A11107 31DD24 PUBLICATIONS

NBSIR 83-2688

|

GUIDELINES FOR ASSESSMENT

f AND ABATEMENT OF ASBESTOSCONTAINING MATERIALS

IN BUILDINGS

MAY 1983

-QC *’**'’“'wa dOO

,U56

uic2688

19l

, ^fAU O* anter for Building Technology

ational Bureau of Standards

epartment of Commerce

Washington, D.C. 20234

Office of Design and Construction

Public Buildings Service

General Services Administration

Washington, D.C. 20405
*
NATIONAL BUREAU

OF STANDARDS

LIBRATY MAY 1 A 1983

yioictcc- Cstrt

Q ^ '*?

y ^

NBSIR 83-2688

i 4 f Cf * GUIDELINES FOR ASSESSMENT AND

ABATEMENT OF ASBESTOS-CONTAINING

MATERIALS IN BUILDINGS

James H. Pielert Robert G. Mathey

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, DC 20234

May 1983

Prepared for: Public Buildings Service

Office of Design and Construction

General Services Administration

Washington, DC 20405

U S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director
• } ,(
ABSTRACT

This report presents guidelines for the assessment and abatement of asbestoscontaining materials in buildings based on available information. Background

information is given on the history and use of asbestos-containing products in

buildings, and regulations pertaining to their use. Included are control measures for buildings containing asbestos materials, procedures for determining

condition of the materials, and abatement techniques for containment and

removal. A summary is presented of recent guide specifications and standards

developed by industry, government agencies, and a standards organization which

are related to asbestos-containing materials in existing buildings. These

documents include guidance for the control, assessment, and abatement of such

materials.

Key words: abatement of asbestos; asbestos; buildings; fireproofing;

insulation; regulations; structural steel

iii
EXECUTIVE SUMMARY

The Public Buildings Service (PBS) of the General Services Administration (GSA)

asked that the National Bureau of Standards (NBS) develop state-of-the-art

guidelines for surveying buildings having asbestos-containing materials and for

selecting and applying assessment and abatement options. The guidelines are based on available information and include a review of the following: (1) history and use of asbestos-containing materials in buildings; (2) examples of

building systems which may affect airborne asbestos fiber levels; (3) related

regulations, standards, and guidelines; (4) techniques to evaluate asbestoscontaining materials; and (5) abatement techniques.

Asbestos has been widely used because it is a relatively inexpensive material

with special chemical, physical, and mechanical properties which make it very

desirable for many building applications. The important properties are mechanical strength, fire resistance, flexibility, and good friction and wear characteristics. The use of asbestos fibers for fireproofing and insulating materials

for building applications began in England in the early 1930s and continued in

the United States through the early 1970s. The literature contains extensive

documentation addressing potential health effects associated with exposure to

airborne asbestos fibers..!/

In occupational areas where asbestos materials are handled or machined directly,

the regulatory approach of the Federal Government has been to establish the

maximum allowable exposure of workers to asbestos fibers, above which protection is deemed necessary. In the United States, the first occupational exposure level to asbestos was proposed in 1938 by the Public Health Service at 30

fibers per cubic centimeter (f/cc).!/ This has been reduced over the years to

the current U.S. Occupational Safety and Health Administration (OSHA) regulation (29 CFR 1910.1001) which stipulates a maximum exposure level of 2.0 f/cc

for fibers greater than 5 pm in length measured on an 8-hour time weighted

average (TWA) basis and 10.0 f/cc for 15 minute sampling times. Phase contrast

microscopy is the method of measurement required by OSHA. OSHA regulations

generally apply in routine occupational asbestos exposure situations at a fixed

location. In 1976 the National Institute of Occupational Safety and Health

(NIOSH) proposed to OSHA a further reduction to 0.1 f/cc for fibers greater

than 5 pm in length measured on an 8-hour TWA basis and 0.5 f/cc for 15 minute

sampling times. However, this has not been acted upon by OSHA. The applicability of current OSHA fiber exposure limits to the general population where

lower asbestos fiber levels exist (such as occupants of buildings where asbestoscontaining materials have been used for fireproofing and insulation) is subject

to much debate. This issue is not addressed in these guidelines. Regulations

of the U.S. Environmental Protection Agency (EPA) cover asbestos emissions to

!/ Since NBS has no medical expertise, there has been no attempt to evaluate

this documentation.

!/ The measurement method for determining the fiber concentration and fiber

characteristics (e.g. diameter, length) used to establish this level is

unknown to the authors of this report.

iv
the outside environment and disposal of asbestos-containing material from job

sites.

Various guide specifications have been developed by agencies of the Federal

Government and private sector organizations to assist architects, engineers,

and building owners in preparing project specifications and contracts for

asbestos abatement work. These were used in preparing these guidelines.

Techniques for the evaluation of the condition of asbestos-containing materials

in buildings reported herein include: (1) regional surveys of groups of buildings; (2) building inspection procedures; (3) bulk and air sampling techniques;

and (4) available methods for evaluating the potential airborne asbestos fiber

level in buildings. The regional survey is needed when an organization has a large inventory of buildings and it is necessary to determine which buildings

have asbestos-containing material that may require abatement. This is followed

by evaluation of buildings identified as containing such materials and includes

discussion with building personnel, review of building plans and specifications,

review of previous asbestos related activities, and walk-through inspections.

If deemed appropriate, sampling activities can be conducted, including bulk

sampling of material to determine its asbestos content and air monitoring to

determine airborne asbestos fiber levels. The guidelines discuss several proposed methods for evaluating the potential asbestos exposure in buildings;

these methods are undergoing analysis and testing..!/

The guidelines conclude with a discussion of available asbestos abatement

techniques and information available in the current literature on their selection. The selection of an appropriate asbestos abatement solution is generally

based on the condition of the asbestos-containing material, its location, the

function and occupancy of the work area, and the cost. The two approaches to

control exposure of asbestos may be either interim or long-term measures. Longterm measures include containment (encapsulation and enclosure) and removal,

while interim measures consist of a management system for asbestos-containing

materials (educational programs, periodic inspections, work procedures, dust

control, etc.). These methods have various advantages and disadvantages which

must be considered in the context of each building in selecting the most

appropriate approach.

U NBS has not evaluated these methods and does not endorse or disapprove

their application.

v
PREFACE AND ACKNOWLEDGMENTS

This research on the assessment and abatement of asbestos-containing material

in buildings was conducted by the Structures Division and the Building Materials

Division of the Center for Building Technology, National Engineering Laboratory,

National Bureau of Standards (NBS). The work was sponsored by the Public

Buildings Service (PBS) of the General Services Administration (GSA) because

of a concern about the presence of asbestos-containing materials in buildings.

This document provides guidelines, based on currently available information, for

surveying asbestos-containing materials in buildings and for selecting and

applying assessment and abatement techniques.

Information used in the preparation of this report was collected from several

sources: (a) field inspections of GSA buildings; (b) GSA personnel at the

central office and regional offices; (c) personnel of other Federal agencies;

(d) standards committees; and (e) an extensive literature survey.

Three documents were used extensively in the development of this report and

the organizations responsible for them are given special acknowledgment.

These documents and organizations are the "Management Procedure for Assessment

of Friable Asbestos Insulating Materials" developed by the Naval Facilities

Engineering Command, and "Asbestos-Containing Materials in School Buildings:

A Guidance Document," Parts 1 and 2 prepared by the U.S. Environmental

Protection Agency.

Special appreciation is extended to Mr. David Dibner, Ms. Erma Striner, and

Mr. James Parker of the PBS, Office of Design and Construction, and to

Mr. Russell Maisch, Mr. Craig Shilder, and Mr. Wing Chan of PBS Office of

Accident and Fire Prevention, for technical support throughout the project.

Appreciation is also extended to Mr. Noel Raufaste of NBS for his guidance and

interagency coordination. The assistance of the Word Processing Center of the

Center for Building Technology in the typing of this report is gratefully

acknowledged.

vi
TABLE OF CONTENTS

Page

ABSTRACT ill

EXECUTIVE SUMMARY iv

PREFACE and ACKNOWLEDGMENTS vi

1. INTRODUCTION 1

1.1 HISTORY OF ASBESTOS USE IN BUILDINGS 1 1.2 CHARACTERISTICS OF ASBESTOS FIBERS 2

1.2.1 Chrysotile Asbestos 3 1.2.2 Amphiboles 3

1.3 PRODUCTS AND MATERIALS CONTAINING ASBESTOS 3

1.3.1 Friable Materials and Woven Products 4

1.3. 1.1 Friable Insulation Material 5 1.3. 1.2 Preformed Thermal Insulation Products 5 1.3. 1.3 Textile Products 5

1.3.2 Nonfriable Materials 5

1.4 AIRBORNE ASBESTOS FIBERS IN BUILDINGS 9

1.4.1 Methods of Fiber Dispersal 9

1.4. 1.1 Natural Deterioration 9

1.4. 1.2 Impact 9

1.4. 1.3 Secondary Dispersal 11

1.4.2 Aerodynamics of Asbestos Fibers 11

1.4.3 Concentrations of Airborne Asbestos Fibers 12

2. EXAMPLES OF BUILDING SYSTEMS WHICH AFFECT AIRBORNE ASBESTOS FIBER

LEVELS 15

2.1 SPRAY-APPLIED FRIABLE INSULATION 15

2.2 HEATING, VENTILATING, AND AIR-CONDITIONING SYSTEMS (HVAC) 23

3. REGULATIONS, STANDARDS, AND GUIDELINES RELATED TO ASBESTOSCONTAINING MATERIALS IN BUILDINGS 28

3.1 BACKGROUND 28

3.2 GOVERNMENT REGULATIONS 28

3.3 GUIDE SPECIFICATIONS FOR ASBESTOS ASSESSMENT AND ABATEMENT 30

vii
TABLE OF CONTENTS

Page

3.3.1 Association of Wall and Ceiling Industries (AWCI) 30

3.3.2 Public Building Service (GSA) 31

3.3.3 Civil Engineering Laboratory (U.S. Navy) 31

3.3.4 Naval Facilities Engineering Command (NAVFAC) 32

3.3.5 Office of Chief of Naval Operations (OPNAV) 32

3.4

AMERICAN SOCIETY FOR TESTING AND MATERIALS ( ASTM) STANDARDS

DEVELOPMENT 32

3.4.1 ASTM Task Group E06.21.06E on Encapsulation of

Building Materials 32

3.4.2 ASTM Standard E849 33

4. EVALUATION OF ASBESTOS-CONTAINING MATERIALS IN BUILDINGS 35

4.1 REGIONAL SURVEY 35

4.2 BUILDING INSPECTION PROCEDURES 35

4.2.1 Discussion with Building Personnel 36

4.2.2 Review of Plans and Specifications 36

4.2.3 Review of Previous Investigations and Abatement

Actions 36

4.2.4 Walk-Through Inspection 36

4.3 SAMPLING TECHNIQUES 37

4.3.1 Field Test for Asbestos 37

4.3.2 Bulk Sampling 37

4.3.2. 1 Selection of an Analytical Technique for Bulk

Samples 38

4. 3. 2. 2 Selection of a Laboratory 39

4.3.3 Air Monitoring 40

4. 3. 3.1 Guidance on Sampling Methods 40

4. 3. 3.2 Measurement Methods for Air Samples 42

4. 3. 3.Comparison of Air Sampling Results with

Federal Regulations 44

4.4 AVAILABLE METHODS FOR EVALUATING THE POTENTIAL ASBESTOS

EXPOSURE IN BUILDINGS 44

5. ASBESTOS ABATEMENT TECHNIQUES 46

5.1 INTERIM CONTROL MEASURES 46

5.2 LONG-TERM CONTROL MEASURES 47

viii
TABLE OF CONTENTS

Page

5.2.1 Containment 47

5.2. 1.1 Encapsulation 48

5.2. 1.2 Enclosure 49

5.2.2 Removal 50

5.2.2.Dry Removal 50

5. 2. 2.Wet Removal 50

5.3 GUIDELINES FOR SELECTING APPROPRIATE ABATEMENT TECHNIQUES 51

6. REFERENCES 54

APPENDIX A SUMMARY OF EPA AND OSHA ASBESTOS REGULATIONS A-l

APPENDIX B REGIONAL OFFICES OF EPA AND OSHA B-l

ix
LIST OF TABLES

Page

Table 1.1 Silicate Minerals and Their Abestiform Varieties 2

Table 1.2 Friable Materials and Woven Products Containing Asbestos ..... 4

Table 1.3 Nonfriable Matrix Bonded Composite Products Containing

Asbestos 7

Table 1.4 Airborne Asbestos Content in Buildings Based on Various

Types of Activities 14

Table 3.1 Historical Outline of Asbestos Standards Related to Worker

Exposure 28

Table 4.1 Summary of Asbestos Bulk Sample Analysis Techniques 39

Table 5.1 Guidelines for Selecting Appropriate Abatement Techniques .... 52

x
LIST OF FIGURES

Page

Figure 1.1 Mechanisms resulting in airborne asbestos fibers in

buildings 10

Figure 1.2 Theoretical settling velocities of asbestos fibers 13

Figure 2.1 Sketch of typical return air plenum configuration with

exposed fireproofing on structural steel and deck 16

Figure 2.2 Exposed fireproofing on ceiling of mechanical room 16

Figure 2.3 Typical composite floor system within return air plenum

with sprayed-on fireproofing 17

Figure 2.4 Damaged sprayed-on fireproofing on vertical steel bracing

members 17

Figure 2.5 Dislodged fireproofing lying on suspended ceiling tiles

within return air plenum 18

Figure 2.6 Horizontal structural member easily accessible to building

occupants with damage fireproofing 18

Figure 2.7 Structural bracing member with damaged fireproofing at

floor level 19

Figure 2.8 Fireproofing damaged by addition of hangers during

modifications to plumbing and HVAC systems 19

Figure 2.9 Damage to fireproofing caused by floor penetrations for

plumbing system modifications 20

Figure 2.10 Damage to fireproofing on structural steel due to HVAC

system modifications 20

Figure 2.11 Damage to fireproofing on structural steel due to

electrical system modifications 21

Figure 2.12 Damage to fireproofing due to modifications of the vertical

partition system 21

Figure 2.13 Damage to fireproofing due to carelessness while materials

were being transported to other areas of the buildings 22

Figure 2.14 Typical HVAC system configuration of high-rise buildings ... 24

Figure 2.15 Typical air supply and return duct system in ceiling of

occupied space (with drop ceiling removed) 24

xi

>
LIST OF FIGURES

Figure 2.16

Figure 2.17

Figure 2.18

Figure 2.19

Figure 4.1

Air filter bank in air-intake room

Drywall ceiling construction with hole cut for maintenance

work in the plenum

Typical drop-in suspended ceiling construction

Typical interlocking panel ceiling construction

Comparison of fiber size range and techniques for particle

size measurement

Page

25

25

27

27

43

xii
1. INTRODUCTION

Many buildings in the United States have asbestos-containing materials in their

construction. Asbestos has been widely used because it is a relatively

inexpensive material with special properties which make it very desirable for

many building applications. In recent years, potential health effects from

asbestos inhalation have been reported in the literature [l-8].i/» Federal

regulations establish the maximum allowable exposure of workers to asbestos,

above which protection is deemed necessary.

