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SOME FACTS ABOUT ASBESTOS
Asbestos can be identified in a mineral sample or product? The best way to identify
asbestos is to use a microscope to examine samples that have not
been ground. Even with finely ground samples, there is no problem
identifying chrysotile because its particle shape is distinct from
the nonasbestiform varieties of serpentine. 
When it comes to health risk an amphibole is asbestiform. Yes, the Occupational
Safety and Health Administration (OSHA) conducted a review of the
health effects of inhalation of non-asbestiform amphiboles. The
agency determined (Federal Register, v.57, no. 10, June 8, 1992 p.
24310) that "available evidence supports a conclusion that exposure
to non-asbestiform cleavage fragments is not likely to produce a
significant risk of developing asbestos-related disease".
Breathing high levels of
asbestos fibers for a long time can lead to an increased risk of
asbestosis, lung cancer and mesothelioma. Asbestosis is a
non-cancerous lung disease related to scarring of the lungs. This
disease occurs in people heavily exposed to asbestos in the
workplace and in household contacts of asbestos workers. Lung cancer
is a relatively common form of cancer, which has been linked to
smoking and a variety of occupational exposures. Cigarette smoking
significantly increases the risk of lung cancer for people exposed
to asbestos. Mesothelioma is a rare cancer of the membranes lining
the lining the lungs, chest, and abdominal cavity. Almost all cases
are linked to occupational asbestos exposure. The symptoms of these
diseases do not usually appear until 20 to 30 years after the first
exposure of asbestos.
Particle shape, particle
solubility, and duration of exposure are reported to be the three
most important factors that determine lung damage. Many researchers
believe that amphibole asbestos particles pose a greater risk than
chrysotile particles because they are less soluble and more rigid
than chrysotile, allowing the amphibole asbestos particles to
penetrate lung tissue and remain longer. The most common type of Asbestos is
Chrysotile.
Chrysotile is the most
common type of asbestos in the United States and the
world.
The types of Asbestos that are mined are:
Currently, Chrysotile
is the only type of asbestos mined on a large scale. It makes up
over 99 percent of present-day production in the world. Only
chrysotile is mined in the United States. In 1999, one firm in
California accounted for all U.S. chrysotile
production.U.S. Asbestos is found in:
Asbestos has been
identified in 20 States and mined in 17 States over the past 100
years. It is found in many common rocks. Appalachians, Cascades,
Coast Ranges of California and Oregon, and other mountain
belts.
In general, chrysotile and
amphibole asbestos varieties occur in areas where the original rock,
under elevated temperatures and pressures, has been changed by
heated fluids (a process referred to as metamorphism).
Although asbestos can be
present in most metamorphic rocks, the bulk of the rock mass does
not contain asbestos. In fact, most commercial asbestos deposits
contain less than 6 percent asbestos by volume. Only a few deposits
contain 50 percent or more asbestos (such as chrysotile deposits
near Coalinga, CA.) The United States still uses Asbestos :
Yes, about 15,000
metric tons (t) of asbestos was used in the United States in 1999;
most was imported from Canada. Major manufacturing uses in the
United States are as follows: asphaltic roofing compounds used on
commercial buildings, 61 percent; gaskets, 19 percent; and friction
products, such as brake shoes and clutches, 13 percent.
15,000 metric tons of Asbestos is a lot:
Relatively speaking,
no. The peak year of asbestos use in the United States was 1973,
when approximately 719,000t of asbestos was used for manufacturing
friction products, flooring, caulks, gaskets, packings, electrical
and heat insulation, plastics, roofing, textiles and a host of other
consumer and commercial products.
There have been thousands
of applications for asbestos. It enabled the production of
inexpensive cement based water supply pipes, and despite the dire
consequences to the installers, asbestos insulation made the
warships of WWII much safer.
In the late 1960s and
early 1970s the consumption of asbestos increased at the rate of 3
to 4 percent annually. In the 1980s and 1990s, consumption declined
5 percent annually.
The decline in Asbestos use was caused by:
Concerns over health
risks posed by high exposures to airborne asbestos brought on much
of this decline. From 1970s onward, public pressure to reduce
exposure to asbestos resulted in lowered exposure standards and
spurred the quest for alternatives to asbestos. Exposure standards
were reduced from 5 fibers per cubic centimeter (f/cc) of air over
an 8 hour time period to 0.1f/cc in the workplace. Many companies
ceased production of asbestos products because of liability issues.
As a result, asbestos consumption in the United States declined
rapidly. Worldwide use of Asbestos:
Worldwide, the use of
asbestos has declined, particularly in Western Europe. Several
Western European countries have banned some or all asbestos
products.
In other regions of the
world, there is a continued demand for inexpensive, durable
construction materials. Consequently, markets remain strong for
asbestos-cement (A/C) products, such as A/C panels for construction
of buildings and A/C pipe for water-supply
lines. The connection between Asbestos and vermiculite is:
The connection between
asbestos and vermiculite was first brought to public attention
recently because of a vermiculite mine near Libby, Mont. Vermiculite
consists of clay materials that expand when heated to form wormlike
particles. Vermiculite is used in concrete aggregate, fertilizer
carries, insulation, potting soil, and soil conditioners.
