. Asbestos has widespread application in all industrial so-
cieties and is a nearly indispensable and ubiquitous material.2-1*
Historically, asbestos remained a curiosity for centuries, with negli-
gible production until the beginning of the 20th century when it was used
as thermal insulation for steam engines. Worldwide production of the
mineral now approaches 5 million tons annually, with chrysotile the prin-
cipal fiber type."' Annual United States consumption is approximately
900,000 tons, with more than 70 percent used in the construction industry.
It has been estimated that a majority (85 to 92 percent) of end-product
uses have effectively immobilized the asbestos fibers by mixing them into
a strong binding material; e.g., cement.6 Fibers are still liberated,
however, during fabricating operations such as grinding, milling or cutting.
The remaining 8 to 15 percent is in a form that will more readily permit
fiber dissemination, such as friable insulation material or bagged fibers
for mixing.
1.2 SPRAY APPLICATION OF ASBESTOS
Of the many uses of asbestos, the technique of spraying fibers onto
structural surfaces has been perhaps the most significant in causing asbes-
tos exposure to construction workers during application and to the general
1-1-2
-------
population thereafter. Such material, in loosely bonded friable form, has
been applied extensively to steelwork to retard structural collapse during
fire, and to overhead surfaces for purposes of acoustic and thermal insu-
lation, decoration, and condensation control.
Spray application of asbestos fireproofing and insulating material
began in England in 1932. Spray application offered the advantage of
rapidly covering large or irregular surfaces evenly and efficiently with-
out the use of mechanical support or extensive surface preparation. Early
spray applications in the U.S. were mainly for decorative use and acoustical
insulation in ceiling material in clubs and restaurants. In 1950 more than
half of all multistory buildings constructed in the U.S. used some form of
sprayed mineral fiber fireproofing.7 In 1968 fireproofing alone accounted
for 40,000 tons of sprayed material.8
The health hazards of spray application of asbestos to spray operators,
other construction workers, and the general public in the vicinity of such
operations were recognized and documented.9 Because of these hazards, the
New York City Council banned spray application in 1972.^ Other cities
and states followed suit, and in 1973 the U.S. Environmental Protection
Agency (EPA) banned spray application of insulating or fireproofing material
containing more than 1 percent asbestos by weight.11 Decorative materials
were not included in the ban, and this omission permitted some continuing
application. One example involved all overhead surfaces in the large
(1200 unit) condominium complex using a friable mixture of 30 percent
asbes tos.12
On March 2, 19 77, EPA proposed an amendment to the national emission
standard for asbestos.13 These amendments would extend the spraying
1-1-3
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restrictions to all materials which contain more than 1 percent asbestos
by weight.
Numerous substitutes for sprayed asbestos materials are currently
available.*1* Most spray materials currently in use contain fibrous glass
or nonasbestos mineral fibers along with cement, gypsum, or other binders
similar to those used for asbestos. These materials can be used for fire-
proofing, thermal and acoustical insulation, and decoration.
The possible carcinogenicity of replacement materials, especially
fibrous glass, is under investigation. The physical dimensions of glass
fibers are much larger than asbestos fibers, and currently there is no
epidemiologic study demonstrating carcinogenicity of this product. Recent
experimental work has indicated carcinogenic potential of fibrous glass
with dimensions reduced to approximately the size of asbestos fiber,15
and similar findings with other minerals may occur in the future.
1.3 POTENTIAL FOR ENVIRONMENTAL CONTAMINATION
Environmental contamination from asbestos-containing surfaces can
occur not only during construction and demolition, but also throughout the
life of the structure. Frequently these surfaces are exposed or accessible
(see Figure 1-1-1). They can include open and visible sprayed ceilings,
walls, or structural members, or surfaces hidden by suspended ceiling sys-
tems accessible to maintenance personnel.
The proportion by weight of asbestos in asbestos-containing material
found in sprayed ceilings or overhead surfaces is generally in the 10 to
30 percent range but may vary from essentially none to nearly 100 percent.16
The remainder may be fibrous glass, various other fibers, and adhesives.
As in other uses, chrysotile asbestos is the most common fiber type.
1-1-4
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Figure 1-1-1. Friable asbestos-containing material hanging from damaged ceilings.
-------
Although the spraying of friable asbestos-containing materials in
construction has all but ceased, sprayed material within existing structures
remains a potential widespread source of asbestos fiber exposure. Although
exact figures are not available, if it is assumed that spray application was
a common practice from 1958 to 1973, and that fireproofing was the major
use of this material, a conservative order-of-magnitude estimate of the total
amount of asbestos sprayed over this period would be 500,000 tons. It is
indeed possible, therefore that sprayed asbestos material within buildings
may become the most significant source, of environmental asbestos contami-
nation in the future.
Considering the large number of people that may be exposed, their
range in age and habits, such as smoking, etc., and the lack of feasible
means of personal protection, this potential source of asbestos exposure
could be significant. It is the purpose of this document to describe the
potential hazards to the public from this source and present rational
alternatives for its control.
1-1-6
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2. ASBESTOS CONTAMINATION OF THE ENVIRONMENT
2.1 ASBESTOS FIBER SIZE AND AMBIENT COMMUNITY CONTAMINATION
During mining, milling, bagging, or spraying, the processing and dis-
turbance of asbestiform minerals can result in the release of fibers and
fiber bundles into the environment. Asbestos fibers, resistant to degrada-
tion by thermal or chemical means, also remain available for release into
the environment from any source, especially from loosely-bound asbestos-
containing materials. As shown in Figure 1-2-1, dispersed asbestos fibers
have a length range from less than 0.1 micrometers (ym) to some tens of
micrometers. This size range of asbestos fibers points out two significant
attributes: aerodynamic capability and respirability. The fibers can
become suspended in air, and thus are available for respiration, and re-
tention in the lung. The fibers may also enter the gastrointestinal tract
directly and via the lung clearance mechanism.
Studies of urban ambient air using electron microscopy have shown
that asbestos concentration levels are generally below 10 ng/m3, and rarely
q &
exceed 100 ng/m . Mean asbestos levels in 49 United States cities were
"k
In this document, asbestos concentrations are expressed as a specific weight;
(i.e., nanograms per cubic meter) when determined by electron microscopy; and
as the number of fibers per cubic centimeter (f/cm3) when measured by phase
contrast microscopy. Depending upon the laboratory, results of asbestos anal-
yses by electron microscopy may be reported on a weight basis, as the number
of fibers present, or both (see footnote on page 1-4-7).
1-2-1
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ANGSTROM UNITS
5 7 10 20
1 T T I T 111
t£T
A*
50 70 100
i i rrrrri
n til nny~
¦ ULTRAVIOLET
i r i mum
7—r
•TOBACCO SMOKE—J
I
-VIRUSES
SMOG
I I I I l|
¦INFRARED
"i—r i i 1111] 1—i—i inn
-8
VISIBLE LIGHT
- SILT j—- FINE SAND
¦ CLOUDS ond FOG 1
GROUND TALC
-J
BACTERIA
HUMAN HAIR-
-ASBESTOS FIBER-
4?
I VISIBLE TO EYE •••
I—MACHINE TOOLS (MICROMETERS etc)*»«
OPTICAL MICROSCOPES 1
SCANNING and TRANSMISSION ELECTRON MICROSCOPES
-I
X-RAY DIFFRACTION
I I I I I III
J I I I I I I I
I I I I I I I
-REAL TIME, MONITORING INSTRUMENTS!
J I I I I I I ll I I L
I I II I
J ' I I I I 111
0.0001
0.001
0.01
0.1 I
SIZE RANGE, Micrometers ((ici)
10
100
1000
(I mm)
Figure 1-2-1. Asbestos size comparison with other particles and measurement techniques.
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found to be 4.3 ng/m3 in 1969, and 2.1 ng/m3 in 19 70. Higher urban read-
ings occurred in communities with asbestos emission sources such as fac-
tories and near construction sites where asbestos spraying was in progress.
A level of 0.1 ng/m3 was found in a single nonurban sample>17~19
2.2 ASBESTOS FIBER AERODYNAMICS
An asbestos fiber, once released into the air by any means, will
enter a phase of downward settling determined in general by its mass, form,
and axis attitude. The range of these fiber characteristics strongly af-
fects settling velocities and hazard potential since those fibers able to
remain aloft for many hours have a higher exposure probability than rapidly-
settling fibers. Settling velocity is strongly dependent upon fiber diam-
eter and to a lesser extent upon fiber length. Figure 1-2-2 shows the
theoretical settling velocities in still air for fibers of varying size,
alignment, and aspect ratio. Note the tendency for a roughly twofold set-
tling between horizontal and vertical fibers. The mathematical derivation
of this graph is presented in Appendix B.
The theoretical settling curve data presented in Figure 1-2-2 are in
close agreement with actual settling data obtained under working conditions.2®
By way of example, fibers 1 to 5 ym in length with an aspect ratio (length
divided by width) of roughly 5:1 would be common in material dispersed
from overhead insulation in buildings. The settling velocities for fibers
5, 2, and 1 pm in length with a 5:1 aspect ratio and with an axis attitude
varying between vertical and horizontal, would be 2 * 10 2, 4 x 10-3, and
10~3 , respectively. The theoretical times needed for such fibers to set-
tle from a 3 meter (9 ft) ceiling are 4, 20, and 80 hours in still air.
Turbulence will prolong the settling and also cause reentrainment of fal-
len fibers.
1-2-3
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Figure 1-2-2. Theoretical settling velocities of fibers.
1-2-4
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During the time that the fiber remains airborne, it is able to
move laterally with air currents and contaminate spaces distant from the
point of release. Significant levels of contamination have been documented
hundreds of meters from a point source of asbestos fibers,9 and fibers
may also move across contamination barrier systems with the passage of
workers during removal of material.^9
2.3 ASBESTOS CONTAMINATION IN BUILDINGS
2.3.1 Basic Concepts
Asbestos fiber contamination of a building interior occurs by three
general modes: fallout, contact or impact, and reentrainment. Considera-
tion of each mode of contaminant entry and fiber aerodynamics is useful in
exposure risk evaluation and the selection of solutions. Fiber fallout
is in great part a consequence of the characteristics of the ceiling ma-
terial itself, while contact (impact) and reentrainment (secondary disper-
sal) result from activity within the structure. As outlined in Fig-
ure 1-2-3, each of the three distinct modes has a characteristic rate of
fiber dispersal.
Fallout
The rate of fiber dispersal in fallout is continuous, low level and
long lived. Fallout may occur without actual physical disruption of the
fiber-bearing material and may simply be a function of degradation of the
adhesive. Variations in the fallout rate (R^) are due to structure vi-
bration, humidity variations, air movement from heating and ventilating
equipment, and air turbulence and vibration caused by human activity. This
rate may also gradually increase due to aging of the adhesive component
of the materials ranging from nearly zero for cementitious mixes in good
repair to roughly 100 ng/m3 for deteriorating dry mix applications.
1-2-5
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SPRAYED ASBESTOS-CONTAINING CEILING MATERIAL
~TR
FALLOUT
o
RATE
Rf
MODE
FALLOUT
IMPACT
SECONOARY
DISPERSAL
IMPACT
RATE »
CAUSES
AIR MOVEMENT
VIBRATION
MAINTENANCE
ACCIDENTAL IMPACT
USUAL ACTIVITY
CUSTODIAL SERVICE
SECONDARY
DISPERSAL
FREQUENCY
CONSTANT
OCCASIONAL
FREQUENT
RATE
LOW
(Rf)
HIGH (RC)
LOW TO (Rr )
HIGH
Figure 1-2-3. Modes and rates of fiber dispersal.
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Contact
Friable sprayed asbestos surfaces have low impact resistance and are
easily damaged. Even minor physical contact can result in fiber release
into the environment. Such contact may be intentional and unavoidable
during maintenance activities, accidental during routine activity, or de-
liberate through vandalism. Contact contamination depends rather simply
upon accessibility and the probability of contact, the function of the
structure, and the activities of the users.
The contact mode of fiber dispersal produces the highest release
rates (R ). The fiber contamination level during even routine maintenance
c
and repair activities may exceed 20 f/cm3, and removal of dry sprayed as-
bestos material can yield fiber contaminations of over 100 f/cm3.20
Reentra inment
The reentrainment of fibers that have already fallen onto interior
surfaces repeatedly causes contamination of the environment, as disturbance
of these settled fibers causes resuspension in the atmosphere (R ). A
fiber released from an overhead sprayed surface may participate in repeated
cycles of resuspension and settling.
It is possible to have fiber counts as high as 5.0 f/cm3 in activi-
ties such as custodial work. These custodial activities may result in
significant levels of contamination and give rise to significant ex-
posures. In a university library with a deteriorating sprayed asbestos
ceiling, custodians were continuously dusting over a mile of shelving
and generating an average of 4.0 f/cm3 contamination level for themselves
and 0.3 f/cm3 for nearby library users.
