Vermiculite Asbestos Attic Insulation

Of concern is zonolite attic insulation.

Vermiculite asbestos attic insulation.

What made the libby vermiculite so dangerous was its proximity to asbestos deposits. When heated to a high temperature flakes of vermiculite expand as much as 8 30 times their original size. However the vermiculite used in about 70 percent of the zonolite product came from the montana mine mentioned a moment ago. The asbestos found in vermiculite is extremely friable and is the most dangerous type amphibole of asbestos.

One common brand was called zonolite. The vermiculite from libby is part of the longest man made environmental disaster in american history. Once vermiculite is disturbed millions of asbestos fibers become airborne. You can also check for markings on the material or its packaging.

This insulation was sold in canada under the name of zonolite and was extracted from the libby mine in montana usa. It was mined there for more than 50 years ending in 1990. The expanded vermiculite is a light weight fire resistant and odorless material and has been used in numerous products including insulation for attics and walls. However some vermiculite insulation contained asbestos fibres which can cause problems if inhaled.

The epa says that vermiculite insulation which is the pebbly stuff found in attics of many older homes is only risky if it contains more than one percent asbestos. As long as this kind of vermiculite based insulation remains undisturbed behind intact walls or in attic spaces and does not become airborne it should not be a concern. Vermiculite is utilized for attic insulation as well as other purposes. It may have shiny flakes and or small accordion like pieces see photos above.

The insulation which was known by the brand name zonolite is most often found in residential attics. Vermiculite in and of itself is not dangerous.