The Vermiculite Institute

Vermiculite and Asbestos-Contamination in Libby, Montana

revised October 3, 2000

On August 22, 2000, the federal EPA (Office of Pollution Prevention and Toxics) released a report entitled: Sampling and Analysis of Consumer Garden Products That Contain Vermiculite.

The official EPA press release said, "The U.S. Environmental Protection Agency announced that a study of gardening uses of vermiculite shows that some products contain low levels of asbestos, but the risk to consumers is very low." Susan Wayland of the EPA's office for prevention, pesticides and toxic substances said, "These levels were very low and do not pose significant health risks."

In magazines like People and McColl's, recent articles have described the plight of the people of Libby, Montana where asbestos from a vermiculite mining operation have hurt people and contaminated the surrounding area.

  • So what is the EPA officially saying about vermiculite and asbestos-contaminated vermiculite?
  • What did the recent EPA report say?
  • And should people be concerned about using any vermiculite being mined and sold today in the United States?

In the EPA's own "FACT SHEET" on Asbestos-Contaminated Vermiculite (August 2000) (found at EPA: Asbestos-Contaminated Vermiculite), the agency writes:

  • "Vermiculite ores often contain a range of other minerals including, in some cases, asbestos. Asbestos is not a major contaminant, and only a few ore deposits have been found to contain more than trace amounts of asbestos minerals."

In another EPA description of vermiculite, the agency writes:

  • "Vermiculite ores from some sources have been found to contain asbestos minerals, but asbestos is not intrinsic to vermiculite and only a few ore bodies have been found to contain more than tiny trace amounts." (See EPA:Vermiculite).

To be sure, asbestos is not a major contaminant in vermiculite mines. It is not found in measurable levels in any of the currently used vermiculite deposits and most specifically not in the Palabora Mine (South African) which supplies ore to The Schundler Company.

Asbestos was present in the infamous Libby, Montana mine described in news stories and more recently in articles in McCall's and People magazines. This asbestos did not develop from vermiculite but from another mineral called diopside, which was present in the Libby mine. Unfortunately, the diopside which developed in the Libby deposit was very unique and very unstable, and eventually formed the asbestos, which was intermingled with the vermiculite deposit. In fact, this diopside didn't just "contaminate" the vermiculite deposit; it was present in levels approaching 22-26 % in the raw ore!

The Libby deposit was first opened in the 1920's. Men and women had been exposed to this heavy concentration of asbestos for decades----long before we became aware of how asbestos affects us, and long before modern industrial mining technology became increasingly concerned about dust levels of any type.

As a result, both miners and their families were exposed to the heavy concentrations in the Libby deposit for many years, and people have died because of it. Today, the mine owners (the W.R. Grace Company) have a number of lawsuits pending against them, and they have lost many in the past and have settled many in the past. Meanwhile, the EPA is working to ensure the mine was closed properly and completely, and to make the town of Libby as safe as possible for future generations.

But the Libby mine was closed in 1990, the vermiculite currently on the market in the United States does not come from Libby, and the EPA report essentially tries to say in a number of ways, again and again, that the levels of asbestos found in 38 samples of vermiculite taken from stores around the country "were very low and do not pose significant health risks." (Two of those samples, in fact, was Libby material used as a "benchmark" of contaminated material, and even that sample did not have levels above what OSHA calls acceptable "excursion" levels of fiber (the amount of exposure an industrial worker would be exposed to for short periods of 30 minutes or less.)

Hopefully our customers and the American public will put the news about Libby into perspective. It is news about a particular mine with a particular, unique geological formation, which caused injury because of its incredible high level of contamination. These stories are not about vermiculite in general, and if and when they suggest asbestos occurs in vermiculite, they are simply wrong.

Without going into a lot of technical detail and argument, The Schundler Company wants to assure its customers that the vermiculite we use has been tested for many years, it is considered the cleanest and safest vermiculite in the world, and it essentially is "asbestos free."

For those interested in some of the Technical Aspects of the EPA study

Some Preliminary Technical Background:

  1. Basically two methods of testing were used: what is called PLM (Polarized Light Microscopy) and TEM (Transmission Electron Microscopy). During PLM analysis, the vermiculite samples are "ground down to a level where the vermiculite plates were barely visible. " (Page 5) During the TEM analysis, the samples were ground down even further until the vermiculite plates were no longer visible to the eye.
  2. Of the 38 samples that were tested: 35 were purchased from retail stores or distributors, one came from a current industrial user of vermiculite, and two were ordered from a store in Kent, Washington which was known to be from the now closed Libby, Montana mine that was and is known to have high levels of asbestos. One might say that these last two were used as the benchmarks of bad, contaminated vermiculite.
The EPA report actually states that of the 38 samples of vermiculite tested with PLM analyses, "none of the samples tested had detectable levels of asbestos" (page 10)---even the two known to be from the terribly contaminated Libby deposit. Using the far more technical TEM analysis, 17 samples had detectable traces of asbestos, but only 5 had quantifiable levels (i.e. greater than 0.1 percent by weight).

When retested, four of the five which had had measurable amounts of asbestos in the first test either had no asbestos detected or had levels below the quantifiable levels.

When the five positive samples were tested by another more stringent test method called SOP 2000, and what is called the Superfund Method. In this testing, no detectable asbestos fibers were observed using PLM, and only one sample had either detectable actinolite/tremolite which was still below the quantification limit.

The EPA then took seven samples including the "bad" Zonolite material and a few which had had detectable fibers, and subjected these to a "consumer use simulation" in which material was poured back and forth from one container to another inside of an enclosed 10x10x10 foot enclosure and during which air monitors were placed outside the enclosure, inside the enclosure, and on the "worker". In these tests, there were no fibers detected on the monitors outside or inside the enclosure; and the monitors on the worker detected levels only slightly above the current OSHA TWA level in two cases--and one of these samples was material from the old Libby operation (the Time Weighted Average level or limit is the amount of dust which a worker can be exposed to if he or she is exposed to it for 8 hours a day, five days a week, throughout the year.) In both of these samples, the levels were not above the OSHA excursion levels (the amount of dust a worker can be exposed to for up to 30 minutes of occasional exposure.)

To be sure, if one reads the report carefully, it becomes evident quickly why the EPA itself said: the "levels were very low and do not pose significant health risks."

For more information about vermiculite, you might want to look at:

Or, call or contact us at:

The Vermiculite Institute
c/o The Schundler Company P.O. Box 513 Metuchen, New Jersey 08840
(ph)732-287-2244 (fax) 732-287-4185

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