United States
Environmental Protection
Agency
Toxic Substances
Summary of the Conference
on Encapsulation of
Asbestos-Containing
Building Materials
June 8-9, 1981
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Conference on Encapsulation of Asbestos-Containing Building Materials
The first day of the conference was devoted to the history
and current status of EPA programs and other research and
study on encapsulants and encapsulation. The speakers were
Larry Dorsey, William Mirick, Ernest Lory, and James
Hubbard.
Larry Dorsey: Mr. Dorsey is manager of EPA's school
asbestos program. EPA has analyzed the encapsulation prob-
lem for 2 years. At present, the American Society for Testing
and Materials (ASTM) is developing performance standards
for encapsulants; the testing of encapsulants will then be
turned over to the private sector. In 1978, the Environmental
Defense Fund petitioned EPA to regulate asbestos in schools
under the Toxic Substances Control Act. Very little was
known about asbestos in buildings at that time. The most
thorough research had been done by Dr. Robert Sawyer at
Yale in 1977. Since many school systems were trying to
operate without good technical information, EPA contacted
experts (among them Dr. Sawyer) to develop a guidance
document, which all the school systems now have. EPA then
began development of a regulation and has since developed
some guidelines. EPA recommends that school systems deal
with asbestos in schools by removing the asbestos, encap-
sulating it, enclosing it, or, in some cases, setting up a
maintenance program and deferring action.
A commonly used method of applying asbestos during con-
struction of schools is to spray it on to beams, ceilings, and
other structural members. In 1973, EPA banned any future
application of asbestos by spraying. In 1978, HEW notified
health departments across the Nation of the problem but
offered no guidelines for dealing with it.
EPA originally envisioned a program requiring the inspection
of every school and an abatement program to correct any
problems. However, EPA has, at this time, proposed a regula-
tion that would require only the identification of all asbestos
materials in schools, a notification to all employees that
asbestos is present or absent, and the establishment of an
asbestos management system where the presence of
asbestos can be verified. No corrective action would be
required. Since disturbing asbestos is hazardous, certain
precautions must be taken, and certain techniques must be
used. EPA is now researching aspects of the asbestos pro-
gram, developing an exposure assessment system, and pro-
viding technical assistance to building officials on how to deal
with their problem. Battelle Columbus Laboratories is issuing
a final report on encapsulants in late summer and Mr. Forest
Reinhardt is in charge of distribution.
William Mirick: Mr. Mirick works for Battelle Laboratories
and for 2 years has done research for EPA on encapsulants.
His presentation describes the basic studies that they
performed.
One problem Battelle encountered was to find a test matrix
that simulated the asbestos materials found in the field. There
is no "typical" asbestos-containing matrix, so Battelle chose a
matrix containing 35% chrysolite mixed with mineral wool as
the base for its study. Battelle used Cafco Blaze Shield CF for
its test matrix because it simulated the properties of this
asbestos-containing material. Cafco Blaze Shield is a mineral
wool substrate with the same water penetrability and the
same degree of impact resistance as this asbestos-containing
matrix. The mineral wool has many other qualities similar to
those of the asbestos-containing material: similar surface
properties and similar penetration qualities. It does not,
however, contain asbestos.
In the field, each material must be examined for differences
and individual tests should be run because the applicator
sometimes changes the product during application. Such
changes can include surface charge and the penetration
qualities. Therefore, an encapsulant may behave differently
when applied to different types of insulation. However, Bat-
telle could run tests on only one test matrix, which is part of
the current problem.
The tests were conducted on the mineral wool friable matrix
sprayed on a surface board. A penetrating test was devised
by first screening the materials in a simple pouring operation
on the friable surface. In the screening, some of them
bunched up and did not penetrate. A final test was devised
that more nearly matched field conditions, in that the encap-
sulant was sprayed on panels mounted upside down.
Sometimes adhesion occurred and sometimes it did not. To
test the penetration, Battelte took core samples and soaked
them in a vial of water. They then measured the core to test
penetration. Battelle measured the impact resistance by drop-
ping a known weight a known distance on the encapsulated
test matrix. They also tested the amount of smoke released in
a fire and determined that, when encapsulants are applied to
friable materials, smoke amounts are higher than they are on
asbestos board or plywood. The flame spread rating also in-
creases.
