Insulating mix is one of many options when it comes to providing insulation for buildings. This substance is sold as a dry mixture to which water is added to create a damp, granular material that may then be poured into cavities in walls, floors, or ceilings. Today, insulating mixes use vermiculite or similar minerals to add heat resistance to the mixture, but for many years, the insulating material of choice for many construction application was asbestos.
This mineral is most dangerous when its fibers become airborne. Unfortunately, the process of preparing the dry insulating mix often kicks up a significant amount of dust, severely endangering the health of workers who mixed it. The asbestos fibers are small enough to penetrate paper masks and even some respirator filters, so construction workers who dealt with asbestos-containing insulating mix may be in danger of developing asbestos-related diseases such as lung scarring, asbestosis, or mesothelioma.
Vermiculite is not always a safe material, either, since it can often be found in mineral deposits along with asbestos. One town where vermiculite was mined for many years — Libby, Montana — has been stricken by hundreds of cases of asbestos-related diseases. Not all vermiculite is contaminated, but insulation made from material in the Libby mines that was sold under the brand name Zonolite is often unsafe.