NYC 9/11 Public Portal Document
CONTRADICTORY ASBESTOS TESTING GUIDANCE
Impossible instructions from NYC PEP
The NYC Department of Environmental Protection (NYC DEP) gave impossible and unsafe
instructions to owners of buildings. Furthermore, the instructions violated the standards set by
the federal EPA. The NYC DEP advised building owners’ to test duets inside buildings to see if
they were over 1%. They said that if the dusts were over 1%, a professional asbestos abatement
contractor should be used for the cleanup:
EPA is using the 1% definition in evabating exterior dust samples in the Lower Manhattan area
near the World Trade Center. All affected landbrds have been instructed to test dust samples
within their buildings utilizing this standard. Landlords were notified that they should not reopen
any building until a competent professional had properly inspected their premise, more than 1%
asbestos was found and testing and cleaning was necessary, it had to be performed by certified
personnel.
Unless the windows were blown out by tiie blast, interior dusts are in too thin a layer to enable
them to be scooped up into ajar or bag. Only dusts that are in “bulk” form, which can be put
into a bag or jar, can be tested for the percentage of asbestos.
If there is only a thin, visible surface dusting, or evai an invisible layer of dust, you are forced to
use what are called “wipe” samples or “microvacuum” samples. Wipe samples can only be
tested for the number of asbestos fibers per area, not a percentage of asbestos in the total dust.
Microvacuum samples are also typically only analyzed for number of structures per area,
although there is a rarely used, very expensive ASTM method for microvacuum samples that can
sometimes be employed to give mass concentration - percent values.
Laboratory results for settled dust layers are reported as “asbestos structures/square centimeter
(structures/cm^).” This cannot be converted into a percentage of asbestos. Thus, it is almost
impossible for building owners to even test for the 1 % level in the first place. See the last
section of this memorandum for more information on asbestos sampling and analysis techniques.
NYC PEP instructions also contrary to stated EPA standard for the cleanup
The NYC DEP instructions also reversed the decision by the federal EPA feat asbestos levels
should be non-detectable. After the disaster, the federal EPA declared that it was applying the
most stringent standard, namely the 70 asbestos structures per millimeter of air in the Asbestos
Hazard Emergency Response Act (AHERA).^ This “70" level is the lowest level that can be
detected in air using the AHERA test method, because of the background level of asbestos in the
filter through which the air is drawn. In other words, the level EPA stated that it required was
NO detectable asbestos, not 1% or lower.
EPA regulations apply the 1% level to the asbestos containing materials themselves, such as
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insulation or asbestos floor tiles, not to the dusts that would result from the presence somewhere
in the building of asbestos containing materials (ACM). EPA assumed that the dusts resulting
from the presence of these ACM somewhere in the building would have much lower levels of
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