Today, most vermiculite is safe. However, that is not to say it cannot contain asbestos.

When we hear the word asbestos we the first association most make is ‘health hazard’. In the past two decades many steps have been taken to remove asbestos from buildings and commercial products in an effort to reduce exposure. While most asbestos containing products were banned by the Consumer Product Safety Commission and regulated by the Environmental Protection Agency, it still exists in older products as well as in trace amounts in newly manufactured products. Among new products that may still contain asbestos are soil retention enhancers, particularly vermiculite.

Vermiculite is mined from natural deposits across the globe and has a host of uses not only for commercial and private gardening, but also as an insulation compound. Vermiculite forms over millions of years due to the weathering of the mineral, biotite. Unfortunately, biotite deposits are nearby to deposits of diopside, which upon being subjected to the same weathering and age conditions becomes asbestos.

It has recently been discovered that material from a mine in Libby MT In Libby, MT one mine shipped hundreds of thousands of tons of asbestos-contaminated vermiculite across the country between 1920 and 1990. It was sold as Zonolite® Attic Insulation and possibly other brands during that time. Vermiculite from the Libby Mine may contain amphibole asbestos. The Libby Mine supplied the majority of the world market in vermiculite-based insulation.

Products made from vermiculite ore produced by the Libby Mine were not widely used after the mid-1980’s and have not been on the market since 1990. Not all vermiculite produced before 1990 contains amphibole asbestos fibers. However, to be safe and in the absence of evidence to the contrary, it is reasonable to assume that if your building has older vermiculite-based insulation, it may contain some amphibole asbestos.

The Health Risks Of Vermiculite Containing Asbestos

Although the overall percentages of amphibole asbestos in bulk vermiculite are very low, the airborne percentages can increase if the material is disturbed. Asbestos poses health risks only when fibers are present in the air that people breathe. If asbestos fibers are enclosed or tightly bound in a product, for example in asbestos siding or asbestos floor tiles, there are no significant health risks. How exposure to asbestos can affect you depends on:

• the concentration of asbestos fibers in the air
• how long the exposure lasted
• how often you were exposed
• the size of the asbestos fibers inhaled
• the amount of time since the initial exposure

When inhaled in significant quantities, asbestos fibers can cause asbestosis (a scarring of the lungs which makes breathing difficult), mesothelioma (a rare cancer of the lining of the chest or abdominal cavity) and lung cancer. The link between exposure to asbestos and other types of cancers is less clear.

Naturally, the discovery that Libby vermiculite may be contaminated with asbestos has raised concerns about the many vermiculite-based products purchased and handled by Americans all across the country. In answer to this, although the Libby mine shut down in 1990, the EPA recommends that if vermiculite is present in your home or building, it should be assumed it is from Libby and it should be treated as if the material contains asbestos. Because of the ongoing public health crisis in Libby, vermiculite has now been targeted by health and regulatory agencies in New York State with very real consequences for building owners and managers.

What should I do if I have vermiculite attic insulation?
The U.S. Environmental Protection Agency is gathering more information about vermiculite insulation and other products containing vermiculite. If you suspect vermiculite insulation is in your building, the safest thing is to leave the material alone. If you decide to remove or must otherwise disturb the material due to a renovation project, consult with an experienced asbestos contractor. The U.S. Environmental Protection Agency has developed information on Current Best Practices for Vermiculite Attic Insulation providing a common sense approach to help you find out what kind of insulation is in your home and decide what to do if you have vermiculite insulation.