Most vermiculite is not contaminated with asbestos. However, the vermiculite ore taken from a mining operation in Libby, Montana, was contaminated with asbestos amphibole minerals, including tremolite and actinolite. Learn more about the history of asbestos in Libby below.

What is Vermiculite?

Vermiculite is a naturally occurring mineral mined in the United States, Brazil, Argentina, Mexico, South Africa, Zimbabwe, Kenya, Uganda, Egypt, India, Russia, China, Japan and Australia. Vermiculite has a flaky, mica-like structure that is flat and shiny in its natural state and puffed and dull when expanded.

When heated, vermiculite exfoliates (or “pops”), forming a lightweight material. The expanded form is light-weight, fire-resistant and odorless, which makes the mineral suitable for use in many products including building insulation, fire-proofing and as a soil amendment. If the vermiculite is contaminated with asbestos, the exfoliation process releases dangerous asbestos fibers into the air.

Learn more about the dangers of asbestos here.

A Short History

During the 1920s the Zonolite Company formed and began mining the vermiculite at Zonolite Mountain. In 1963, W.R. Grace bought the operations. The mine itself was approximately six miles from the town of Libby. A transfer facility was located approximately three miles from Libby where vermiculite was loaded on trains or trucks.

Two expansion (“popping”) facilities operated at different times within the town; these plants heated vermiculite to approximately 600 degrees Fahrenheit to expand the crystals. The vermiculite from the Libby mine was contaminated with tremolite asbestos and the expansion of this form of vermiculite caused a serious health risk to both workers and consumers who used the final product in one of its many applications.

At its peak, the Libby mine may have provided 80 percent of the world’s vermiculite, most of which was contaminated with what would become known as Libby Amphibole Asbestos. The contamination was not limited just to the mine site; Libby residents were able to pick up free truckloads of asbestos-contaminated vermiculite for use at home.

The vermiculite was used to pave driveways and in public areas (boat ramps, ice rink, running track, baseball fields and school yards). Children played in piles of vermiculite that could be found throughout the community. Also, attic insulation contaminated with Libby asbestos may still be in schools, businesses and as many as 35 million homes around the United States alone.
The EPA Responds
The vermiculite mining operation was finally closed in 1990. In 1999, the EPA sent an Emergency Response Team to Libby as a response to local health concerns and related national news articles about asbestos-contaminated vermiculite. The EPA assessed the risk to public health and then began taking actions to reduce the risk. In 2002, the EPA added Libby Asbestos to the National Priorities List as a superfund cleanup site. In 2009, the EPA declared (under the Comprehensive Environmental Response, Compensation and Liability Act [CERCLA]) Libby’s asbestos problem to be a public health emergency.
Lincoln County ARP is Born
The Lincoln County Asbestos Resource Program was founded to help you and your family to create and maintain an asbestos-free environment through education and community resources. We work on a ground level with the local community to ensure Lincoln County is asbestos aware and safe!

Learn more about what the ARP is about here!