Vermiculite

Agent Name
Vermiculite
CAS Number
1318-00-9
Formula
Al.Fe.4H2-O.H-O.Mg.O3-Si.O
Major Category
Mineral Dusts
Category
Other Mineral Dusts
Description
A hydrated magnesium-iron-aluminum silicate that expands up to 20 times when heated to 1093 degrees C; [Hawley]
Sources/Uses
Used for insulating, fireproofing, soil conditioning, oil well drilling, packing, and absorbing various materials; Also used in concrete, plaster, animal feed, and as a filler in paint, rubber, and plastic; [Hawley] Vermiculite installed in the past as loose-fill insulation in attics should be considered to be contaminated with asbestos. [Reference #1]
Comments
Vermiculite ores are commonly contaminated with actinolite and tremolite (noncommercial asbestos fibers). A mine and mill in Libby, Montana was closed in 1990, but health surveys showed increased asbestos-related lung and pleural diseases in former millers and miners as well as in residents. Studies of workers exposed to vermiculite in South Carolina and South Africa did not show increased incidence of lung fibrosis and pleural thickening. [Rosenstock, p. 415]
Biomedical References

Diseases, Processes, and Activities Linked to This Agent