NYC 9/11 Public Portal Document
CONTRADICTORY ASBESTOS TESTING GUIDANCE
Impossible instructions from NYC DEP
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 dusts
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 evaluating exterior
dust samples in the Lower Manhattan area
near the World Trade Center. AN affected landlords
have been instructed to test dust samples
within their buildings util¢ing this standard. Landlords
were notified that they should not reopen
any building until a competent professional had
properly inspected their premise. If more than
asbestos was found and testing and cleaning was 1%
necessary, it had b be performed by certified
pers onn et.
Unless the windows were blown out by the 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 even 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
although there is a rarely used, very expensive ASTM structures per area,
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/cm2)." 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 memcxandum for more information on asbestos sampling
and analysis techniques.
NYC DEP instructions also contrary to stated EPA standard for
the cleans p
The NYC DEP instructions also reversed the decision by the federal
EPA that 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 Ievel 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
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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NYC-WTC 000125935
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