The Public Buildings Service (PBS) of the General Services Administration (GSA)

asked that the National Bureau of Standards (NBS) develop state-of-the-art

guidelines for surveying buildings having asbestos-containing materials and for

selecting and applying asbestos abatement options. The guidelines include the

following: (1) history and use of asbestos-containing materials in buildings;

(2) examples of building systems which may affect airborne asbestos fiber

levels; (3) related regulations, standards, and guidelines; (4) evaluation

techniques; and (5) abatement techniques.

1.1 HISTORY OF ASBESTOS USE IN BUILDINGS

Asbestos minerals have been used for many purposes because they are relatively

inexpensive materials and their fibers have desirable characteristics of

durability, flexibility, strength, and resistance to heat and wear [1]. Asbestos fibers have been used in thousands of applications including: materials

for roofing, flooring, fireproofing, friction products; reinforcing in cement,

pipes, sheets, and coatings; and thermal, electrical, and acoustical insulations. During the five years ending in 1975 the amount of asbestos fiber used

in the United States averaged approximately 800,000 tons annually [2]. It has

been estimated that about 90 percent of the asbestos used has gone into products or applications which have effectively immobilized the fibers by mixing

them with a strong binding material [3]. Fibers may be liberated from these

products by cutting or grinding during their fabrication or use. The other

ten percent of the asbestos has been used in applications where the fibers

may be more easily released.

The major use of asbestos fibers in buildings has been in spray-applied

insulation on structural members and walls and ceilings. This sprayed-on

material, in loosely bonded friable form, has been applied extensively to

structural steel members, such as beams and columns, for fire protection and

to walls and ceilings for thermal and acoustic insulation, architectural

decoration, and control of condensation. This type of application offered the

advantages of rapidly covering large surfaces and irregular surfaces evenly

and efficiently without the use of mechanical support or extensive surface

preparation.

— References are listed in section 6. —2 /

' Since the National Bureau of Standards has no medical expertise, there has

been no attempt to evaluate these references.

1
The spray application of asbestos fibers for fireproofing and insulation was

first used in England in the early 1930s [3]. In the United States, early

spray applications were mainly in clubs and restaurants for decorative use and

acoustical insulations on ceilings. In 1950, some form of sprayed mineral

fiber fireproofing was used in more than half of the multistory buildings con- structed in the United States. Fireproofing alone accounted for 40,000 tons

of sprayed material in 1968 [3].

Many substitutes for sprayed asbestos materials are currently available. Most

of these spray materials 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 fireproofing, thermal and acoustic insulation,

and decoration.

1.2 CHARACTERISTICS OF ASBESTOS FIBERS

Asbestos is a generic term applied to a group of naturally occurring mineral

silicates that are separable into fibers [4]. During the early 1970s the

definition of asbestos was changed by court action because of the public and

scientific attention to asbestos pollution. The definition accepted by the

Minnesota court which set a precedent during the trial of Reserve Mining

Company, stated, "asbestos is a generic term for a number of hydrated silicates

that, when crushed or processed, separate into flexible fibers made up of

fibrils" [5]. The redefinition of fiber as pertaining to asbestos (U.S.

District Court, District of Minnesota, Fifth Division, Fall, 1973) that was adopted by most environmental and public health scientists states that, "a

fiber is a mineral which is at least three times as long as it is wide" [5].

This definition of fiber eliminated the difficult task of testing the flexibility and the presence of fibril composition of submicroscopic particles, and

retained only the shape of the particle as a decisive criterion [5].

The asbestos fibers used in buildings are from asbestiform varieties of silicate

minerals. Table 1.1 lists some common silicate minerals and their asbestiform

varieties which are the source of asbestos fibers that are used commercially.

Table 1.1 Silicate Minerals and Their Asbestiform Varieties [9]

Mineral Mineral Group Asbestiform Variety

Anthophyllite Amphibole Anthophyllite asbestos

Cumraingtonite-grunerite Amphibole Cummingtonite-gunerite asbestos

(amosite)

Tremolite-actinolite Amphibole Tremolite-actinolite asbestos

Riebeckite Amphibole Crocidolite asbestos

Serpentine Serpentine Chrysotile asbestos

2
It is noted that only a very small quantity of the amphibole and serpentine

minerals occur as the asbestiform variety of the mineral [9]. The quality of

asbestos depends on the mineralogy of the asbestiform variety, the degree of

asbestiform development of the fibers, the ratio of asbestiform fibers to

acicular crystals or other impurities, and the length and flexibility of the

fibers [9]. The characteristics of the asbestos vary with the different

asbestiform varieties; however, the commercially used asbestos materials have

fibers that are incombustible, have high tensile strength, exhibit good thermal

and electrical insulating properties, and have moderate to good chemical

resistance [3].

1.2.1 Chrysotile Asbestos

Chrysotile asbestos, although finely fibrous, belongs to the class of silicates

with sheet crystal structures. The sheets of the chrysotile minerals are composed of alternating layers of silica tetrahedrons bound together by hydroxyl

groups and magnesium ions. The fibrous form of chrysotile asbestos consists of

spirally wound tubes which result from the growth pattern of the mineral sheet

structure. Chrysotile fibers are very small in diameter, tubular, and very

soft and flexible. The average diameter of individual fibrils is less than

0.1 micrometers (ym) [9]. Mineralogical identification and measurement of

chrysotile fibers requires a high level of skill and experience.

1.2.2 Amphiboles

Amphiboles have a fibrous nature derived from a chain-like silicate crystal

structure. The fibers are larger in diameter than chrysotile fibers, and are straight and solid in nature, and hard and springy. The average amphibole

asbestos fibril diameter is less than 0.5 ym [9]. Identification and measurement of chrysotile asbestos minerals are generally more easily made, particularly from air samples, than those of amphibole asbestos because of the

structural and chemical differences within the amphibole group. Identification

and measurement of amphibole asbestos can be difficult because of the large

range of chemical composition and morphology.

1.3 PRODUCTS AND MATERIALS CONTAINING ASBESTOS

The level of fiber release from asbestos-containing materials depends, in

general, on the characteristics of the material containing the asbestos fibers.

In some materials such as cement-asbestos and vinyl floor tiles, the asbestos

fibers are firmly bound or encased. The release of fibers in these materials

is generally not considered a problem. However, cutting, sanding, or grinding

of materials containing firmly bound or encased fibers will cause some fiber

release [5]. Asbestos fibers may be more readily released from soft, loosely

bound, or friable materials such as sprayed fireproofing and insulating

materials

Asbestos-containing construction materials have been divided into two major

categories: friable materials and woven products; and nonfriable matrix-bonded

composite products [5].

3
1.3.1 Friable Materials and Woven Products

Friable materials have been described by the U.S. Environmental Protection

Agency [EPA] as those which can be "crumbled, pulverized, or reduced to powder

in the hand" resulting in the release of fibers with minimal applied force or mechanical disturbance [4]. Among woven products, asbestos fibers and other

organic and inorganic fibers are used in rovings, yarns, and cords. These

fibers are also woven, braided, or knitted into textile products. Binding

agents are usually not used in these textile products.

The most commonly used friable materials and woven products containing asbestos

are listed in table 1.2. They include insulating material, preformed thermal

insulation products, and textile products.

Table 1.2 Friable Materials and Woven Products Containing Asbestos!/

Subdivision Generic Name

Asbestos

% by weight Dates of Use Binder/Sizing

Friable

Insulating

Material

Preformed

Thermal

Insulating

spray-applied

insulation

batts, blocks,

& pipe covering

1-95 1935-1970 sodium silicate,

Portland cement,

organic binders

Products 85% magnesia 15 1926-1949 magnesium

carbonate

Textiles!.^

calcium silicate

cloth

6-15 1949-1971 calcium

silicate

blankets 100 1910-present none felts 90-95 1920-present cotton/ wool

blue stripe 80 1920-present cotton

red stripe 90 1920-present cotton

green stripe 95 1920-present cotton

sheet 95-50 1920-present cotton/ wool

cord/ rope/yarn 80-100 1920-present cotton/ wool

tubing 80-85 1920-present cotton/ wool

tape/ strip

curtains

90 1920-present cotton/wool

(theater,

welding)

60-65 1945-present cotton

— Table was taken from reference [5]. —2 / The Navy prohibits use of these products when acceptable nonasbestoscontaining substitutes have been identified.

4
1.3.

1.1

Friable Insulation Material

Spray-applied or trowelled-on friable insulation material has traditionally

been used In building construction for thermal insulation, condensation control,

acoustical control, and fireproofing of steel. This type of asbestos-containing

insulation was first used by the construction industry in the United States In

the mid-1930s. Friable insulating materials containing asbestos were used

generally on the surfaces of metal, wood, concrete, brick, and plaster. Spray

application methods were devised to reduce the cost and time for installing

continuous sheets of material, particularly on irregular surfaces. The major

use of sprayed mineral fiber in buildings is for fireproofing. Generally, friable insulating material used in buildings was a blend of 5 to 95 percent

asbestos fibers combined with other materials such as mineral wool fibers,

vermiculite, sand, bentonite clay binders, or cellulose fibers and other filler

materials.

1.3. 1.2 Preformed Thermal Insulation Products

Preformed thermal insulation products include batts and blocks for boilers and

preformed pipe converings. From 1926 to 1949 chrysotile asbestos fibers were generally used for preformed thermal pipe insulation. This type of insulation

contained about 15 percent asbestos and 85 percent magnesium carbonate. From

1949 to 1971 this material contained about 6 to 15 percent asbestos fibers with

the remainder calcium silicate [5].

1.3. 1.3 Textile Products

Asbestos textile products are durable and have other desirable properties such

as electrical insulation, thermal resistance, and acid resistance. For many

years the commonly used asbestos textile products were cloth, cord, rope, yarn,

tubing, tape, strip, felts, and blankets. The chrysotile asbestos content of

these products may vary from 80 to 100 percent. Other fibers normally blended

in the products include wool, cotton, crocidolite or amosite asbestos fibers.

Asbestos yarns produced by spinning are used as the basic component in the

manufacture of rope, tubing, tape and strips. Asbestos cord has been defined

as a multi-ply yarn used for electrical element insulation and tying cord for

asbestos cloth [5].

Asbestos tape, strip, and tubing have been used for insulating electrical

conductors and for wrapping high-temperature pipe joints. Cloth made from

asbestos ranges in weight from a few ounces to several pounds per square yard

and is woven in a wide variety of styles, textures, grades and thicknesses.

Important uses for asbestos cloth have been covering for pipe insulation,

electrical insulation, and theater curtains.

1.3.2 Nonfriable Materials

Nonfriable materials have been described [5] as matrix-bonded composite

products prepared by mixing fibers with various bonding agents such as starch,

glue, plastics, cements, and asphalt. The degree of bond of asbestos fibers

within the composite material or the fiber's immobilization covers a wide

5
range. Release of bonded fibers varies according to use, environmental

conditions, and physical damage to which the products are subjected.

Nonfriable matrix-bonded products for buildings have been divided into the

following categories: cementitious products, paper products, roofing felts,

asbestos compounds, asbestos ebony, flooring tiles and sheet products, wallcoverings, and paints and coatings [5]. The most commonly used nonfriable

bonded composite products containing asbestos are listed in table 1.3.

