Asbestos is a naturally occurring mineral that is found underground in many regions of the world. Asbestos is somewhat unique as a mineral in that its consistency is similar to that of cotton or other fibrous materials. Asbestos can be found in nearly every country and on every continent in some variety. Among asbestos, there are two sub classifications and each sub classification features a few distinct varieties. The first variety of asbestos is known as chrysotile asbestos, which is curly and also referred to as "serpentine." The fibers in this variety are coiled or tightly wound when examined under a microscope. The second variety is called. Amphibole asbestos is much straighter and more needle-like.
Serpentine versions of asbestos were the only variety that was ever mined on a large scale. The mention of the word asbestos today conjures up images of an industrial pollutant and dangerous toxin. However, this was not always common knowledge and asbestos was used extensively up until the late 1970’s in the United States and is still used today in many countries with less stringent regulations. Asbestos’ consistency proved to be especially adept for inclusion in insulation compounds. Asbestos was rigid and extremely heat resistant, meaning it could withstand fire and prevent heat transfer while not easily breaking down. Needless to say, these qualities were sought of in many materials, making asbestos a near "wonder" material before its health dangers became evident.
Asbestos was used in many materials but among the more popular were ceiling tiles, floor tiles, home insulation, siding, and concrete. Asbestos was usually not the primary construction material but rather would be added to the compounds to provide them with insulation or fire retardant qualities. It proved to be so versatile that nearly every component of construction has included asbestos at some time. Today there are other materials that are used for these purposes. However, much of the original asbestos-containing materials have not been replaced and still remain in many structures. In fact, nearly 80% of structures built prior to 1978 still contain some asbestos-containing materials.
A common misconception however, is that all asbestos is dangerous. While certainly all human exposure to asbestos is potentially dangerous, not all asbestos-containing materials are liable to cause exposure. These materials must be in a "friable" state to causes exposure and release asbestos into the air. To be rendered friable, asbestos containing materials must be able to be crushed or pulverized by human hand or other pressure. For this reason, many asbestos containing materials that are in homes are not immediately dangerous, though they should be replaced at first sign of damage. Often it is when these materials are disturbed, such as they may be in industrial settings that exposures occur.