The Libby mine opened in
1921 and once accounted for almost 80 percent of the world’s
vermiculite production. The Libby deposit is unique among commercial
U. S. vermiculite deposits in having an average amphibole asbestos
content of 4 to 6 percent. Many workers developed health problems as
a result of those exposures. Some residents of Libby who were
exposed to high levels of asbestos also have been diagnosed with
asbestos related symptoms.
Officials are concerned
about the asbestos content of the soils around Libby, about workers
who processed the Libby vermiculite ore in manufacturing plants
scattered throughout the United States.
Vermiculite is still being sold:
The Libby vermiculite
mine closed in 1990, and shipments of vermiculite from the Libby
mill site ended in 1992. However, products made from the Libby
vermiculite may still be available from retailers who sell from old
stocks. The only certain way to know whether vermiculite came from
Libby mine is to ask the manufacturer.
For information on
regulations and health effects of asbestos exposure, contact these
agencies online:
- Consumer Product
Safety Commission (
www.cpsc.gov)
U.S. Environmental
Protection Agency (www.epa.gov)
Mine Safety and
Health Administration ( www.msha.gov)
Occupational Safety
and Health Administration (www.cdc.gov/niosh/)
National Institutes
of Health (www.nih.gov)
COMMONLY ASKED QUESTIONS &
ANSWERS
Can asphalt shingles be
recycled and used for road paving purposes?
If these asphalt shingles contain asbestos in excess of 1%, their
recycling may be subject to various requirements under Subpart M. An
asbestos shingle is usually non-friable; therefore, its removal is
not subject to Subpart M. However, once the shingle is damaged, the
asbestos material becomes friable and Subpart M may apply.
Demolition and Renovation must be disposed of as asbestos
–containing waste material in accordance with the requirements of
61.150(b) and, therefore, can not be recycled.
Is a house relocation including the moving of a mobile home
subject to Subpart M?
Yes, but only remove that asbestos that would be disturbed.
Moving of the house or mobile home from its foundation or from any
load-supporting structural element is considered to be a demolition
under Subpart M regardless of whether or not the mobile home is
affixed to a foundation.
The basis of the NESHAP is for the owner/operator to thoroughly
inspect (survey) for the presence of asbestos. What is meant by a
"thorough inspection"?
There is no such thing as a perfect inspection. The inspector
should consider all factors pertaining to a particular situation in
determining the appropriate number of samples "sufficient to
determine" the presence of asbestos including but not limited to a
homogenous area, construction dates, and materials mixed on site.
EPA recommends that samples be collected such as described in the
3-5-7 sampling rule ( 3 samples-<1000 sq. ft., 5
samples-1,000-5,000 sq. ft. 7 samples->5,000sq.ft) since most
demolition and renovation activities would cause the ACM to become
RACM (see Asbestos in Buildings: Simplified Sampling Scheme for
Friable Surfacing Materials-pink book).
In the preamble to the Asbestos NESHAP regulations published in
the Federal Register on November 11, 1990, the EPA stated that FAX
systems are not sufficiently reliable to allow their use for
transmitting notices. Is a faxed notification revision acceptable to
EPA?
A faxed notification revision is not acceptable to EPA due to
transmission and verification problems associated with faxed
documents.
"Timely removal" for crumbled TSI throughout a school’s
crawlspace: Because this material cannot be repaired, it must be
removed. How soon, in terms of units of time, must it be
removed?
Removal is not the only option for addressing crumbled TSI
throughout a school’s crawlspace. Other appropriate response actions
include encapsulation, enclosure, or sealing up of the crawlspace. A
removal time period cannot be definitvely states since "timely
removal" would vary on a case-by- case basis.
When is a farm building (barn, shed, etc) subject to the NESHAP
if it is renovated or demolished?
NESHAP does not apply to residential structures having four or
fewer dwelling units. However, a farm building that is being used
for commercial purposes is considered to be a commercial structure
subjecting it to the NESHAP.
Are there circumstances under which an ACM roof removal operation
is NOT regulated by the NESHAP?
There are circumstances under which an ACM roof removal operation
is not subject to the NESHAP. The applicability of the NESHAP to
Category I and II non-friable ACM depends on 1. the condition of the
material at the time of demolition or renovation, 2. The nature of
the operation to which the material will be subjected, and 3. the
amount of ACM involved. In addition to friable ACM, RACM also
includes 1. Category I non-friable ACM that has become friable, 2.
Category I non-friable ACM that has been or will be sanded, ground,
cut, or abraded and 3. Category II non-friable ACM that has already
been or is likely to become crumbled, pulverized, or reduced to
powder.
Are there circumstances under which the removal of an ACM roof on
other than residential buildings is exempt from the NESHAP
notification requirements?