Asbestos cementitious products are composed primarily of portland cement

reinforced with chrysotile asbestos fibers. The cement content may vary from

about 10 to 75 percent by weight depending on the required properties of the

material. Cement-asbestos pipe is generally made using chrysotile and crocidolite asbestos fibers in the ratio by weight of 3 to 1 respectively. The strong

asbestos fibers serve to reinforce the cementitious material. Asbestos-cement

products are used for many building purposes including siding shingles, flat

sheets, pipe, roofing shingles, corrugated sheets, facings for acoustical material, table tops, electrical conduits, and laminated panels. In many cases,

asbestos-cement partitions and ceiling panels are accessible to the interior

work environment, and thus, subject to damage.

Clapboard, a thin sheet of asbestos-cement material, has been used extensively

under siding on wood frame buildings. Clapboard was produced in 1944 and 1945.

Asbestos-cement siding shingles have been extensively produced and used on wood

frame buildings for many years. Asbestos-cement roofing shingles are available

but have not had extensive use. A great deal of asbestos-cement pipe has been

used for water mains, sewage and industrial liquid-waste disposal lines,

conduits, vent pipes, flues, and chimneys for heaters.

The large variety of paper products made from chrysotile asbestos fibers

includes corrugated, indented, reinforced, and millboard products. Asbestos

paper has good heat resistance, is chemically inert, and has good electrical

and thermal insulating properties. The paper products have been made for

about 50 years or more and generally contain 75 to 99 percent asbestos. Sodium

silicate is the primary binder for corrugated and indented papers, while for

millboard, asbestos fibers are bound with starch, lime, and clay.

Asbestos roofing felts impregnated with asphalt are used to fabricate membranes

for waterproofing and weatherproofing the roofs of buildings. Roofing felts or sheets may also be both impregnated with an asphalt and coated with an asphaltic composition. The asbestos fiber content of the felt is 85 percent or greater. Asbestos saturated felts are also used to cover hot steam lines on

the outside of buildings.

Asbestos-containing compounds for exterior and interior construction uses may

contain either organic or inorganic binders. Examples of products containing

organic binders such as linseed oil and asphalt are caulks, sealants, cold

applied adhesives, joint compounds, roofing asphalt, mastics, and asphalt tile

cement. Inorganic binders are used in plaster, stucco, and grout.

6
Table 1.3 Nonfriable Ma

Asbestoai' >2J

trlx Bonded Composite Products Containing

Subdivision Generic Name

Asbestos

(% by

weight)

Dates of Use Binder/ Sizing

Cementitious extrusions 8 1965-1977 Portland cement

Products panels:

corrugated 20-45 1930-present Portland cement

flat 40-50 1930-present Portland cement

flexible 30-50 1930-present Portland cement

flexible 30-50 1930-present Portland cement

perforated

laminated 35-50 1930-present Portland cement

(outer

surface)

roof tiles 30-20 1930-present Portland cement

clapboard & shingles

clapboard 12-25 1944-1945 Portland cement

siding 12-14 unknown- Portland cement

shingles present

roofing 32-20 unknown- Portland cement

shingles present

pipe 20-15 1935-present Portland cement

Paper corrugated:

Products high 90 1935-present sodium silicate

temperature

moderate 70-35 1910-present starch

temperature

indented 98 1935-present cotton and

organic binder

millboard 85-85 1925-present starch, lime,

clay

Roofing smooth surface 10-15 1910-present asphalt

Felts mineral surface 10-15 1910-present asphalt

shingles 1 1971-1974 asphalt

pipeline 10 1920-present asphalt

— Table was taken from reference [5].

2 / — The Navy prohibits use of these products when acceptable nonasbestoscontaining substitutes have been identified.

7
Table 1.3 (continued)

Subdivision Generic Name

As bestos

(X by

weight)

Dates of Use Binder/ Sizing

Asbestos- caulking putties 30 1930-present linseed oil

Containing adhesive (cold 5-25 1945-present asphalt

Compounds applied)

joint compound

roofing asphalt 5 1945-1975

unknownasphalt

asphalt

mastics 5-25

present

1920-present asphalt

asphalt tile 13-25 1959-present asphalt

cement

roof putty 10-25 unknown- asphalt

plaster/ stucco 2-10

present

unknown- Portland cement

spackles 3-5

present

1930-1975 starch, casein.

sealants 50-55 1935-present

synthetic

resins

caster oil or

fire/ water

cement

,

20-100 1900-1973

polyisobutylene

clay

insulation

cement

,

55 1920-1973 clay

finishing

cement, magnesia 15 1926-1950 magnesium

Asbestos 50 1930-present

carbonate

Portland cement

Ebony

Products

Flooring vinyl/ asbestos 21 1950-present poly(vinyl)-

Tile and

Sheet Goods

tile

asphalt/ asbestos 26-33 1920-present

chloride

asphalt

tile

sheet goods/ 30 1950-present dry oils

Wallcovering

resilient sheet

vinyl wallpaper 6-8 unknownPaints and roof coating 4-7

present

1900-present asphalt

Coatings air tight 15 1940-present asphalt

8
Asbestos ebony products are used in the construction industry in electrical

panels and circuitry. These products contain about 50 percent asbestos fibers

and portland cement as a binder. With regard to other building products,

asphalt floor tile contains about 25-35 percent asbestos fibers and asbestos

vinyl tile contains about 20 percent asbestos fibers. The backings of some sheet goods and resilient sheets contain asbestos. Some of the better quality

wallcoverings may contain about 7 percent asbestos fibers. Asphaltic exterior

paints may contain about 9 percent asbestos fibers. Some coatings used for

sealing cracks and joints may contain about 15 percent asbestos fibers.

1.4 AIRBORNE ASBESTOS FIBERS IN BUILDINGS

1.4.1 Methods of Fiber Dispersal

The concentration level of airborne asbestos fibers present at any given time

in a building is dependent on three generating mechanisms shown graphically in

figure 1.1. These are natural deterioration, impact, and secondary dispersal.

Three groups of people within the building may be subject to airborne asbestos

fibers: (1) building occupants; (2) maintenance and operation (M/0) personnel;

and (3) contractor personnel. All three groups may be subject to asbestos

exposure due to natural deterioration of asbestos-containing materials resulting in the release of fibers into occupied spaces. In addition, fibers can be

distributed by the air distribution system. This may occur when asbestos

fibers are released into the ceiling air return plenum due to natural deterioration or impact of asbestos-containing materials during M/0 activities in the

plenum. Exposure may also occur from secondary dispersal of fibers that have

already fallen onto interior surfaces. M/0 personnel and contractor personnel

may be exposed to airborne asbestos when their operations disturb the sprayed-on

asbestos-containing fireproofing and insulation materials.

1.4. 1.1 Natural Deterioration

Fallout of asbestos fibers may occur by a slow, continuous degradation of the

insulating surface and may be accelerated by air movement and vibration which

occurs in most buildings. This happens without actual physical disruption of

the asbestos fiber containing material and depends on the bond between the

adhesive and fibers. Fiber dispersal in fallout may occur at a continuous

rate over a long period of time [3]. Factors which affect variations in fallout rate include: vibration of the structure; changes in humidity; air movement from heating, cooling, and ventilating equipment; and air turbulence and

vibration caused by human activity. The fallout rate may increase due to

aging and degradation of the adhesive component of the insulating or other

material. There may be little or no release of fibers from cementitious mixes

in good condition, whereas higher rates may occur for deteriorated friable

materials.

1.4. 1.2 Impact

The level of asbestos fiber release resulting from contact and impact depends

upon the accessibility of the fiber-containing material and the likelihood of

9
MODE CAUSES FREQUENCY FIBER RELEASE RATE

FALLOUT/

EROSION

AIR MOVEMENT,

VIBRATION,

DETERIORATION

CONSTANT LOW

IMPACT MAINTENANCE,

ACCIDENTAL

IMPACT

OCCASIONAL HIGH

SECONDARY

DISPERSAL

USUAL ACTIVITY

CUSTODIAL

SERVICE

FREQUENT LOW TO HIGH

Figure 1.1 Mechanisms resulting in airborne asbestos fibers in

buildings!/

U Figure taken from reference [5].

10
contact. The function of the building and the activities of the occupants may

affect the release of asbestos fibers into the environment. Friable sprayed

asbestos surfaces are easily damaged because of their low impact resistance.

For these surfaces, even minor physical contact may release fibers. These

releases are generally localized and of short duration.

The dispersal of asbestos fibers by contact produces the highest release rates.

It has been reported that the level of airborne fiber concentration during

routine maintenance and repair activities has, in some cases, exceeded 20 fibers

per cubic centimeter (f/cc), and the removal of dry sprayed asbestos material

has in reported cases resulted In airborne fiber concentration levels of over

100 f/cc [3].i/ • These levels are considerably higher than those allowed under

current federal regulations (see section 3.2).

1.4. 1.3 Secondary Dispersal

Reentrainment of fibers which have already settled on surfaces (e.g. above

ceiling tiles, on floors and furniture) can occur after initial release by

natural deterioration or impact [3]. In addition, particles released from the

insulation are subject to possible fragmentation and subsequent reentrainment

due to activity in the area. Secondary dispersal is a function of the activity

level of a building area and may involve repeated cycles of resuspension and

settling.

Fiber counts as high as 5 f/cc have been reported from activity within a building such as custodial work [3]_L' . In cases where settled fibers are present, custodial activities may result in increased levels of airborne fibers.

In a library with a deteriorating sprayed asbestos ceiling, continuous dusting

of extensive areas of shelving raised the average fiber level for the custodians

to 4 f/cc, and to 0.3 f/cc for nearby library users [3]i/.

1.4.2 Aerodynamics of Asbestos Fibers

Dispersed asbestos fibers generally have a length ranging from less than 0.1

pm to some tens of micrometers. Asbestos fibers released into the air will

settle downward at a rate depending on their mass, form, axis attitude, and

air movement. Fiber characteristics strongly affect settling velocity and

total time of suspension. The settling velocity depends mainly upon the fiber

diameter and to a lesser extent upon fiber length. Settling time is also

affected by the fiber alignment, fiber axis vertical or horizontal, and its

aspect ratio (length divided by diameter).

I Fibers 1 to 5 pm in length and an aspect ratio of about 5:1 are common in

I material dispersed from overhead insulation in buildings [3]. The theoretical

settling velocities for fibers 5, 2, and 1 pm long having an aspect ratio

of 5:1 and with their axis attitude varying between vertical and horizontal,

would be 2 x 10“^, 4 x 10“^, and 1 x 10“^ cm/s, respectively [3]. The

j — The measurement techniques for determining the fiber concentration and

i fiber characteristics (e.g.

,

diameter, length) were not reported.

11
theoretical times needed for these fibers to settle from a 9 ft high ceiling

to the floor would be 4, 20, and 80 hours in still air, respectively [3].

Turbulence will increase the settling time and also cause reentrainment of

fallen fibers. Figure 1.2 shows the theoretical settling velocities in still

air for fibers of varying size, alignment, and aspect ratio.

While fibers are airborne they are able to move laterally with air currents

into areas distant from the point of release. Significant levels of contamination have been documented hundreds of meters from the point of release of asbestos fibers [3]. Also, fibers may be transported across contamination barrier

systems with the passage of workers during the removal of asbestos-containing

materials

.

1.4.3 Concentrations of Airborne Asbestos Fibers

EPA has reported that airborne asbestos fiber levels within buildings with

deteriorating asbestos-containing material may be significantly greater than

outdoor ambient air level [3]. Determinations of fiber levels during periods

of quiet activity conditions, such as at night when the building is not occupied, may be misleading [3]. Routine activities in buildings containing sprayed

asbestos surfaces may result in higher airborne fiber levels. EPA reports that

normal activities in school buildings with accessible sprayed asbestos surfaces

may result in indoor airborne asbestos concentrations in the 10 to 50 f/cc range

[ 3

]_' . As mentioned previously, custodial work could result in the disturbance

and reentrainment of the accumulations of fibers which were released from

sprayed surfaces by natural deterioration and contact. Airborne fiber levels

from reentrainment may be higher due to custodial work, depending on cleaning

methods and location of the work relative to the occupants. Such activities

result in reported airborne asbestos fiber levels that exceed regulatory limits

established by the U.S. Occupational Safety and Health Administration (OSHA)

given in table 3.1. Table 1.4 gives estimates of airborne asbestos content in

buildings based on various types of activities [5].

U The measurement technique for determining the

characteristics (e.g.

,

diameter, length) were

fiber concentration and fiber

not reported.

12
SETTLING

VELOCITY

,

cm/

tec.

Figure 1.2 Theoretical settling velocities of asbestos fibers^ — Figure taken from reference [5].

13
Table 1.4 Airborne Asbestos Content in Buildings Based on Various Types of Activities^' >_'

Activity Main Mode of Activity Mean Count^/

Classification Contamination Description ( f / cc)

Quiet fallout none 0.0

Nonspecific

routine

reentrainment office 0.4

Maintenance impact re lamping 1.4

plumbing 1.2

cable movement 0.9

Custodial mixed: impact cleaning 15.5

reentrainment dry sweeping 1.6

dry dusting 4.0

bystander 0.3

heavy dusting 2.8

Renovation mixed: impact ceiling repair 17.7

reentrainment tract light 7.1

hanging light 1.1

partition 3.1

pipe lagging 4.1

Vandalism impact ceiling damage 12.8

Removal, dry impact stripping 40

Removal, wet

amended

impact stripping 2.8

U Table was taken from reference [5].

2 / — See section 3.2 and appendix A for current Federal regulations for

exposure to airborne asbestos fibers. —' The measurement techniques for determining the fiber concentration

and fiber characteristics (e.g.

