Asbestos in Vermiculite Insulation
Some residential vermiculite insulation may contain asbestos!
What is asbestos?
Asbestos is a mineral fiber. Asbestos fibers are long, thin, and very strong, yet flexible enough
to be woven together. Until the 1970’s, asbestos was commonly added to a variety of building materials to strengthen
them, provide heat insulation and make them fire resistant. Although most products today do not contain asbestos, some older
materials in your home may, including pipe and sprayed-on insulation, floor tiles, and roofing and siding materials.
What is vermiculite?
Vermiculite is a naturally occurring mineral used in construction, insulation
and gardening products. It looks like shiny, small pieces of popcorn (as pictured above), and is usually
light-brown or gold in color.
Vermiculite came from mines in Libby, Montana (closed
in 1990) as well as other mines in the U.S. and other countries. Vermiculite is still mined and distributed
for a number of uses, including insulation.
Why should I be concerned about vermiculite insulation?
Much of the Libby vermiculite was used as attic insulation. It was sold under
the product name Zonolite. The Environmental Protection Agency (EPA) estimated in 1985 that 940,000 American homes contained
Zonolite attic insulation.
Over 70% of vermiculite ore mined worldwide came from the Libby, Montana mine.
The ore from this mine also included a natural deposit of amphibole/tremolite asbestos. Much of the vermiculite from Libby
was contaminated with asbestos. Asbestos fibers are invisible to the eye and can only be professionally detected. Homeowners
should consider the following:Vermiculite mined today for use in insulation is from a source considered to be free of asbestos contamination.
What might vermiculite insulation in my home look like?
Vermiculite is ideal for attic insulation because of it’s
properties as a lightweight, fire-resistant, absorbent and odorless material. Vermiculite in insulation is a pebble-like,
blown-in product and is usually lightbrown or gold in color. Sizes of vermiculite products range from very fine particles
to large (coarse) pieces nearly an inch long.
If you have vermiculite insulation
in your attic, you should assume that the material may contain asbestos.
Testing vermiculite insulation
for asbestos is not always necessary. Vermiculite sold under the name Zonolite originated in Libby, Montana, and should
be assumed to contain asbestos.
I find vermiculite insulation in my home, should it be removed?
Homeowners may wish to consider the following points:
- First, due
to the physical characteristics of vermiculite and where it may be installed, the potential for contamination of the air throughout your home may be low.
- Second, if the insulation will not be disturbed and is not contaminating the
home environment (e.g. it’s sealed behind tight walls, floors, or isolated
in an unfinished attic, which is vented outside) it may be best to leave it alone. Furthermore, signs should be posted inside the attic saying “CancerHazard: Insulation contains asbestos, do not disturb or create dust.” Posting signs will ensure that electricians, plumbers, inspectors and others doing
work on your home will be notified of the potential for exposure and can take necessary steps to protect themselves.
- Last, if home renovations involve removal of walls or other
areas where vermiculite insulation is
located, extra precaution is necessary and removal by a trained and certified professional prior to renovation may be warranted.
What can I do to prevent asbestos exposure?The following steps can help minimize asbestos exposure during
very minor home renovations (such as installing a ceiling light or computer cable):
Wear gloves, eye protection and a HEPA respirator (not just a dust mask).
- Tape off rooms with plastic sheeting to
prevent contaminating other areas of the home; keep the vermiculite damp to prevent spreading dust.
- Keep windows open for good ventilation
and wipe up all dust and debris using wet cleaning methods (wet-wiping and wet-mopping).
HEPA vacuum can be used for clean up of minor dust or debris. Do not use a home/shop vacuum.
- If renovations involve
more extensive removal or exposure to asbestos containing insulation, it’s best to hire a professional, state-certified, asbestos removal contractor.
What are the health risks associated with asbestos exposure?
Asbestos fibers must be inhaled to cause
disease. Disturbing vermiculite insulation or dust containing asbestos will result in exposure unless precautions are taken.
When insulation containing asbestos is disturbed, lightweight asbestos fibers are released into the air and can be inhaled.
In general, the more you are exposed to asbestos, the greater your risk of developing related diseases. Exposure may not have
immediate health consequences, however. In many cases, individuals do not develop related diseases for years or even decades
Those at highest risk for exposure and disease are long-term vermiculite processing plant
employees or workers regularly installing or handling products containing asbestos without proper protection. Those at lower
risk include people who occasionally disturb attic insulation during activity in the attic or minor “handyman”
jobs. The lowest risk would be for people who live in a home where the vermiculite insulation is isolated and they have had
no direct contact with the materials.Some asbestos-exposed workers, family members, and those living in the neighborhoods
of asbestos plants have developed mesothelioma. Mesothelioma
is a rare type of cancer that begins in the tissue surrounding the lungs, stomach, and heart. Mesothelioma has also been found in individuals who were exposed to asbestos
only once decades earlier. The only known cause of mesothelioma is asbestos.
Exposure to a lot of asbestos over a long time (like in an occupational setting)
can cause permanent lung damage known as asbestosis. Asbestosis
causes shortness of breath and increases the risk of serious lung infections. Smoking also increases the risk of developing illness from asbestos exposure.
For more information
For health related questions, contact your local public health
agency or the Ohio Department of Health.
More information can be found on the internet at:
EPA Website on Vermiculite: http://www.epa.gov/asbestos/pubs/verm.html
EPA Factsheet on Vermiculite Insulation: