Forwarding WTC air monitoring scope for final review, Aug 2002

NYC 9/11 Public Portal Document

Environmental Protection Agency Pt. 763. Subpt. E, App. A 10. Grief—open structure for mounting do not take cross contamination possibilities on the sample to aid in its examination in into account should not be used. the TEM. The term is used here to denote a 2. Material and supply checks for asbestos 200-mesh copper lattice approximately 3 mm contamination should be made on all critical In diameter. supplies, reagents, and procedures before 11. Intersection—Nonparallel touching or their use in a monitoring study. crossing of fibers, with the projection having 3. Quality control and quilty assurance an aspect ratio of 5:1 or greater. steps are needed to Identify problem areas 12. Laboratory sample coordinator—That per­ and isolate the cause of the contamination son responsible for the conduct of sample (see Reference 5 of Unit Ill.L.). Control handling and the certification of the testing checks shall be permanently recorded to doc­ procedures. ument the quality of the information pro­ 13. Filter background level—The concentra­ duced. The sampling firm must have written tion of structures per square millimeter of quality control procedures and documents filter that is considered indistinguishable which verify compliance. Independent audits from the concentration measured on blanks by a qualified consultant or firm should be (filters through which no air has been performed once a year. All documentation of drawn). For this method the filter back­ compliance should be retained Indefinitely ground level is defined as 70 structures/mm^. to provide a guarantee of quality. A sum­ 14. Matrix—Fiber or fibers with one end mary of Sample Data Quality Objectives Is free and the other end embedded in or hidden shown in Table II of Unit II.B. by a particulate. The exposed fiber must 4. Sampling materials. meet the fiber definition. a. Sample for airborne asbestos following 15. NSD—tia structure detected. an abatement action using commercially 16. Operator—A. person responsible for the available cassettes. TEM instrumental analysis of the sample. b. Use either a cowling or a filter-retaining 17. PCM— Phase contrast microscopy. middle piece. Conductive material may re­ 18. SAED—Selected area electron diffrac­ duce the potential for particulates to adhere tion. to the walls of the cowl. 19. SBM—Scanning electron microscope. c. Cassettes must be verified as "clean" 20. STEM—Scanning transmission electron prior to use in the field. If packaged filters microscope. are used for loading or preloaded cassettes 21. Structure—a microscopic bundle, clus­ are purchased from the manufacturer or a ter. fiber, or matrix which may contain as­ distributor, the manufacturer’s name and lot bestos. number should be entered on all field data 22. S/cm’—Structures per cubic centimeter. sheets provided to the laboratory, and are re­ 23. StonF—Structures per square milli­ quired to be listed on all reports from the meter. laboratory. 24. TEM—Transmission electron micro­ d. Assemble the cassettes In a clean facil­ scope. ity (See definition of clean area under Unit III.A.). B. Sampling e. Reloading of used cassettes is not per­ 1. Sampling operations must be performed mitted. by qualified individuals completely inde­ f. Use sample collection filters which are pendent of the abatement contractor to either polycarbonate having a pore size of avoid possible conflict of Interest (See Ref­ less than or equal to 0.4 gm or mixed cel­ erences 1. 2, and 5 of Unit III.L,) Special pre­ lulose ester having a pore size of less than or cautions should be taken to avoid contami­ equal to 0.45 gm. nation of the sample. For example, materials g. Place these filters in series with a that have not been prescreened for their as­ backup filter with a pore size of 5.0 gm (to bestos background content should not be serve as a dlHuser) and a support pad. See used: also, sample handling procedures which the following Figure 1:

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NYC-WTC_000139296