Chain of custody form, 21 West Street, Nov 2001

NYC 9/11 Public Portal Document FAX NO. 212 210 6724 P. 06/42 FEB-28-2002 THU 1101 AM CLOSINGS 0 ROSE

Rose Associates Inc. JLC Project #01.2099 October 23, 2001 page ? Air Sampling Ana(vslle and Procedure Introduction measuring the filter content of a known volume of air Air camplinci Is defined as the process of period of time. Each sample is cross-referenced by entrained on a filter membrane over a specified ensure, proper, consistent handling through a chain (told i$eslgnation and a JLC lai, internal code to an HEPA filter clean bench to avoid any possible of custody. Sample preparation takes place within contamination.

Methodology Occupational Safety and es proo~dures or ese $amp es conform to the idat anal institute of Health (h1iLSH) standards. approximating the breathing zone of persons anticipated to Air sampling was conducted at a leveloperations. Samples collected should represent the areas t e present in the area during normal typical airborne fiber concentration. 25 millimeter, 0,8 micrometer (pm) cellulose ester All samples were collected on fully cxpoecd membrane air sampling cassettes with conductive cowl.

Analytical Procedures waft removed and placed on A sootion of thipfilter approximating twenty-five percent of the total filter exposed to approximately 250 microliter (h I) of acetone a pre-cleaned microscope slide and then applied arm a clean #1.: cover slip was placed vapor. A lingle 3,0 - 3.5 pi drop of triacetin was •,s heated on a slide heater until clarity allowed analysis to upon the filter. The prepared slide was then ); be conducted. Microscope in accordance with NIOSH 7400 Analysis was accomplished utilizing a Phase Contrast Ii' method, counting t ule "A."

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

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

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