What is Asbestos?
Asbestos is a naturally occurring mineral fiber found in certain types of rock formations in many locations throughout the world. Asbestos can take the form of long, thin, separable fibers. When milled for various applications, asbestos is a very small fiber, about 5 microns, that can not be seen by the naked eye. The small fiber looking objects you may see when you tear a piece of linoleum paper backing are not asbestos fibers, they are supporting binders, those supporting binders you see are like the size of a 10 foot diameter red wood tree, the asbestos fibers inside the supporting binder would be the size of a needle–clearly not visible. Asbestos can only be positively identified with a microscope, specific preparation techniques, and training in identifying asbestos fibers from other similar fibers.
There are two major groups of Asbestos:
The major difference between serpentine and amphiboles is related to their chemical composition, acid-resistant properties, and their effects on human health.
Chrysotile asbestos does not persist in the lungs after inhalation; it is quickly eliminated by the body. A prolonged exposure to high concentrations of chrysotile fibers is required for the clinical manifestation of pulmonary damage to appear. In the past, such high exposures were frequent but that is no longer the case today. Today, chrysotile is the only asbestos fiber commercialized, and still imported into the US. A trip to your local hardware store will demonstrate the continued use of asbestos, go to the area with roof patching material and read the ingredients.
Amphibole asbestos, on the other hand, because of their toxicity and their high biopersistence, are mainly responsible for mesothelioma and pulmonary diseases even caused after a short or moderate exposure.
Asbestos was used extensively in the past in building materials for its thermal insulating properties and fire resistance. It was also used in industrial products, and automotive parts and components because of its strengthening properties. It is well recognized as a health hazard and is highly regulated by OSHA, EPA and many state and local agencies. These agencies regulations were created to reduce asbestos exposure.
Where was asbestos used primarily?
People have been using asbestos for a long time. One of its earliest known usages was in Egypt where the queen would amuse guests by tossing an asbestos woven table cloth into the fireplace. The table cloth would not burn but all the food and drink stains would disappear leaving the table cloth like new.
Today most products made do not contain asbestos. Those few products which still contain asbestos that could be inhaled are required to be labeled as such. However, until the 1980’s, many types of building products and insulation materials used in buildings contained asbestos.
Some common building products that might have contained asbestos in the past include: