What is Vermiculite?

Vermiculite is a naturally occurring mineral with heat and fire resistant properties similar to asbestos.  Unlike asbestos, vermiculite itself does not present any significant health risk to humans.  Vermiculite resembles mica in appearance and, when heated, expands into a work-like accordion shape.  This process of expansion is commonly referred to as exfoliation. Vermiculite is used today for insulation.  Typically vermiculite products are pebble-like with a light-brown or gold color.

In the year 2000 vermiculite production approached 550 kilotons world wide.  Vermiculite is mined all over the world, with major mines located in China, Brazil, South Africa, the United States, and Zimbabwe.  Today's largest vermiculite mines are located in South Africa, the northwestern corner of China, and along the Appalachian mountain range around Virginia in the eastern United States. 

Mesothelioma and Vermiculite

Vermiculite is often associated with asbestos, leaving many people to believe that vermiculite poses a similar health threat.  There is no scientific evidence to suggest that vermiculite alone can cause asbestos-related health conditions like Mesothelioma.  Instead most of the connection between vermiculite, asbestos, and asbestos-related diseases like Mesothelioma stems from the experience of a vermiculite mine in Libby, Montana.

Vermiculite and Mesothelioma in Libby, Montana

Vermiculite is typically found in mineral veins deep within the earth.  These veins commonly have a wide variety of ores including vermiculite.  The vermiculite mine in Libby, Montana was unique in the fact that the vermiculite formed in conjunction with the formation of asbestos.  Most vermiculite deposits were formed in the pre-Cambrian (1.5-3 Billion years ago) period, whereas the vermiculite deposits in the Libby mine were formed in the Triassic age (225 million years ago).  The relatively young age of the vermiculite ore in the Libby mine may be directly correlated to the formation of asbestos nearby. 

Vermiculite Health Concerns

While vermiculite is relatively harmless, a good portion of vermiculite mined from the Libby mine also contained asbestos.  Thus any vermiculite insulation that can be traced back to the Libby, Montana mine may pose a significant health risk to anyone who may come into contact with it.  If you have vermiculite insulation in your home and believe that it may have originated from the Libby, Montana mine please contact your local EPA agency or state health department.