,

diameter, length) were not reported.

14
2. EXAMPLES OF BUILDING SYSTEMS WHICH AFFECT AIRBORNE ASBESTOS FIBER LEVELS

2.1 SPRAY-APPLIED FRIABLE INSULATION

The predominant use of asbestos-containing material in buildings has been the

spraying of insulation on structural members and on walls and ceilings. This

friable sprayed-on material has been applied extensively to structural steel

members such as beams and columns for fire protection and to walls and ceilings

for the purpose of providing thermal and acoustic insulation, architectural

decoration, and control of condensation.

Structural steel used in buildings suffers a reduction of mechanical properties,

such as strength, stiffness and ductility, when exposed to elevated temperatures. Because of this loss of mechanical properties, it must be protected

from fire exposure by covering with fireproofing materials. Spray-applied

fireproofing containing asbestos was used widely until the early 1970s because

it was inexpensive, quick to Install, involved only one building trade, and was easily integrated with the overall construction process.

Sprayed applications of asbestos-containing materials have been used extensively

for fireproofing of exposed structural steel members and the underside of metal

decking in composite concrete/ steel floor systems (figure 2.1). The bottom of

the floor system can be either exposed (figure 2.2) or enclosed with a dropped

ceiling structure to form a plenum (figures 2.1 and 2.3). Vertical steel

members (columns, bracing, etc.) are also often coated with fireproofing

(figure 2.4).

As discussed previously, fireproofing on structural steel members and other

spray applied friable insulation may be subject to natural deterioration and

physical damage. While it is difficult to observe natural deterioration,

the result of physical damage is generally quite obvious. This damage can be

caused by:

A. maintenance and operations work within the ceiling plenum which may

cause fireproofing to be dislodged and fall onto the suspended

ceiling (figure 2.5).

B. location of asbestos-containing material on vertical surfaces at floor

level or on low horizontal surfaces which can be contacted by building

occupants (figures 2.4, 2.6 and 2.7).

C. modifications made to the building since construction including:

(1) addition of a fire sprinkler system; (2) modifications to the

heating, ventilating, and air conditioning (HVAC), electrical, and

plumbing systems, (figures 2.8, 2.9, 2.10, and 2.11); and (3) changes

to the office partition system (figure 2.12); and

D. contractor carelessness when doing work in the vicinity of asbestoscontaining material (figure 2.13).

15
Figure 2.1 Sketch of typical return air plenum configuration with exposed

fireproofing on structural steel and deck

Figure 2.2 Exposed fireproofing on ceiling of mechanical room

16
Figure 2.3 Typical composite floor system within return air

plenum with sprayed-on fireproofing

Figure 2.4 Damaged sprayed-on fireproofing on vertical steel bracing

members

17
Figure 2.6 Horizontal structural member easily accessible to

building occupants with damaged fireproofing

18
Figure 2.7 Structural bracing member with damaged fireproofing

at floor level

Figure 2.8 Fireproofing damaged by addition of hangers during modifications

to plumbing and HVAC systems

19
I

I

Figure 2.9 Damage to fireproofing caused by floor penetrations

for plumbing system modifications

Figure 2.10 Damage to fireproofing on structural steel due to

HVAC system modifications

20
Figure 2.11 Damage to fireproofing on structural steel due to

electrical system modifications

Figure 2.12 Damage to fireproofing due to modifications of the vertical

partition system

21
I

I

Figure 2.13 Damage to fireproofing due to carelessness while

materials were being transported to other areas

of the buildings

22
Elevator motors, fans, and pumps are quite often located on floors or roofs

supported by structural steel and steel deck protected with fireproof ing.

Vibrations caused by such equipment can dislodge fireproofing material or other spray-applied insulation and increase the potential for asbestos fiber

dispersal.

2.2 HEATING, VENTILATING, AND AIR CONDITIONING SYSTEMS (HVAC)

The HVAC system has the potential for circulating asbestos fibers throughout

the building if fibers are released from asbestos-containing materials [5].

This is particularly true for buildings where the HVAC system can be

characterized as shown on figure 2.14 and discussed below.

Large modern buildings have equipment rooms which take in fresh air and

distribute conditioned air to different floors. Depending on the horizontal

dimensions of the building, the equipment room and air supply system may be

divided into several vertical zones which service different sections of the

building. Typically, a high rise building will have one equipment room at

approximately mid-height and another at the topmost level of the building.

Large fans in the equipment room force the preconditioned air into ducts which

contain acoustical insulation. The ducts lead to vertical risers which carry

the air to the various floors for distribution by the local supply ducts

(figure 2.15). On each floor the exhaust air is either ducted directly to a large vertical riser, or, more likely, the air is exhausted directly into the

ceiling plenum between the suspended ceiling and the floor above (figures 2.1

and 2.15). This plenum may contain plumbing, electrical, mechanical, and

utility equipment. More importantly, as was previously discussed, the underside of the floor may be coated with sprayed fireproofing which may contain

asbestos to provide a fire rating to the structural steel and steel floor deck

assembly. The return air exhausted into the plenum contacts the fireproofing

with the potential for dislodging fibers and circulating them throughout the

building (see figure 2.1).

At several locations within the ceiling plenum, metal ducts conduct the return

air into vertical risers. The air is then returned through the vertical risers

to the return air chamber where it exhausts into a spill chamber. The vertical

risers may contain structural members with fireproofing or thermal insulation

with the potential that fibers may be dislodged and circulated throughout the

building by the HVAC system. Depending on the temperature of the outside air

and the building return air, the return may be entirely exhausted to the outside, or may be recirculated to some degree. Dampers control the degree of air

recirculation and the amount of fresh air used. The air to be recirculated

passes through recirculation dampers and mixes with fresh air which has been

drawn through intake dampers. The intake air is sometimes prefiltered with

coarse fiberglass filters. The mixed air is then drawn through the filter bank,

which consists of multi-pocketed bags made of fiberglass or other fibrous

material (figures 2.14 and 2.16).

The accessibility of the unducted air return plenum to building occupants may

affect the dispersal of asbestos fibers. Such accessibility often depends on

the type of suspended ceiling construction. This can range from drywall

23
f I SPILL 1 DAMPERS INTAKE * DAMPERS

1/ Taken from reference

[ 6 ].

Figure 2.14 Typical HVAC system configuration of high-rise buildings-^/

Figure 2.15 Typical air supply and return duct system in ceiling of

occupied space (with drop ceiling removed)

24
w,.. I

Figure 2.16 Air filter bank in air-intake room

Figure 2.17 Drywall ceiling construction with hole cut for

maintenance work in the plenum

25
construction (figure 2.17) which makes the ceiling inaccessible on a routine

basis to lay-in panels which can be easily removed (figure 2.18). Between

these two extremes there are various types of suspended panel systems with

mechanical interlocks which restrict unwanted access (figure 2.19). Easy-toremove ceiling panels allow M/0 personnel and occupants easy access to an area which may have dislodged fireproofing. However, M/0 personnel have more frequent access to the ceiling plenum due to their job functions than building

occupants.

26
Figure 2.18 Typical drop-in suspended ceiling construction

Figure 2.19 Typical interlocking panel ceiling construction

27
3. REGULATIONS, STANDARDS, AND GUIDELINES RELATED TO ASBESTOS-CONTAINING

MATERIALS IN BUILDINGS

3.1 BACKGROUND [5]

The regulatory approach of the Federal Government has been to establish by

law the maximum allowable exposure of workers to asbestos, above which protection is deemed necessary. Standards have been based on the number of respirable asbestos fibers (which are greater than a minimum length) suspended in the

air. See section 4.3 for a discussion of the measurement methods for analyzing

(1) bulk samples for asbestos content by weight, and (2) air samples for airborne asbestos fiber levels. A discussion of the historical development of

regulations related to airborne asbestos fiber levels follows.

3.2 GOVERNMENT REGULATIONS [5]

Table 3.1 presents a historical outline of the reduction of worker exposure to

asbestos which has occurred in the United States. The more recent Federal

regulations pertaining to sprayed asbestos materials have been issued by EPA

and OSHA. In general, OSHA regulations cover occupational asbestos exposure

situations at a fixed location. EPA regulations cover emissions to the outside

environment and the removal and disposal of material from job sites.

Table 3.1 Historical Outline of Asbestos Standards

Related to Worker Exposure^'

Year Agency Basis of

Standard

Asbestos

Exposure

Level

(f/ cc)

1938 U.S. Public Health Service proposed^/ 30

1969 Walsh-Healy Public Contract Act informed^/ 12

1971 OSHA informed 12

1972 OSHA informed 5.0

1976 OSHA informed 2.0

1977- NIOSH proposed 0.1

1978 (to OSHA)

— Table based on information from reference [5].

2 / — "Proposed" means not incorporated into Federal regulations.

3 / — "Informed" means incorporated into Federal regulations.

28
Asbestos industry regulations were first introduced in the United Kingdom in

1931. These regulations required the adoption of certain precautions aimed at

reducing the exposure of workers to asbestos dust [10]. In 1938, the U.S.

Public Health Service proposed a maximum exposure level of 30 f/cci/. As

environmental issues took on additional importance, the 1970 Occupational

Safety and Health Act was passed which emphasized the need for standards to

protect the health of workers exposed to potential hazards at their place of

work. A standard for occupational exposure to asbestos was included in an OSHA

standard published in 1971. The standard, based on a 1969 Federal Standard

issued under the Walsh

exposure limit of 12 f

This was followed by an OSHA Standard for Exposure to Asbestos Dust published

in the Federal Register, Vol. 37, No. 110, on June 7, 1972 (29 CFR 1910.93a).

This standard was recodified to 29 CFR 1910.1001 in the Federal Register dated

May 28, 1975. This regulation applies to workers handling or exposed to

asbestos fibers or material containing asbestos fibers. The regulations stipulated a maximum exposure of 5 f/cc for fibers greater than 5 p in length over

an 8-hour period on a time weighted average (TWA) basis. A level of 10 f/cc

for a 15-minute sampling period was the maximum allowed any-time excursion.

This standard for occupational exposure also defines 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 original requirement for maximum exposure given in OSHA regulation 29 CFR

1910.1001 was reduced on July 1, 1976 to 2 f/cc for fibers greater than 5 pm

in length determined over an 8-hour period on a time weighted average (TWA)

basis. Maximum levels for 15-minute sampling times remained at 10 f/cc. Phase

contrast microscopy was identified as the method of measurement. (See section

4. 3. 3.

for discussion of phase contrast microscopy.) Appendix A contains a summary of these regulations.

There has been considerable discussion concerning the adequacy of the 2 f/cc

occupational standard [8]. In December 1976, the National Institute of Occupational Safety and Health (NIOSH) proposed to OSHA a further lowering of airborne

asbestos fibers over 5 pm in length to 0.1 f/cc TWA with 0.5 f/cc as the maximum

permissible any-time excursion. Phase contrast microscopy was retained as the

method of measurement. This NIOSH proposal has not been adopted as a Federal

regulation.

Regulations promulgated by the U.S. Environmental Protection Agency on April 6,

1973, apply to the renovation or demolition of structures having asbestos-

-Healey Public Contracts Act, also included an asbestos

/cc (of fiber length greater than 5 pm).?/.

U The measurement technique for determining the fiber concentration and fiber

characteristics (e.g.

,

diameter, length) are unknown.

hi The method of measurement for determining fiber concentration is unknown to

the authors of this report.

29
containing materials and to the spraying of materials of not more than 1 percent

asbestos (see appendix A). Furthermore, OSHA regulation 29 CRF 1910.1001 for

asbestos discussed above specifies procedures for removal and stripping of friable sprayed asbestos fireproofing and insulation materials and requires that

EPA be notified when 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.

Since regulations affecting nearly all aspects of potential exposure to asbestos

are being reconsidered by OSHA and EPA, any questions concerning these current

regulations should be referred to the agencies' regional offices. EPA and OSHA

Regional Offices are listed in appendix B.

Most State and local governments adhere to current EPA and OSHA regulations;

however, in instances where the problem is acute or has received public attention, special bylaws or ordinances may have been passed which are more stringent

than federal regulations. State departments of health, labor, and environmental

protection can provide additional guidance in the event that more stringent

state regulations are in effect or if difficulty is experienced in locating

an approved disposal site for asbestos-containing debris.

3 . 3 GUIDE SPECIFICATIONS FOR ASBESTOS ASSESSMENT AND ABATEMENT-^/

3.3.1 Association of Wall and Ceiling Industries (AWCI)

In December 1981, the Foundation of the Wall and Ceiling Industry of the

Association of the Wall/ Ceiling Industries-International, Inc. published "Guide

Specifications for the Abatement of Asbestos Release from Spray - or TrowelApplied Materials in Buildings and Other Structures [11]." The guide specifications are intended to assist architects, engineers, and building owners in

preparing project specifications and contracts for asbestos abatement work.

The guide specifications were prepared by an Ad Hoc Task Group that included

six contractors, two representatives from EPA, and one representative from each

of the following organizations: AWCI, Public Works Canada, HUD-FHA, Alberta

Labour (Canada), GSA, and OSHA. The guide specification has not been officially

adopted or "approved" by the public agencies participating in its development.

The authors of the document made an attempt to ensure that the guide specifications reflect the best technology for asbestos abatement currently available.

However, they do not claim that use of the specifications will guarantee a riskfree, successful abatement job, and do not take responsibility for any work done

using these specifications. The guide specifications point out that technology

relating to asbestos abatement is changing rapidly and more advanced techniques

may become available.