1-2-7
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2.3.2 Airborne Asbestos Concentrations
Table 1-2-1 presents data from studies on asbestos contamination in
buildings. Consistent with the basic concepts outlined above, under
quiet conditions contamination levels are low; under conditions of general
activity an increase is seen; and contact and reentrainment create rela-
tively high contamination levels. If friable sprayed surfaces are dis-
turbed or damaged for any reason, fibers are released into the environ-
ment. Even the machining or cutting of cementltious asbestos, for exam-
ple, can release fibers in excess of the OSHA ceiling limit of 10 f/cm3.15
Exposure probabilities for both workers and building users can be
estimated to some degree by consideration of the three modes of contami-
nation and the general activity within the building. Quiet activity refers
to background conditions within a structure or it may represent the usual
activity level in an area with low probability of either contact or reen-
trainment of asbestos. Under these conditions contamination levels may
approach the fallout rate and be negligible. For buildings with deterio-
rating asbestos material, however, quiet activity contamination levels
may be significantly higher than outdoor ambient air levels. Studies that
have included quiet activity condition testing have found levels from
near"the ambient background to approximately 100 ng/m3 by electron micro-
scopy,18 and 0.02 f/cm3 by optical microscopy.20 Determination of asbestos
contamination levels during periods of quiet activity conditions are ex-
tremely misleading in the estimation of actual exposure since only fallout
or similarly low rates are seen.20
Routine activities in a structure containing sprayed asbestos sur-
faces will usually result in eli rated fiber levels. Although statistically
1-2-8
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Table 1-2-1. AIRBORNE ASBESTOS IN BUILDINGS
Sampling conditions or situation
Mean counts
(f/cm3)
Number of
samp 1es
Standard
deviation
1.
University dormitory, UCLA''1
Exposed friable surfaces, 98% amosite
Central student activities
0. 1
0 to 0 8
(range)
2.
Art and Architecture Building, Yale
University ^ Exposed friable ceilings,
202 chrysotilc
Ambient air, City of Now Haven
0 00
12
0.00
Fallout
Qu i e t cond111ons
0.02
15
0 02
Con tact
Cleaning, moving books in stack area
15 5
3
6 7
Rolamping light fixtures
I 4
2
0.1
Removing ceiling section
17 . 7
3
8 2
Ins La 11 i ng t rack 1 i gh t
7 7
6
2 9
Installing hanging lights
1 1
5
0 8
Installing parLition
3 1
U
1 1
Recntrammcnt
Custodians sweeping, dry
1.6
5
0.7
Dusting , dry
U.O
6
1.3
Proximal to cleaning (bystander exposure)
0.3
-
0 3
General Activity
0 2
36
0 1
3.
Office buildings, Eastern Connecticut*6
Exposed friable ceilings, 5 to 30%
chrysot i lc
Custodial activities, heavy dusting
2.8
8
1.6
4.
Private homes, Connecticut.^
Remaining pipe lagging (dry) amosite
and chrysotilc asbestos
U. 1
8
1 8 to 5.8
(range)
5.
6.
Laundry contaminated clothing,'® Chrysotile
Office building, Connecticut ^
Exposed sprayed ceiling, 18%
chrysot i 1 e.
0 4
12
0.1 to 1 2
(range)
Routine activity
Under asbestos ccnling
79a
99a
3
2
40 to 110
(range )
Remote from asbestos ceiling
40a
1
7.
Urban Crammar School, New Haven
Exposed coiling, 15£ chrysotile asbestos
8.
Custodial activity sweeping, vacuuming
Apartment Building New Jersey, heavy
housekeeping.1^ Tremolite and chrysotile
643 a
296a
2
1
186 to 1100
(range)
9.
Office buildings, New York City.1®'^®
Asbestos in ventilation systems
2 5 to 200a
0 to 800
(range)
Quiet conditions and routine activity
^Nanograms/cubic motor. Determined by electron microscope
1-2-9
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significant, fiber levels may only be a few orders of magnitude above
background levels in the hundreds of ng/m3 range by electron microscopy,18
and 0.2 f/cm3 optically.20 Routine activity may also, however, result in
significant and intense contamination. A school population in a building
with accessible sprayed asbestos surfaces may experience significant en-
vironmental contamination with exposures in the 10 to 50 f/cm3 range.20
Increased fallout, occasional contact, and reentrainment may all contribute
to the highly variable fiber levels found under these activity conditions.
Custodial work will result in the disturbance and reentrainment of
accumulations of asbestos fibers released from sprayed surfaces by fallout
and contact. Exposure from reentrainment is high during custodial activity
with variation depending upon both cleaning methods and proximity to the
respiratory zone of the worker. Resulting levels may exceed OSHA occupa-
tional exposure limits.20
Maintenance work such as replacement of light bulbs may involve direct
contact with sprayed asbestos surfaces and result in significant fiber dis-
semination. Such activities may also result in exposures that exceed regu-
latory limits established by OSHA. One study, for example, showed main-
tenance worker exposure above 20 f/cm3 in a university building with ex-
posed sprayed asbestos ceilings.20
Removal of sprayed asbestos surfaces during renovation not only causes
high contamination levels for the duration of the work but also increases
the released fiber burden within the structure that is available for sub-
sequent reentrainment. In such cases, exposures involve the renovation
worker and the routine building user as well. Both contact and reentrainment
release mechanisms are involved with very high levels occurring during actual
contact. Fiber concentrations can exceed 100 f/cm3.20'21
1-2-10
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Razing of a structure can result not only in high level local conta-
mination, but can cause fiber contamination of the surrounding community
due to the aerodynamic capability of the asbestos fiber. This type of
activity is of great significance, but is beyond the scope of this report
and is not considered further. The potential for continued exposure re-
mains following a demolition operation if proper housekeeping or clean-up
procedures are not followed. The operation cannot be considered complete
unless the material removed is adequately sealed in bags and is disposed
of in an approved sanitary landfill as required by EPA regulation.
2.4 ASBESTOS-RELATED DISEASES
Asbestos fibers find entry into the body by inhalation and ingestion.
The retained mineral fibers are found in tissues throughout the life-
time of the host, even long after cessation of exposure.22'23 Such asbestos
fibers found in human tissues are generally undetected by optical micros-
copy, and require an electron microscope.22 21+ Fibers may migrate to other
organs following retention in the lung.2-' Asbestosis and certain malignancies
are related to exposure to fibers of the asbestos minerals. Asbestosis is
a progressive restrictive pulmonary fibrosis associated with inhalation of
asbestos fibers, and is a classic occupational disease.26-31*
Malignancies related to the inhalation and possibly ingestion of as-
bestos fibers by epidemiologic studies include carcinomas of the lung,
mesotheliomas of the pleura and peritoneum, and neoplasms of other
sites.35-37 Asbestos has a potent cocarcinogen effect with cigarette
smoking in carcinoma of the lung. Asbestos workers who are smokers have
over 90 times the risk of nonexposed' nonsmokers.33 ^
1-2-11
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Both the presence of asbestosis and occupational asbestos exposures
have been linked with the incidence of malignancy.^-1+9 However, studies
of the incidence of excess malignancies and the epidemiologic markers of
pleural calcification and mesotheliomas have shown a much wider scope of
asbestos-related malignancy.50-53 The population at risk includes not
only those engaged in the manufacture and use of asbestos products, but
also bystanders and others limited to neighborhood and familial exposures. 51+~
Definition of the relationship of low levels of asbestos exposure and
carcinogenesis remains uncertain and difficult. The extended latency period,
lack of adequate past exposure data, effect of other carcinogens, and
variability of human response makes the quantification of risk approximate
only. Asbestos-related malignancies exhibit latency periods of 20 to 40
years and may follow exposures of much less duration and magnitude as seen
with asbestosis.53-59»G1
Excess malignancies have been found in proximity to emission sources
and in households of asbestos workers.52!54'59 In these cases the expo-
sures seem to have been variable and generally low (about 100 nanograms/
m3).1® Asbestos fiber contamination levels within or exceeding these
ranges have been documented near building sites using sprayed asbestos,7'18
within a university building with sprayed asbestos ceilings,20 in offices,
schools, and apartment buildings with exposed friable asbestos ceilings,
with use of materials such as spackling compound,®2 and near roads and other
areas covered with asbestos-containing crushed rock.53 This indicates con-
tinuing environmental contamination and exposure to asbestos at levels con-
sidered carconogenic. An expanding population at risk has been identified
by these findings of widespread exposure. The impressive annual asbestos
1-2-12
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production and evidence of urban environmental contamination has led ob-
servers to conclude that the incidence of asbestos-induced malignancies
has only begun to be defined.^>^3}2k,64-66
1-2-13
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3. EXISTING STANDARDS
Government regulations pertaining to sprayed asbestos materials have
been issued at the federal level by the U.S. Environmental Protection
Agency and the Occupational Safety and Health Administration, U.S. De-
partment of Labor. Some state and local government units have also de-
veloped regulations pertaining to these materials. The OSHA Standard for
Exposure to Asbestos Dust was published in the Federal Register,67
Vol. 37, No. 110, on June 7, 197 2 (29 CFR 1910.93a). This standard was
recodified to §1910,1001 in the Federal Register dated May 28, 1975.58
The regulations apply to handling asbestos fibers or material containing
asbestos fibers, including removal procedures. This standard for occupa-
tional exposure defines permissible exposure limits, methods of compliance
with regulations, personal protective equipment including clothing and
respiratory protection, methods of measurement of airborne asbestos fibers,
signs and labels warning of asbestos hazard, housekeeping methods for fiber
control and waste disposal, recordkeeping for monitoring and exposures,
and medical examinations.
The regulations originally stipulated a maximum exposure of 5.0 fibers/
cm3 greater than 5 ym in length over an 8-hour period on a time weighted
average (TWA) basis. A maximum of 10.0 fibers/cm3 for a 15-minute sampling
period was the allowed any-time excursion. On October -9, 1975 OSHA
1-3-1
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proposed a limit of 0.5 f/cm3 TWA and 5.0 f/cm3 maximum excursion over a
15-minute period and on July 1, 1976 the original requirement in the regu-
lation was reduced to 2.0 f/cm3 with the maximum excursion permitted re-
maining at 10.0 f/cm3.®® Most recently, the National Institute of Occupa-
tional Safety and Health proposed to OSHA a further lowering of the TWA
limit to 0.1 f/cm3 TWA with 0.5 f/cm3 as the maximum permissible any-time
excursion,7® These numerical limits are based partly on limited studies
of asbestos carcinogenesis and it is possible that lower exposures may be
significant.71'72
Regulations promulgated by the U.S. Environmental Protection Agency
on April 6, 1973, apply to the renovation or demolition of structures con-
taining asbestos and to the spraying of asbestos materials.73 The national
emission standard for asbestos11 specifies procedures for removal and
stripping of friable sprayed asbestos fireproofing and insulation materials
and requires EPA notification that such removal is to take place. The
required work practices include wetting, containment, container labeling
and disposal of the removed material in an approved sanitary landfill.
Fiber levels are not specified but the regulations require that there be
no visible emissions exterior to the structure.
The spray application of asbestos material for fireproofing and in-
sulation is prohibited where the material contains more than one weight
percent asbestos. Decorative materials were not included in the ban, how-
ever, and this omission has permitted some continued application. One
example includes all overhead surfaces in a large (1200 unit) condominium
• , 1 O
complex using a friable mixture of 30 percent asbestos.
1-3-2
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EPA has recently taken action to halt the spray application of as-
bestos containing materials for decorative and other purposes. On March 2>,
1977, EPA proposed amendments, to the national emission standard for as-
bestos,7^ These amendments would extend the spraying restrictions to all
materials which contain more than 1 percent asbestos by weight.
Most state and local governments adhere to current EPA and OSHA regu-
lations; however, in instances where the problem is acute or has received
public attention, special bylaws or ordinances have been passed which are
more stringent than federal regulations. For example, the State of New
Mexico has a 10 ng/m3 ambient air regulation,75 and Connecticut has an
ambient air limitation proposal of 30 ng/m3,76 The State Department of
Environmental Protection for New Jersey issued, a guidance document on this
subject in May 1977 and California, Florida, Massachusetts, and Wisconsin
have formed executive and legislative committees to assess the problem.
The New York City Council banned spray application in 1972.10 Other
cities and states have followed suit. The City of New Haven has a local
ordinance prohibiting existing exposed friable ceilings of any asbestos
content in dwelling.77 This was enacted in 1977 and is presently being
enforced in the case of an apartment building.
Since regulations affecting nearly all aspects of potential exposure
to asbestos are changing rapidly, any questions concerning current EPA regu-
lations should be referred to the regional office of the Environmental Pro-
tection Agency. Information on current OSHA regulations may be obtained
from the U.S. Department of Labor — OSHA Regional Offices. A listing of
the EPA and OSHA Regional Offices is given in Appendix I. State Departments
of Health, Labor, and Environmental Protection will provide additional
1-3-3
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guidance in the event that more stringent state regulations are in effect,
or if difficulty is experienced in locating an approved disposal site for
the asbestos-containing debris.
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4. ANALYTICAL TECHNIQUES
Two general areas of analysis are discussed within the scope of this
document. The first, asbestos identification, is concerned with determin-
ing the presence, type and amount of asbestos within a bulk sample such as
insulation or ceiling material. The second involves estimation of the
amount of asbestos suspended in the ambient air. This airborne fiber con-
centration level can be used to estimate exposure risk. The techniques for
examination of bulk samples are relatively straightforward and give an
unambiguous result in most cases; however, the identification, and especially
quantification of asbestos, in ambient air is very much "state-of-the art"
— the methods used are somewhat controversial and the results ambiguous.
These two distinct types of fiber analysis may not be within the capa-
bility of the same commercial testing laboratory. It is emphasized that
bulk sample analysis services to determine whether asbestos is present in
the material are difficult to obtain. Moreover, the analysis must be per-
formed in a competent manner otherwise it could lead to an expensive and
needless removal task. Failure to identify asbestos fibers, on the other
hand, would allow an existing hazard to continue.
