The Vermiculite Institute


revised Oct. 12, 2000

Recently there have been several newspaper articles, a three-part NPR series, and a 20/20 show about asbestos contamination at the former W.R. Grace vermiculite mine located in Libby, Montana.

Most of these articles have mentioned the fact that this problem was not inherent in all vermiculite mines, but a problem of that particular Libby, Montana mine because of its unique geological formation and location. What also has been surprising and newsworthy in Libby, Montana has been the relatively recent development of health problems not just among the miners themselves, but among some of their families.

The focus of all these articles has been on the asbestos contamination at the Libby, Montana mine, not at other mines. As a result of these articles and news stories, however, many people have become confused and concerned about vermiculite in general.

Vermiculite itself does not contain asbestos; it was just the Libby, Montana mine which was contaminated because of the presence in the mountain of a secondary mineral called diopside. (To read more about diopside, go to sites like The Mineral Diopside.)

In a simplified description, in the Libby deposit there was originally biotite and diopside. With weatherization over millions of years, the biotite turned into vermiculite and the diopside turned into the asbestos.

Knowledge about the problems at Libby is not new. There have been law suits based on asbestos exposure dating back to the mid 1970's, many cases have been settled or resolved years ago, and the owner of the mine, the W.R. Grace and Company, closed the mine and most of its vermiculite processing plants thoughout North America ten years ago.

When other companies in the vermiculite industry became aware of the asbestos problems at Libby, they became very concerned and began testing for possible asbestos contamination in their operations. And today, any new source of vermiculite is tested for asbestos. These testing reports are scrutinized to make sure the vermiculite is safe, and MSDS sheets are maintained to comply with all OSHA and Community-Right-to-Know laws.

The Schundler Company has been one of the largest and most consistent customers of Palabora Mining Company in North America. And unlike the Libby, Montanta ore, Palabora vermiculite has proven to be one of the safest sources of vermiculite in the world.

When Libby's asbestos problem became known in the 1970's, the Palabora Mining Company and American Vermiculite Company, its North American sales company, were among the first to check South African vermiculite for asbestos.

In October, 1976, Atlanta Testing and Engineering located in Norcross, Georgia, used x-ray diffraction and optical analysis to do a mineralogical study of Palabora's vermiculite. Further studies were done with scanning electron microscopy (SEM) of the crude, unexpanded vermiculite. The conclusion: "The results of our analysis program confirm that the sample of crude vermiculite ore provided by American Vermiculite Corporation is composed of high grade vermiculite containing only minor traces of impurities. No asbestos was found during this intensive analysis program."

Then in October, 1979, Palabora Mining Company had another, more extensive study done of the actual mine in Phalaborwa, South Africa. The study was conducted by the Ontario Research Foundation---at the time one of the best asbestos research companies in the world. The Ontario Research Foundation was told to examine the Palabora African vermiculite (with samples from the mine itself, from specimens of crude ore arriving from the mine and from expanded products made from the crude ore) so as to determine if there were any asbestos fibers of any kind in any of the samples.

Ontario Research Foundation used "transmission electron microscopy, using selected area electron diffraction and energy dispersive X-ray techniques for fibre indentification. This method does not involve pulverization of the material, and therefore permits measurement of fibre sizes."

To sum up the results of the testing, let us quote from the salient sections of the "Conclusions" of the report:

  1. "No amphibole asbestos was detected, either intercalated between the vermiculite layers or in the associated dust."
  2. "No chrysotile asbestos fibres which could be positively identified were detected in the material."
  3. "No additional fibres appear to be generated after exfoliation of vermiculite."
  4. "No asbestos fibres could be positively identified in this product."

Considering the reputation of the Ontario Research Foundation in the field of asbestos detection and identification, we were extremely confident during the 1980's that our Schundler vermiculite was safe to use both for our workers and for our customers.

Nevertheless, again in March 1994 Palabora had another study of its vermiculite done by the Institute of Occupational Medicine located in Edinburgh. In this study, samples were sent to Savannah Laboratories & Environmental Services Inc. in Savannah, GA, and to Tracerco in Billingham England, and once again trasmission electron microscopy (TEM) was used. The conclusion: "No asbestos or asbestiform fibres were detected in any of the PP&V and VOD vermiculite samples analysed by the Institute of Occupational Medicine." (PP&V and VOD are different areas of the deposit at Palabora Mining Company's vermiculite deposit.) Also, "when compared with existing and proposed legislation and standards for asbestos and free silica, all of the PP&V and VOD samples easily meet and surpass all relevant trigger or action levels."