A/ Inclusion of these documents does not represent NBS endorsement or disapproval of their content.

30
The guide specifications are intended to be revised to fit the conditions of

each particular job. The specifications include actions required by regulations

as well as guidance on current work practices. The guidance is based upon

experience with abatement procedures and offers procedures for complying with

the regulatory requirements.

The guide specifications recommend that building owners and their representatives require that contractors who submit bids for asbestos abatement work

demonstrate that they have had experience in such work. It further states that

they should require contractors to submit letters of reference from the owners

of the buildings where this work was done, and air monitoring data taken during

this work. As an alternative to, or in addition to, previous experience,

building owners should require of contractors submitting bids that the contractors have successfully completed a training course in asbestos abatement work.

If so, the contractors should be required to submit letters from the firm,

agency, or association which conducted the training course and a syllabus of

the session. Training sessions should include instruction in applicable regulations, work area isolation, worker protection, the selection, use, and maintenance of respirators, proper asbestos abatement techniques, and proper work

area decontamination procedures.

3.3.2 Public Buildings Service (GSA)

The Public Buildings Service of GSA has issued Tentative Guide Specifications

on Asbestos Abatement Procedures [12]. It covers all work necessary to reduce

airborne asbestos fiber concentrations to a required level and to maintain it

at or below that level during construction. It also covers procedures for the

removal and/or containment of friable asbestos-containing material. The document requires the contractor to assume full responsibility and liability for

compliance with all applicable Federal, State, and local regulations pertaining

to the protection of workers, visitors to the site, and persons occupying areas adjacent to the site.

3.3.3 Civil Engineering Laboratory (U.S. Navy)

The Civil Engineering Laboratory, Naval Construction Battalion Center, in

February 1981 issued Technical Report R883 "Management Procedure for Assessment

of Friable Asbestos Insulating Material" [5]. This document provides procedures for evaluating friable asbestos-containing materials. An asbestos "hazard

index" is presented for determining if an abatement project should be initiated.

The "hazard index" is currently being tested at Naval facilities. The document

also includes guidance on proper interim control measures, as well as guidance

for selecting and specifying appropriate long-term control measures, standardized safety procedures, and personnel protection during maintenance and control

of friable asbestos-containing insulating systems, including their disposal.

The long-term control measures emphasize the need for cost-effective alternatives which will meet current fiber pollution restrictions.

Although the document does not present guide specifications for asbestos

abatement, it does provide information with regard to the factors to be considered in contract preparations. The document also presents samples of technical

31
specifications for dry removal, wet removal, and encapsulation of friable

aabestos insulating material and asbestos contaminated items. The sample

technical specifications were prepared in accordance with EPA, OSHA, and Navy

regulations on handling asbestos materials.

3.3.4 Naval Facilities Engineering Command (NAVFAC)

NAVFAC has prepared a draft guide specification NFGS-02075, “Removal and

Disposal of Asbestos Materials" [13]. This draft guide specification is

Intended to be used by Naval personnel as a model in preparing project specifications. It covers the safety procedures and requirements for the removal and

disposal of friable asbestos-containing material. Non-friable materials con- taining asbestos normally do not require special handling and disposal procedures unless such materials are sawn, pulverized, or handled in such a manner

that will cause dust and airborne asbestos fibers to be released. If the project contains nonfrlable asbestos that is considered to be hazardous due to

material condition, then the nonfrlable asbestos shall be specified to be

removed in accordance with procedures established for friable material.

3.3.5 Office of the Chief of Naval Operations (OPNAV)

On February, 12, 1982 OPNAV issued Instruction 6260. IB, "Control of Asbestos

Exposure to Naval Personnel and Environs" [14]. These instructions are intended

to enable U.S. Navy personnel to comply with the national safety and health

standards for asbestos regarding occupational health and to comply with the

National Emmlsslon Standard for asbestos for environmental protection.

3.4 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS DEVELOPMENT

3.4.1 ASTM Task Group E06.21.06E on Encapsulation of Building Materials

In ASTM Committee E6 on Performance of Building Constructions, a Task Group on Encapsulation of Building Materials (E06.21.06E) is charged with the development of a Standard Specification for Encapsulating Agents for Friable AsbestosContaining Building Materials. A draft standard is in preparation and may be

changed prior to being adopted as an approved standard. The present scope of

this draft describes the testing and performance of encapsulants designed to

reduce or eliminate the release of asbestos fibers from the matrix of friable

spray- or trowel-applied asbestos-containing building materials.

The "draft" standard consists of two separate test protocols with acceptance

criteria:

1. a series of laboratory tests which show whether an encapsulant is

capable of acceptable performance on a specified asbestos-f reei/

matrix, and;

1/ This is necessary since EPA does not allow the use of asbestos

laboratory test samples.

in preparing

32
2. a series of tests to be conducted in the field at each location

where encapsulation is being considered, which show whether an encapsulant is acceptable on the specific asbestos-containing

matrix.

This ASTM draft standard does not provide a means for determining whether

encapsulation or any other control technique is suitable for any particular

installation of friable asbestos-containing material and does not give guidance

for making such a determination. The purpose of this draft standard is to provide guidance for the selection of an encapsulant once the decision to encapsulate has been made. It is assumed that users of this standard have already

made a decision to encapsulate friable asbestos-containing material and that

this decision is appropriate.

The proposed test methods for laboratory testing are: cohesion and adhesion,

penetration, deflection, surface abrasion, air erosion, fire resistance, sur- face burning, and surface impact. With regard to field testing, the proposed

test methods are: adhesion and cohesion, penetration (for penetrating encapsulants only), and fiber release. The test protocols in this standard do not

cover the permeability to water vapor of encapsulants when applied to friable

materials, or the mildew and fungus resistance of encapsulants, or the ability

of penetrating encapsulants to aid control of application amounts by tinting.

These properties may be determined by other standard test methods.

For information a’

“ ^ i of the ASTM draft standard the reader is

3.4.2 ASTM Standard E849

The ASTM Standard E849 , Standard Practice for Safety and Health Requirements

Relating to Occupational Exposure to Asbestos [15], was approved in April 1982.

This standard is intended to be used for occupational exposures including mining, milling, transportation, manufacturing and product use. The scope

excludes occasional work that may involve intermittent exposure and pathologically inert particulates such as certain asbestos cement dusts. Section 3.1

of the standard states that it is meant to

M (a) protect against the development

of asbestos related disease; (b) be measurable by techniques that are valid,

reproducible, and available to industry and official agencies; and (c) be

attainable with existing technology".

The maximum exposure to asbestos for a specific time required by the standard

calls for the concentration of airborne asbestos particulates not to exceed

permissible occupational environmental limits of 2.0 f/cc based on an 8 hour

time weighted average and 10.0 f/cc based on peak levels. The fibers are defined as monitored particulates with an aspect ratio of at least 5:1, a minimum length of 5 pm, a maximum diameter of 3 pm, and the appearance of a fascine (bundle of sticks effect).

—

American Society for Testing and Materials, 1916 Race Street, Philadelphia,

referred to ASTM

PA 19103.

33
The ASTM Standard E849 Includes annexes with mandatory Information on characteristics of asbestlform minerals, epidemiology and toxicity tests,

rationale for the 5:1 aspect ratio, midget impinger Instrument for mineral

dust sampling, and personal protective equipment.

34
4. EVALUATION OF ASBESTOS-CONTAINING MATERIALS IN BUILDINGS

It is necessary that a consistent approach be followed in determining the

condition of asbestos-containing material in an agency's building inventory.

The methodology presented below represents a compilation of procedures developed from a review of the literature, analysis of procedures used by Federal

and local governmental agencies, and those found most effective in an asbestos

survey NBS performed for GSA.

4.1 REGIONAL SURVEY

When an organization has a large inventory of buildings which are geographically

dispersed, it is necessary to determine, on a regional basis, which buildings

have friable asbestos-containing material and may require abatement action.

This is necessary for setting priorities and establishing budgets.

Scope of Survey

A. A representative of the regional office who is knowledgeable of

asbestos assessment should visit every building in the region to

identify locations where asbestos-containing materials may have been

applied. Samples of suspected materials should be taken from these

locations for testing. Even though fireproofing and insulation

containing asbestos were applied only in the period following World

War II to the early 1970' s, no building should be excluded from such

a survey. Buildings constructed before and after this period of time

may have undergone renovations where asbestos materials were used.

Each floor including basements, penthouses, or attics should be

visually inspected. Materials containing asbestos may be located in

numerous areas of any building: (1) in open view on ceilings, walls

or piping throughout the entire building; (2) in one particular room

(computer, keypunch); (3) in corridors and staircases; (4) in

restricted access areas such as mechanical rooms, or penthouses, or

(5) in enclosed spaces such as air plenums above suspended ceilings

or vertical air shafts.

B. Bulk samples of material suspected of containing asbestos should be

analyzed to confirm its presence and to assist in assessing the potential airborne asbestos fiber level of each building. The general

condition and the location of the material should be noted. Sampling

techniques, including an inexpensive and simple field test for quickly

determining whether asbestos is present in building materials, are discussed in more detail in section 4.3.

C. Based on data collected in A and B, buildings should be selected

for detailed follow-up investigation as outlined in section 4.2.

4.2 BUILDING INSPECTION PROCEDURES

After it has been determined through the regional survey that a building has

friable asbestos-containing material, a more thorough inspection should be made.

35
The following steps may be taken in determining the location, type and

condition of asbestos materials needed to evaluate the building with regard

to asbestos applications.

A. 2.1 Discussion with Building Personnel

Maintenance and operations staff will probably be most familiar with the

building and applications of asbestos-containing materials. They should be

able to provide information on the special procedures followed in the building

when working around asbestos-containing materials and building documentation

(plans, specifications, etc.). Historical information relative to previous

asbestos evaluations, abatement actions taken or planned, etc., can also be

obtained from the staff.

A. 2.2 Review of Plans and Specifications

Building construction records should be reviewed to determine where asbestoscontaining materials may be located, to establish the type and concentration of

asbestos in the material, and to assist in evaluating building systems which may

affect airborne asbestos fiber levels. Since records may erroneously report

either the presence or absence of asbestos, reliance on building records alone

is not recommended.

A. 2.

3

Review of Previous Investigations and Abatement Actions

Many buildings have had previous asbestos investigations and/or abatement

actions taken and this information should be reviewed. This historical

perspective allows an evaluation of the condition of the material over time and

would be vital in preparing future recommendations.

A. 2.

A

Walk-Through Inspection

The following can be accomplished during the inspection of the building:

a. compare as-built condition of the building to that shown on available

plans and specifications;

b. determine location and condition of asbestos-containing materials with

appropriate photographic documentation;

c. evaluate building systems which may affect airborne asbestos fiber

levels (e.g., open air return plenums);

d. select portions of the building which may require follow-up sampling

and evaluation; and

e. determine the characteristics of the building occupancy which may

affect the selection of asbestos abatement actions (e.g., effect of

temporary relocation of tenants).

36
4.3 SAMPLING TECHNIQUES^/

After material which may contain asbestos fibers is located in a building, it

is necessary to first confirm its presence, and then to determine if asbestos

fibers are being released to the air. Guidance for the sampling and analysis

of asbestos-containing materials has been prepared by EPA [16].

4.3.1 Field Test for Asbestos^

Kim and Kupen have developed an inexpensive and simple field test (K2 test) for

quickly determining whether asbestos is present in building materials [17],

The K

2 test is a color screening test that reveals the presence of the magnesium or iron found in asbestos. The test procedure consists of mixing a small

sample of material with selected chemicals and reagents which cause the magnesium or iron to be released. These elements then react with the reagents to

produce either a red color for iron or a blue color for magnesium. No color

change means that neither iron nor magnesium is present and indicates the

absence of asbestos. If magnesium or iron is present, a sample should be sent

to a laboratory to confirm the presence of asbestos. If a test is negative,

however, the probability of finding any asbestos by further testing is extremely

low and does not warrant laboratory analysis [17].

O While the validity and accuracy of the test has been shown by laboratory

analysis, field experience has indicated the following problems”/

A. Some field personnel feel uneasy doing the test because "tearing" of

the bulk sample is involved, resulting in potential asbestos exposure

even though precautions are taken (respirators are worn, wet samples

are used, etc.).

B. Some nontechnical personnel collecting samples do not want the

responsibility of screening and deciding.

4.3.2 Bulk Sampling [4,5,16]

Once suspected asbestos-containing material has been identified in a building,

the entire building should be inspected for identical materials. If other

forms of suspected materials which differ in texture, fiber type, or color

(other than paint) are found, these should be noted as different material areas and sampled separately. After inspecting the building and taking samples, the

samples should be analyzed by a laboratory. The remainder of this section

U NBS has not evaluated the measurement methods discussed in this report and

therefore neither endorses nor disapproves their adequacy. — A description of the test method is available from Publications

Dissemination, DTS, National Institute for Occupational Safety and Health,

4676 Columbia Parkway, Cincinnati, Ohio 45226.

o / Private communication with test developer.

37
discusses the selection of an analytical technique, the selection of a laboratory, and practices to ensure quality of results.