Airborne asbestos fiber analysis is used for evaluating exposure and
the effectiveness of fiber control during renovation, demolition, or
removal. Here too, the number of commercial laboratories suitably equipped
and staffed is limited.
1-4-1
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4.1 BULK SAMPLES ASBESTOS ANALYSIS
There are three methods of asbestos fiber identification which are
reliable and are in common use for bulk sample analysis: petrographic
microscopy, X-ray diffraction, and electron microscopy.
4.1.1 Petrographic Microscopy
The petrographic microscope is a transmitted polarized light instru-
ment, widely used in the geological and chemical sciences for identifica-
tion and characterization of crystalline substances based upon their optical
and crystallographic properties. The techniques are well established and
the equipment is relatively low in cost. It is an effective method for
identification of the particular mineral species present. A possible
drawback in the use of petrographic microscopy is the high level of skill
and experience required of the microscopist. Bulk sample optical microscopy
involves the ability to adequately search a sample and successfully recognize
and identify the suspect material. An experienced microscopist, however,
should be able to locate and identify even small amounts of asbestos in
bulk samples
4.1.2 X-Ray Diffraction
In this technique X-rays are diffracted by a small sample of the sus-
pect material and a pattern uniquely characteristic of any crystalline
materials present is produced. With some instruments a permanent diffrac-
tion tracing is produced. This method requires a significant investment
in equipment, references, mineral standards, and technical expertise. In
routine examination procedures, X-ray diffraction of bulk samples may
fail to detect small concentrations of asbestos, and other silicates or
cyrstalline phases may significantly interfere with accurate identification.
1-4-2
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However, the technique usually yields information with a high degree of
diagnostic reliability, and a printed record. It is usually used as a con-
firmation of petrographic microscopy impressions and not as a screening
procedure.80
4.1.3 Electron Microscopy
Specific and accurate fiber identification can be achieved by examina-
tion of the structure of individual fibers or fibrils, especially if used
in conjunction with electron diffraction or energy dispersive X-ray analy-
sis. The extrapolation of precise electron microscope data, however, to
significant bulk sample information is inefficient and costly. Its use in
identification is usually confined to resolving ambiguities raised by
petrographic microscopy and X-ray diffraction. The main use of the electron
microscopy technique is in the examination of air samples.
4.2 AIRBORNE ASBESTOS ANALYSIS
Estimation of the amount of asbestos suspended in air is presently
performed by two techniques:
1. Fiber counting by optical or light microscopy using the
phase contrast technique.
2. Asbestos mass or fiber population estimation by electron
microscopy.
For either method, a pump is used to draw a volume of air through
a membrane filter at a known rate. An example of a unit specifically
designed for this purpose is shown in Figure 1-4-1. This sampling pump
and filter are usually stationary, but other designs may be carried.by the
worker with the sampling orifice near the respiratory zone. Common sampling
rates are 2.0 liters per minute (£/min) in low volume sampling, and 10 £/min
1-4-3
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Figure 1-4-1. Commercially available aerosol monitoring kit.
(Photo Courtesy Millipore Corporation, Bedford, Massachusetts)
-------
in high volume sampling. The low volume rate is usual for personnel monitor-
ing, and high volume for general environmental sampling. Sampling times are
on the order of 30 minutes to 1 hour or more, depending upon anticipated
fiber concentrations. The filter may be retained within its container and
stored indefinitely. Also, each filter may be repeatedly counted since
only a small segment is removed for each examination. The same filter may
thus be examined by various methods of asbestos quantification and by sev-
eral laboratories for comparison or verification. Care must be taken in
transporting samples to avoid loss of fibers-from the filter surface by
mechanical agitation.
4.2.1 Fiber Counting by Phase Contrast Microscopy
Phase contrast microscopy is routinely performed following the optical
method specified by Occupational Safety and Health Administration (OSHA)
regulations for determination of airborne asbestos in occupational settings.®-'
A pump draws air through a filter having an 0.8 pra effective pore size. A
segment of the filter is then mounted, treated chemically to make the filter
membrane transparent, and examined using a special microscope reticle and
counting procedure with phase contrast illumination at 400 to 500 magnifica-
tion.81-83 Particles are observed for shape and size. Any particle having
a length to width (or aspect) ratio greater than 3:1, and a length of 5 mi-
crometers or greater, is counted as a fiber. Results are presented as the
number of fibers per cubic centimeter of air (f/cm3).
Phase contrast microscopy is an optical technique for viewing small
particles rather than a method for measuring specific properties of a sub-
stance. It is a technique based entirely on the shape of the particle rather
1-4-5
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than a method for measuring specific properties of a substance. It is not
inherently specific for asbestos. Consequently, all particles satisfying
a 3:1 length to width ratio are counted as asbestos fiber. Also, both the
resolution limit of optical microscopy (see Figure 1-2-1) and the 5 ym
lower cut-off for fiber length precludes identification of a much larger
fiber population which may be present and which is of biologic significance.
In some cases fibers and fibrils uncounted because of the 5 ym limitation
of the standard may be greater in number than those counted by one or more
orders of magnitude.16 >81+ Some studies have indicated that fibers smaller
than 5 ym possess potential for biological activity,®5 and that fibers of
diameter less than 0.5 ym and length greater than 3.0 ym may be highly
significant in carcinogenesis.86'87
4.2.2 Fiber Counting by Electron Microscopy
The electron microscopy (EM) permits detailed examination and identifi-
cation of asbestos fibers of all sizes. Both scanning electron microscope
(SEM) and transmission electron microscopy (TEM) are used. The magnifi-
cation necessary to identify asbestos in its smallest dimension is within
the range of these instruments. The actual counting is usually carried out
at 15,000 to 20,000 magnification. Electron microscopy is presently the
definitive method for fiber counting and exposure estimation. Following
sample preparation, a large number of fields are examined for fibers. Each
field is a few hundred micrometers square in area such that many fields
must be examined to make the determination statistically valid. Each fiber
observed is counted and its length (£.) and width (w) measured. The fiber
volume can be calculated by assuming it to be either a right cylinder or
tubular in shape. (The assumption of a cylinder gives a volume about
1-4-6
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20 percent smaller.) The mass of fibers is estimated by multiplying the
calculated volume by the mineral density, usually taken as 2.6 g/cm3.
The accuracy of the calculated fiber mass is primarily dependent upon the
representativeness of the fiber population actually measured.
At this time, laboratories vary in sample preparation, instrument
selection, and in results. There is presently no standard electron mi-
croscopy technique. A provisional optimum procedure is under development
by the Environmental Protection Agency and is intended to increase uni-
formity and enhance inter laboratory agreement.88
There has.been great concern and some misunderstanding over inter- and
intra-laboratory variability in fiber counting results. Apart from the
errors to be anticipated from variation in laboratory procedures, high
errors are intrinsic when extrapolating a count of possibly a few tens of
fibers from a relatively miniscule fraction of a large sample to a total
fiber count.^ The multiplying factors used to scale-up the count for a
specific volume of air may be as high as 106 or more.
The time required for sample preparation for EM techniques is lengthy,
the equipment a major investment, and highly trained and qualified personnel
a necessity.
Vc
This and other EPA documents are available through the National Technical
Information Service (NTIS), 5285 Port Royal Rd., Springfield, Virginia 22161.
^It will be noted that determinations by optical (phase contrast) microscopy
are expressed in numbers of fibers per unit volume of air whereas results by
electron microscopy may be expressed either as number of fibers or mass of
fibers per unit volume of air. The high resolution of the electron micros-
copy permits the analyst to measure the length and width of each fiber. Know-
ing the fiber's dimensions, its volume can be calculated (i.e., I * w2).
Assuming a mineral density of 2.6 g/cm3, the mineral's weight is obtained.
1-4-7
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4.2.3 Conversion Between Optical and Electron Microscopy
The conversion of data obtained by one method to units of the other is
not generally considered appropriate in the case of airborne asbestos
measurement. The optical technique counts not only asbestos but all fibers
generally, while EM is mineral specific. Fiber size range visible by EM is
essentially complete, while that seen optically is truncated both physically
land by regulation. In some cases the fiber size distribution will, fall
below 5 lim, producing a zero count optically, but will still have a signif-
icant count when examined by electron microscope.16'2® Given the size dis-
tribution of a specific fiber population that extends above and below 5 pm
such conversion is possible. However, in the general situation it is quite
unreliable.
Table 1-4-1 lists some advantages and disadvantages of analytical
techniques available.
1-4-8
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Table 1-4-1. A COMPARISON OF ASBESTOS ANALYSIS TECHNIQUES AVAILABLE
Me thod
Advantages
Disadvantages
1.
Bulk
Sample Analysis
a.
Petrographic microscopy
Relatively rapid and low
cost per analysis, suited for
exact identification of mine-
ral(s) present and estimate of
abundance.
High level of operator training
and experience required.
b.
X-ray diffraction
Unambiguous mineral fiber
identification, rapid
"fingerprinting" of sample
with permanent record.
High investment in training
personnel and capital equipment.
May not detect minor fiber abun-
dances especially if other
crystalline phases are present.
c.
Electron microscopy
"Absolute" determination of
fibers present, and identi-
fication of mineral species.
High equipment and analysis
costs. Highly trained operator
required.
2.
Ambient Air Sample Analysis
a.
Phase contrast microscopy
Low cost per 'analysis, low
cost for equipment, exten-
sive training not required,
presently the most detailed
standard procedure available.
Limited resolution, fibers less
than 5 um not counted, therefore,
hazardous situations may be
missed altogether.
b.
Electron microscopy
Closest to obtaining "abso-
lute" fiber count because
of high resolution and
identification ability.
In addition to disadvantages in
l.(c) above, procedural standards
not available, poor precision and
accuracy.
-------
PART II
THE CONTROL OF EXPOSURES TO SPRAYED ASBESTOS
-------
1. DETERMINING ASBESTOS EXPOSURE LEVELS
1.1 INTRODUCTION
As discussed in Part I, exposure to asbestos fibers is a recognized
health hazard. Following long latency periods, asbestosis and malignancies
of varying type and site may follow both occupational and nonoccupational
exposures. Although the mechanism and epidemiology of asbestos carcino-
genesis is not yet well defined, accumulating evidence suggests the signifi-
cance of exposures at even very low fiber concentrations.
The specific source of asbestos exposure covered in this document is
fiber release from sprayed, friable asbestos-containing material. For
approximately 20 years, sprayed asbestos was extensively used in the con-
struction industry. The sprayed, friable material can release fibers into
the environment at rates dependent upon both deterioration and the dis-
turbance of the material. The released fibers are durable, possess aero-
dynamic capability, and are potentially carcinogenic without documented safe
threshold levels.
The combination of the factors of widespread use, a large potentially-
exposed population, and carcinogenicity has created a potential health
hazard of significant proportion.
Part II presents recommendations for techniques of material analysis,
procedures for hazard estimation, and alternative solutions to potentially
hazardous situations. Regulations of the Environmental Protection Agency
II-l-l
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and the Occupational Safety and Health Administration are discussed in
greater detail, and specific removal procedures and specifications are
presented.
1.2 FACTORS TO CONSIDER
The applications, mixtures, and locations of sprayed asbestos material
have been highly variable. The estimation of exposure hazard or risk from
such material must involve consideration of a number of factors. There is
no simple formula for all situations. The primary consideration should be
to minimize exposure to asbestos. The following factors should be consid-
ered in assessing the risk of asbestos exposure and establishing priorities
for corrective action:
1. Analysis of material. Establish the presence of asbestos
in the sprayed material by competent examination. This is
the first, and essential step in hazard estimation. The
higher the proportion or percentage by weight of asbestos
in the material, the greater the number of fibers released
for a given event. However slight the damages, there will
be a release of some fibers, and even friable material con-
taining only 1 or 2 percent asbestos can disperse a signifi-
cant number of fibers if it is extensively damaged.
2. Age and deterioration of the material. Cohesiveness of most
materials will decline with age, and the rate of fiber loss
will increase.
3. Location and accessibility of the material. With ceilings,
for example, a height of approximately 10 ft (3 meters) is a
reasonable limit for direct contact. Possibility of contact
II-1-2
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for any other reason must be considered, however.. . This
will include gymnasiums and classrooms where objects can
be hurled against the fiber surface. The 3-meter rule
would not apply in such circumstances.
Function of the space with respect to both the intended
and actual use of the area. Population using space.
This is a significant consideration. An active popula-
tion, such as that of an urban senior high school may
result in more contact fiber dispersal to a significant
extent. High frequency of use and activity usually
means high fiber levels in the space.
Necessity to penetrate or disturb the material for main-
tenance, cleaning, or any other reason. This includes
penetrations for heating and ventilation, lighting, and
plumb ing.
Presence of high humidity or water damage. Although used
for condensation control in some applications, sprayed
asbestos-containing materials tend to deteriorate rapidly
in humid environments and are susceptible to fragmentation
from leaking water.
Accumulated epidemiologic evidence indicates that asbestos
levels exceeding as little as 100 nanograms per cubic meter
should be suspect in causing adverse health effects and thus
some action to reduce exposure is warranted.^® It may be
advisable to determine levels elsewhere in the building and
outside to ascertain that the fiber levels are due to the
sprayed material rather than some other source.
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8. OSHA, EPA, and state and local regulations will influence
the selection of any action to reduce asbestos exposure
levels. Until permanent action can be taken to reduce as-
bestos fiber release, temporary measures may be used. These
include the alteration of various custodial and maintenance
activities which can result in asbestos emissions by contact
or by resuspension. Permanent actions include enclosure,
encapsulation, or removal of the asbestos material.
