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NYC 9/11 Public Portal Document

WSA Management JLC Project # 01-2240 December 13, 2001 page 2 Air Sampling Analysis and Procedure Introduction of air defined as the process of measuring the filter content of a known volume Air sampling is period of time. Each sample is cross-referenced by entrained on a filter membrane over a specified a chain ure proper, consistent handling through possible internal code to field designation and a JLC lab of custody. Sample preparation takes place wit hin an HEPA filter clean bench to avo d any

contamination.

Methodology Institute of Occupational Safety and Test procedures for these samples conform to the National Health (NIOSH) standards. eathing zone of ersons ed level approximating Air sampling was conducted at a Sampples collected represent shouldpep thep e art a'so present in the area during normal operat be typical airborne fiber concentration. 25 millimeter, 0.8 micrometer (pm) cellulose ester All samples were collected on fully exposedconductive cowl membrane air sampling cassettes with

Analytical Procedures twenty-five filter ved and laced on approximating A section of the filter approximately microliter ({al) of acetone -cleaned microscope slide and then exposedrto at orox was laced a pre triacetin n nd a lean 1.5 cover as applied vapor. A single 3.0 - 3.5 NI drop of lalplowedpanalysis to then heated o a slide heate#until clarity upon the filter. The prepared slide was be conducted. NIOSH 7400 accomplished utilizing a Phase Contrast Microscope in accordance with Analysis was method, counting rule A.

Phase Contrast Microscopy Microscope, (PCM) an Olympus BH-PC Phase Contrast dissolving the filter JLC Environmental's laboratory uses Samples were analyzed by first equipped with a Walton-Beckett Graticule. PCM at 400x chemical process (described above) and then counting the fibers with background, through a light contrast between the object and the magnification. Phase contrast increases the microscopic fields or 100 enhancing the microscopists ability to see fibers. Normally, 100 thus first. fibers are counted, whichever occurs

Analytical Results samples. The represents the results of the analysis of the The "Summary of Analytical Results" met than 0.0 fibers/cubic PCM limit of reliable quantification is less st b recentiinedand re of air. If final tests (f/cc) work i e do not meet these requirements, the entire

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