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NYC 9/11 Public Portal Document

WSA Management JLC Project # 01-2214 November 16, 2001 page 2 Air Sampling Analysis and Procedure S.

Introduction known volume of air sampling is defined as the process of measuring the filter content of a Air time. sample is cross-referenced entrained on a filter membrane over a specified per, conshstent handling through a chany code to ensureofro p field designation and a JLC lab internal bench to avoid any possible custody. Sample preparation takes place within an HEPA filter clean of contamination.

Methodology Institute of Occupational Safety and Test procedures for these samples conform to the National Health (NIOSH) standards.

conducted at a level approximating the breathing zone of persons anticipated to Air sampling was area's operations. Samples collected should represent the be present in the area during normal typical airborne fiber concentration. cellulose ester exposed 25 millimeter, 0.8 micrometer (pm) All samples were collected on fully conductive cowl. membrane air sampling cassettes with

Analytical Procedures placed on filter approximating twenty-five percent of the total filter was removed and A section of the microliter (p1) of acetone then exposed to approximately 250 a pre-cleaned microscope slide and was applied and a clean #1.5 cover slip was placed vapor. A single 3.0 - 3.5 pl drop of triacetin heated on a slide heater until clarity allowed analysis to then upon the filter. The prepared slide was be conducted. with NIOSH 7400 was accomplished utilizing a Phase Contrast Microscope in accordance Analysis method, counting rule A.

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

Analytical Results The represents the results of the alysis of the samples. The "Summary of Analytical Results" centimeter fibers/cubic nn (f/cc) o air. mpl If final tests PCM limit of reliable quantification is less than 0.01 -tested. entire work site must be re-cleaned and re do not meet these requirements, the

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