Encapsulants can be either penetrating or bridging.
Penetrating encapsulants are fairly low in solids and are
therefore low in viscosity (about as thin as water). They are
usually 15 to 35 percent solids and are not pigmented. Bridg-
ing encapsulants have a much higher viscosity, are higher in
solids, and are usually pigmented. Because bridging encap-
sulants are high in viscosity, they do not penetrate as well.
With careful application they can penetrate up to one half
inch, but this penetration may take 3 or 4 coats.
Penetrating sealants, when applied correctly, encapsulate
each asbestos fiber, resulting in a matrix somewhat like vinyl
floor tile. Bridging sealants do not penetrate as well but
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Conference on Encapsulation of Asbestos-Containing Building Materials
bridge better on beams and contoured surfaces. Using bridg-
ing encapsulants on large flat surfaces may cause serious
problems. Without support, large surface areas may hang
down, releasing fibers. Mr. Mirick believes strongly that only
15 to 20 percent of the jobs around the country should use
encapsulation.
The following rules should be used when considering
encapsulation:
• Never use encapsulation on material where there is
evidence of water damage.
• Never use encapsulation for a friable asbestos material 2
or more inches thick without some new means of sup-
port (chicken wire has been used).
Difficulties arise in encapsulating an area that has already
started to deteriorate and is hanging down in clumps. ASTM
has devised a test which involves hanging a 2-pound weight
on a jar lid attached to the asbestos-containing material to
test its cohesive strength. Materials with poor cohesive
strength should not be encapsulated.
Most tests were done on the test matrix and are not all en-
compassing. Therefore, Mr. Mirick strongly recommends that
contractors test the actual substrate to be encapsulated. Tests
include a hand brush test (if clumps are disturbed, the sealant
is not adequate) and a simple test to determine whether the
encapsulant has adhered to the surface of the matrix. Ten of
the 150 encapsulants tested proved acceptable on the mineral
wool test matrix.
An extensive question and answer period followed. Issues
raised included the massive problem of getting the material
studies to the public and the legal problems that may arise
with or without a law. It was also pointed out that latex paint
is usually no sollution, although it is being used in some
cases. It may actually create bigger problems.
Ernest Lory: Mr. Lory works for the Navy Civil Engineering
Laboratory in California.
Because of the increasing awareness of the danger of
asbestos fibers in causing cancer, the Navy launched a pro-
gram to survey its shore properties. The program involved
22,000 buildings. They found that friable insulation material
(FIM) containing asbestos had been used in offices, schools,
gymnasiums, pools, industrial facilities, and machine shops.
The Navy's friable asbestos abatement program consisted of
surveying the buildings, locating and identifying the FIM, and
sampling it. (The Navy also uses the term SAI, short for
Spray-Applied Insulation, to mean any insulation that can be
crumbled, pulverized, or reduced to powder in the hand. SAI
is synonymous with FIM.) FIM, which can be collected by
scraping a plastic scraper across the surface, has three
categories: fibrous insulation, granular/cementitious insulation,
and insulating/fireproofing concrete. Fibrous FIM may contain
asbestos. Tamped finishes are usual where FIM is in view.
Untamped fibrous FIM is found in areas of limited access,
boiler rooms, penthouses, etc. Granular/cementitious material
has a course granular surface and can be wiped by hand. It is
used to absorb sound and for decoration. Insulating/fireproof-
ing concrete is foamy in appearance and may contain ver-
miculite or mica. Insulating concrete is used on steel high-rise
structures and is normally hidden from view. However, it may
release fibers into the air system. After World War II,
asbestos was used in amounts of 20 to 30 percent, usually of
the chrysotile group. After the EPA restrictions, mineral wool
and vermiculite more or less replaced asbestos.
FIM materials look deceptively similar, may contain
vermiculite, rockwool, or fibrous glass, and may contain from
0 to 100 percent asbestos. Therefore, use of the petrographic
microscope, a transmitted polarized light microscope (PLM)
with dispersion staining, has become standard in analyzing
the bulk material. Slide analyses of the differing types of
materials used in buildings reveal some general charac-
teristics, although each building and situation must be
separately analyzed, since various compounds of binders are
used by applicators.
