Tuesday, June 23, 2009

Handling Vermiculite Insulation for Building Inspections and Air Monitoring

The Environmental Protection Agency’s (EPA) recent decision to declare a public health emergency at the Libby asbestos site in Montana has brought vermiculite insulation back in front of people’s minds. EPA’s announcement did not mention what to do if you have this type of insulation. Remember there are some major issues with this type of insulation. First it seems the vermiculite can actually hide the tremolite asbestos from detection, leading to false results. When individuals disturb the vermiculite insulation it can release tremolite asbestos at significant levels into the air.

Because of these technical issues EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) both recommend that if you find vermiculite insulation that you not test it for asbestos. Instead they recommend you assume the vermiculite insulation is from Libby and assume it contains asbestos. The Libby mine was the source for over 70% of the vermiculite sold in the United States from 1919 to 1990. EPA and ATSDR feel that the technical issues involving vermiculite sampling can complicate testing for the presence of asbestos fibers and interpreting the risk from exposure. This is a significant statement and interesting that it has not been published more.

Based on this, as an asbestos inspector, environmental inspector, home inspector, and/or air quality consultant, you must evaluate vermiculite insulation as containing asbestos (without sampling). In addition, you must inform the owner that sampling the material will not provide a definitive answer. EPA and ATSDR both recommend that professional asbestos abatement contractors handle any disturbance of the vermiculite insulation. The best practice for air monitoring and analysis of these projects, for the protection of the public, is Transmission Electron Microscopy. As these issues are not well known, even in the asbestos industry, it is important for owners to be aware of this potential problem and take the precautions necessary.

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