What is Asbestos?


Asbestos is a naturally-occurring fibrous silicate mineral found predominantly in metamorphic rock. Asbestos minerals crystallize in narrow veins as parallel bundles of tiny fibers. These fibers are very small, and may remain airborne for several hours when broken-up and dispersed into the air. Asbestos is very resistant to acids, fire, and heat. Asbestos is also known for it's high tensile strength.
There are two categories of asbestos: serpentine and amphiboles. The serpentine group is comprised of chrysotile, also known as "white asbestos." Chrysotile fibers are hollow and pliable. Over 95% of all asbestos used in the United States is the chrysotile variety. The amphibole group is comprised of amosite and anthophyllite, crocidolite also known as "brown" or "blue" asbestos as well as actinolite, tremolite, and anthophyllite. Amphibole fibers are hard and straight.

How Was Asbestos Used?
Asbestosí resistance to chemicals and heat, high tensile strength, and low cost made it a very attractive ingredient in thousands of building and thermal insulation products. Some typical uses of asbestos include transite pipes, floor tiles, sheet floorings, drywall, drywall texture, drywall joint compound, insulation, automotive brakes and clutches, electric wiring insulation, transite siding, structural fireproofing and roof shingles.
In the late 1970ís, the U.S. began banning the use of asbestos in most building products due to studies confirming the harmful health effects caused by exposure to airborne asbestos. Manufacturers were allowed to deplete their existing stocks of asbestos materials, so some asbestos products were still being installed in buildings in the 1980's.
The last ban on manufacturing with asbestos building products was stayed by the U.S. Supreme Court in the late 1980ís. This makes it possible for certain building materials such as mastics, adhesives, and wall texturing to be made with asbestos. With the advent of the North American Free Trade Agreement (NAFTA), other asbestos-containing building products are currently being shipped into the U.S. from Mexico and Canada.
 
What is Asbestos Abatement?
Asbestos abatement is the removal, repair, encapsulation, enclosure, or clean-up of asbestos-containing materials (ACMs). Abatement is performed in academic and non-academic buildings and utility tunnel systems to assist departments with a planned renovation or maintenance activity, and to ensure compliance with federal and state regulations. On some occasions, unplanned, emergency abatement is performed to remove asbestos materials from mechanical equipment to allow critical repairs to be performed, or to clean-up an area contaminated by asbestos when a building system suddenly fails (e.g. roof leaks, steam system failures).