Overview
Workers at vermiculite exfoliation plants processing ore from Libby, Montana faced extreme asbestos exposure, among the highest ever documented in any occupation. The Libby vermiculite deposit was heavily contaminated with tremolite asbestos, and over 200 processing plants across the United States received this contaminated material.
The Libby vermiculite disaster is considered one of the worst environmental health catastrophes in U.S. history. Thousands of workers, family members, and community residents have developed asbestos-related diseases from this single source.
The Libby Vermiculite Story
How the Libby mine seeded a nationwide exposure problem
The vermiculite mine near Libby, Montana operated from 1923 to 1990, producing about 70% of all vermiculite sold in the United States. The ore was heavily contaminated with tremolite asbestos, a particularly dangerous form of the mineral.
Where the contaminated ore ended up after it left Montana
Raw vermiculite was shipped to over 200 exfoliation plants across the country, where it was heated to expand the mineral for use in Zonolite attic insulation, potting soils, fireproofing, and construction aggregates. Plants in Minneapolis, Phoenix, and Newark processed shipments from Libby for decades.
Why workers received no real protection for most of the operation
W.R. Grace and its predecessor companies knew about the contamination. Workers were not warned of the danger, families were exposed through contaminated clothing brought home from shifts, and surrounding communities were exposed by plant emissions drifting into the neighborhood.
Asbestos Exposure at Exfoliation Plants
| Task | Description | Exposure Level |
|---|---|---|
| Ore handling | Unloading and moving raw vermiculite | Extreme |
| Exfoliation | Heating process to expand vermiculite | Extreme |
| Bagging | Packaging finished product | Very High |
| Maintenance | Equipment repair and cleaning | Very High |
| General facility | Working anywhere in plant | High |
How Workers Were Exposed
Documents revealed that W.R. Grace knew about the asbestos contamination for decades but concealed this information from workers, regulators, and the public.
Major Exfoliation Plant Locations
Workers faced exposure in Libby, Montana at the mine and mill; at the exfoliation plant in Minneapolis, Minnesota; in Phoenix, Arizona; in Newark, New Jersey; and at more than 200 other plants across the United States that processed Libby ore from the 1920s into the 1990s.
Products Containing Libby Vermiculite
Libby vermiculite went into Zonolite attic insulation installed in millions of homes, Monokote spray fireproofing applied to structural steel, consumer potting soils sold for garden use, pool additives, and a range of industrial fireproofing products.
Health Consequences
Libby vermiculite workers face extremely elevated risk of mesothelioma, a cancer of the chest or abdominal lining; asbestosis with severe progressive lung scarring; dramatically elevated lung cancer rates; and pleural disease that thickens and scars the lining around the lungs. The tremolite asbestos from Libby is particularly potent, causing disease at lower exposure levels than other asbestos types.
Legal Options
Libby vermiculite workers have strong legal claims. W.R. Grace established a major trust fund through its bankruptcy specifically for Libby-related claims, with billions of dollars available through a streamlined claims process. Trust claims often run alongside product-liability suits against other responsible companies, premises-liability claims against plant owners, VA benefits for exposure during military service, and workers’ compensation through a former employer.
Libby vermiculite exposure claims receive special attention due to the documented severity of exposure and W.R. Grace’s concealment of the hazard.