Asbestos however, is still a relevant hazard today in a number of different capacities. While most asbestos containing products were banned by the Consumer Product Safety Commission and regulated by the Environmental Protection Agency, unfortunately it still exists in hundreds of 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 myriad 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, former biotite deposits are often in close proximity to deposits of diopside, which upon being subjected to the same weathering and age conditions becomes asbestos.

In Libby, MT one particular mine shipped hundreds of thousands of tons of asbestos-contaminated vermiculite across the country. However, they were not the only manufacturers of vermiculite to ship asbestos with their products. Many other manufacturers were doing the same thing before EPA testing and regulations finally forced them to limit the amount of residual asbestos dust in the vermiculite. In the early 1990’s the W.R. Grace Company closed its mine in Libby, Montana and over 20 processing plants located across the country. As a result, there are many regions where there simply isn’t a local vermiculite processing plant. Because of a lot of bad publicity about Libby and the Libby vermiculite mine, many of the larger “box stores” no longer stock and supply vermiculite.

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

Today, most vermiculite is safe. However, that is not to say it cannot contain asbestos. Vermiculite which is accompanied by a great deal of dust likely has residual asbestos in its contents and should be used with caution. Current EPA regulations ban products which contain 1% or more asbestos. Unfortunately even products containing less that 1% asbestos are still extremely hazardous, particularly when in loose dust form as vermiculite often is manufactured.

It is no surprise then that hundreds of the Libby mine’s employees and residents of the town were diagnosed with mesothelioma, a rare and aggressive cancer that is known only to be caused by asbestos exposure. Options for mesothelioma treatment are limited, so many of these residents were able to secure financial compensation for their families through litigation. Mesothelioma incidence is also known to be high in commercial gardeners and other occupations which deal with large amounts of loose vermiculite.

Fortunately, exposure to asbestos-contaminated vermiculite can be avoided if consumers follow these simple precautions:

• Note the appearance of the vermiculite. If it seems to carry a great deal of residual dust, dispose of it outdoors.
• Read the label. Most manufacturers of vermiculite mark their products packaging with “Non Dusty” labels. These refined granules are often slightly more expensive but they are certainly the safest.
• Apply vermiculite on non-windy days to minimize airborne particulate matter. Wet-down soil once applied.

References:
Environmental Protection Agency. EPA Asbestos Materials Ban.1989
Consumer Product Safety Commission. Asbestos Consumer Products.