Mr. Lory then showed slides that demonstrated the analysis
of the fiber contents and the binding agents used in the
matrix.
X-ray techniques are used on suspect samples, and a pattern
uniquely characteristic of any crystalline materials is pro-
duced. This was used for quality control on PLM analysis.
After analysis, material condition, location, function, and cost
are considered in selecting the best corrective action. Basic-
ally, personnel must decide whether to remove the asbestos
or control exposure by containment. Enclosure and encapsula-
tion are the containment methods available.
The time lag before corrective action should be covered by
an interim control program that comprises the following:
• An information network to inform the occupants
• Alerts to maintenance personnel of the hazards
• Periodic air inspections
• A plan to establish procedures for tradespeople that will
protect them and not disturb fibers.
Removal is recommended when the following conditions
appear:
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Conference on Encapsulation of Asbestos-Containing Building Materials
• The material is friable and deteriorated
• The material is accessible and subject to damage by van-
dals or routine activities
• The material would be damaged by maintenance
activities.
Enclosure by barrier and wainscotting can be used if the air
from the enclosed space does not connect to the air plenum.
Enclosure cannot be used if maintenance activities disturb it,
if water damage could occur, or if condensation builds up.
Encapsulation integrity depends on the bonding qualities of
the asbestos material and the internal cohesion of the FIM.
Therefore, the amount of deterioration or water damage
should be assessed before deciding on encapsulation.
Encapsulants are composed of three parts: the volative vehi-
cle (solvent), the nonvolatile vehicle (resin), and the pigment.
The pigment and resin are in the solvent, which evaporates
as the coating cures. The resin is the binder that forms a film,
which is the important feature of the encapsulant. The resin is
composed of polymers or prepolymers that make up the
coating film. When the pigment content is low the resin con-
tent is high, and the encapsulant therefore has more binding
quality. Three encapsulating categories must be looked at in
choosing a product: the performance on different substrates,
the compatibility with other coatings, and the flexibility and
toughness. Also, the ASTM committee is trying to find a
standardized definition of friability and is working on an
asbestos material classification system. The use of bridging
versus penetrating materials is also being addressed.
(At this point several slides of top surfaces and cross-
sectional surfaces of FIM encapsulated with different sealants
were shown to illustrate the penetration and binding qualities
or lack of such.)
The Navy will continue work in this field for 1 year and will
try to further characterize encapsulating agents and determine
potential field test methods as part of a guide for selecting an
encapsulating agent. Eventually, the Navy hopes to develop a
guide that will state the overall performance of certain'generic
types.
James Hubbard: Mr. Hubbard works at the Engineering
Experiment Station at the Georgia Institute of Technology.
Mr. Hubbard chiefly described his experience with a school
system for which he is analyzing problems concerning
asbestos. The schools in the system were using a material of
25 percent chrysolite and 75 percent mineral wool. It was
sprayed mostly on steel beams above a drop ceiling; how-
ever, the air stream of the building could get fibers in it from
any vibrations. Air monitoring tests using an optical micro-
scope were done before and after the material was sealed.
(Transmission electron microscopy is the preferred method to-
day.)
He did fiber release tests on both the treated and untreated
ceiling and found that more fibers were released from the
sealed ceiling. However, these results were not consistent in
every case tested. He tested five different encapsulants. One
of the sealants did not cause more fibers to be released. The
bridging agents were the worst. He concluded that in areas
where students could disturb the material, sealants or encap-
sulants were not acceptable. His theory was that the sealant
caused the surface of the fiber bundles to harden, but that
the internal fibers could be released by pressure because they
were smaller than the bundles and more airborne.
(At this point Mr. Hubbard showed several cross-section
slides with the sealant in place to analyze the penetration
level.) He speculated that the sealing quality shown by his
tests was less effective than that obtained in tests done by
Mr. Lory. He thought possibly the friable material was older
and may have had a layer of oil on its surface. This discre-
pancy only emphasizes that each case is individual and
should be analyzed separately.
The second study that Mr. Hubbard conducted concerned 15
percent chrysotile in perlite, which is one of fFfe semi-
cementitious materials. The school had already applied a
sealant, but wanted to test it to determine any hazards. They
found a low count of fibers under normal daily conditions, but
the surface was accessible to the students, and they had
scraped it. Subsequent fiber release tests showed that more
fibers were released in the air from the sealed material than
from the unsealed material.
