Vermiculite Asbestos Attic Insulation

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.

Vermiculite asbestos attic insulation.

The asbestos found in vermiculite is extremely friable and is the most dangerous type amphibole of asbestos. What made the libby vermiculite so dangerous was its proximity to asbestos deposits. The insulation which was known by the brand name zonolite is most often found in residential attics. It may have shiny flakes and or small accordion like pieces see photos above.

Once vermiculite is disturbed millions of asbestos fibers become airborne. However the vermiculite used in about 70 percent of the zonolite product came from the montana mine mentioned a moment ago. Of concern is zonolite attic insulation. It was mined there for more than 50 years ending in 1990.

However some vermiculite insulation contained asbestos fibres which can cause problems if inhaled. Vermiculite is utilized for attic insulation as well as other purposes. 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. One common brand was called zonolite.

When heated to a high temperature flakes of vermiculite expand as much as 8 30 times their original size. That s good news because most zonolite a type of vermiculite insulation falls into that category. You can also check for markings on the material or its packaging. 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.

This insulation was sold in canada under the name of zonolite and was extracted from the libby mine in montana usa. Vermiculite attic insulation is a pebble like pour in product and is usually light brown gray or gold in color.