NYC 9/11 Public Portal Document
Sumntaty ofAsbestos S:xntpling Results Page 2 4 of
Address: 250 South End Date sampled: November 14, 2001
Results of Phase Contrast Microscopy (PCM) testing of 250 South End Avenue, November 14,
2001
lrea Sampled lOutside Common Residence I Residence 2
Sample Numbers
-0-2 A-C-2 -R1-2
Concentration of Fibers in Air
0.003 0.005 <0.001 0.002
t this location (f/cc)*
Concentration of Fibers in Air :0.001 to 0.001 <0.001 to 0.002 <0.001 to 0.003 0.001 to 0.003
t background locations (f/cc)
NYC Re-occupancy 0.01 0.01 0.01 0.01
tandard (f/cc) *
* f/cc is fibers in each cubic centimeter (cc) of air. This is calculated from the number of fibers seen on the air
filter and the volume of air pulled through the filter measured in cubic centimeters.
** New York City Department of Environmental Protection asbestos clearance criteria for post-abatement work
(Rules of the City of New York, Title 15, Chapter 1)
Asbestos in air as determined by TEM analysis: TEM analysis is very specific and can
distinguish between asbestos and non-asbestos fibers, such as textiles, fiberglass, or cellulose.
This analysis determines if the fibers seen in the PCM analysis are asbestos, or if they are some
other material. TEM analysis was conducted on all air samples that showed more than 0.003 f/cc
in the air by PCM analysis. No asbestos fibers were found in the TEM analysis of the air samples
in your building where PCM levels exceeded 0.003 f/ec.2
Results of Transmission Electron Microscopy (TEM) testing of 250 South End Avenue,
November 14, 2001
rea Sampled Common
Sample Numbers A-C-2
Concentration of Asbestos Fibers in Air at this location < 0.001
f/cc)*
Concentration of All Fibers in Air at background locations 0.001 to 0.003
f/cc)
NYC Re-occupancy Standard (f/cc) ** 0.01
* f/cc is fibers in each cubic centimeter (cc) of air. This is calculated from the number of fibers seen on
the air filter and the volume of air pulled through the filter measured in cubic centimeters.
** New York City Department of Environmental Protection asbestos clearance criteria for post-abatement
work (Rules of the City of New York, Title 15, Chapter 1)
2The TEM method employed here, NIOSH 7402, counts fibers of the same size as those detected by PCM analysis.
Fibers reported here are greater than or equal to 5 microns in length and 0.25 microns in width.
NYC-WTC 000121066
OCR can misread numbers and units. Confirm readings against the page image before using them.