There are circumstances under which the removal of an ACM roof on
other than residential buildings is not subject to NESHAP only if it
is RACM. This depends on the friability of the ACM roofing material
and on the likelihood that the ACM roofing material will become
friable during renovation.
Are there circumstances under which ACM roofing can be disposed
of as non-asbestos waste?
If ACM roofing material is not friable or rendered friable during
demolition or renovation activities, it is not RACM under NESHAP. If
the ACM roofing material is not RACM, it is not considered to be
asbestos waste. In situations where ACM roofing material is not
RACM, the material may be disposed of at any landfill.
Under what circumstances is there a requirement to sample mortar
or concrete?
There is no requirement to collect samples under NESHAP. However,
the collection of samples may be necessary in order to perform a
"thorough inspection" to determine the presence of RACM.
What is asbestos?
Asbestos is a generic name given to the fibrous variety of six
naturally occurring minerals that have been used in commercial
products. Asbestos is made up of fiber bundles. These bundles, in
turn, are composed of extremely long and thin fibers that can be
easily separated from one to another. The bundles have splaying ends
and are extremely flexible.
The term "asbestos" is not a mineralogical definition. It is a
commercial designation for mineral products that process high
tensile strength, flexibility, resistance to chemical and thermal
degradation, and high electrical resistance and that can be
woven.
What minerals occur as asbestos?
The minerals that can crystallize as
asbestos belong to two groups: serpentine (chrysotile) and amphibole
(crocidolite, amosite, anthophyllite asbestos, tremolite asbestos
and actinolite asbestos). Amphiboles are distinguished from one
another by the amount of sodium, calcium, magnesium and iron that
they contain. Serpentine and amphibole minerals can have fibrous or
nonfibrous structures; the fibrous type is called asbestos.
Asbestiform varieties of several other amphiboles have been
identified. Other minerals are similar to asbestos in their particle
shape, but they do not possess the characteristics required to
classify them as asbestos (see definition of asbestos above).
Checklist: Asbestos
Asbestos in its several commercial forms has been show to be
associated with the development of a variety of disease entities,
including asbestosis, bronchogenic carcinoma, mesothelioma and
cancer.
The disease resulting from asbestos exposure may be progressive,
even in the absence of further exposure; the inhaled fibers trapped
within the lung continue their biological action. In its severe
forms, death results from the inability of the body to obtain enough
oxygen or from the heart's failure to pump blood through the scarred
lungs.
In its advanced stages, asbestos is evident by characteristic
manifestations on X-rays, by restrictive pulmonary function or by
clinical signs, such as finger clubbing or rales (dry, cracking
sounds within the lung). Its most important symptom is dyspnea, or
undue shortness of breath.
This is a partial checklist of some, but not all, rules to follow
when dealing with asbestos hazards, based on 1910.1001 -- Asbestos,
Subpart Z, Subpart Title Toxic and Hazardous Substances.
Monitoring
- Is the area properly monitored? You must
have air samples representative of the 8-hour TWA and 30-minute
short-term exposures of each employee.
- Has the employee been notified of
monitoring results within 15 working days?
- Are asbestos areas which exceed TWA or
excursion limits regulated?
- Are regulated asbestos-containing areas
demarcated?
- Is access to asbestos-containing areas
limited?
- Is each employee entering a regulated area
supplied and required to wear a respirator?
- Are activities like eating, drinking,
smoking, chewing tobacco or gum, or applying make-up prohibited in
regulated areas?
- Have engineering controls been set to
reduce employee exposure to asbestos?
- Has a compliance program been written and
implemented?
- Do lunchrooms and eating areas have a positive pressure,
filtered air supply?
Ventilation
- Are local exhaust ventilation and dust
collection systems designed, constructed, installed and maintained
in accordance with ANZI Z9.2-1979?
- Are hand-operated and power-operated tools
that produce or release asbestos fibers, like saws, scorers,
abrasive wheels and drills, provided with local exhaust
ventilation systems?
- Is asbestos handled, mixed, applied,
removed, cut, scored or manipulated in a wet state to prevent
airborne fibers?
- Have the asbestos-containing materials
been wetted, enclosed or ventilated to prevent airborne fibers
during removal from bags, cartons or other containers in which
they have been shipped?
- If you are using compressed air, are you using it with a
ventilation system to capture the dust?
Respirators, protective clothing
- Has each employee been allowed to choose
either a tight-fitting, air-purifying respirator or a negative
pressure respirator?
- Are employees allowed to change filter
elements whenever an increase in breathing resistance is detected,
and is an adequate supply of filters available?
- Has the employer checked to make sure the
respirator used by the employee has the least possible facepiece
leakage and fits properly?
- Are fit tests performed every six months
after the initial test?
- Are employees provided with coveralls or
other full-body clothing and equipment, like gloves, head and foot
coverings, face shields, vented goggles, etc.?
- Are employees provided with clean change
rooms with two separate lockers or storage facilities to prevent
contamination of the workers' street clothes?
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