4.3.2. 1 Selection of an Analytical Technique for Bulk Samples [5]

Many materials suspected of containing asbestos consist of a mixture of asbestos

and other components such as fibrous glass, rockwool, slagwool, woodpulp, and

paper fibers. Bulk samples of building materials are analyzed by microscopic

inspection to determine whether asbestos is present and, if it is present, in

what quantities and types. Lentzen, et al. [18], discuss a statistical approach

to evaluate precision and accuracy of laboratory measurements of asbestos in

bulk insulation material. There are three possible fiber identification techniques: polarized light microscopy (also known as petrographic microscopy),

x-ray diffraction, and electron microscopy.

Polarized light microscopy is the technique most widely used, primarily because

the technique is well established and the analysis is relatively low in cost.

The technique involves the identification of substances by their optical and

crystallographic properties; an experienced microscopist can locate even small

amounts of asbestos in bulk samples. Accuracy below five percent is questionable and should be regarded as a trace. Samples below five percent tend to be

inhomogenous.

X-ray diffraction is a more expensive technique which involves exposing a small

sample of the material to x-rays and identifying minerals by their unique diffraction patterns. The technique usually yields information with a high degree

of diagnostic reliability. However, it is not suitable as an independent method of analyzing samples to determine whether they contain asbestos for two reasons. First, X-ray diffraction cannot differentiate between fibrous and

nonfibrous forms of serpentine and amphibole minerals, and cannot positively

identify a mineral as asbestiform. Second, it may fail to detect small concentrations of asbestos (less than two percent to four percent if fibers are not

concentrated during laboratory preparation). For these reasons, X-ray diffraction should be used only as a supportive technique to confirm results achieved

by polarized light microscopy.

The third microscopic technique is electron microscopy. Although specific and

accurate fiber identification can be achieved using this technique, particularly

if it is used in conjunction with polarized light microscopy and X-ray diffraction, the cost of electron microscopy is extremely high, and the availability

of laboratories which can conduct the analysis is limited. Electron microscopy

is not a precise method for determining asbestos concentration. Analytical

methods of analysis recommended by EPA are polarized light microscopy with or without dispersion staining and X-ray diffraction [16]. EPA does not recommend

electron microscopy as a method for analysis; its primary usefulness lies in

its ability to resolve any ambiguities arising from the use of polarized light

microscopy and X-ray diffraction. If data on the length, width, concentration,

and species of mineral fibers are needed, microscopy methods are necessary for

mineral fiber analysis. Because of the small size of the particles, electron

microscopy is necessary [19].

38
Table 4.1 from reference [5] summarizes the advantages and disadvantages of the

three bulk sample analysis techniques.

Table 4.1 Summary of Asbestos Bulk Sample Analysis Techniques^/

Method Advantages Disadvantages

Petrographic

Microscopy

(Polarized

light microscopy)

Relatively rapid and low

cost per analysis, suited

for exact identification

of minerals present and

estimate of abundance

High level of operator training

and experience required; fibers

with diameters of less than

0.5 y® cannot be identified

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

abundances (less than 2-4 percent), especially if other

crystalline phases are present

Electron

Microscopy

Absolute determination of

fibers present and identification of mineral

species

High equipment and analysis

costs; highly trained operator

required

U Table taken from reference [5].

4. 3. 2.

Selection of a Laboratory

The identification of asbestos in bulk materials is not a routine laboratory

procedure. Only laboratories which are actively engaged in using polarized

light microscopy or X-ray diffraction to determine whether asbestos is present

in bulk samples should be considered for this service. GSA requires proof of

qualifications of testing laboratory and personnel be submitted for approval

by the contracting officer [12].

EPA sponsors an analytical proficiency program for bulk sample analysis with

approximately 75 laboratories currently participating in the program [16]. EPA

periodically sends these laboratories samples of materials with the asbestos

content known only to the agency. EPA compares the results determined by the

laboratories with the actual asbestos content of the materials. The results

for commercial laboratories which participate in the program are available from

39
EPA by calling (800) 334-857lI/. EPA has published a procedure for evaluating

the performance of laboratories which have not participated in the program [16].

In order to ensure that the laboratory has analyzed the samples according to

the procedure requested, and to facilitate the recordkeeping process, it is

important that complete reporting of the analytical results be obtained from

the laboratory. A complete and signed report should be obtained from the

laboratory and should include the following:

1. Sample identification number and name of requesting organization.

2. Analytical method used to analyze the sample.

3. Percent of each type of asbestos present.

4. Type and amount of fibrous material present in the sample.

4.3.3 Air Monitoring [4,5,16]

Air monitoring, currently the most widely used measurement method for

determining airborne asbestos fiber levels, is subject to measurement inaccuracies inherent with the methodology employed. Also, it provides only an estimate of the actual number of fibers in the air at any given time while extent

of fiber release may vary widely over time. Levels may vary depending on the

level of the activities in the building, as well as changes in the building

condition.

4. 3. 3.1 Guidance on Sampling Methods

Considering the current state-of-the-art, it is not possible to outline a statistically based approach for collecting and analyzing air samples in a building. Such approach would have to consider all relevant factors such as building construction characteristics, occupancy type, typical activities of

occupants, etc. The following general guidance is provided in selecting an air sampling program.

Conditions under which air sampling should be scheduled in a building are:

(1) normal occupant activity, (2) custodial activity, (3) routine maintenance

near asbestos-containing materials, and (4) application of building modifications directly affecting asbestos-containing materials (e.g., movement of

partitions, construction of floor penetrations). Sampling under "quiet" conditions, such as at night, may be misleading because asbestos fibers more likely

would become airborne as a result of disturbance through human activity.

Reference [5] lists the following criteria as basic to any air monitoring

program:

1/ Research Triangle Institute, Research Triangle Park, North Carolina.

40
1. Samples obtained should be representative of the airborne fibers at

the sampling point.

2. Numbers of samples must be sufficient to compensate for the variation

of concentration with time and space and represent "full shift"

exposure to the worker.

3. Samples taken for short periods of time with low volume personal

monitoring pumps can only be satisfactory in high dust concentrations

where a measurable amount of asbestos can be captured.

4. Long period sampling instruments must be used in low concentrations

to obtain environmentally significant samples.

5. Samples must be taken within the workers' breathing zone or in the

immediate work areas, as well as outside of the controlled area, as necessary, to properly characterize airborne asbestos fiber levels.

6. All persons monitoring asbestos-containing material, as well as persons

evaluating samples of the material, must be judged proficient in these

disciplines, in accordance with generally accepted methods.

Locations and building activities where air monitoring may be conducted include:

A. Occupied Space (offices, medical, food preparation, etc.)

Monitoring devices for collecting personal samples should be placed in

the breathing zone of persons who occupy the room during normal building activities. The exposed filter should face downward within the

breathing zone.

B. Air Return Plenums and Vertical Shafts

In open air return plenums where structural members are coated with

fireproofing containing asbestos, the air should be sampled for

asbestos fibers periodically during normal building activities and

when renovation or asbestos abatement projects are underway. Vertical

shafts which return the air from the horizontal plenums to the main air

supply rooms should also be sampled.

C. Maintenance Activities

Periodic samples should be taken in areas where maintenance activities

are being conducted to determine whether excessive fiber release is

occurring.

D. Building Renovation and Asbestos Abatement Activities

Air monitoring should be conducted during renovation projects which

damage asbestos-containing material and during abatement projects.

Area sampling should be done inside the sealed workspace, immediately

41
outside the workspace, near all major openings, and inside the clean room and decontamination room. Adjacent occupied space and air return

plenums should also be monitored. Personal sampling of abatement

workers should be conducted.

OSHA regulation 29 CFR 1910.1001 sets limits for permissible exposure to

airborne concentrations of asbestos fibers for renovation and asbestos

abatement activities (see appendix A).

4.3. 3.2 Measurement Methods for Air Samples

Phase contrast microscopy is specified in section 1910.1001(e) of Title 29,

Code of Federal Regulations, as the method of fiber content measurement of air

samples (see appendix A). A sample is collected by drawing air through a membrane filter at a known rate. 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 magnification. Particles are observed for shape and size.

Results are presented as the number of fibers per cubic centimeter of air drawn

through the filter. This method has limits on the fiber size range on which it can be used with only particles having a length-to-width (aspect) ratio greater

than 3:1 and a length of 5 yra or greater counted as fibers (see figures 1.2 and

4.1). Secondly, reference [6] points out that fibers other than asbestos (e.g.,

cellulose, glass fibers) which are likely to be present in ambient air would be

counted by phase contrast microscopy. Finally, the measurement method would

miss very thin fibers of any type (<0.5 ym in diameter). It should be noted

that substitution of another fiber measurement method, such as those listed

below, would require a special interpretation by OSHA.

The electron microscopy method permits detailed examination and identification

of asbestos fibers of all sizes. Either scanning electron microscopy or transmission electron microscopy is used. Magnification necessary to identify

asbestos in its smallest dimension is within the range of these instruments.

Fiber size range detected by electron microscopy is all inclusive while that seen optically by phase-contract microscopy is much more limited. In some cases, the distribution of fiber length will fall below 5 ym, producing a zero fiber count by phase contrast microscopy, but the same sample may have a significant fiber count when examined by electron microscopy. Analysis by electron

microscope is extremely expensive (maybe 15 times costlier than phase contrast

microscopy) and time-consuming, and the number of laboratories which can conduct the analysis is limited.

An EPA provisional method [20] is also used for the measurement of airborne

asbestos concentrations. The main features of this method include depositing

an air sample on a polycarbonate membrane filter, examining an electron microscopy grid specimen in a transmission electron microscope and verifying fiber

identity by selected area electron diffraction.

42
RESPIRABLE PARTICLE

§0^00. S ILTj

GROUND TALC

ASBESTOS FIBER

REAL TIME, MONITORING fill

Immi INSTRUMENTS Mm

FINE SAND

HUMAN

HAIR

r—VISIBLE TO EYE machine tools

micrometers

OPTICAL MICROSCOPES 1 c^V SCANNING and TRANSMISSION ELECTRON MICROSCOPES M

X-RAY DIFFRACTION

0.0001 0.001 0.01 0.1 1.0

Size Range, um

10 100 1000

(lmm)

Figure 4.1 Comparison of fiber size range and techniques for

particle size measurement

1 / Taken from reference [5].

43
4.3.3. 3 Comparison of Air Sampling Results With Federal Regulations

Specific guidelines are not currently available for occupant exposure to

airborne asbestos fibers in buildings having in-place asbestos-containing materials (fireproofing, insulation, etc.) that are not disturbed by maintenance,

renovation, or removal activities. What the limit should be is unknown, but

subject to much debate. As noted previously, the EPA has developed some guidelines for schools [3,4,21], but air sampling is not included.

The OSHA regulation 29 CFR 1910.1001 (appendix A) has set the permissible

exposure level for asbestos fibers at 2.0 fibers (longer than 5 pm) per cc of

air on an 8 hour TWA basis for situations where work in the building disturbs

the in-place materials containing asbestos. Allowable concentrations of airborne asbestos fibers when work is taking place is 10.0 fibers (longer than

5 pm) per cc of air.

OSHA also has issued an instruction for Minimum Airborne Fiber Concentrations

for Initiating and Continuing Asbestos Medical Examinations [22]. The enforcement guidelines require that medical examinations be given for an asbestos con- centration equal to or greater than 0.1 fibers, longer than 5 pm, per cc of air on an 8 hour TWA basis.

4.4 AVAILABLE METHODS FOR EVALUATING THE POTENTIAL ASBESTOS EXPOSURE IN

BUILDINGsJ/

Several asbestos exposure indexes have been developed for application in

buildings which are claimed by the developers to provide a basis for making

decisions regarding abatement actions.

EPA published a draft guidance document [4] in 1979 which identified eight

factors which should be considered by school officials when determining whether

a hazardous condition exists due to the presence of friable asbestos. They are;

(1) condition of material, (2) water damage, (3) exposed surface area,

(4) accessibility, (5) activity and movement, (6) air plenum or direct air

stream, (7) friability, and (8) asbestos content (as determined by bulk analysis). This was followed by the development of a "Draft Asbestos Exposure

Assessment Algorithm" [23] which is a methodology for obtaining a quantitative

exposure number which can be used to select various options for asbestos

control. EPA has the algorithm under evaluation and has not, as this writing,

published it in final form.

The algorithm was prepared taking into account fiber characteristics, asbestos

risk factors, and experience with school exposure situations. It does not

consider factors such as duration of exposure and population characteristics.

— NBS has not evaluated these methods and neither endorses nor disapproves

their application. They are included for the reader as a guide for the

assessment and abatement of asbestos-containing materials. It is recommended

that the reader contact the organizations which developed these evaluative

methods if additional information is required.

44
There are three steps in applying the guide: (1) the eight factors are assigned

a numerical value corresponding to their proper description; (2) the numerical

values are combined by a mathematical formula to produce the exposure number;

and (3) the exposure number is compared to the corrective action scale.

GSA has taken the EPA algorithm developed for schools and modified it to be more representative of highrise buildings which are owned and leased by the Federal

Government [24].

The Navy has developed a hazard index (see section 3.3.3) with the assumptions

that potential health hazards associated with the presence of friable asbestos

depends on; (1) the level of exposure, (2) the number of persons exposed to

asbestos fibers; and (3) the duration of exposure [5]. The level of exposure

depends on the percent of asbestos fiber as determined by bulk analysis, friability of the material, and level of activity in the space where asbestos is

located. The index recognizes that as the number of people exposed to a particular concentration of airborne asbestos fibers increases, the chance of some adverse effects also increases. Therefore, the asbestos hazard index number

will be greater where a large number of people are exposed than for a situation

where lesser numbers of people are exposed. The length of time an individual

is exposed to a given level of asbestos fibers contributes to the likelihood

of adverse health effects. Therefore, the hazard index number will be greater

when the number of hours that individuals are exposed in a year is greater.