Therefore, in Mr. Hubbard's opinion, the material must be
disposed of or treated in another way. Sealing asbestos-
containing material is not a viable solution because students
come into contact with it and can scrape it. Unless some
method is available to completely enclose asbestos down to
the substrate, Mr. Hubbard is pessimistic about using encap-
sulants except in nonaccessible areas that are out of the air
plenum.
He made one recommendation—to cover the material with
another surface after the sealant or bridging agent, perhaps
using a thicker surface film that completely hides the fibers
from the surface. This second material would prevent fiber
release from inadvertent brushing.
-End of Day 1-
The second day of the conference was devoted to discussion
on field experience with encapsulants and general considera-
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Conference on Encapsulation of Asbestos-Containing Building Materials
tions affecting decisions to use encapsuiants. The speakers
were Forest Reinhardt, Robert Sawyer, John Arpin, Joe Mar-
tin, Ralph Self, David Spinazzolo, Robert Berhinig, Magnus
Hienzsch, Eugene Secor, Anthony McMahon, and Dhun Patel.
Or. Sawyer was the panel spokesman and briefly commented
on each speech.
Forest Reinhardt works for EPA and is actively involved
with ASTM in developing performance standards for
encapsuiants.
Mr. Reinhardt began the morning session with a short presen-
tation covering EPA's work with ASTM, ongoing research on
encapsulation, and how EPA proposes to address some prob-
lems in the encapsulation program.
One major problem is the lack of funds to subject new for-
mulations and products to standardized testing, thereby
inhibiting their development. Another problem is the need for
field testing because laboratory test results on mineral wool
mixtures may not apply in the field. Further, EPA is not in a
position to approve encapsuiants.
To address these problems, EPA and ASTM are working
together to develop a performance standard for encapsuiants
that will apply to both laboratory and field tests. This stan-
dard will allow manufacturers to test their products at their
own expense. A subcommittee of ASTM Committee E-6,
composed of manufacturers, contractors, government
officials, and representatives of testing laboratories, is work-
ing on the standard.
A tentative list of tests written by experts from the subcom-
mittee includes laboratory tests for cohesion and adhesion,
penetration, flexibility, surface abrasion, surface impact
resistance, fiber release, fire resistance, flame spread, smoke
generation, toxic gas generation, and aging. The proposed
field tests, to establish that the encapsulant will perform on
the asbestos-containing material on which it is actually used,
are for cohesion and adhesion, bonding, fiber release, and
penetration.
Finalization and approval of the standard will take about 18
months. In the meantime, EPA plans to issue interim test pro-
tocols for the laboratory and field tests, with a quality
assurance program for the laboratory tests. Mr. Reinhardt
believes that these interim guidelines will be issued approx-
imately 1 month after the contract with Battelle is finalized.
The protocols will serve as guidance until the ASTM tests are
final. The test protocols will be similar to Battelle's tests for
toxic gas and smoke generation, flame spread, abrasion,
impact, and fiber release, and will allow other laboratories to
perform the tests, not just Battelle. '
EPA strongly recommends that any contractor planning to
use an encapsulant first conduct a field test. Test procedures
are now being written for curing, adhesive and cohesive
strength, resistance to abrasion and impact, fiber release,
penetration, and film thickness.
EPA needs input for the protocols from as many sources as
possible. EPA has written "Guidelines for the Use of Encap-
suiants on Asbestos-Containing Materials" in consultation
with Battelle as a review of the advantages and disadvan-
tages of encapsuiants.
Dr. Robert Sawyer is from Yale University and is a leading
authority on asbestos.
Dr. Sawyer gave a slide presentation covering the basic
characteristics of asbestos, the abilities and deficiencies of
measuring systems, and basic information on asbestos-related
diseases.
The presentation included slides of asbestos-related diseases;
the link between asbestos and mesothelioma; the
aerodynamic characteristics of asbestos fibers, which may
stay airborne for up to 80 hours; respirator use; asbestos in
lagging at Ellis Island; limitations of OSHA standards' protec-
tion; faults of bulk sample analysis (use of contrast optics
instead of microscopy); use of polarized light microscopy
(PLM) as the optimal method of analyzing bulk samples of
building materials; difficulties in identifying asbestos fibers;
effects of work area activities on air sampling; problems of
interpreting air sampling data and relating them to possible
exposure problems; advantages of encapsulation (rapid and
economical); problems of delamination after encapsulation
due to the weight of the sealant; and problems with
respirator programs (worker reluctance to wear).
