What is vermiculite?

Vermiculite is a naturally occurring mineral used in construction, insulation and gardening products. It looks like shiny, small pieces of popcorn, and is usually light-brown or gold in color. Vermiculite came from mines in Libby, Montana (closed in 1990) as well as other mines in the U.S. and other countries. Vermiculite is still mined and distributed for a number of uses, including insulation.  more

Vermiculite is a volcanic mineral that is fire-resistant and has strong insulation properties. The Environmental Protection Agency notes that when vermiculate is heated, it expands into worm-like or accordion-like pieces and may release asbestos fibres. Vermiculite has been used in various industries including construction, agricultural and horticultural markets for more than 80 years.  more

Vermiculite is a hydrated basaltic mineral with some unusual properties which have caused it to be popular in industrial manufacturing since the early 1900s. Many consumers probably interact with vermiculite, since it is used as a filler in a wide range of products, and it can also be found in things like insulation, absorbent materials, and soil mixes. Direct contact with vermiculite is relatively rare, since it is used as a constituent rather than a primary ingredient, although people who work with some forms of insulation may handle vermiculite. There are two interesting things about vermiculite which make the mineral desirable to manufacturers. The first is its physical structure, which takes the form of crystalline layers like mica. The second is the water trapped inside the vermiculite. If the mineral is heated, the water turns to steam, forcing the mineral to expand, and the layers fold out like an accordion, creating strands of very lightweight, porous material. When ...  more

Vermiculite is a naturally occurring mineral that may contain asbestos. Vermiculite has the unusual property of expanding into worm-like accordion shaped pieces when heated. The expanded vermiculite is a light-weight, fire-resistant, absorbent and odorless material. These properties allow vermiculite to be used to make numerous products, including attic insulation, packing material and garden products. Asbestos contamination in vermiculite and vermiculite products has become a national concern to a variety of federal agencies including the Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA) Agency for Toxic Substances and Disease Registry (ATSDR), and the Consumer Protection Safety Commission (CPSC), as well as to many private citizens throughout the country. Additional information about vermiculite can be found at http://www.epa.gov/asbestos/verm.html.  more

Vermiculite is a naturally occurring mineral used in construction, insulation and gardening products. It looks like shiny, small pieces of popcorn, and is usually light-brown or gold in color. Vermiculite came from mines in Libby, Montana (closed in 1990) as well as other mines in the U.S. and other countries. Vermiculite is still mined and distributed for a number of uses, including insulation. Why should I be concerned about vermiculite insulation? Much of the Libby vermiculite was used as attic insulation. It was sold under the product name Zonolite. The Environmental Protection Agency (EPA) estimated in 1985 that 940,000 American homes contained Zonolite attic insulation. Over 70% of vermiculite ore mined worldwide came from the Libby, Montana mine. The ore from this mine also included a natural deposit of amphibole/tremolite asbestos. Much of the vermiculite from Libby was contaminated with asbestos. Asbestos fibers are invisible to the eye and can only be professionally ...  more