Forwarding WTC air monitoring scope for final review, Aug 2002

NYC 9/11 Public Portal Document

Pt. 763, Subpt. E, App. A 40 CFR Ch. I <7-1-00 Edition) 5, Provide laboratory blanks with each "Proposed Analytical Method for Determina­ sample batch. Maintain a cumulative aver­ tion of Asbestos in Air.” age of these results. If there are more than 53 8. Chatfield, E,J., Chatfield Tech. Cons., fibers/mm^ per 10 200-mesh grid openings, the Ltd,, Clark, T., PEI Assoc,, "Standard Oper­ system must be checked for possible sources ating Procedure for Determination of Air­ of contamination, borne Asbestos Fibers by Transmission Elec­ 6, Perform a system check on the trans­ tron Microscopy Using Polycarbonate Mem­ mission electron microscope daily, brane Filters,” WERL SOP 87-1, March 5, 7, Make periodic performance checks of 1987. magnification, electron diffraction and en­ 9. NIOSH Method 7402 for Asbestos Fibers, ergy dispersive X-ray systems as set forth in 12-11-86 Draft. Table III under Unit II,I, 10. Yamate, G,, Agarwall, S,C., Gibbons, 8, Ensure qualified operator performance R,D„ HT Research Institute, "Methodology by evaluation of replicate analysis and for the Measurement of Airborne Asbestos by standard sample comparisons as set forth in Electron Microscopy," Draft report, USEPA Table III under Unit II,I, Contract 68-02-3266, July 1984, 9, Validate all data entries, 11, "Guidance to the Preparation of Qual­ 10, Recalculate a percentage of all com­ ity Assurance Project Plans,” USEPA, Office putations and automatic data reduction of Pollution Prevention and Toxics, 1984. steps as specified in Table III under Unit II,I, III. Nonmandatoiy Transmission Electron 11, Record an electron diffraction pattern Microscopy Method of one asbestos structure from every five samples that contain asbestos. Verify the A. Definitions of Terms identification of the pattern by measure­ 1. Analytical sensitivity—Airhome asbestos ment or comparison of the pattern with pat­ concentration represented by each fiber terns collected from standards under the counted imder the electron microscope. It is same conditions. The records must also dem­ determined by the air volume collected and onstrate that the identification of the pat­ the proportion of the filter examined. This tern has been verified by a qualified indi­ method requires that the analytical sensi­ vidual and that the operator who made the tivity be no greater than 0.005 s/cm’. identification is maintaining at least an 80 2. A^jestlform—A specific type of mineral percent correct visual identification based fibrosity in which the fibers and fibrils pos­ on his measured patterns, sess high tensile strength and flexibility. 12, Appropriate logs or records must be 3. Aspect ratio—A ratio of the length to the maintained by the analytical laboratory width of a particle. Minimum aspect ratio as verifying that It is in compliance with the defined by this method is equal to or greater mandatory quality assurance procedures, than 5:1. J, References 4. Bundle—A structure composed of three or more fibers in a parallel arrangement For additional background information on with each fiber closer than one fiber diame­ this method, the following references should ter. be consulted, 5. Clean area—A controlled environment 1, "Guidance for Controlling Asbestos-Con­ which is maintained and monitored to assure taining Materials in Buildings,” EPA 560/5- a low probability of asbestos contamination 85-024, June 1985, to materials in that space. Clean areas used 2, "Measuring Airborne Asbestos Following In this method have HEPA filtered air under an Abatement Action,” USEPA, Office of positive pressure and are capable of sus­ Pollution Prevention and Toxics, EPA 600/4- tained operation with an open laboratory 85-049, 1985, blank which on subsequent analysis has an 3, Small, John and E, Steel, Asbestos average of less than 18 structures/mm^ in an Standards; Materials and Analytical Meth­ area of 0.057 mm^ {nominally 10 200 mesh grid ods, N,B,S, Special Publication 619, 1982, openings) and a maximum of 53 structures/ 4, Campbell, W,J„ R,L, Blake, L,L, Brown, mm2 for no more than one single preparation E,E, Cather, and J,J, Sjoberg, Selected Sili­ for that same area. cate Minerals and Their Asbestlform Vari­ 6. Cluster—A structure with fibers In a ran­ eties, Information Circular 8751, U,S, Bureau dom arrangement such that all fibers are of Mines, 1977, Intermixed and no single fiber Is Isolated 5, Quality Assurance Handbook for Air Pol­ from the group. Groupings must have more lution Measurement System, Ambient Air than two intersections. Methods, EPA 600/4-77-027a, USEPA, Office of 7. £D—Electron diffraction. Research and Development, 1977, 8. EDXA—Energy dispersive X-ray anal­ 6, Method 2A; Direct Measurement of Gas ysis. Volume through Pipes and Small Ducts, 40 9. Fiber—A structure greater than or equal CFR Part 60 Appendix A, to 0.5 gm in length with an aspect ratio 7, Burdette, G,J„ Health & Safety Exec, (length to width) of 5:1 or greater and having Research & Lab, Services Div,. London. substantially parallel sides.

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