John Arpin represents Arpin Products, which conducts R&D
for the U.S. Army. He has spent 5 years formulating
encapsuiants.
Mr. Arpin discussed techniques for control of asbestos.
The major issues identified were pinpointing problem
material, proper control of material, development of encap-
suiants, and improper removal of asbestos. Additional prob-
lems are the lack of contractor expertise and ultimate disposal,
of the material.
Dr. Sawyer recapped Mr. Arpin's presentation with a plea for
good contractor specifications and reiterated the risks
generated by removal.
Joe Martin is a consultant on asbestos from the Law
Engineering Testing Company. He has a master's degree in
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Engineering from Vanderbilt University.
Mr. Martin summarized the use of encapsulation as opposed
to other types of asbestos abatement and the related prob-
lems. He expressed concern for the development of interim
guidelines until the ASTM standard is developed. One current
problem is that workers continue to enter work areas where
asbestos levels are still high. Mr. Martin suggested using an
operations maintenance manual that at least informs them of
the dangers. Air sampling as a means of assessing asbestos
exposure problems was again criticized because, unless it is
performed using precise calculations and quality control
techniques, the results are meaningless. Variations between
OSHA and NIOSH requirements for air samples were also
reviewed.
Mr. Martin reiterated that air sampling is designed for
industrial settings and is not appropriate in most field
settings.
He also discussed the improper use of encapsulants when
removal is indicated. Encapsulation does not always prevent
exposure, since normal maintenance may expose the worker.
Dr. Sawyer recapped by reviewing options for
abatement—including removal, establishment of a manage-
ment system, encapsulation, or enclosure—and techniques of
air sampling. Dr. Sawyer observed that placing a sampling
device in a work area will automatically reduce airborne
asbestos concentrations because contractors and workers
know they are being watched.
Ralph Self represents the North Carolina Department of
Education. He has worked for 2 years on the problem of
asbestos in North Carolina's schools.
Mr. Self reviewed the development and implementation of
the Asbestos in Schools Program in North Carolina in terms
of encapsulation.
Program development was aided by Mr. Pat Curran, who is
an industrial hygienist familiar with asbestos.
The program initially focused on exposure assessment and
the "8-factor algorithm," which provided a point of departure
for analysis.
Using this algorithm, Mr. Self and Mr. Curran found that cer-
tain areas should not be encapsulated, including areas of high
accessibility and areas with extensive water damage, or areas
with a high friability factor.
Encapsulation was not encouraged at the start of the program
because of insufficient information; however, an increasing
number of options are now being considered.
Mr. Self repeatedly emphasized the importance of good con-
tractor specifications and the use of an industrial hygienist
Dr. Sawyer recapped the presentation by noting the need for
a competent engineer and industrial hygienist. Additionally,
he noted that the 8-factor algorithm should be a complement
to common sense. It should not be used by itself to deter-
mine corrective actions.
David Spinazzolo represents Spinazzolo-Nash, Inc., an
asbestos removal and encapsulation contractor located in
Richmond and Hampton, Virginia.
Mr. Spinazzolo reviewed the problem of asbestos control
from the contractor perspective, since his firm has done a
number of asbestos jobs. He echoed the need for good con-
tractor specifications and stated that most current specifica-
tions are too general to work properly in every situation. He
also stated that the purchaser of services should provide an
industrial hygienist for air sampling, not the contractor.
Mr. Spinazzolo stated that the most important protective gear
for workers is the respirator. Other protective clothing can
only make workers uncomfortable and provides little or no
protection. Mr. Spinazzolo felt that encapsulation materials do
not generally fail. He encouraged using them in the context of
the 8-factor algorithm. Proper curing of the product was
stressed, since most are water based. Sealed rooms do not
provide sufficient air movement.
Variation and costs for each job were noted.