1.3 ASBESTOS ANALYSIS
The methods of asbestos determination are listed in order of the
simplest and least expensive (record review) to the more technical and
costly (airborne fiber monitoring).
1. Record review: Architectural or contractor specifications
and records are available for most large structures. In
many instances these will identify the sprayed material
and may include the type and proportion of asbestos contained.
Instances where records erroneously report either the presence
or absence of asbestos have occurred, and reliance on building
records alone is not recommended.
2. Visual inspection: The surface of sprayed asbestos materials
generally have an appearance that may vary from a loose, fluffy,
or sponge-like composition to that of a dense, nearly solid
surface. If the material is friable, it will crush with hand
pressure. The thickness of most sprayed asbestos material com-
monly varies from 0.25 cm (1/8 inch) to over 5.0 cm (2 inches).
Uncoated material may be slightly gray, brown, or blue in
II-1-4
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coloration depending upon the proportion and type of
asbestos used. Such surfaces readily collect dust, and
will acquire a dark gray tinge with time. The presence
or absence of asbestos, however, cannot be determined
reliably by texture, color, or general appearance.
3. Bulk material analysis: The identification and quantifi-
cation of asbestos in a bulk material sample is a procedure
requiring appropriate equipment, technique, and expertise.
In view of both the health and economic implications, compe-
tent analysis to determine the presence and proportion of
asbestos is a necessity.
Laboratory analysis of the material should be performed by:
a. Petrographic microscopy as performed by a laboratory of
recognized competence in optical crystallography.
b. X-ray diffraction as necessary as a supplement to petro-
graphic microscopy.
c. Electron microscopy only if ambiguity exists following
analysis by petrographic microscopy and X-ray diffraction.
It is again emphasized that the identification of asbestos in bulk
samples involves expertise in optical crystallography and is not a routine
laboratory procedure. A laboratory certified and proficient in NIOSH
asbestos fiber counting methodology may lack both the equipment and com-
petence for identification of asbestos in bulk samples. The use of polar-
ized light microscopy (petrographic) and various refractive index liquids
for dispersion staining is usually sufficient to allow identification of
II-1-5
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the individual forms of asbestos and estimation of the amount present.^
An experienced microscopist using petrographic techniques is able to rapidly
detect small quantities of asbestos in a bulk sample.
X-ray diffraction supplements optical microscopy by "fingerprinting"
any crystalline phases present, though the presence of many of these phases
in addition to asbestos may make interpretation difficult. X-ray diffrac-
tion provides a permanent tracing of the analysis, but is more expensive
than petrographic microscopy, requires expertise, so does petrographic,
and low quantities of asbestos fibers may not be detected. Depending
on the laboratory, an amount less than 2 to 4 percent may be missed.
A recommended technique for obtaining a bulk sample from a sprayed
asbestos material is outlined in Appendix C, along with cost and reference
laboratory information.
4. Airborne asbestos fiber counting: Sampling and analysis for
airborne asbestos may establish the existence of asbestos
contamination.12>20 ,21 An adequate study of airborne con-
tamination requires sampling during various indoor activities
and sampling of outside or community ambient levels, with
inclusion of control samples. Sampling within a structure
under only quiet conditions may be particularly misleading
because asbestos fibers become airborne usually as a result
of disturbance through human activity.20 The direct moni-
toring of persons engaged in these activities will best de-
fine potential exposures.1® These activities include usual
behavior of building users, maintenance, custodial and house-
keeping work.
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If exposure levels are sufficiently elevated, examination of
the samples by optical microscopy will probably determine the
presence of asbestos. In cases of lower contamination levels
or a predominantly small size population of fibers, electron
microscopy will be necessary for complete asbestos
quantification.
The lack of standards for airborne asbestos in nonoccupational
environments and expense of sampling and analysis have dis-
couraged airborne asbestos testing. An exposed and friable
surface, the identification of asbestos within the material, and
documentation of air contamination from such surfaces surely
provide an impetus to reduce potential carcinogen exposure to
as low a level as is possible.
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2. ASBESTOS CONTROL MEASURES
2.1 TEMPORARY CONTROL MEASURES
During the interval between identification and resolution of an as-
bestos exposure problem it may be possible to significantly reduce exposure
by control of maintenance, custodial, and repair activities. Temporary
measures may include alteration of various work procedures such as main-
tenance or renovation that could potentially cause asbestos contamination.
Wet cleaning methods for example, could be used in place of dry dusting
and sweeping in any essential custodial work. In addition, maintenance
and custodial workers should be protected by approved filtered respirators.
Building user and bystander exposure could be reduced substantially
by appropriate rescheduling of necessary custodial and maintenance work.
Table II-2-1 shows the reduction in fiber counts that was obtained in one
case using wet cleaning methods and specific scheduling.70 Custodial
activities were categorized as above and below waist level. Air sampling
was carried out at the respiratory zone of a worker wearing respiratory
protection. While significant reductions were achieved, exposures were
not eliminated and the use of such techniques should be temporary.
II-2-1
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Table II-2-1. CUSTODIAL ASBESTOS EXPOSURES AND EFFECT OF WET METHODS
Custodial
activity
Fiber count means:
f/cm^ (number)3
Before
control
Following
control
Above waist
4.0 (6)
0.3 (4)
Below waist
1.6 (5)
0.2 (4)
Bys tander
0.3 (6)
b
aNIOSH method, phase contrast
microscopy.
Elimination of exposure to by-
stander by rescheduling should
not be regarded as a permanent
solution. The long settling
times for fibers (see Figure 1-2-2)
and the possibility of resuspension
should be considered before per-
mitting normal traffic to resume
in the area.
2.2 LONG-TERM CONTROL MEASURES
The long-term alternatives to reduce or eliminate asbestos exposure
from sprayed friable asbestos material are outlined in Table II-2-2.
Anticipated fiber concentrations, and comments on working conditions are
included. These methods of resolution fall within two general categories:
1. Asbestos containment through use of a sealant (encapsu-
lation) or barrier (enclosure) system.
2. Complete removal of the asbestos material from the structure.
Selection of the appropriate method or combination of methods will
depend upon a number of factors including characteristics of the asbestos
material, structure use and configuration, user activity, and cost.
II-2-2
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Table II-2-2. ALTERNATIVES FOR REDUCTION/ELIMINATION OF CONTAMINATION FROM SPRAYED ASBESTOS
Alternat ives
Typical fiber concen-
tration in work area
(f/err )a
Corrents
1. RenovaL
a.
Dry methods
(loose material)
82.2b
(ll)c
Much dust and debris made worV conditions difficult. Squired
hose supplied respirators (verj, restrictive). Fibers :c.e
across deccntani-iat ion barriers."^
"> 100.0
(-)
Very dusty conditions,
Building contamination
c on t ar. ma t i on control irpossiblc .
evident.?
b.
Wet methods
(1)
Untreated
(loose material)
23.1
(6)
Little dusting. Heavy
water runoff.^
(2)
Ar.ended water
(loose material)
2.8
(56)
Nearly no water runoff
dus ting.1- > 2 ^
Acceptable conditions.' No visible
(3)
Amended water
(Loose material in-
adequate HpO application
18.4
(12)
Some dusting evident,
contractor performance
Dry patches in material noted.1- Pour
in vetting-naterial.
(4)
Amended water
(cement i t i ous material)
0.5
(5)
No dusting noted, good penetration of water. Material falling
off in sheets and chunks intact.*-
2. Re
Mention
a.
Ceiling barrier, lath
(loose material). Dry
6.4
(9)
Contact and disturbance of material during installation by wood
strips with visible emissions
b.
Ce i1ing, hangers
(loose material). Dry
1.1
(12)
Penetration of ceiling
movenen t.^-
by hangers and subsequent disturbance by
c .
Sealant, encapsulation
(1oose mater ia 1).
o
o
(15)
Force of application varied during spraying adju^ frerts. One air
sample that produced a zero count by optica) nirroboc;;( had
7 * 10* ng/n- by TEM indicating significant snail particle re-
lease by spray contact disturbance .'-
^Detenr.ired by NIOSK Method, phase contrast microscopy.
b
Mean.
CNumber of observations.
-------
Asbestos removal provides a final solution by elimination of the
contaminant source. It requires, however, renovation involving friable
asbestos material, with significant problems of worker protection, pre-
vention of environmental contamination, and considerable interruption of
activities in the building.
Containment by sealing, encapsulation, or barrier systems usually re-
sults in much lower levels of asbestos contamination during alteration,
takes less time, and may be less expensive, especially if replacement is
avoided. The asbestos source remains, however, and damage, deterioration,
or failure of the protective system will result in recurrence of asbestos
contamination. Consequently, if asbestos containment is selected as the
long-term solution, then some form of continuous or semicontinuous ambient
monitoring program is necessary to assure that the protective system main-
tains its integrity over time. Maintaining low fiber levels may require
strictly controlled maintenance and custodial activities for the life of the
building. Also, the problem of asbestos exposure and environmental con-
tamination will present itself again at the time the building is demolished.
2.3 ASBESTOS EMISSION CONTROL AND PERSONNEL PROTECTION
The work associated with asbestos containment or removal involves
disturbance of the fiber matrix by contact, with dispersal of fibers into
the environment. The dispersal is massive in dry removal of loose friable
material; localized, but high, in installation of hangers or lath for a
barrier system and can be significant even in spraying a sealant onto a
friable asbestos surface. Whatever course of action is selected for as-
bestos containment or removal, asbestos contamination or emission control
and personnel protection are required by EPA and OSHA regulations to
II-2-4
-------
prevent exposure of workers, bystanders, building users, and the community.
Asbestos contamination control minimizes fiber dispersal in the removal
area, fiber emissions to the outside environment, and residual asbestos
contamination. The basic steps are:
1. Fiber containment: Barriers will prevent movement of fibers
to other building spaces and into the community. Barrier
systems should be used to enclose any work area and may be
used to isolate a room or an entire building. Ventilation
and heating systems must be shut down and all openings and
vents sealed, and any building equipment or furniture enclosed
in a protective cocoon. Any object, duct, window, or passage-
way that could be contaminated should be isolated Special
care should be taken to locate and seal all possible openings.
2. Fiber control: Wetting the asbestos-containing material will
reduce friability and change the aerodynamics of the released
fibers. The addition of a wetting agent will enhance penetra-
tion, reduce the amount of water needed, and generally increase
the control effectiveness.
Since fiber dispersal probability and concentrations are potentially
high, protection of working personnel is necessary and includes instruction,
respiratory protection supervision, and decontamination. The following
list is considered appropriate to both provide and document worker pro-
tection. This protection should also apply to any other person entering
a removal job site.
II-2-5
-------
1. Ins truct ion: OSHA regulations specify the use of certain
equipment, decontamination procedures, and work sequences.
Adequate instruction of the work force is absolutely
essential.
2. Respiratory protection: Each worker should be afforded
respiratory protection as appropriate to anticipated fiber
levels according to OSHA regulations 29 CFR 1910.1001.
3. Supervision: Adequate supervision is necessary to maintain
the performance required for safety. Adequate instruction
will help to a great extent, but continuously effective
respirator use and decontamination will depend upon con-
tinuous and effective supervision.
4. Personnel decontamination: Following each day's activities,
decontamination is necessary to prevent exposure of family
and personnel contacts. A decontamination facility should
be provided and include a changing room, shower room, and
equipment storage area. An outline of a decontamination
procedure is given in Appendix D.
II-2-6
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3. ASBESTOS CONTAINMENT
3.1 ENCLOSURE SYSTEMS
Enclosure of a sprayed asbestos surface places a barrier between the
asbestos-containing material and the area of activity. Either a suspended
barrier or an attached lath system is usually used. Depending upon the
integrity and type of barrier system, a dissemination of fibers by fallout
will take place behind the barrier only, and exposures below the barrier
will be greatly reduced. Contamination from contact will theoretically
be prevented by the barrier. A barrier system must not connect with an
air plenum system, and the enclosed space should not communicate in any
way with portions of the occupied building.
Installation of hangers or lath necessitates contact and penetration
and will result in asbestos fiber dissemination, frequently in excess of
existing OSHA regulations. Consequently, worker exposure protection in
accordance with OSHA should be required during this work. Furthermore,
fiber dissemination by fallout will continue with accumulation of fibers
behind the barrier system. Consequently, entry into these areas will re-
quire protection and fiber containment precautions.
The uncertainties in its long-term effectiveness, the need for con-
tinued air monitoring, and the remaining problem at the time of demolition
or renovation make this method unattractive.
II-3-1
-------
3.2 ENCAPSULATION WITH SEALANTS
Encapsulation with sealants may make replacement of sprayed asbestos
materials unnecessary. The use of a sealant means retention of the as-
bestos material and recurrence of the problem if the sealant is damaged
or penetrated. In addition, this postpones asbestos control to the time
of major renovation or building demolition. . The use of sealants 'may -be
restricted by characteristics of the sprayed asbestos surface i,tself. The
integrity of an encapsulated surface depends upon bonding between the
sprayed asbestos material and supporting structural members. A sprayed
asbestos ceiling for example, with initially poor adhesion to a smooth
hard structural ceiling surface will result in shearing and failure of the
full thickness of sprayed material and the applied sealant. Accessibility
and user behavior should also be carefully considered. Sealant used on
asbestos surfaces within reach of children in a school will probably .be
damaged eventually leading to continued asbestos exposure.
