Environmental Engineering Reference
In-Depth Information
ments which isolated the abatement area from other building spaces. Abate-
ment workers were required to wear approved respirators designed to
protect them from exposures above the then-permissible exposure limit
(PEL) for asbestos of 0.2 f/cc.
In the early 1990s, it was evident there was a need for accredited per-
sonnel with a minimum level of standardized training in all asbestos abate-
ment work. As a consequence, AHERA was amended to require that all
asbestos professionals working in public and commercial buildings be
trained and accredited according to a revised model accreditation plan
(MAP). The USEPA NESHAP for asbestos was also amended to require that
buildings be inspected for regulated ACM prior to renovation or demolition
activities. Regulated ACM includes friable ACM which, when dry, can be
crumbled and pulverized by hand pressure, and nonfriable ACM, which can
be reduced to powder by mechanical means. Under the revised NESHAP,
nonfriable ACM is regulated, and in many cases must be removed prior to
renovation or demolition. USEPA identified and designated two categories
of nonfriable ACM. Category I and category II nonfriable ACM can be
distinguished from each other by their potential to release fibers when dam-
aged. Category II ACM is more likely to become friable when damaged. It
includes asbestos cement shingles and fibrocement boards or panels. Cate-
gory I ACM includes asbestos-containing gaskets, packings, resilient floor
covering, mastics, and roofing products. Unlike AHERA, under which ACM
inspections are limited to indoor materials, NESHAP requires inspectors to
locate and identify ACM in both interior and exterior environments.
During the early 1990s, it became evident that school occupants such as
students and nonmaintenance staff were at relatively low risk of asbestos
exposure and disease in buildings in which ACM was present. As a conse-
quence, USEPA concluded that expanding inspection and management plan
requirements to public and commercial buildings was not warranted. How-
ever, there was increasing scientific evidence that service workers were at
special risk of exposure and developing asbestos-related disease. Therefore,
in 1994, OSHA revised its construction industry standard to require building
owners to designate all thermal system insulation and surfacing materials
installed prior to 1980 as presumed ACM (PACM). Building owners have a
duty under the revised OSHA construction industry standard to inform
employees and workers who work or will work in areas with PACM or
known ACM. They must be informed of its presence and location and
employ appropriate work practices to ensure PACM/ACM will not be dis-
turbed. The Occupational Safety and Health Administration requires that
building owners post signs at the entrance to mechanical rooms and rooms
where service workers can reasonably be expected to enter.
Designation of PACM, or its rebuttal by conducting a full AHERA-type
inspection, is in good measure a
OSHA asbestos inspection/man-
agement requirement in public and commercial buildings which is designed
to protect service workers. It is, for the most part, a self-enforcing rule.
de facto
