Zonolite Attic Insulation Safety Facts
There have been reports concerning the association of trace amounts of asbestos
fibers with Zonolite® Attic Insulation. This product--discontinued by Grace
in the early 1980s for economic reasons--was made with expanded vermiculite originating
from the Libby, Montana deposit.
As part of the manufacturing process, Grace took steps to remove asbestos fibers
from the vermiculite used in Zonolite® Attic Insulation.
- Asbestos fibers were separated from the vermiculite ore at the mine.
- The vermiculite was further processed at expanding plants to remove remaining asbestos
to the maximum extent feasible.
In the 1970s, the government began regulating the use of products containing intentionally
added commercial asbestos, such as fireproofing insulation. As a responsible manufacturer,
Grace conducted its activities in compliance with these regulations.
In connection with the development of the National Emission Standard for Asbestos,
issued in 1973, the association of asbestos fibers with vermiculite in the Libby
ore was extensively discussed with the EPA staff.
In the late 1970s, Grace conducted air-sampling tests of Zonolite® Attic Insulation.
Designed to replicate the installation procedure in typical homes, air sampling
was conducted prior to, during and after installation. The results:
- Asbestos fibers in the attic space during installation were at levels well below
what was then considered a permissible lifetime occupational exposure.
- Air sampling indicated no asbestos fibers were detected in the attic within six
hours after installation.
Based on these results, Grace concluded that no unreasonable risk of injury was
posed to a homeowner installer.
Zonolite® Attic Insulation was primarily used in older homes to retrofit or add
to existing insulation. It was seldom used in new home construction. We believe
now, as we did during the time we sold the product, that there is no unreasonable
risk of injury or illness associated with the presence of this insulation in homes.
Homeowners who have Zonolite® Attic Insulation in their homes should leave it
in place. Homeowners who have questions about the product can contact Grace at 617-876-1400
(in Massachusetts) or 800-354-5414 (elsewhere in the U.S.). For more information,
please visit the web site www.libbyissues.com.