In 1997, IOM (Institute of Occupational Medicine) was asked again to evaluate Palabora Mining Company's vermiculite. Vermiculite was examined using stero-binocular microscopy, polarised light microscopy, electron microscopy, and x-ray diffractometry. The results again were very good. "No amphibole asbestos or chrysotile fibres were detected in any of the samples of crude or exfoliated vermiculite collected.....Therefore, all of the vermiculite materials tested comply with the proposed 0.1% European packaging (HSE, 1994b) and labelling of carcinogen requirements and the 0.1% trifer value reguired for labelling of hazardous materials in the U.S."

The latest study conducted by IOM (Institute of Occupational Medicine) on Palabora Mining Company's vermiculte is dated March 10, 2000. Samples of each commercial grade were examined with stereo-binocular microscopy and polarised light microscopy. Electron microscopy and X-ray diffractometry was to have been used on any samples in which asbsetos fibers were detected. In the final analysis, "no amphibole or chrysotile asbestos fibers were detected in any of the samples of crude vermiculite collected. (so) quantitative analysis of the vermiculite materials was not undertaken." And once again, "all of the vermiculite materials tested complied with the proposed 0.1 % European packaging and labelling of carcinogen requirements (HSE, 1994b) and the 0.1% trigger value required for labelling of hazardous materials in the U.S."

Finally because of the current confusion about vermiculite and asbestos, our plant was inspected recently (February 7, 2000) by representatives of the federal Environmental Protection Agency. Twelve samples of our vermiculite were taken from random areas of our ore piles, and then tested by Lockheed Martin Technology Services Group. According to their final report "no asbestos fibers were identified in any of the samples by either PLM or TEM analysis." (Quoted from the EPA report issued on March 14, 2000 regarding this inspection and the subsequent testing. see The EPA Report on Schundler Vermiculite--March 2000)

Because of the problems at Libby, due diligence demands that all vermiculite mines continue to be tested --- even though there seems to be continuing evidence that the problems at Libby were unique to Libby. At all the mines currently supplying vermiculite crude ore to processing companies in North America, Europe, and the rest of the world, testing has been done. From what we have been able to gather and ascertain, fibrous or asbestiform materials have either not been found or detected, or only trace amounts below current regulatory limits have been detected. Furthermore, they all comply with current EPA, OHSA, and European regulatory agencies.

For instance, when Virginia Vermiculite first began developing its mine in 1979, testing was done by Walter C. McCrone Associates. Using petrographic microscopy with the aid of dispersion staining, no asbestiform minerals were detected in any of the samples tested. Shortly thereafter, Ontario Research was asked to do a thorough study similar to the Palabora Mining Company's study in 1979 with no chrysotile fibers found and no other harmful fibers found (amphibole fibers). Ongoing testing at this major domestic supplier of crude vermiculite ore has continued ever since. In all of these test, the mine has been able to operate and sell vermiculite ore in full compliance with OSHA, MSHA, and EPA regulations.

Vermiculite from Yuli (also known as Korla) in northwestern China also has been used in North America. When it was first tested by the University of Liege using a polarizing microscope in 1986, the testing found no asbestos. And in 1997, for instance, the Institute of Occupational Medicine (IOM) in England reported "no amphibole asbestos were detected by SEM, indicating <0.001% present in the original bulk sample. Therefore, these materials or products containing them should not present any significant health risk." At the same time, the RJ Lee Group (in Monroeville, Pa) used TEM, XRD, and PLM analysis to test Yuli ore.

Because of this ongoing testing, we are confident the material we use from the Palabora Mining Company continues to be safe for both industrial and comsumer use. And we are confident other sources of safe and essentially asbestos-free vermiculite are available throughout the world.

We are sorry if our customers have become alarmed because of the recent publicity, but we hope this information will allay your concerns about vermiculite in general, and about our vermiculite in particular.

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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