As previously discussed, one of the most common indoor contaminants is asbestos, in both commercial and residential buildings. Asbestos was a very common building component from about 1920 to 1978. It is not unusual to still find friable products like pipe insulation or non-friable products like vinyl asbestos floor tiles in both residential and commercial buildings from this era. I have VAT in several rooms in my own home.
What is important to remember is that undisturbed asbestos building products represent a very low risk of fiber release and exposure. EPA recommends managing these products in place and has stated that vinyl floor tiles and similar non-friable products “would rarely if ever release fibers” into the environment. In general these products have been present in buildings for decades and there is little reason why they cannot safely remain as long as they are not disturbed.
If it is time for removal or demolition, however, the situation changes. The first task is to determine whether asbestos is actually present. Asbestos products are identified by visual inspection and laboratory testing of the material. EPA does not allow one to assume a product is not asbestos, with two exceptions: fiberglass and rubber insulation, and products that are obviously comprised of wood. All other suspect materials must be tested to show that they do not contain asbestos. One can assume a product is asbestos but why would you?
EPA requires formal training and certification for an asbestos inspector, including an initial 3-day course and annual refresher training. EPA also certifies the laboratory through the National Institute of Standards and Technology AHERA program. The standard testing method is polarized light microscopy (PLM), which has been used for mineral identification for decades. For some non-friable materials such as vinyl floor tiles and roofing, analysis by transmission electron microscopy (TEM) may be necessary to conclusively prove that the material does not contain asbestos. The asbestos inspection and testing process is a pretty specialized undertaking.
So what to do after you find that a building material contains asbestos? As noted above, as long as the product will remain undisturbed it presents very little risk and can remain indefinitely. But various demolition and renovation activities should trigger some specialized procedures to prevent the release of asbestos fibers to unaffected areas of the building.
In the state of New Jersey, a contractor who removes just about any type of asbestos containing material must be licensed and certified. The primary exception involve outside non-friable materials such as roofing products. Exterior roofing, siding and water pipes can be removed by a contractor who has fulfilled some simple OSHA requirements. A partial exception involves interior non-friable materials such as floor tiles. A contractor can gain an exemption from the State licensing, but must be able to demonstrate that his removal methods will not release fibers.
When asbestos is removed from inside a building, some measure of cleanliness is needed. Air testing is a useful tool after abatement is completed, either by removal or demolition. This testing will ensure that the asbestos material has been adequately removed and that airborne asbestos fibers have been eliminated. The standard air testing method is TEM since it can see the smallest fibers. TEM can also be useful in showing that asbestos products still in place, such as the fiber cement ducts under slabs, are not releasing fibers during normal use.
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