EPA air monitoring chain of custody, Jan 2003

NYC 9/11 Public Portal Document

Pt. 763, Subpt. E. App. A 40 CFR Ch. I (7-1-00 Edition) analysis to exceed the 70 s/mm^ concentra­ 11. After finishing with a grid, remove it tion. (Generally this means the first four fi­ firom the microscope, and replace it In the bers Identified as asbestos must exhibit an appropriate grid holder. Sample grids must identifiable diffraction pattern for chrysotile be stored for a minimum of 1 year from the or amphibole.) date of the analysis; the sample cassette e. The micrograph number of the recorded must be retained for a minimum of 30 days diffraction patterns must be reported to the by the laboratory or returned at the client’s client and maintained in the laboratory’s request. quality assurance records. In the event that examination of the pattern by a qualified in­ G. Sample Analytical Sequence dividual Indicates that the pattern has been 1. Under the present sampling require­ misidentified visually, the client shall be ments a minimum of 13 samples is to be col­ contacted. lected for the clearance testing of an abate­ f. Energy Dispersive X-ray Analysis ment site. These include five abatement area (EDXA) is required of all amphiboles which samples, five ambient samples, two field would cause the analysis results to exceed blanks, and one sealed blank. the 70 s/mm^ concentration. (Generally 2. Carry out visual inspection of work site speaking, the first 4 amphiboles would re­ prior to air monitoring. quire EDXA.) 3. Collect a minimum of 5 air samples in­ g. If the number of fibers in the non­ side the work site and 5 samples outside the asbestos class would cause the analysis to work site. The indoor and outdoor samples exceed the 70 s/mm^ concentration, the fact shall be taken during the same time period. that they are not asbestos must be con­ 4. Remaining steps in the analytical se­ firmed by EDXA or measurement of a zone quence are contained in Unit IV of this Ap­ axis diffraction pattern. pendix. h. Fibers classified as chrysotile must be identified by diffraction or X-ray analysis H. Reporting and recorded on a count sheet. X-ray anal­ 1. The following Information must be re­ ysis alone can be used only after 70 s/mm^' ported to the client for each sample ana­ have been exceeded for a particular sample. lyzed: 1. Fibers classified as amphiboles must be a. Concentration In structures per square Identified by X-ray analysis and electron dif­ millimeter and structures per cubic centi­ fraction and recorded on the count sheet. (X- meter. ray analysis alone can be used only after 70 b. Analytical sensitivity used for the anal­ s/mm^ have been exceeded for a particular ysis. sample.) c. Number of asbestos structures. J. If a diffraction pattern was recorded on d. Area analyzed. film, record the micrograph number on the e. Volume of air sampled (which must be count sheet. Initially supplied to lab by client). k. If an electron diffraction was attempted f. Copy of the count sheet must be Included but no pattern was observed, record N on the with the report. count sheet. g. Signature of laboratory official to indi­ 1. If an EDXA spectrum was attempted but cate that the laboratory met specifications not observed, record N on the count sheet. of the method. m. If an X-ray analysis spectrum Is stored. h. Report form must contain official lab­ record the file and disk number on the count oratory Identification (e.g., letterhead). sheet. 1. Type of asbestos. 10. Classification Rules. a. Fiber. A structure having a minimum I. Quality Control/Quallty Assurance length greater than or equal to 0.5 gm and an Procedures (Data Quality Indicators) aspect ratio (length to width) of 5:1 or great­ Monitoring the environment for airborne er and substantially parallel sides. Note the asbestos requires the use of sensitive sam­ appearance of the end of the fiber, l.e.. pling and analysis procedures. Because the whether It Is flat, rounded or dovetailed. test is sensitive, it may be Influenced by a b. Bundle. A structure composed of three or variety of factors. These include the supplies more fibers in a parallel arrangement with used in the sampling operation, the perform­ each fiber closer than one fiber diameter. ance of the sampling, the preparation of the c. Cluster. A structure with fibers in a ran­ grid from the filter and the actual examina­ dom arrangement such that all fibers are tion of this grid in the microscope. Each of intermixed and no single fiber Is Isolated these unit operations must produce a prod­ from the group. Groupings must have more uct of defined quality If the analytical result than two intersections. Is to be a reliable and meaningful test result. d. Matrix. Fiber or fibers with one end free Accordingly, a series of control checks and and the other end embedded in or hidden by reference standards are to be performed a particulate. The exposed fiber must meet along with the sample analysis as indicators the fiber definition. that the materials used are adequate and the

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