The sealing of sprayed asbestos surfaces involves applying material
that will envelop or coat the fiber matrix and eliminate fallout and pro-
tect against contact damage. Sealants are usually applied to asbestos
surfaces by spraying and consist of polymers with an agent added to en-
hance penetration into the fiber matrix. Sealants which are currently
available .include water-based latex polymers, water soluble epoxy resins
and organic solvent-based polymers of various types.
Nearly any sealant or encapsulation method will reduce fallout con-
tamination. The more effective sealants, however, will have resistance
to impact and will reduce asbestos release due to contact. In one study,
latex paint sprayed over a friable asbestos surface was effective in
11—3 — 2
-------
reducing background fiber levels in the building from fallout. This coat-
ing failed, however, to significantly reduce building asbestos exposure
levels during routine activity due to contact or reentrainment.20 Even
in the case of a fairly resistant sealant, suitable protection should be
used against heavy physical damage. A system of routine inspection and
repair should insure the integrity of a sealant system.
Application of a sealant by spraying will cause dissemination of small
fibers by contact. A sealant should be applied with as much caution and
at as low a nozzle pressure as possible to reduce contact disturbance.
The potentially high concentration of small asbestos fibers could cause
significant worker exposure and thus, workers require protection with
respiratory devices and decontamination. Such asbestos fiber contamination
from application of sealants is usually not detectable by the NIOSH method
of optical microscopy, and may require electron microscopic examination
for definition.12»52
An effective sealant should possess the following characteristics:
1. The sealant should eliminate fiber dispersal by adhering
to the fibrous substrate with sufficient penetration to
prevent separation of the sealant from the sprayed asbestos
material.
2. It should withstand most impact and penetration and still
protect the enclosed sprayed asbestos material.
3. It should possess enough flexibility to accommodate atmo-
spheric changes and settling of the structure over time.
4. It should have high flame retardant characteristics and a low
toxic fume and smoke emission rating. This is, of course,
II-3-3
-------
essential if the enclosed sprayed asbestos material was used
initially for fire retardation and protection of structural
members.
5. It must be easily applied by nonspecialized personnel, with
relative insensitivity to errors in preparation or application.
Ease of repair by routine maintenance personnel is desirable.
6. The sealant must be neither noxious nor toxic to application
workers and structure users thereafter. Since spraying
creates fiber dissemination and exposure, fiber containment
by barriers is desirable during application even though this
may be incompatible with ventilation necessary for toxic vapor
removal.
7. It should have some permeability to water vapor to prevent
condensation accumulation, and resistance to solution by common
cleaning agents.
8. It should have suitable stability to weathering and aging.
9. It should be acceptable by architectural and esthetic standards.
Sealant selection and application should be made with consideration
given to the configuration, dimensions, use and characteristics of the
structure involved. The listed characteristics above may assume differing
\
levels of importance in consideration of the specific application.
Additional considerations in selecting a sealant are:
1. The coated structural member should be inspected. Bonding
between the sprayed asbestos material and structural member must
be adequate to accommodate the added weight and cohesive mass
of the encapsulated asbestos material.
II-3-4
-------
2. Sealants are not generally recommended when surfaces are
accessible to physical damage, such as low ceilings in school
corridors or stairwells.
3. The cost of asbestos stripping versus encapsulation should
be estimated. A complex or relatively inaccessible surface
may defy economical asbestos removal, and present an ideal
situation for encapsulation.
4. Replacement material needs for fireproofing and thermal or
acoustical insulation must be met after removal. Such replace-
ment may be avoided by encapsulation.
5. The moving of furniture, equipment, or partitions necessary
in asbestos removal may be significantly reduced if encapsu-
lation is used.
Sealants for asbestos material are presently being evaluated by the
Environmental Protection Agency, Power Technology and Conservation Branch,
Industrial Environmental Research Laboratory, Cincinnati, Ohio 45268.
II-3-5
-------
4. ASBESTOS REMOVAL
Building characteristics, the inability to eliminate exposure, and
the uncertainties of asbestos disease epidemiology may be the crucial
factors in the decision to remove the sprayed friable asbestos materials.
Both EPA and OSHA regulations influence the manner in which asbestos
stripping or removal is accomplished. Work practices during asbestos
stripping and disposal operations are covered by EPA regulation 40 CFR 61,
subpart B: National Emission Standard for Asbestos.^ Landfill disposal
and site requirements are covered by 40 CFR 61.25, waste disposal sites.
Worker protection during removal or stripping operations is covered by
OSHA regulations 29 CFR 1910.1001, occupational exposure to asbestos.
These regulations are discussed in detail in Appendices G and H.
4.1 DRY REMOVAL
Dry removal of untreated friable asbestos material is definitely not
recommended, but may be necessary in instances of unavoidable damage
through the use of wet removal techniques. Dry removal requires specific
EPA approval. As shown in Table II-2-2, dry removal results in heavy
airborne asbestos contamination with fiber counts that can exceed
100 f/cm3. The potential for worker, structure, and community contamina-
tion is high, and complete fiber containment by a series of barriers is
necessary, along with an elaborate system for debris removal and worker
II-4-1
-------
decontamination. Studies have shown that significant contamination can
occur across a double barrier entrance under working conditions during
dry removal. Considering existing data on dry removal and fiber behavior
in settling and movement, contamination spread and heavy exposure appear
unavoidable.
Dry vacuum methods for rapid removal of debris from demolition areas
rely upon evacuation of all fallen visible asbestos material through
vacuum lines that penetrate the barrier system. The material is drawn
through the lines to a point usually outside the structure, deposited in
sealed containers, and the accumulated material removed to a disposal site.
The vacuum system exhaust is filtered to prevent contamination of the
external environment. A vacuum system using an extraction air velocity
1 meter/second (200 ft/min) and an HEPA (high efficiency particulate)
filtered exhaust is in use in Great Britain.91 Evaluation of both in-
ternal containment and external exhaust cannot be considered complete
because of a lack of appropriate air sampling data.
4.2 WET REMOVAL
Wet removal is based upon the ability of water to lower both the
friability of the sprayed material and the aerodynamic capabilities of the
released fibers. Water will render the material less friable and more
cohesive, and greatly reduce the release of fibers, thus reducing airborne
asbestos levels. Fibers that are released will fall rapidly if wet. A
suggested work sequence for wet removal is listed in Appendix E.
Table II-2-2 lists anticipated fiber contamination levels using
water. As shown, asbestos exposure levels may be reduced by as much as
75 percent using wet removal rather than dry removal. The use of plain
II-4-2
-------
water, however, is not entirely satisfactory because of slow penetration,
incomplete wetting, and bothersome runoff. Even with extensive soaking,
areas of dry material will remain. The runoff not only is a safety and
cleanup problem, but the resulting slurry will carry fibers to other areas
where they will reentrain following evaporation.
Water penetration into a hydrophobic fiber matrix is significantly
increased with a wetting agent or surfactant. "Wet" water is a common
item in use by fire departments, industry, and agricultureThis tech-
nique greatly reduces the amount of water needed for saturation, increases
the cohesiveness of the fiber matrix, and increases the probability of
individual fiber wetting. This effect, as shown in Table II-2-2, results
in a significant improvement in working conditions and significantly re-
duced environmental contamination. Use of amended water can reduce fiber
counts by more than 90 percent as compared to dry removal. This reduction
of fiber contamination within the work area not only reduces potential
worker exposure but relieves much of the dependence upon containment barrier
systems for isolation of fibers within removal areas. Table II-4-1 lists
some wetting agents available commercially.
II-4-3
-------
Table II-4-1. COMMERCIALLY AVAILABLE WETTING AGENTS FOR WET REMOVAL OF
ASBESTOS IN BUILDINGS3
Aquatrols Corp. of America
Leffingwell Chemical Co.
1400 Suckle Highway
Box 188
Pennsauken, NJ 08110
Brea, Calif. 92921
Occidental Chemical Co.
Rohm and Haas Co.
Institutional Division
Ag. Chemical Dept.
Box 198
Independence Mall
Lathrop, Calif. 95330
W. Philadelphia, Pa. 19105
Target Chemical Co.
Thompson-Hayward Chemical'Co.
1280 N. 10th St.
Box 2383
San Jose, Calif. 95112
Kansas City, Kans. 66110
Vineland Chemical Co.
Box 745
Vineland, NJ 08360
The inclusion of this information should not be construed
as a product endorsement by the EPA or the authors.
II-4-4
-------
5. REGULATIONS AND COMPLIANCE BY CONTRACTORS
Fiber control, containment and worker protection are necessary in
asbestos abatement work since there will be environmental contamination
regardless of the work method used. A considerable potential will exist
not only for worker exposure, but also contamination of the structure,
the community, and worker homes.
In most operations there has been an effort by the contractor to
minimize asbestos contamination by compliance with OSHA and EPA regula-
tions and by additional control procedures as appropriate.16'20 However,
in some operations violations of both regulations and common sense have
occurred. Some contractors have removed asbestos absolutely dry instead
of wet as agreed, removed asbestos without respirators, dropped asbestos-
loaded bags down laundry chutes where they have ruptured, served coffee in
removal areas, and allowed heavily contaminated workers to leave the job
site.16,21
A number of factors will influence contractor work practices:
1. Attitude of purchaser of services: The purchaser of service
will be motivated to control asbestos exposure for various
reasons. These may include concern for well-being of build-
ing users, fear of future legal involvement and claims by
users or their survivors, or fear of employee or union
II-5-1
-------
action. Asbestos exposure situations have, on occasion,
become political issues, a cause of panic and overraction,
and a sensationalistic subject for the press. The climate
created by these pressures has caused careless and mis-
informed actions that can lead to increased exposures
rather than decreased exposures. The harassed school
principal, apartment building owner, or corporation
executive often seeking the quickest and cheapest con-
tractor services may create a potential for significant
exposures and contamination.
Once a contractor leaves the job site, there are currently
no regulations protecting building users. Poor clean-up
of the removal area can lead to continual reentrainment
and resuspension. To ensure proper clean-up by the con-
tractor, the purchaser of contract services should provide
the contractor with definitive job specifications for as-
bestos removal. An example is included in Appendix F.
2. OSHA regulations: In general, the OSHA regulations are
effective in routine occupational asbestos exposure situa-
tions at a fixed location. However, application to tran-
sient demolition workers who have no fixed place of em-
ployment is difficult. Demolition and removal operations
are mobile, often brief, quite variable in conditions.
Exposures, however, may be extremely high. Present regula-
tions do not require worker instruction regarding the
hazards of asbestos exposure and the use of respirators.
II-5-2
-------
Also, there are ambiguous requirements for decontamination
since the place of employment is not fixed. Showering is
not presently required. (Proposed OSHA regulations address
these points with specific regulations requiring instruction,
respiratory protection, reporting, and decontamination by
showering for any regulated area where exposure occurs.)
3. EPA regulations: The EPA regulations cover emissions into
the outside environment, and disposal of material from job
sites. Regulatory coverage does not apply to the building
environment apart from the prohibition of many initial uses
of asbestos materials.
4. Contractor economics: Protection of workers, building users,
and the general community, means time, effort, and cost to
a contractor. The contractor who is both aware and concerned
about these problems faces economic pressure from those who
are not. This is not only discouraging, but in a low bid
competition may mean the difference in the awarding of the
contract. Consequently, safety precautions may be compromised.
As yet, there is no generally applicable equalizing force
such as enforced regulations or licensing of qualified con-
tractors. Consequently, as recommended above, the purchaser
must write definitive job specifications to ensure the use
of adequate safety measures by contractors.
5. Contractor and worker attitudes: Asbestos is a material
that has been used in construction for some time, and its
carcinogenic potential has only recently gained recognition.
II-5-3
-------
Many workers have become accustomed to handling asbestos
without precaution, and retraining is difficult. Compound-
ing this is the fact that the latency period of asbestos-
related disease is frequently quite long. This has not
only blurred the vision of professional observers, but has
blinded that of many workers and contractors to the conse-
quences of asbestos exposure. Unconcerned or uninformed
removal workers incur exposures for themselves, fellow
workers, and their families.
Contract specifications written for asbestos work should effectively
complement OSHA, EPA, and local regulations and may include specific
requirements for exposure and contamination prevention. The informed
purchaser, or one who must satisfy an informed building user and community,
will be motivated to define contractor performance in asbestos work. Such
specifications may include requirements for contractor competence in as-
bestos removal, OSHA and EPA compliance, special contamination control,
and air sampling. Such specifications essentially restrict bidding con-
tractors to those who know the work and regulations. This will encourage
and protect the competent contractor's investment in equipment and train-
ing. Definitive job specifications for asbestos removal similar to those
presented in Appendix F, therefore, are recommended.
II-5-4
-------
APPENDICES
-------
APPENDIX A
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A-l
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8. Levine, H. L. Sprayed Mineral Fiber Association. Personal Communi-
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-------
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A-3
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A-4
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A-5
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50. Jacob, G. and H. Bohlig. Roentgenological Complications in Pulmonary
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51. Kiviluoto, R. Pleural Calcification as a Roentgenologic Sign of Non-
Occupational Endemic Anthophyllite-Asbestosis. Acta. Radiol. Suppl.
194, 1-77. 1960.
52. Wagner, J. C., C. A. Sleggs and P. Marchand. Diffuse Pleural Meso-
theliona and Asbestos Exposure in North Western Cape Province.
Brit. J. Ind. Med. 17, 250-271. 1960.
