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NYC 9/11 Public Portal Document

WSA Management JLC Project # 01-2171 October 29, 2001 page 2 Air Sampling Analysis and Procedure

Introduction filter air sampling is defined as the process of measuring feren ced by Air period time. is entrained on a filter membrane over a specified ensure proper, consistent handling through a chain and a JLC lab internal code to y possible field designation an HEPA filter clean bench to avoid an of custody. Sample preparation takes place within contamination.

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

Analytical Procedures filter wmas ved laced on approximating twenty-five percent A section of the filter andpetone 250 crolite~ (N) of a exposed approximately or a pre-cleaned microscope slide and then was applied 1.5 sawa triacetin vapor. A single 3.0 - 3.5 NI drop of heated a slide heate#until clartyslalplowed na ysis to upon the filter. The prepared slide was then be conducted. accordance with NIOSH 7400 was accomplished utilizing a Phase Contrast Microscope in Analysis method, counting rule A.

Phase Contrast Microscopy Microscope, (PCM) an Olympus BH-PC Phase Contrast JLC Environmental's laboratory uses Samplesthenre analyzed by first ssolving the 1ter equipped with a Walton-Beckett Graticule. th PCM at 400x counting the fibers with above) and through a chemical process (described light contrast between the ct the background, magnification. Phase contrast increases the r 00 copid fi microscopic enhancing the microscopists ability to see fibers. Normally, thus first. fibers are counted, whichever occurs

Analytical Results ts of the analysis of the ples. The of Analytical Results" represents the The "Summary bers/cubic centimeter (f/cc) of air. If final tests firesul PCM limit of reliable quantification is less than 0.01 re-tested. meet these requirements, the entire work site must be re-cleaned and do not

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