Application and testing of this index is underway in U.S. Navy facilities.
5. ASBESTOS ABATEMENT TECHNIQUES [5]

Selection of the appropriate corrective measure to accomplish the most efficient

long-term asbestos abatement solution should be based on the condition of the

asbestos-containing material, its location, the function and occupancy of the

work area, and the cost. Each building area containing such material should be

considered separately in evaluation and selection of abatement techniques.

In the selection of a corrective measure or technique, it should be determined

whether the situation requires entire removal of asbestos materials to eliminate

exposure or merely control of the exposure by containment methods. Encapsulation and enclosure are containment methods that only prevent or reduce exposure

to asbestos-containing material but do not eliminate the source. Consideration

should be given to the effectiveness and permanency of containment methods.

The source of airborne asbestos fibers may reappear because of inadequate longterm performance of corrective abatement techniques or materials and damage to

corrected areas caused by repair or remodeling activities. The two approaches

to the control of airborne asbestos fiber levels may be either interim or longterm measures. Two important considerations in the selection of either of these measures are the level of deterioration of the asbestos-containing material and

function of the material. For example, if fireproofing has deteriorated to the

point that the required protection is no longer provided to structural members,

interim measures may not be a proper selection even though very feasible.

5.1 INTERIM CONTROL MEASURES

EPA has prepared guidelines for establishing and maintaining a management

system for asbestos-containing materials in schools [21]. The document recommends that an asbestos management system should be implemented for each building with friable asbestos-containing material in order to control the level of

airborne asbestos fibers and to coordinate related activities. During the

period between identification and resolution of an asbestos exposure problem,

the management system team should establish an educational and training program

and procedures that will reduce levels of airborne asbestos fibers by control

of maintenance, custodial, and repair activities. If a containment abatement

measure is selected, a continuing inspection and monitoring program should be

initiated. The management, system team should offer to oversee the engineering

program and should be composed of members from the buildings’ architectural/

engineering staff, planning and estimating office, building maintenance shop,

safety office, and if available, an industrial hygienist.

The management system program should include as a minimum, the following

activities:

• An educational program to inform the occupants of the building of the

asbestos-containing materials.

• A recordkeeping system on file with the building's architectural/

engineering staff and with the building's maintenance personnel.

• Records of the location of the asbestos-containing materials and of

inspections and reevaluations of the conditions of these materials.

46
• Periodic surveys for detecting any changes in the condition of the

asbestos-containing materials.

• Maintenance work procedures to limit the release of airborne asbestos

fibers.

• Proper dust control procedures for the custodial staff.

In the interim period, the level of airborne asbestos fibers may be reduced

significantly during essential custodial work if oil-treated dust mops and

cloths or damp mops are used Instead of dry dusting and sweeping. Vacuuming

should be carried out using high efficiency particulate air (HEPA)i' filtered

vacuum cleaners or other systems to effectively filter asbestos fibers. An

industrial hygienist can advise and approve proper custodial methods and

equipment to reduce levels of airborne asbestos fibers.

5.2 LONG-TERM CONTROL MEASURES

The long-term control measures include containment and removal methods.

Containment methods include encapsulation and enclosure, and removal may be

accomplished by wet or dry methods. These long-term methods can be used separately or in combination in a building. A brief description of these methods

follows:

® Encapsulation - asbestos-containing material is coated or impregnated

with a bonding agent or sealant which restricts release of fibers.

o Enclosure - asbestos-containing material is separated from the building

work area environment by barriers such as impervious sheathing.

• Wet Removal - asbestos-containing material is removed using amended

water (wetting agent) and disposed of by burial in sealed containers

at an EPA-approved landfill site.

• Dry Removal - asbestos-containing material is removed dry and disposed

by burial in sealed containers at an EPA-approved landfill site.

Removal or containment of asbestos-containing material generally requires

specialized equipment and persons involved in working with the material who

should be made aware of EPA, OSHA, and local regulations and standard procedures

through training. Superintendents, foremen, and contract inspectors should

check for compliance with regulations and proper work practices.

5.2.1 Containment

Containment of asbestos-containing material by encapsulation or enclosure

systems in general takes less time than removing the material and is less

1/ HEPA filters in conformance with ANSI Z9. 2-1971," Design and Operation of

Local Exhaust Systems."

47
expensive, especially if replacement of material can be avoided* It must be

understood that the airborne asbestos fiber source remains and that damage,

deterioration, or failure of the protective system may result in recurrence of

asbestos fiber release. Therefore, the selection of containment as a control measure requires that a periodic inspection program be established* This is

necessary to ensure that the protective system maintains its integrity over long periods of time, especially over the expected service life of the protective system. If a containment system is selected, strictly controlled maintenance and custodial activities are required for the life of the building, as long as asbestos-containing material is present. Problems may recur later when

a building is renovated or demolished if asbestos-containing materials are damaged. Encapsulation and enclosure measures are discussed below.

5.2. 1.1 Encapsulation

Encapsulation involves sealing asbestos-containing materials with an appropriate

coating. Sealing of surfaces of asbestos-containing materials is accomplished

by applying a coating material that will envelop or coat the fiber matrix,

restricting the release of fibers, and afford protection against contact

disturbance. Encapsulation should not be chosen if the asbestos-containing

material is not well bonded to the substrate.

Sealants are of two types: those that penetrate the sprayed asbestos material

and those that cover or bridge the material with a tough protective coating.

Each of the two types of sealants has some specific advantages. Penetrating

sealants cause improved cohesive strength and impact resistance of friable

materials when the matrix is sufficiently saturated. Penetrating sealants also

exhibit varying degrees of penetration from about 13 to 32 mm (1/2 to 1-1/4 in).

Some may penetrate to the substrate or structural member to which the friable

asbestos is applied. The bridging type of sealants exhibit, in general, better

flexibility and abrasion resistance than the penetrating types and form a con- tinuous surface membrane over the asbestos-containing material. Sealants cur- rently available include water-based latex polymers, water-soluble epoxy resins,

and organic solvent-based polymers. See section 3.4.1 for discussion of an ongoing ASTM standards activity on encapsulating agents for asbestos-containing

material.

Encapsulation can be a practical method to control the release of asbestos

fibers, but certain limitations make it useful only in a relatively small

number of cases. Encapsulation is often advisable in situations where the

asbestos-containing material is virtually impossible to remove such as on denser, harder materials generally referred to as trowelled on or cementitious

materials [25]. EPA estimates that encapsulation is an appropriate control

technique in no more than 10 to 15 percent of all cases where asbestoscontaining material requires corrective action [25].

Encapsulation of friable asbestos-containing material should not be considered

when the surfaces of these materials are:

accessible to personnel (low ceilings, corridors, or stairwells);
• potentially subject to physical damage (by vandalism, sports

activities, routine maintenance, or general use of building);

• potentially subject to water damage (history of roof leaks,

plumbing problems, or accumulation of condensation); or

• potentially subject to forceful structural vibrations (rooms

below or adjacent to heavy moving equipment or sports activity).

The best way to determine whether an encapsulant will perform on a given

surface is to field test it by applying it to a small section of the surface.

Several encapsulants should be field tested in this manner before a final

decision is made regarding which one to select.

The use of sealants is governed by the characteristics of the friable material

surface. Integrity of an encapsulated surface depends upon the bond between the

material and substrate to which it was applied and the cohesive strength of the

friable material. A sprayed ceiling, for example, with initially poor adhesion

to a smooth, hard structural ceiling surface, may result in bond and shear failure of the total thickness of sprayed asbestos containing the applied sealant.

5.2. 1.2 Enclosure

Enclosure of sprayed asbestos-containing material involves placing an impervious barrier between the material and areas of building occupancy. These

enclosures could be placed either on walls or ceilings. Depending upon the

integrity and type of barrier system, fiber fallout will occur only behind the

barrier, and exposure outside the barrier will be greatly reduced. Entry into

these enclosed areas requires protection of personnel and fiber containment

precautions.

In selecting an enclosure system, consideration must be given to existing

plumbing, electrical or mechanical systems which require accessibility for

maintenance, repair or renovation. If the sprayed asbestos-containing material

behind the enclosure is disturbed during maintenance on heating, ventilating,

lighting, or plumbing systems, asbestos fibers may be released into the building, especially if it is an open air return plenum. Where possible, all utilities should be removed and rerouted from the enclosure space, and, when

feasible, access should not be built into this space. The space behind a barrier system should not connect with an air plenum, and air from the enclosed

space should not circulate within the occupied building unless a HEPA filtration

system is installed for cleaning return air. Fire sprinkler systems may require

relocation.

Like encapsulation, enclosure reduces the potential for dispersal of airborne

asbestos fibers but does not eliminate the source and poses similar problems as encapsulation during building renovation or demolition. Enclosure of asbestoscontaining material can be selected as a control measure, provided that the

material will not be expected to be subjected to: (1) frequent damage during

routine maintenance activities; (2) water damage; and (3) condensation buildup.

49
5.2.2 Removal

Removal of asbestos-containing material provides a long-term solution by

elimination of the fiber source. Removal of friable asbestos material poses

significant problems of worker protection, prevention of environmental con- tamination, and considerable interruption of building activities. Replacement

with asbestos-f ree material must also be considered.

Removal of sprayed asbestos material may be considered [5] when any one of the

following conditions is present:

• The material is friable and significantly deteriorated or damaged.

• The material is accessible and potentially subject to damage by

vandalism or activities in the space.

• The material will be damaged during routine maintenance activities.

Critical factors which must be considered in the decision to remove sprayed

asbestos-containing material include building characteristics, inability to

eliminate exposure in another way, surfaces to which the material is applied,

and cost. Asbestos-containing material may be removed by dry or wet methods.

5.2.2.

1

Dry Removal

Dry removal of asbestos-containing material is not recommended by EPA, but may

be necessary if unavoidable damage to building components, utility systems, and

equipment would occur through the use of water amended with a wetting agent or

if temperatures are below freezing [5]. If it is necessary to use the dry

removal technique, extreme caution must be exercised to prevent contamination

of workers, of areas outside the controlled area, and of the environment from

the uncontrolled release of asbestos fibers. If well-managed, however, dry

removal can be successfully performed. Written permission from EPA is required

for dry removal.

5. 2.2.2 Wet Removal

Airborne asbestos fiber levels in removal operations may be reduced by using

wet removal instead of dry removal [5]. Wet removal is based upon the ability

of water to lower both the friability of asbestos-containing material and the

airborne concentration of released fibers, thus reducing airborne asbestos

levels. Because of the additional weight, released fibers settle rapidly. Use

of plain water may not be entirely satisfactory because of slow penetration,

incomplete wetting, and runoff. Even with extensive soaking, areas of dry

material will remain. Runoff is not only a safety and cleanup problem but can cause corrosion on metal parts of equipment and electrical systems as well as damage to floor surfaces (peeling of tile). The resulting slurry can also be

transported by foot traffic to nonremoval areas, where fibers will reentrain

following evaporation of the water.

Water penetration into a fiber matrix may sometimes be significantly increased

with a wetting agent or surfactant which reduces the surface tension of water

50
droplets. Water amended with a wetting agent is commonly used by fire

departments, industry, and agriculture. This wetting technique reduces the

amount of water needed for saturation, increases cohesiveness of the fiber

matrix, and increases the probability of individual fiber wetting. 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 and significantly improves working

conditions, but relieves some of the dependence upon containment barrier

systems in confining fibers to the removal area. Written permission from EPA

is required for wet removal [5].

5.3 GUIDELINES FOR SELECTING APPROPRIATE ABATEMENT TECHNIQUES

Guidelines for selecting appropriate abatement techniques are presented in

table 5.1. This table contains a summary of corrective methods in addition to

information about the advantages and disadvantages of each method, and

conditions for which each method is appropriate or inappropriate.

In addition to the information presented in table 5.1, the following additional

factors should be considered in the selection of control measures.

• If the material is removed and fireproof ing/ thermal/sound insulation

requirements still exist, material with similar performance

characteristics must be applied.

• If the asbestos-containing material is accessible below the (2.7 m)

9-ft level on walls, the material will be subject to future accidental

or intentional contact and damage. However, in warehouses, gyms and

similar facilities, the level to which material is subject to contact

and damage is higher than the (2.7 m) 9-ft level.

• If the asbestos-containing material is not removed, the problem must

be addressed at the time of demolition.

• If an enclosure system is used, thermal insulating material will still

be functional. Condensation problems and water problems, however, may

still occur.

51
Table 5.1 Guidelines for Selecting Appropriate Abatement Techniques (5, 21)

Method Advantages Disadvantages When Appropriate When Inappropriate

Encapsulation Controls exposure without removal of asbestos.

Asbestos source remains.

Fireproofing, acoustical, or thermal qualities may be reduced.

Removal not feasible. Removal feasible.

Material has poor adhesive

or cohesive strength.

Weight of sealant may

cause delamination.

Usually most rapid

and economical.

If material is damaged

or deteriorating, additional

weight of the sealant may

cause delamination.

Material still retains

bonding integrity.

Material is deteriorating

or severely damaged.

