NYC-WTC_000230980

NYC 9/11 Public Portal Document

Summary of Asbestos Sampbug Results Page 2 of 4 Address: 25.0 South End Date sampled: November 14, 2001

Results of Phase Contrast Microscopy (PCM) testing of 250 South End Avenue, November 14, 2001 Areji Sampled Outside Common Residence 1 Residence 2

Sample Numbers A-0-2 A-C-2 A-Rl-2 A-R2-2

Concentration of Fibers in Air 0.003 0.005 <0.00 i 0,002 at this location (fi'cc)*

Coucuittration of Fibers in Air <0,001 toO.OOt <0.001 to 0.002 <0.001 to 0.003 <0.001 to 0.003 at background locations (f/cc) NYC Re-occupancy 0,01 0.01 0,01 0.01 Standard (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 Cily Dcparlinenl ofETiviroiimental Protection asbestos clearance criteria for post-abatement work (Rules of the City of New York, Title 15, Chapter 1)

Asbestos in air as delerniined by TEM analysis: TEM analysis is veiy 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 0.0G3 fee 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/cc

Results of Transmission Electron Microscopy (TEM) testing of 250 South End Avenue, November 14, 2001 Area Sampled Common

Sample Numbers A-C-2 Concentration of Asbestos Fibers in Air at this location <0.001 TvcA _____________________________________ Concentration of All Fibers in Air at background locations < 0,001 to 0.003 (fihe)________________________________________ NYC Re-occupancy Standard (f/cc) ** 0.01 * ficc is fibers in each cubic centimeter (cc) of air. This is calculalcd rrom ibe mnribcr of fibers seen on the air filter and tlie voluiuc of air pulled throngh (he filler incasnrcd in cubic centimeters. ** New York Cily Department of Rnmronmental Protection asbestos clearance criteria for post-abatement work (Rules of the City of New York, Title 15, Chapter 1)

The TEM method employed hem, NIOSH 7402, counts fibers of the same size as those detected by PCM analysis Fibers reported here are greater 1haii or equal to 5 mierous in length and fl.2,5 microns in width.

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NYC-WTC_000230990