Attic Vermiculite Identification
Approximately one million homes in the United States contain vermiculite attic insulation. One of the major past sources of this vermiculite was commercially produced vermiculite insulation from Libby, Montana, containing trace levels of asbestiform amphibole, which is known to cause asbestos-related diseases. Although the Libby mine is closed and part of a Superfund site, the existing insulation in many older houses and buildings still needs to be tested for asbestos. When vermiculite insulation is found in an attic, evaluating it for asbestos has traditionally involved collecting a sample and submitting it for potentially time-consuming analyses at an off-site laboratory.