Dr. Sawyer's recap included comment on the need for good
specifications, and job communication, and the use of a com-
petent industrial hygienist for jobs requiring air sampling. He
then reviewed the legal and contractual obligation of the con-
tractor. With good specifications, less-than-reputable contrac-
tors cannot underbid reputable contractors. He also reviewed
the problem of heat stress and effective procedure.
An extensive question and answer period followed. Topics of
discussion included:
Need for Government Enforcement. Dr. Sawyer called for
augmentation of OSHA regulations along with total enforce-
ment on the job site.
Use of Proper Equipment and Technology to Avoid the
Tactics of Fly-by-Night Contractors. One contractor com-
plained that because he presented a job based on the best
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equipment and procedures, another contractor was able to
underbid him.
Need for Adequate Specifications that are Stricter than
OSHA or EPA Standards. Dr. Sawyer advocated the use of
the more stringent AWCI specifications on every asbestos
removal job.
Need for Worker Education about the Hazards of
Asbestos and the Use of Encapsulants. Dr. Sawyer
pointed out that OSHA regulations are deficient in that they
have no provision requiring asbestos worker education so that
a worker need not be informed about showering to prevent
contamination.
Proper Disposal. One contractor complained that because
no inspectors check on the disposal of the drums containing
asbestos, shady contractors can underbid those reputable
contractors.
Use of Negligence Suits for Enforcement. Mr. Spinazzolo
pointed out that OSHA isn't the only vehicle to obtain
enforcement, that law suits are also an effective tool.
Media Interest. In addition to litigation, Mr. Spinazzolo cited
the press as a way to thwart disreputable contractors by
publicizing those contractors who have had a history of
worker protection and environmental contamination problems.
Certification of Asbestos Industrial Hygienists. Unless
the use of a certified industrial hygienist is written into the job
specifications, the individual who turns up to do the analysis
may be incompetent.
Contractor Certification Problems. Dr. Sawyer explained
that a contractor may qualify on paper as competent, but on
the actual job site, he may not do what he is supposed to.
Management Systems. It was conceded that no definitive
management system exists for asbestos control, but the Iden-
tification and Notification rule package does contain details
saying what to do.
Manufacture Problems. William Rusek of Pentagon Plastics
described how some encapsulates get on the market simply
by the manufacturer submitting a product he already makes
to EPA through Battelle in the belief that it may work as an
encapsulant. The name of the product then gets mailed out
on an EPA list which is read by thousands of people, but in
reality the product may not be an effective encapsulant at all.
ASTM Standards. One participant called for stringent ASTM
specifications for encapsulates. In addition to which, the com-
pany must prove it has the knowledge and personnel to help
the people out in the field.
Testing of Products. Architect Magnus Hienzsch contended
that the tests done on encapsulants are not applicable to
encapsulants per se but rather are the usual tests made on
other finishing materials. Mr. Dorsey pointed out that in the
past 2'/2 years since Battelle started its testing program, the
techniques developed have become more sophisticated, but
EPA is not in the business of approving or certifying
encapsulants.
ASTM Contractor Participation in Development of
Standards (Contractor Committee). John Wilson (EPA) ex-
plained that AWCI Federal officials, Canadian groups, and a
variety of contractors are developing guide specifications for
the construction industry. The final draft is expected to be fin-
ished in a week.
Compliance with Various Building Code Requirements.
A participant pointed out that as a consequence of the
building codes requiring testing by approved agencies, a
manufacturer would have to test according to UL or UL-
approved agencies' specifications. This means that a
manufacturer may have to test as many as 20 substrates.
Testing for Code Compliance. Because of all the variables
involved in tests, some manufacturers expressed uncertainty
as to whether they were in compliance with the building
codes. One position taken was that as long as the encap-
sulant meets the rating standards, it conforms to the code.
Use of the Algorithm. George Grossman of Public Works,
Canada, wanted to know if any thought was being given to
considering the differences in the types of asbestos as factors
in the algorithm. Forest Reinhardt said no, that the govern-
ment did not distinguish between the various forms of
asbestos as far as regulation was concerned.
New Jersey's Control Program for Schools. Or. Patel said
that out of about 2,500 schools in the State, about 250 have
asbestos. About 100 schools have removed the asbestos.
Encapsulation as an Alternative to Removal. One partici-
pant urged that New Jersey not rely only on removal but use
the encapsulation alternative to protect children's health.
