Utah Department of Environmental Quality Find Two Salt Lake City Asbestos-Containing Vermiculite Sites

Asbestos-containing vermiculite ore processed at two sites in Salt Lake City, Utah.

From 1924 to 1991, 80% of the world’s supply of raw vermiculite ore came from Libby, Montana. During this time more than 5.8 million tons of asbestos-contaminated ore from Libby was shipped by rail to 240 different addresses across the United States for processing into insulation.

The vermiculite ore from the Libby mine was contaminated with a particularly dangerous form of asbestos -- amphibole asbestos of the tremolite-actinolite series. As a result, processing facilities nationwide were contaminated with the asbestos.

Salt Lake City had two sites where vermiculite ore was processed using a method called "exfoliation" to produce insulation as well as other building materials labeled under the "Zonolite" and "Monokote" brands.

The former exfoliation facility sites were located at 333 West 100 South, Salt Lake City, where Vermiculite Intermountain processed Libby ore from 1940-1984. The plant relocated to 733 West 800 South, Salt Lake City, and operated three more years under the name of Intermountain Products before closing in 1987.