Management system required;

precautions necessary to prevent damage during

maintenance of renovation

Damage to material not probable.Damage to material is probable.

Continuing inspections

required to check for damage to encapsulated

surface.

Limited accessibility

of material. Water damaged materials.

Materials are more than

one inch thick.

Maintenance of damaged or deteriorating encapsulated

surfaces required.

Complex surfaces to be covered.In rooms which are subjected to high

vibration.

Encapsulated material is difficult to remove. Economic or time

advantage.

Enclosure Controls exposure. Asbestos source remains. Removal not feasible. Removal feasible.

Damaged or deteriorating

material causing high

levels of fiber fallout.

May be rapid,

economical uncomplicated method.

Fiber fallout continues

behind enclosure.

Disturbance or entry

into enclosed area not likely.

Water damaged materials.

May be costly if enclosure

disturbs functions of other

systems (e.g. , enclosure

may require lighting and plumbing changes).

Economic advantage. Damage to enclosure

likely.

Entry into enclosure

probable for repairs

and maintenance.

Management system required;

precautions necessary for entry into enclosure for maintenance or renovation.

Material is accessible. Continuing inspection

and maintenance of enclosure doubtful.

1

52

!<
t

j Table 5.1 (Continued)

Method Advantages Disadvantages When Appropriate When Inappropriate

Enclosure

(continue)

Continuing inspection

required to check for damage to enclosure system.

Maintenance of damaged

enclosure system required.

Wet Removal

| (Must obtain

EPA approval)

Eliminates asbestos

source. Usually one of the most

costly and complicated

methods.

High exposure. Removal is not feasible

because of cost, location

of material, and kind of surface to which material

has been applied (e.g.

,

removal of material from

complex surfaces such as pipes, lines, and ducts).

Ends exposure

possibility.

Usually one of the most time-consuming methods.

Replacement with substitute

material may be necessary.

Material is deteriorating

or damaged.

Material is accessible.

When temperature is below freezing.

Corrosion a problem.

Dry Removal

(Must obtain

EPA approval)

Eliminates asbestos

source. Usually one of the most costly and complicated

methods.

High exposure. Removal is not feasible

because of cost, location

of material, and kind of surface to which material

has been applied (e.g.,

removal of material from

complex surfaces such as pipes, lines, and ducts).

Ends exposure

possibility.

Usually one of the most time-consuming methods. Material is deteriorating

or damaged.

When wet removal is appropriate.

Replacement with substitute

material may be necessary. Material is accessible.

Extremely high potential

for worker exposure. Temperatures are below

freezing during removal

operations.

Corrosion of metallic

connectors is of major

concern.

53

b
r

6.

REFERENCES

I 1. Asbestos-Properties, Applications, and Hazards , Volume 1, Edited by L.

Michaels and S. S. Chissick, John Wiley & Sons, 1979.

2. Asbestos: An Information Resource , Richard J. Levine, Editor, U.S.

Department of Health, Education, and Welfare, DHEW Publication Number (NIH)

79-1681, May 1978.

3. Asbestos-Containing Materials in School Buildings: A Guidance DocumentPart 2 , U.S. Environmental Protection Agency, March 1979.

4. Asbestos-Containing Materials in School Buildings: A Guidance Document - —Part 1, U.S. Environmental Protection Agency, March 1979.

5. Management Procedure for Assessment of Friable Asbestos Insulating Material , Technical Report R883, Civil Engineering Laboratory, Naval Construction

Battalion Center, February 1981.

6. Asbestos Contamination of the Air in Public Buildings , William J. Nickolson,

et al. , Mount Sinai School of Medicine, Prepared for U.S. Environmental

Protection Agency, NTIS No. PB 250980, October 1975.

7. School Asbestos Program Questions and Answers , U.S. Environmental

Protection Agency, April 1979.

,

[ 8. Workplace Exposure to As best os -Review and Recommendations, DHHS (NIOSH)

Publication No. 81-103, NIOSH-OSHA Asbestos Work Group-April 1980, U.S.

Department of Health and Human Services and U.S. Department of Labor,

November 1980.

9. Selected Silicate Minerals and their Asbestiform Varieties-Mlneral

Definitions and Identification-Characterization , Campbell, W.J.,

Blake, R.L. , Brown, L.L. , Cather, E.E. , and Sjoberg, J.J., Information

Circular 8751, U.S. Department of the Interior, Bureau of Mines, 1977,

(56 p.)

10. Asbestos: Health Precautions in Industry , Health and Safety Executive, Her

Majesty’s Stationary Office, Edinburgh, Scotland, 1977.

11. Guide Specifications for the Abatement of Asbestos Release from Spray- or Trowel-Applied on Asbestos-Containing Building Materials in Structures , Published by the Foundation of the Wall and Ceiling Industry, December

1981.

12. Tentative Guide Specifications on Asbestos Abatement Procedures , PBS (PCD)-01547T, General Services Administration, Washington, DC,

October 1982.

13. Removal and Disposal of Asbestos Materials , Draft NAVFAC Guide

Specifications, Section 02075, January 1982.

54
14. Control of Asbestos Exposure to Naval Personnel and Environs , OPNAV

Instruction 6260. IB, February l2, 1^82.

15. ASTM Standard E849-82, Standard Practice for Safety and Health

Requirements Relating to Occupational Exposure to Asbestos , American

Society for Testing and Materials, Philadelphia, PA, 1982.

16. Asbestos-Containing Materials in School Buildings: Guidance for Asbestos

Analytical Programs , U.S. Environmental Protection Agency 560/ 13-80-017A,

December 1980.

17. Quick Screening Test for Asbestos , W.S. Kim and J.W. Carter, II, American

Industrial Hygiene Association Journal, pp. 198-201, March 1981.

18. Preparation of Asbestos "Standards" for Methods Verifications and

Laboratory Evaluation , Lentzen, D.E. , Brantly, E.P., Gold, K.W. , and

Myers, L.E. , National Bureau of Standards Special Publication 619, Asbestos

Standards: Materials and Analytical Methods, March 1982, pp. 44-52.

19. An Overview of Electron Microscopy Methods , Rudd, Clayton 0., NBS Special

Publication 506, Proceedings of the Workshop on Asbestos: Definitions

and Measurement Methods, Gaithersburg, Maryland, July 18-20, 1977, Issued

November 1978, pp. 221-233.

20. Electron Microscope Measurement of Airborne Asbestos Concentrations-A

Provisional Methodology Manual , Samudra, Anant V., Harwood, Colin F.

,

Stockman, John D. , EPA-600/2-77-178 Revised June 1978, Environmental

Sciences Research Laboratory, Office of Research and Development, U.S.

Environmental Protection Agency, Research Triangle Park, N.C. 27711.

21. Asbestos-Containing Materials in School Buildings: A Guidance

Document-Part 3 , Environmental Protection Agency, August 1981.

22. Minimum Airborne Fiber Concentrations for Initiating and Continuing

Asbestos Medical Examinations, OSHA Instruction CPL 2-2. 21A, February 18,

1981.

23. Draft Asbestos Exposure Assessment Algorithm , Office of Toxic Substances,

U.S. Environmental Protection Agency, September 21, 1979.

24. GSA Asbestos Exposure Algorithm , General Services Administration, Accident

and Fire Prevention Branch, Washington, D.C.

25. Guidelines for the Use of Encapsulants on Asbestos-Containing Materials , Office of Toxic Substances, U.S. Environmental Protection Agency, June

1981.

55
jII
APPENDIX A - SUMMARY OF EPA AND OSHA ASBESTOS REGULATION si/

EPA 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 operations 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

§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 stanwork practice dards, notification requirements, stripping

requirements of friable asbestos material, wetting, exhaust

ventilation systems, restriction of spraying

of asbestos containing material, waste material

handling and labeling, and disposal 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.

Procedures to prevent emissions are described:

adequate wetting, local exhaust ventilation

systems, proper movement and handling, and

exceptions to wetting requirements.

Spraying of over one percent asbestos material

on structural members is prohibited. Waste

disposal methods in renovation shall not produce visible emissions: waste material will

be placed in locktight container while wet,

and disposed of in sites in accordance with

provisions of §61.25.

1 / Taken directly from reference [5].

A-l
§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 resolve certain

ambiguities and omissions in the present standard.

The applicability of regulations on renovations, removing, and stripping

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.

OSHA REGULATIONS PERTAINING TO ASBESTOS

Applicable regulations of the Occupational Safety and Health Administration

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 . are summarized below:

Section 1910.1001 Content

(a) Lists definitions. Definitions of asbestos and asbestos fibers,

size limitation of 5 micrometers or longer.

(b) Sets limits for permissible Eight-hour time-weighted average TWA: two

exposure to airborne concen- fibers, longer than 5 micrometers, per

trations of asbestos fibers. cubic centimeter of air (f/cc). Maximum

concentrations: 10 f/cc.

(c) Methods of compliance,

recommend methods to meet

limits for exposure.

(1) Engineering methods: isolation,

enclosure, ventilation, dust collection,

should be used to meet the exposure limits.

(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 specific

requirements for both respiratory protection and special clothing for removal

workers.

A2
(d) Personal protective equipment

is specified for various

conditions.

Respiratory protective equipment and

special clothing are required whenever the

exposure limits can reasonable be expected

to be exceeded. Equipment approved by the

agency is referenced.

Respiratory protection:

(d)(2)(i) Concentrations up to ten

times the allowable limit (20 f/cc

TWA, or 100 f/cc ceiling limit): air

purifying respirator.

(d)(2)(ii) Concentrations up to 100

times the limit (200 f/cc TWA, or 1000 f/cc ceiling limits) require

powered air purifying respirator.

(d)(2)(iii) Concentrations above 100

times the limit require type "C" 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.

Section 1910.1001 Content

(e) Method of measurement of

fiber concentrations is

defined.

Determinations of airborne concentrations

of asbestos fibers shall be made by the

membrane filter collection method with

phase contrast microscopy.

(f) Specific procedures of

measurement and monitoring

Personnel monitoring, environmental monitoring, and frequency of monitoring are covered.

(g) Caution signs and labels

are defined.

Specifications and use of signs are outlined. Posting of work sites and use of

caution labels on asbestos material are described.

(h) Housekeeping to reduce

exposure and waste disposal

methods are described.

Cleaning of all objects of accumulated

asbestos debris, and sealing in impermeable, sealed containers.

(i) Specifies recordkeeping and

requirements for maintenance

and retention of records.

Employer records on exposure. Time

requirements and record disposition are covered. Records of monitoring should be

retained for three years.

A(J) Lists medical examination Applicability, specific requirements,

requirements. frequency of medical evaluations. Annual

and termination examination requirements

are listed.

A4
APPENDIX B REGIONAL OFFICES OF THE

U.S. ENVIRONMENTAL PROTECTION AGENCY AND THE

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

Deleware, 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, Michigan, Ohio, and Wisconsin

230 South Dearborn Street

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

324 E. 11th Street

Kansas City, Missouri 64106

(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

215 Fremont Street

San Francisco, California 94105

(415) 556-2320

Region X

Alaska, Idaho, Oregon, Washington

1200 Sixth Avenue

Seattle, Washington 78101

(206) 442-1220

B-l
APPENDIX B (cont)

OSHA REGIONAL OFFICES

Region I Connecticut, Maine, Massachusetts,

New Hampshire, Rhode Island

and Vermont

16-18 North Street

1 Dock Square Building

Boston, Massachusetts 02109

(617) 223-6712/3

Region II

New York, New Jersey, Puerto Rico,

Virgin Islands, and Canal Zone

1515 Broadway

(1 Aster Plaza)

New York, New York 10036

(212) 399-5941

Region III

Deleware, 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

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, Missouri 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) 837-3883

Region IX

Arizona, California, Hawaii, Nevada,

Guam, American Samoa, and

Trust Territory of the Pacific

P.0. Box 36017

9470 Federal Building

450 Golden Gate Ave.

San Francisco, California 94102

(415) 556-0586

Region X

Alaska, Idaho, Oregon, Washington

Room 6048

Federal Office Building

Seattle, Washington 98174

(206) 442-5930

B-2
NBS»114A (REV. 2-ao) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 83-2688

2. Performing Organ. Report No Publication Date

May 1983

4. TITLE AND SUBTITLE

Guidelines for Assessment and Abatement of Asbestos-Containing Materials in Buildings

5. AUTHOR(S)

James H. Pielert, Robert G. Mathey

6. PERFORMING ORGANIZATION (If joint or other than NBS. see Instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

S. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Public Buildings Service

Office of Design and Construction

General Services Administration

Washington, DC 20405

10. SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information,

bi bliography or literature survey, mention it here)

If document includes a significant

This report presents guidelines for the assessment and abatement of asbestoscontaining materials in buildings based on available information. Background

information is given on the history and use of asbestos-containing products in

buildings, and regulations pertaining to their use. Included are control measures for buildings containing asbestos materials, procedures for determining

condition of the materials, and abatement techniques for containment and

removal. A summary is presented of recent guide specifications and standards

developed by industry, government agencies, and a standards organization which

are related to asbestos-containing materials in existing buildings. These

documents include guidance for the control, assessment, and abatement of such

materials.

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

abatement of asbestos; asbestos; buildings; fireproofing; insulation; regulations;

structural steel

13. AVAILABILITY

[X^] Unlimited

| | For Official Distribution. Do Not Release to NTIS

PH Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

|—

|

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

75

15. Price

Wo. 00

USCOMM-DC 8043-P80