53. Selikoff, I. J., J. Churg and E. C. Hammond. Relation Between Exposure
to Asbestos and Mesothelioma. NEJM 272, 560-565. 1965.
54. Newhouse, M. L. and H. Thompson. Mesothelioma of Pleura and Peritoenum
Following Exposure to Asbestos in the London Area. Brit. J. Industr.
Med. 22, 261-269. 1965.
55. Lieben, J. and H. Pistawka. Mesothelioma and Asbestos Exposures.
Arch. Environ. Health. 14, 599. 1967.
56. Harries, H. M. Asbestos Hazards in Naval Dockyards. Ann. Occup. Hyg.
11, 135-145. 1968.
57. Dalquen, P., et al. Epidemiologie der Pleuramesothelioma Vorlaufiger
Bericht uber 119 Paell aus dem Hamburger Raum, Prax. Preumol.
23:547, 1969.
A-7
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58. South African Medical Research Council. 1971 Annual Report of the
National Institute for Occupational Diseases. Johannesburg, S.A.
1972.
59. Anderson, H., R. Lillis, S. Daum, A. Fischbein and I. J. Selikoff.
Household Contact Asbestos Neoplastic Risk. Annals N.Y. Acad. Sci.
271, 311-323. 1976.
60. Selikoff, I. J., E. C. Hammond and J. Churg. Carcinogenicity of
Amosite Asbestos. Arch. Environ. Health. 25, 183. 1972.
61. Wagner, J. C., G. Berry and V. Timbrell. The Effects of the Inhalation
in Rats. Brit. J. Cancer. 29, 252-269. 1974.
62. Rohl, A. N., A. M. Langer, I. J. Selikoff and W. J. Nicholson.
Exposure to Asbestos in the Use of Consumer Spackling, patching,
and taping compounds. Science, 189, 551-553. 1975.
63. Rohl, A. N., A. M. Langer and 1. J. Selikoff. Environmental Asbestos
Pollution Related to Use of Quarried Serpentine Rock. Science. Vol.
196:1319-1322. 1977.
64. Thompson, J. G., R. 0. C. Kaschula and R. R. MacDonald. Asbestos as
a Modern Urban Hazard. South African Med. J. 27, 77. 1963.
65. Wagler, F., H. Muller and M. Anspach. Gibt es Eine Endemische
Asbestos. Z. Ges. Hyg. 8, 246. 1962.
66. Selikoff, I. J. Widening Perspectives of Occupational Lung Disease.
Prev. Med. 2, 412-437. 1973
A-8
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67. U.S. Department of Labor. Occupational Safety and Health Administra-
tion. 29 CFR 1910.93a. Fed. Reg. 37(110). June 7, 1972.
68. U.S. Department of Labor. Occupational Safety and Health Administra-
tion. 29 CFR 1910.1001 Standard for Exposure to Asbestos Dust.
Fed. Reg., 40(103). May 28, 1975.
69. U.S. Department of Labor. Occupational Safety and Health Administra-
tion. 29 CFR 1910 Occupational Exposure to Asbestos. Fed. Reg.,
40(197). October 9, 1975.
70. National Institute for Occupational Safety and Health. (1977). Revised
recommended asbestos standard. Department H.E.W., (NIOSH) 77-169.
71. Timbrell, V. Criteria for Environmental Data and Bases of Threshold
Limit Values. In: Biological Effects of Asbestos: (Bogovski, P.,
J. C. Gilson, V. Timbrell and J. C. Wagner (eds.)). IARC Scientific
Publication No. 8. International Agency for Research on Cancer.
Lyon, France.
72. Gillam, J. D., J. M. Dement, R. A. Lemen, J. K. Wagoner, V. E. Archer
and H. P. Beliger. Mortality Patterns Among Hard Rock Gold Miners
Exposed to an Asbestiform Mineral. Ann. N.Y. Acad. Sci., 271:336-44.
1976.
73. U.S. Environmental Protection Agency, National Emission Standards for
Hazardous Air Pollutants. Fed. Reg., 38(8820). April 6, 1973.
74. U.S. Environmental Protection Agency, National Emission Standards
for Hazardous Air Pollutants. Fed. Reg. 42(41). March 2, 1977.
A-9
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75. New Mexico, State of. Sect. 201 Ambient Air Quality Standards, Air
Quality Control Regulations. Adopted by the New Mexico Health and
Social Services Board on January 23, 1970. Amended on June 26, 1971
and June 16, 1973.
76. Bruckman, L. and R, A. Rubino. Rational Behind a Proposed Asbestos
Air Quality Standard. J. Air Poll. Control Assoc. 25:1207-1212.
1975.
77. New Haven. An Ordinance prohibiting the use of sprayed-on asbestos
on exposed surfaces in residences and the requiring of its removal.
City of New Haven, Conn. Ordinance Section 16:60 - 16:68. 1977.
78. Julian, Y. and W. C. McCrone. Identification of Asbestos Fibers by
Microscopal Dispersion Staining. Microscope 18:1-10. 1970.
79. McCrone, W. C. Detection and Identification of Asbestos Fibers.
Environ. Health Pers. 9:57. 1974.
80. McCrone, W. C. and I. M. Stewart. Asbestos. American Laboratory.
April 1974.
81. Bayer, S. G., R. D. Zumwalde and T. A. Brown. Equipment and Procedures
for Mounting Millipore Filters and Counting Asbestos Fibers by Phase
Contrast Microscopy. Available From U.S. Department of Health,
Education and Welfare, National Institute for Occupational Safety and
Health, 1014 Broadway, Cincinnati, Ohio 45202. 1969.
A-10
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82. U.S. National Institute for Occupational Safety and Health. Criteria
for a Recommended Standard Occupational Exposure to Asbestos.
Department H.E.W., Washington, D.C. 1972.
83. Millipore Corp. Monitoring Airborne Asbestos With the Millipore
Membrane Filter. Application Procedure 501. Bedford, Massachusetts.
1972.
84. Dement, J. M., R. D. Zumwalde and K. M. Wallingford. Discussion
Paper: Asbestos Fiber Exposures in a Hard Rock Gold Mine. Ann. N.Y.
Acad. Sci. 271:345-352. 1976.
85. Natush, D. F. S. and J. R. Wallace. Urban Aerosol Toxicity: The
Influence of Particle Size. Science 186:4165. 695-699. 1974.
86. Stanton, M. F., R. Blackwell and E. Miller. Experimental Pulmonary
Carcinogenesis With Asbestos. Am. Ind. Hyg. Assoc. J. 30:236-244. 1969.
87. Pott, F., F. Huth and K. H. Friedrichs. Tumorigenic Effect of Fibrous
Dusts in Experimental Animals. Environ. Health Perspect. 9, 313-315.
1974.
88. U.S. Environmental Protection Agency. Electron Microscopy Measurement
of Airborne Asbestos Concentrations. EPA-600/2-77-178. 1977.
89. Stewart, I. W. C. McCrone Assoc. Inc., Chicago, 111. Personal
Communication. 1977.
90. U.S. Environmental Protection Agency. Amendment to 40 CFR Part 61,
Chapter 1. 1975.
A-ll
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91. Envirocor Ltd. "Code of Practice for the Safe Handling and Disposal
of Asbestos." Litchfield, Staffordshire, U.K. 1976.
92. Valoras, N. , J. Letey and J. F. Osborn. Absorption of Non-Ionic
Surfactants by Soil Materials. Soil Sci. Soc. Amer. Proc. 33,
345-348. 1969.
93. Dahneke, B. E. Slip Correction Factors for Nonspherical Bodies.
J. Aerosol Sci. 4:139, 147, 163, 1973.
94. Bragg, G. M., L. Van Zuiden and C. E. Hermance. The Free Fall of
Cylinders at Intermediate Reynold's Numbers. Atmos. Environ.
8:755. 1974.
95. Fuchs, N. A. Mechanics of Aerosols. Pergamon Press, New York. 1964.
96. Harris, R. K., Jr. and D. A. Fraser. A Model for Deposition of
Fibers in the Human Respiratory System. Am. Ind. Hyg. J.
37:73. 1976.
97. Davies, C. M. The Sedimentation of Small Suspended Particles.
Symposium on Particle Size Analysis. P. 25, London. 1947.
98. Happel, J. and H. Brenner. The Motion of a Rigid Particle of
Arbitrary Shape in an Unbounded Fluid. Low Reynolds Number Hydro-
dynamics. p. 222, Prentice-Hall, Englewood Cliffs, N.J. 1965.
A-12
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APPENDIX B
AERODYNAMIC BEHAVIOR OF AIRBORNE FIBERS
The aerodynamic behavior of fibrous-shaped aerosol particles is go-
verned by the interaction of opposing forces: a driving force such as
is caused by gravitational acceleration, and the viscous resistance of
the gaseous medium within which the particles move. In this context, a
useful characterizing parameter is the aerodynamic equivalent diameter,
defined as that diameter of a sphere of unit density whose settling velo-
city equals that of the particle under consideration. Although this
equivalence applies to particles of any size, this approach is usually
limited to motion in the Stokes regime; i.e., where viscous drag predo-
minates. The theoretical modeling of fiber aerodynamics becomes rather
• Q O
complex when slip corrections are required; 0 i.e. , when the aerodynamic
dimensions of the particle approach the molecular mean free path of the
gas matrix. At the other extreme, when the fiber Reynolds number (referred
to its diameter) exceeds the range from about 0.1 to 1, drag coefficient
corrections become significant.94
In practice, most particles of biological interest, including those
of fibrous shape, fall well within the range covered by the Stokes model.
The generally accepted theoretical model for the calculation of the equiv-
alent aerodynamic diameter of the fibers is based on the assumption that
B-l
-------
the fibers can be approximated by ellipsoids of revolution. This concept
has also been used to predict the deposition of fibers in the human
Two extreme cases can be recognized: (1) motion of the ellipsoid
(or fiber) along its axis of revolution, and (2) motion perpendicular to
the axis of revolution. It should be considered that the gravitational
settling motion of any particle with three mutually perpendicular planes
of symmetry (such as an ellipsoid of revolution) will be invariant during
its descent, maintaining its initial orientation through its fall tra-
jectory. In practice, however, asbestos fibers, for example, may not
always be perfectly straight and the above-mentioned rule may not hold.
As noted above, acicular particles can be approximated by ellipsoids
of revolution falling under the action of gravity in either of two atti-
tudes described under (1) and (2), or any intermediate angle with respect
to the direction of motion. In general, an acicular particle falling with
its axis vertical will have a higher terminal velocity than the case when
its axis is normal to the direction of motion. Intermediate angles will
exhibit intermediate velocities.
Two equations represent the two extreme axis-to-motion angles defined
qr q c
respiratory system.vJ
above^
For case (1): D
4/3 d
(1)
2g2-l
g
arc cosh (6)
(g2_i)3/2
e2-i
and for case (2): D
8/3 L
(2)
B-2
-------
where D is the diameter of the sphere having the same settling velocity.
L is the ellipsoid major axis length (or fiber length)
d is the ellipsoid minor axis length (or fiber diameter)
g is the length-to-diamter ratio, L/d or aspect ratio.
Equations (1) and (2) have also been expressed as:98
-23 2B2-
and
°2 = 3 d
-1 (6 2—1)
232-3
*7 (3)
3^2 \b - hr-i"
£n(B + /b2-1)
!-l (g2-l)3/2
which for the case 8 > > 1 can be approximated by:
2 d B
-1
(4)
D1 = 3Un(2g) - h) (5)
and
= 4 d e ,
D2 3(£n(2g) + H) W
respectively
Once the value of D has been determined for a given particle, and
provided that the particles fall vertically (no lateral glide) and do not
change their orientation during their vertical motion, D can be replaced
in the classical Stokes equation for a spherical particle, in order to
calculate its settling velocity:
(M - M )g
V = —2 £— (7)
s 3ir nD y '
where V is the settling velocity
s
M and M are the masses of the particle and the displaced gas,
^ ® respectively
(Mg is usually negligible)
B-3
-------
g is the acceleration of gravity
n is the coefficient of gas viscosity.
The rigorous equations presented above were solved for the typical
density of asbestos fibers of 2.6 g/cm3 and for air at standard condi-
tions. The results are shown in Figure B-l, which is a plot of fiber
settling velocity as a function of fiber length and diameter for the two
axis-to-motion orientations mentioned above. These curves show that the
settling velocity of fibers is only weakly dependent on fiber length but
strongly dependent on fiber diameter, and that in the limit (0 -* 00) the
settling velocity for a vertical fiber is twice that of a horizontally
falling fiber.
In practice, for straight fibers the settling velocity will probably
fall between the two extreme orientation values, because the fiber axis
will be changed randomly as a result of Brownian molecular bombardment
and in the case of nonstagnant air conditions, by large-scale turbulence.
It is of interest to note that for fibers whose diameter is of the order
of 0.1 pm, gravitational sedimentation occurs at the rate of only a few
centimeters per hour, even though their length may be as much as 100 ym.
B-4
-------
-------
APPENDIX C
ASBESTOS SAMPLE COLLECTION
C.l BULK ASBESTOS SAMPLE COLLECTION
A bulk sample is collected to determine whether the
ceiling or other construction material contains any
asbestos mineral. Use a small sealable glass or plastic-
capped container. Holding the container as far as
possible from the face, obtain a full thickness core
sample of the sprayed material by penetrating the sur-
face with the container using a twisting motion. Any
surface coating such as paint on a cement material must
be penetrated. The container is then capped, wiped,
and sealed with tape. Labeling should include building
identification, address, building type, sample source
location, and date. Disturbance of the material other
than at the sampling point should be kept to a minimum.