Robert Berhinig represents Underwriters Laboratories' Fire
Protection Department. He holds a degree in civil engineering
and is a member of ASTM and the National Fire Protection
Association.
Mr. Berhinig covered fire performance characteristics that
should be considered when using an encapsulating agent.
A goal of encapsulation should be to maintain, not reduce,
the fire performance properties. Considerations include: fire
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performance of the materials; code requirements, specifically,
surface flammability; and hourly fire resistance of the
materials.
ASTM is developing a method to evaluate the use of encap-
sulants on representative materials, with the goal of maintain-
ing the overall fire performance.
Magnus Hienzsch is an architect for the Naval Facilities
Engineering Command. He has dealt with asbestos problems
since 1976.
Mr. Hienzsch discussed how the use of encapsulants affects
acoustics.
Before using an encapsulant in an acoustically critical
building, it must be tested to determine the sound absorption
of the material. To preserve the acoustical quality of the
building, removal of the problem material may be the only
alternative because encapsulants may degrade the acoustical
level required.
Mr. Hienzsch suggested using contractor licenses to ensure
performance. If performance is poor, the bonding company
and the State can revoke the license.
Eugene Secor is a chemist for H.B. Fuller, which was one of
the first companies to become actively involved in encapsula-
tion. Mr. Secor has been working with asbestos since 1973.
Mr. Secor covered the permeability, chemical compatibility,
and suitability of an encapsulant over insulation systems.
Permeability describes how moisture moves through the film
formed by the sealant. It generally moves from a location of
high relative humidity to one of low relative humidity.
Sealants usually cannot cure in closed spaces that are
encapsulated. Permeability is expressed in "perm" value. The
lower the perm value the more impermeable the material is to
the passage of water vapor.
Encapsulants should form permeable films. Permeability is
determined for bridging agents by running ASTM 396 or 398
tests. Penetrating materials will generally have better
breathability and removal of moisture than bridging agents.
Research in the compatibility of encapsulants and insulation
systems is very limited. Most encapsulants use polymers of
known properties. Insulation systems are generally alkaline in
nature. The chemical compatibility problem is that these
polymers resist alkaline environments.
A common physical compatibility problem is the use of starch
or clay binders, which tend to resolubilize, causing the
system to fail.
Regarding the use of encapsulants over insulation systems,
Mr. Secor stated that each system is different and must be
evaluated individually. He did, however, make the following
general observations.
• The soft, fluffy insulation used in fireproofing is not
suitable for encapsulation.
• The vermiculite perlite insulation is relatively easy to
encapsulate.
Anthony McMahon has worked for the New Jersey Depart-
ment of Environmental Protection since 1973. He has been
working with asbestos for about 5 years.
Mr. McMahon discussed New Jersey's position on asbestos
control.
New Jersey's position in almost all cases is to recommend
against the use of encapsulants because if the surface has
deteriorated to the point of needing control that surface
should be removed. One reason for this position is the diffi-
culty in maintaining quality control during application.
Mr. McMahon then discussed the history of asbestos control
in New Jersey. Decisions on the use of encapsulants were
delayed until the Battelle study and/or other studies could
provide information. The prevailing attitude today is that the
performance of encapsulants must be demonstrated, and they
must last for longer periods of time.
Contractor training for removal consists of a one-day training
course that must be taken before a contractor can be placed
on a bidder's list. The contractor is taken off the list when
guidelines and contract specifications are flagrantly violated.
Mr. McMahon concluded with a plea to end the search for
the perfect sealant and instead apply resources to control by
removal.
Dhun Patel is Chief of Environmental Health and Hazard
Evaluation for the New Jersey Department of Health.
Dr. Patel's presentation discussed the elements of the New
Jersey Governor's task force; the development of minimum
specifications for contractors, including those for training; and
the development of a position on the use of sealants in New
Jersey.
Dr. Patel amplified Mr. McManon's observations. In short.
New Jersey's position remains that the risk of failure, plus the
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Conference on Encapsulation of Asbestos-Containing Building Materials
high cost of removal if a system does fail, warrants the
excluding of sealants as a means of control.
He suggested that New Jersey's minimum specification
enforcement, required inspection program, and the training
program on certification for asbestos workers best protect
public health.
