Asbestos in Vermiculite Compounds

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In 1916, an adventurer and entrepreneur named Edward Alley was exploring some of the abandoned mines in the Cabinet Mountains of western Montana when flame from the torch he was carrying brushed against the ceiling of the mine.Asbestos Contaminated Vermiculite Alley heard a pop and a sizzling noise. The flame had caused some type of mineral in the rock to suddenly expand into a soft, pliable substance.

Alley was not certain what he had discovered, but was certain there would be a market for it.

What Edward Alley found was vermiculite – by itself, a relatively harmless and highly absorbent form of clay. Over the years, there were indeed markets and uses for this remarkable substance, including soil conditioning and amendment for gardening, fireproofing and as a loose-fill insulation material. Eventually, it became the main ingredient of a highly popular form of insulation marketed by W.R. Grace & Company.

What Alley did not know was that the vermiculite he discovered was contaminated with a particularly deadly form of asbestos called tremolite. Ironically, Alley died less than twenty years later from exposure to the very substance with which he had made his fortune.

From 1920 until the early 1980s, vermiculite insulation, which was marketed under the Zonolite brand starting four years after Alley’s death, was used in the construction of homes throughout the U.S. and Canada. The management of W.R. Grace & Company, which took over Universal Zonolite Inc. in 1963, was fully aware of the health hazards of the tremolite with which the vermiculite was contaminated. Internal memos taken from the corporation’s own records show that nearly half of the workers employed for over 10 years were found to have contracted lung diseases when examined by the company’s own physicians. The results of these exams were not shared with the employees however.

Asbestos Vermiculite Sample

Typically, those who were at the head of the Grace corporation were more concerned with profits than with the well-being of its employees and the community in which it operated. The tragic results of this inexcusable, but all-too-common corporate malfeasance was thoroughly documented in 1999 and 2000 by Seattle Post-Intelligencer reporter Andrew Schneider.

It is important to understand that not all vermiculite is contaminated by asbestos. Vermiculite mines in Brazil and South Africa as well as the U.S. outside of western Montana regularly test their product for the presence of asbestos contamination. Virtually all contaminated vermiculite was from the W.R. Grace & Company operation in Libby, Montana.