Controlling the Hazard and Liability of Asbestos in
Vermiculite Insulation (PEN 16 continued)

Testing for Asbestos in Vermiculite

Vermiculite insulation in loose form can be readily visually identified as a light weight, silvery grey or blonde, granular, layered material, with particle sizes of about 2 to 10 millimeters. If vermiculite is known to have been installed prior to 1990, visual identification should be adequate to confirm the material as asbestos-suspect.

The visual identification can be confirmed by laboratory testing, although caution in selecting the laboratory is advised. The laboratory should be accredited by one of
the two US agencies that qualify laboratories for the analysis of asbestos in bulk samples. Even these laboratories require extra care to detect the very fine fibres at these low concentrations. Laboratories that do not specialize in asbestos analysis should never be relied on for asbestos analysis.

If the owner decides to test the vermiculite for asbestos content, the US EPA advises using a respirator effective against asbestos during sample collection. The sample should be taken from the bottom and lower section of insulation since the finer particles or dust (which contains a higher concentration of asbestos) tend to settle out of the vermiculite particles. Sampling only the top of the insulation may provide a false negative analysis for asbestos.

It is extremely important to note that the overall percentages of asbestos in the bulk vermiculite are very low, possibly below existing legal limits for asbestos. None-the-less, the airborne concentrations can be very high when the material is disturbed, due to the very fine and loose nature of the asbestos. A recent US EPA study of six homes in Vermont showed elevated airborne asbestos concentrations even in cases where the laboratory could not detect asbestos in the bulk material. Therefore EPA recommends that all loose-fill insulation visually identified as vermiculite, and installed prior to 1990, be treated with asbestos precautions.

If you wish Pinchin Environmental to test your samples, please follow the instructions here.

Risk to Occupants and Contractors

Pinchin Environmental is aware of many studies that confirm the potential for harmful asbestos exposures when vermiculite insulation is disturbed. The US EPA study referred to earlier indicated that, in homes with vermiculite insulation, asbestos was not detected in the air or dust samples in the home in the absence of disturbance of the insulation. However even relatively minor disturbances generated excessive levels of airborne asbestos in the area of disturbance.

It is not possible, partly because of the variable amounts of the asbestos in the vermiculite, to predict with certainty the actual airborne concentration. The current occupational exposure limit for asbestos is 0.1 fibers per cubic centimeter of air (f/cc). Compared to this, levels of airborne asbestos measured in various studies using either optical or electron microscopes confirmed very elevated exposure levels as shown in the accompanying table.

These results strongly support the following recommendations for homes from the US EPA publication “Current Best Practice for Vermiculite Attic Insulation”.

This same advice should be followed if vermiculite insulation is found in other settings.

• Vermiculite insulation should be left undisturbed. Due to the uncertainties with existing testing techniques, it is best to assume that the material may contain asbestos.
  
  
• Do not store boxes or other items in the attic if retrieving the material could disturb the insulation.
• Children should not be allowed to play in attics with open areas of vermiculite insulation.
• If renovations are planned that might disturb the vermiculite, it should be first removed by professionals trained and certified to handle asbestos.
• The homeowner or maintenance personnel should never attempt to remove the insulation. Hire professionals trained and certified to safely remove the material.

Recent Developments in Hazard Recognition and Information

The concern throughout North America over the asbestos in vermiculite is increasing sharply due to government attention and increased public awareness. The US EPA launched a National Consumer Awareness Campaign on the issue in May 2003. Their publication "Current Best Practices for Vermiculite Attic Insulation - May 2003" is now being distributed across the US and is available to Canadians via the EPA homepage.

A major court case on behalf of homeowners with vermiculite attic insulation is being heard in late 2003. This will increase both awareness and concern over vermiculite insulation.

This increased awareness has started to impact property transfers in Canada. As a result of vermiculite attic insulation being found during pre-purchase home inspections, several home sales have fallen through in Ottawa and Toronto. Some other sales have been completed on the basis that the vermiculite would be removed. Pinchin is currently working on techniques to perform the removal of vermiculite in a more cost-effective basis and it is anticipated that this will be field tested by late summer 2003.

The Canadian government, through the Safe Environments Program (SEP) of Health Canada have prepared an advisory publication on Zonolite in the "It's Your Health" series.This is currently being reviewed within Health Canada prior to release to the public. To date there has been no reaction or policy from Consumer and Corporate Affairs similar to the UFFI removal program. Demand for something of this sort is almost certainly bound to develop once the cost impacts on homeowners become apparent.To date, these costs seem to be of the order of $10,000 per home. Although these developments have largely focused on the residential uses of asbestos, there have been a number of clean-ups or removals performed in commercial buildings, financial institutions and municipal facilities. Vermiculite is certainly not simply a residential issue.

Asbestos in vermiculite attic insulation (TEM, 880X)

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