A respirator approved for asbestos dust will insure pro-
tection while performing this work.
Repeat the procedure at several adjacent sites.
C-l
-------
Approximate sample analysis costs for bulk material sample:
Method Approximate cost
Petrographic microscopy $25.00 - $100.00a
with dispersion staining
X-ray diffraction $75.00 - $150.00
Cost per sample generally varies with total number of
samples submitted.
C.2 AIR SAMPLING FOR ASBESTOS FIBER
This procedure is followed to estimate concentration
levels of airborne fiber before, during and after a removal
or encapsulation operation. The source method also serves
long-term ambient-air monitoring requirements following a
sealing operation or installation of a barrier system.
The general procedure calls for drawing a known volume of
air through a membrane filter using a calibrated sampling
pump. Procedural details suggesting sampling times and
other parameters, and sources of equipment are available
in the literature.82>8^>88>8^
Analysis of the membrane filters can be carried out by
either phase contrast Optical Microscopy or by Scanning
or Transmission Electron Microscopy. While the former
technique is less costly, the latter gives a more complete
estimate of number and size of fibers present. The latter
technique (EM) is especially valuable in distinguishing
mineral fiber from cellulose, glass fiber or other fibers
which may be present in the material being removed.
C-2
-------
Price range for asbestos fiber analysis in air samples.
Method Approximate cost
Phase contrast optical $35.00 - $50.00
microscopy (NIOSH Method)
Electron Microscopy $300.00 - $500.00
(SEM, TEM)
A list of laboratories accredited for phase contrast microscopy as-
bestos counting (NIOSH) may be obtained from the American Industrial
Hygiene Association, 66 South Miller Road, Akron, Ohio 44313.
C-3
-------
APPENDIX D
RECOMMENDED DECONTAMINATION PROCEDURE
An adequate decontamination area consists of a serial arrangement of
connected rooms or spaces. All persons without exception should pass
through this decontamination area for entry into and exit from the work
area for any purpose. Parallel routes for entry or exit are not recom-
mended; if such routes exist they will eventually be used.
D.l DECONTAMINATION AREAS
1. Outside room (clean area): In this room the worker leaves
all street clothes and dresses in clean working clothes
(usually disposable coveralls). Respiratory protection
equipment is also picked up in this area. No asbestos con-
taminated items should enter this room. Workers enter this
room either from outside the structure dressed in street
clothes, or naked from the showers.
2. Shower room: This is a separate room used for transit by
cleanly dressed workers entering the job from the outside
room, or by workers headed for the showers after undressing
in the equipment room.
D-l
-------
3. Equipment room (contaminated area): Work equipment, foot-
wear, additional contaminated work clothing are left here.
This is a change and transit area for workers.
4. Work area: The work area should be separated by polyethylene
barriers from the equipment room. If the airborne asbestos
level in the work area is expected to be high , as in dry re-
moval, an additional intermediate cleaning space may be added
between the equipment room and the work area.
D.2 DECONTAMINATION SEQUENCE
1. Worker enters outside room and removes clothing, puts on
clean coveralls and respirator, and passes through into
the equipment room.
2. Any additional clothing and equipment left in dirty room
required by the worker is put on. (When the work area is
too cold for coveralls only, the worker will usually provide
himself with additional warm garments. These must be treated
as contaminated clothing and left in the decontamination
unit.)
3. Worker proceeds to work area.
4. Before leaving the work area, the worker should remove all
gross contamination and debris from the overalls. In prac-
tice this is usually carried out by one worker assisting
another.
D-2
-------
The worker proceeds to equipment room and removes all
clothing except respiratory protection equipment. Extra
work clothing may be stored in contaminated end of the unit.
Disposable coveralls are placed in a bag for disposal with
other material. The worker then proceeds rapidly into the
shower room. Respiratory protection equipment should be
removed last to prevent inhalation of fibers during removal
of contaminated clothing.
After showering, the worker moves to the clean room and
dresses in either new coveralls for another entry or street
clothes if leaving.
Respirators are picked up, cleaned and wrapped by protected
workers in a separate area by washing. The respirators are
then brought to the clean room by an outside worker. The
cleaners then exit through the shower units as usual.
D-3
-------
APPENDIX E
STRIPPING SEQUENCE FOR WET AND AMENDED WATER METHODS
PREPARATION
1. Isolation of the work area heating and ventilation system is
carried out first to prevent contamination and fiber dispersal
to other areas of the structure during stripping.
2. The work area is prepared by removing as much furniture,
equipment, and miscellaneous items as possible. Anything re-
maining should be sealed with polyethylene sheeting. It
should be noted that in situations of deteriorating asbestos
surfaces such activity may result in contact and reentrainment
contamination to significant levels, and personnel protection
should be used.
3. The removal area is isolated, restricting access according to
OSHA regulations. This is done by sealing corridors and
entry ways with polyethylene barriers. The decontamination
area should be set up at this time.
4. Removal of ceiling mounted objects such as lights, partitions,
and other fixtures should precede the actual asbestos removal
'operation. This will usually result in contact with the
ceiling with potential significant exposure. Localized water
spraying during fixture removal will reduce fiber dispersal.
E-l
-------
5. Asbestos removal: Water spraying with respraying as required
if dust occurs during removal of the material by dislodgement
and scraping. (See Figure E-l).
6. Removal of debris: Collection of the material and labelling
according to OSHA regulations using six mil or heavier plastic
bags. The use of 55-gallon drums is strongly recommended as
a secondary containment system for the bags. (See Figure E-2).
7. Gross clean up: All debris must be placed in bags and drummed
for disposal. Spraying of fallen material may be required since
higher counts are possible during this operation. Continued
spraying of the fallen material is recommended. It should be
noted that water-soaked fall material left overnight can lose
mucb of its water content due to evaporation.
8. Repeated cycles of cleaning at intervals is suggested to collect
settled fibers. A minimum of two such cycles is recommended
with 24 hours intervals between.
9. Disposal: Disposal should be in accordance with EPA guidelines.
Special high cost hazardous waste material disposal services
are usually not necessary if the sanitary landfill disposal
area and procedures are performed within the EPA regulations.
10. Stringent visual inspection of the removal site should be per-
formed to insure adequacy and completeness of the removal
procedure.
11. Air sampling: Airborne asbestos sampling should be performed
both during and following asbestos stripping operations.
During stripping sampling in the removal work area, outside
E-2
-------
Figure E-l. Removal of asbestos-containing ceiling material. Note use
of headgear, coveralls and respiratory protection.
-------
Figure E-2. Drum with 6-mil plastic liner to contain removed debris
E-4
-------
containment barriers and within the decontamination area
should adequately determine the adequacy of contamination
control. Air sampling will supplement post-removal visual
inspections and establish the completeness of the removal
process. Post-removal sampling during custodial activity
is most likely to reveal residual contamination from
settled fibers.
E-5
-------
APPENDIX F
SUGGESTED SPECIFICATIONS FOR ASBESTOS REMOVAL
The following are suggested specifications which should be presented
to a prospective contractor to determine whether a renovation or asbestos
removal job can be accomplished in a safe and satisfactory manner.
1. Documentation of Performance in Asbestos Removal
a. The contractor shall furnish documentation of successful
performance in asbestos removal. This will include name
and address of purchaser of service, location of work
performed, and a record or air monitoring for asbestos as
required by OSHA 1910.1001.
b. The contractor will have at all times in his possession
at his office (one copy) and in view at the job site
(one copy), OSHA regulation 1910.1001, Asbestos, and
Environmental Protection Agency AO CFR Part 61, subpart B:
National Emission standard for asbestos, asbestos stripping
work practices, and disposal of asbestos waste.
2 . Scope of Work
a. The contractor shall furnish all labor, materials, services,
insurance and equipment necessary for the complete removal
of all asbestos located at the site in accordance with the
F-l
-------
guidelines or regulations of the responsible state
agency, EPA and OSHA.
b. The contractor shall furnish proof that employees
have had instruction on the dangers of asbestos ex-
posure, on respirator use, decontamination, and OSHA
regulations.
Worker's Dress and Equipment for Asbestos Removal
a. Work clothes will consist of full body coveralls,
disposable head covers, boots, or sneakers, and respi-
ratory protective equipment as required by OSHA regu-
lations. Eye protection and hard hats should be avail-
able as appropriate.
b. Coveralls should be of a paper disposable type.
c. Respiratory protection for workers shall be provided
by the contractor as required by current OSHA regulation.
Decontamination
All workers, without exception:
a. Will change work clothes at designated areas prior to
start of day's work. Lockers or acceptable substitutes
will be provided by the contractor for street and work
clothes.
b. All work clothes will be removed in the work area
prior to departure from this area. Workers would then
proceed to showers. Workers will shower before lunch
and at the end of each day's work. Hot water, towers,
soap, and hygienic conditions are the responsibility of
the contractor.
-------
3. No smoking, eating or drinking is to take place once beyond
the clean room at the job site. Prior to smoking, eating or
drinking, workers will fully decontaminate by showering.
Each worker will then dress into a new clean disposable
coverall to east, smoke or drink. This new coverall can then
be used to reenter the work area.
4. Work footwear will remain inside work area until completion
of the job.
5. Pre-Asbestos Removal Preparation
a. The contractor will thoroughly seal all openings and
fixtures including, but not limited to, heating and ven-
tilating ducts, sky lights, doors, windows, and lighting
with polyethylene taped securely in place.
b. Polyethylene sheets (6 mil minimum) will be used to
cover the entire floor and wall surfaces.
c. The contractor will set up a decontamination facility in
a predesignated area which will house the changing room,
shower area, and equipment area.
d. Adequate toilet facilities should exist in the work area to
avoid decontamination for this purpose. Where such faci-
lities do not exist, the contractor will provide portable
service.
e. Procedures will be written for evacuation of injured
workers. Aid for a seriously injured worker will not
be delayed for reasons of decontamination.
F-3
-------
6. Methods of Asbestos Removal
a. The asbestos material will be sprayed with water
containing an additive to enhance penetration. The
additive, or wetting agent, will be 50 percent poly-
ethylene ester and 50 percent polyoxyethylene ether
at a concentration of 1 ounce per 5 gallons of water.
A fine spray of this solution must be applied to pre-
vent fiber disturbance preceding the removal of the
asbestos material. The asbestos will be sufficiently
saturated to prevent emission of airborne fibers in
excess of the exposure limits prescribed in the OSHA
standards referenced in these specifications.
b. Removal of the asbestos material will be done in small
sections with two-person teams, on staging platforms,
if needed. The material will be packed into labeled
6-mil plastic bags held within 55-gal drums prior to
starting the next section to prevent the material from
drying.
c. Packed and sealed drums, with the required labeling,
will be delivered to a predesignated disposal site for
burial. Labels and all necessary signs shall be in
accordance with EPA and OSHA standards.
d. Following removal, the entire area will be wet cleaned.
After a 24-hour period to allow for dust settling, the
entire area will be wet cleaned again. During this
settling period, no entry, activity, or ventilation will
F-4
-------
be allowed. Twenty-four hours after the second cleaning
all surfaces in the entire work area will be thoroughly
vacuumed and wet mopped.
e. All polyethylene material, tape, cleaning material, and
clothing will be placed in plastic-lined drums, sealed and
labeled as described above for the asbestos waste material.
f. All equipment will be cleaned of asbestos material prior
to leaving the work area.
7. Air Monitoring
a. Throughout the removal and cleaning operations, air sample
monitoring will be conducted to ensure that the Contractor
is complying with all codes, regulations and ordinances.
The method to be used is described in OSHA standards,
1910.93a. The air monitoring technician and his equipment
will be subject to approval of the purchaser's represen-
tative. Prior to the start of any work, the technician's
method of measurement and proof that his method is approved
by the Secretary of Labor of the United States will be
submitted to the purchasers representatives for his approval.
b. Air monitoring will be performed to provide the following
samples during the period of asbestos removal:
F-5
-------
Area to be Number of Minimum sample volume
sampled samples in liters
Work area 4 60
Outside work area barriers 2 120
Outside building 2 240
Samples will be taken after the actual removal
operation has begun.
8. Clean-up and Guarantee
a. After the second cleaning operation the following test
should be performed: A complete visual inspection should
be made to insure dust free conditions, and two air
samples within 48 hours after completion of all cleaning
work should be taken. (Minimum volume of air sample
240 liters).
b. If noncompliance occurs, repeat cleaning and measurement
until space is in compliance. Refer to 29 CFR 1910.1001, 7a.
9. Disposal of Asbestos Material and Related Debris
a. All asbestos materials and miscellaneous debris in
sealed drums will be transported to the predesignated
disposal site in accordance with the guidelines of the
U.S. Environmental Protection Agency.
b. Workers unloading the sealed drums and machinery operators
will wear respirators when handling material at the
disposal site.
F-6
-------
c. The bags may be dumped from the drums into the burial site.
The drums may be reused. However, if a bag is broken
or damaged, the entire drum should be buried.
10. If, at any time, the purchaser's representative decides
that work practice are violating pertinent regulations or
endangering workers, he will immediately notify in writ-
ing the on-site contractor representative that operations
will cease until corrective action is taken.
Figure F-l shows the general sequence which should be followed in an
asbestos removal operation.
F-7
-------
Sealed bags are transported to
sanitary landfill for disposal.