A question and answer period followed with extensive discus-
sion of the following topics.
Criticism of New Jersey's position against the use of
sealants. One participant predicted that New Jersey would
regret its decision one day, that removal of asbestos will
prove too expensive, and that potential problems will go
unreported.
Risks Generated by Removal. A participant said that if
removal is not done properly, it is a far greater danger than if
the asbestos were left alone.
Notification and Monitoring of Removal Projects. Dr.
Patel stated that the State Dept. of Environmental Protection
(DEP) and the State Dept. of Health must be informed 2
weeks in advance of a removal project so that EPA can be
informed in order that EPA and DEP check that they are
going to the right place. The people at the facilities are in-
spected to see that they are properly protected. The results of
air measurements are obtained after two clean-ups and per-
sonnel permitted back inside only if the levels are low
enough.
Frequency of New Jersey Training Programs. Dr. Patel
replied to a questioner that architects and contractors attend
training once a month.
Proof of Worker Attendance at Training. Dr. Patel said
that the workers are handed a card with their picture on it to
show they attended the course.
Life Expectancy of Encapsulation. An assumption of 15-20
years life expectancy for a sealant was made.
Application of Material. A contractor described the way his
firm applied a penetrating encapsulant from the penetrating
layer to the laminating coat.
Effect of Encapsulants on Thermal Insulation Values.
Gene Secor admitted that little testing had been done on the
effects of encapsulants on thermal properties. He said bridg-
ing encapsulants probably would not have a great deal of
effect on thermal efficiency in an insulation system.
Penetrating encapsulants, he believed, would have a greater
effect.
Dangers of Replacing Asbestos with Equally Hazardous
Substances. John Metya of Flexaclad Corp. speculated that
by substituting mineral wool, cellulose, fiberglass and
vermiculite for asbestos, a product as dangerous or almost as
dangerous as asbestos was being used.
Need for Good Contractor Specifications to Obtain Fair
Bidding Practices. Mr. Metya attributed the wide range in
contractors' bids on encapsulation jobs to the lack of job
specifications detailing what must be done.
Specifying the Type of Asbestos Treatment. Mr. Metya
noted that asbestos products differ in type and application to
such an extent that no treatment can be specified.
Testing of Systems Using Encapsulants. Mr. Berhinig said
he knew of no encapsulant being evaluated as a system
although there are tests for properties such as surface flam-
mability on other materials.
Effect of an Encapsulant on Overall Fire Performance.
Mr. Berhinig said that contractors will be asked to show that
use of their encapsulant will not compromise the fire perfor-
mance of the asbestos-containing material, adding that spray-
ing a cementitious ceiling that is probably gypsum plaster will
not be a problem but encapsulating sprayed-on fireproofing
could alter its heat transmission properties.
Encapsulants Meeting Building Code Specifications. Mr.
Berhinig pointed out that whether an encapsulant is used or
not is immaterial as far as the uniform building code is con-
cerned because the code requirements don't change.
Fire Resistance. Mr. Berhinig described Class A
materials as having relatively low surface flammability.
This classification implies that certain conditions were
met regarding application rate, substrate, etc. and that
the ASTM performance standard would follow along
the same lines in achieving its classification
designations.
Need for Product Certification. A contractor raised the
question of the need for certification of encapsulants, stating
that without it, the architect will ultimately not get the proper
information he should have.
Contractor Competency and Certification. Dr. Sawyer
responded by saying that a better way to achieve contractor
competency rather than by certification is by building into the
specifications a demonstration of competency factors. He
stated that certification doesn't work.
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Conference on Encapsulation of Asbestos-Containing Building Materials
Contractor Education. Mr. Dorsey said that EPA would not
be able to set up a certification program but could provide
contractor education. He added that EPA could not set up a
contractor committee to set up an association for the purpose
of establishing a certification program.
Health Risk in Certain Human Populations. A participant
stated that based on Or. I. J. Selikoff's statistics, when you
exclude the effect of smoking, asbestos workers are at no
greater hazard than the regular public.
Smoking as a Carginogen With Asbestos. Dr. Sawyer
concurred that the most potential carcinogenic effect known
in medicine is the combination of smoking and asbestos
exposure.
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