Respirator protects worker during asbestos removal.
Asbestos material being loaded in
approved containers.
Plastic barrier protects building occupants from the
asbestos removal area.
Ceiling asbestos wetted to decrease
airborne fibers during removal process.
Figure F-l. Sequence of steps in an asbestos removal operation.
-------
APPENDIX G
U.S. ENVIRONMENTAL PROTECTION AGENCY REGULATIONS
PERTAINING TO ASBESTOS
The U.S. EPA Regulations contained in Title 40, Code of Federal
Regulations, Part 61, as amended, applicable to asbestos removal oper-
ations are summarized below:
Subpart A - General Provisions
This subpart contains definitions (61.02), regional EPA office
addresses (61.04), waiver information (61.10), (61.11) and other pertinent
information.
Subpart B - National Emission Standard for Asbestos
Section Content
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§61.21 Definitions Terms relating to asbestos material, visible
emissions, demolition, friable asbestos
material, renovation, wetting, removal,
stripping, and waste material are defined in
this section.
§61.22 Emission standard, Contains information on application of stan-
work practice re- dards, notification requirements, stripping
quirements of friable asbestos material, wetting, exhaust
ventilation systems, restriction of spraying
of asbestos containing material, waste
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Section Content
material handling and labelling, and dis-
posal regulations including site requirements.
Specifies the applicability of standard to
stripping or removal of asbestos materials of
more than 80 meters (260 feet) of covered pipe,
or 15 square meters (160 square feet) of
friable asbestos materials used to cover a
structural member.
Written notification to Regional EPA Admin-
istrator is required 10 days prior to begin-
ning of renovation (information to be pro-
vided is listed).
Procedure to prevent emissions are described:
adequate wetting, local exhaust ventilation
systems, proper movement and handling, and
exceptions to wetting requirements.
Spraying of over 1 percent asbestos material
on structural members is prohibited.
Waste disposal methods in renovation shall
not produce visible emissions: waste ma-
terial will be placed in locktight container
while wet, and disposed of in sites in
accordance with provisions of §61.25
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Section Content
§61.25 Waste disposal sites This section contains regulations on
emissions access restrictions, sign
posting, and operating methods for
asbestos waste disposal sites.
Amendments to 40 CFR, Part 61 have been proposed and are found in the
Federal Register of Wednesday, March 2, 1977. The proposed amendment will
resolve certain ambiguities and omissions in the present standard.
The applicability of regulations on renovations, removing and strip-
ping asbestos is broadened by deletion of phrases which limit application
of the regulation to asbestos sprayed for insulation and fireproofing
only. The proposed changes would enable the terms to cover all sprayed
friable asbestos material, for whatever the intended purpose.
The amendment also clarifies the definition of structural member,
and specifically includes nonload-supporting members such as ceilings and
walls in the scope of the regulation.
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APPENDIX H
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION REGULATIONS
PERTAINING TO ASBESTOS
Applicable regulations of the Occupational Safety and Health Admin-
istration U.S. Department of Labor are contained in Title 29, Code of
Federal Regulations, Part 1910. Regulations specific to asbestos removal
or stripping are contained in Section 1910.1001 et seq. and are summarized
below:
Section 1910.1001
Content
(a) Lists definitions.
Definitions of asbestos and asbes-
tos fibers, size limitation of
5 micrometers or longer.
(b) Sets limits for permissible Eight-hour time-weighted average
exposure to airborne con- TWA: two fibers, longer than 5
centrations of asbestos
micrometers, per cubic centimeter
fibers.
of air (f/cm3). Maximum concen-
trations: 10 f/cm3.
(c) Methods of compliance
(1) Engineering methods: isolation,
recommend methods to
enclosure, ventilation, dust col-
meet limits for exposure. lection should be used to meet the
exposure limits.
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Section 1910.1001 Content
(2) Worker protection: Wet methods
will be used, insofar as practicable,
to prevent the emission of fibers
in excess of the limits.
(2)(iii) This section lists speci-
fic requirements for both respira-
tory protection and special clothing
for removal workers.
Personal protective equip- Respiratory protective equipment
ment is specified for and special clothing are required
various conditions. whenever the exposure limits can
reasonably be expected to be ex-
ceeded . Equipment approved by the
agency is referenced.
Respiratory protection:
(d)(2)(i) Concentrations up to
10 times the allowable limit
(20 f/cm3 TWA, or 100 f/cm3 ceiling
limit): air purifying respirator.
(d)(2)(ii) Concentrations up to
100 times the limit (200 f/cm3 TWA,
or 1000 f/cm3 ceiling limits) re-
quire powered air purifying respirator.
(d)(2)(iii) Concentrations above
100 times the limit require type "C"
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Section 1910.1001
Content
Method of measurement of
fiber concentrations is
defined.
Specific procedures of
measurement and monitoring.
Caution signs and labels
are defined.
Housekeeping to reduce
exposure and waste dis-
posal methods are
described.
supplied air respirator, continuous
flow or pressure demand class,
(d)(3) Special clothing shall be
provided if limits are exceeded.
Includes coveralls, head coverings,
foot coverings.
When clothing requirement is met,
laundering service or disposal
should be provided.
Determinations of airborne concen-
trations of asbestos fibers shall
be made by the membrane filter col-
lection method with phase contrast
microscopy.
Personnel monitoring, environmental
monitoring and frequency of moni-
toring are covered.
Specifications and use of signs are
outlined. Posting of work sites
and use of caution labels on asbestos
material are described.
Cleaning of all objects of accumu-
lated asbestos debris, and sealing in
impermeable, sealed containers.
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Section 1910.1001 Content
(i) Specifies recordkeeping and Employer records on exposure. Time
requirements for main- requirements and record disposition
tenance and retention of are covered. Records of monitoring
records. should be retained for 3 years.
(j) Lists medical examination Applicability, specific requirements,
requirements. frequency of medical evaluations.
Annual and termination examination
requirements are listed.
A notice of proposed of rule-making for occupational exposure to as-
bestos (29 DFT Part 1910) is found in the Federal Register, Thursday,
October 9, 1975. The major issues relevant to removal and stripping oper-
ations contained in this proposal are:
1. Lowering of the exposure limits to 0.5 f/cm3 TWA and lowering
of the ceiling limit to 5 f/cm3. Ceiling concentration sampling
time is defined as a period up to 15 minutes.
2. The applicability of the standards to transient work forces,
such as those found in demolition and removal is discussed.
This reflects a concern for exposures in work places of a non-
fixed nature, and resolves the ambiguities in this area.
3. No one type of respiratory protection is required in removal
or stripping activities, but is in proportion to anticipated
concentrations of asbestos.
4. The regulated area concept is introduced as any work area where
a person may be exposed to airborne concentrations of asbestos
fibers in excess of the limits imposed.
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5. Decontamination by showering is required.
6. An employee information and training program is required.
A revised recommended asbestos standard was promulgated by NIOSH in
December 1976. The recommended exposure level in this document is 0.1 f/cm3
8-hour TWA with ceiling concentrations not to exceed 0/5 f/cm3 based on
a 15-minute sample. The essential purpose of this reduction is to ma-
terially reduce the risk of asbestos-induced cancer. The analytical tech-
nique of phase contrast microscopy is retained in this recommended standard.
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APPENDIX I
U.S. ENVIRONMENTAL PROTECTION AGENCY AND
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION
EPA REGIONAL OFFICES
Region I
Connecticut, Maine, Massachusetts,
New Hampshire, Rhode Island and
Vermont
John F. Kennedy Federal Building
Room 2303
Boston, Massachusetts 02203
(617) 223-7210
Region II
New York, New Jersey, Puerto Rico,
Virgin Islands, and Canal Zone
Federal Office Building
26 Federal Plaza
New York, New York 10007
(212) 264-2525
Region III
Delaware, District of Columbia,
Maryland, Pennsylvania, Virginia,
and West Virginia
Curtis Building
Sixth and Walnut Streets
Philadelphia, Pennsylvania 19106
(215) 597-9814
Region IV
Alabama, Florida, Georgia, Kentucky,
Mississippi, North Carolina, South
Carolina, and Tennessee
345 Courtland St., NE
Atlanta, Georgia 30308
(404) 881-4727
Region V
Illinois, Indiana, Minnesota, Michi-
gan, Ohio, and Wisconsin
230 South Dearborn
Chicago, Illinois 60604
(312) 353-2000
Region VI
Arkansas, Louisiana, New Mexico,
Oklahoma, and Texas
First International Building
1201 Elm Street
Dallas, Texas 75270
(214) 749-1962
Region VII
Iowa, Kansas, Missouri, and Nebraska
1735 Baltimore Avenue
Kansas City, Missouri 64108
(816) 374-5493
Region VIII
Colorado, Montana, North Dakota,
South Dakota, Utah, and Wyoming
1860 Lincoln Street
Denver, Colorado 80295
(303) 837-3895
Region IX
Arizona, California, Hawaii, Nevada,
Guam, American Samoa, Trust Territory
of the Pacific
100 California Street
San Francisco, California 94111
(415) 556-2320
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Region X
Alaska, Idaho, Oregon, Washington
1200 Sixth Avenue
Seattle, Washington 98101
(206) 442-1220
DEPARTMENT OF LABOR
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION
REGIONAL OFFICES3
Region I
Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont
John F. Kennedy Federal Building
Government Center
Room 1804
Boston, Massachusetts 02203
(617) 223-6712/3
Region II
New York, New Jersey, Puerto Rico, Virgin Islands, and Canal Zone
1515 Broadway
(1 Astor Plaza)
Room 3445
New York, New York 10036
(212) 399-5941
Region III
Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and
West Virginia
Suite 2100
Gateway Building
3535 Market Street
Philadelphia, Pennsylvania 19104
(215) 596-1201
Region IV
Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South
Carolina, and Tennessee
Suite 587
1375 Peachtree St., NE
Atlanta, Georgia 30309
(404) 881-3573
aThe regional offices should be contacted to find the area office nearest
you.
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Region V
Illinois, Indiana, Minnesota, Michigan, Ohio, and Wisconsin
Room 3263
230 S. Dearborn Street
Chicago, Illinois 60604
(312) 353-4716/7
Region VI
Arkansas, Louisiana, New Mexico, Oklahoma, and Texas
Room 602
555 Griffin Square Building
Dallas, Texas 75202
(214) 749-2477
Region VII
Iowa, Kansas, Missouri, and Nebraska
Room 3000
911 Walnut Street
Kansas City, Mo. 64106
(816) 374-5861
Region VIII
Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming
Room 15010
Federal Building
1961 Stout Street
Denver, Colorado 80294
(303) 387-3883
Region IX
Arizona, California, Hawaii, Nevada, Guam, American Samoa, and
Trust Territory of the Pacific
P.O. Box 36017
9470 Federal Building
450 Golden Gate Ave.
San Francisco, California 94102
(415) 556-0586
Region X
Alaska, Idaho, Oregon, and Washington
Room 6048
Federal Office Building
909 First Avenue
Seattle, Washington 98174
(206) 442-5930
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APPENDIX J
COMMERCIAL SOURCES OF MATERIALS, AND EQUIPMENT
FOR ASBESTOS REMOVAL OPERATIONS
AIR SAMPLING PUMPS
1. Bendix
Environmental Science Division
1400 Taylor Avenue
Baltimore, Maryland 21204
2. Millipore Corporation
Bedford, Massachusetts 01730
3. Mine Safety Appliance Company
201 North Braddock Avenue
Pittsburg, Pennsylvania 15208
4. National Environmental Instruments, Inc.
P.O. Box 590
Warwick, Rhode Island 02888
5. Willson Products Division
ESB Incorporated
P.O. Box 622
Reading, Pennsylvania 19603
VACUUMS: INDUSTRIAL HEPA FILTERED
1. American Cleaning Equipment Corporation
111 South Route 53
Addison, Illinois 60101
2. NILFISK of America, Inc.
P.O. Box 713
201 King Manor Drive
King of Prussia, Pennsylvania 19406
Note: It is recognized that equipment and services other than those cited
in this report may be available. Mention of company or product names
is not to be considered an endorsement by the authors.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO 2
EPA-450/2-78-014
3. RECIPIENT'S ACCESS 1 01* NO.
4. TITLE AND SUBTITLE
Sprayed Asbestos-Containing Materials in Buildings:
A Guidance Document
5. REPORT DATE
Januarv 1978
6. PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
Robert N. Sawyer, M.D., Yale University
Charles M. Spooner, Ph.D., GCA/Technology Division
8. PERFORMING ORGANIZATION REPORT NO.
OAQPS No. 1.2-094
9 PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning and Standards
Environmental Protection Agency
Research Triangle Park, North Carolina 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO
68-02-2607
12. SPONSORING AGENCY NAME AND ADDRESS
DAA for Office of Air Quality Planning and Standards
Office of Air and Waste Management
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This guidance document summarizes the available information on sprayed
asbestos-containing materials in buildings. It describes actions that
may be taken when a building owner knows or suspects that friable asbestos
materials are present. Application of sealant coats and removal of asbestos
materials are discussed.
17. KEY WORDS AND DOCUMENT ANALYSIS
a DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Air pollution
Pollution control
Hazaidous pollutants
Guidelines
Asbes tos
Sealants
Removal Procedures
Air pollution control
IS. DISTRIBUTION STATEMENT
Unlimited
19 SECURITY CLASS (This Report)
llnr 1 a s s \ f i pd
21. NO. OF PAGES
1 T"?
20 SECURITY CLASS (This page}
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