40 CFR Part 763 (EPA AHERA) Part 3.5 PDF

Pt. 763, Subpt. E, App. A 40 CFR Ch. I (7–1–07 Edition) C. Sample Shipment Ship bulk samples to the analytical laboratory in a separate container from air samples. D. Sample Receiving 1. Designate one individual as sample coordinator at the laboratory. While that individual will normally be availa...

Pt. 763, Subpt. E, App. A 40 CFR Ch. I (7–1–07 Edition) C. Sample Shipment Ship bulk samples to the analytical laboratory in a separate container from air samples. D. Sample Receiving 1. Designate one individual as sample coordinator at the laboratory. While that individual will normally be available to receive samples, the coordinator may train and supervise others in receiving procedures for those times when he/she is not available. 2. Bulk samples and air samples delivered to the analytical laboratory in the same container shall be rejected. 786 VerDate Aug<31>2005 14:36 Aug 06, 2007 Jkt 211171 PO 00000 Frm 00796 Fmt 8010 Sfmt 8002 Y:\SGML\211171.XXX 211171 EC01AP92.003</MATH> rfrederick on PROD1PC67 with CFR E. Sample Preparation 1. All sample preparation and analysis shall be performed by a laboratory independent of the abatement contractor. 2. Wet-wipe the exterior of the cassettes to minimize contamination possibilities before taking them into the clean room facility. 3. Perform sample preparation in a wellequipped clean facility. NOTE: The clean area is required to have the following minimum characteristics. The area or hood must be capable of maintaining a positive pressure with make-up air being HEPA-filtered. The cumulative analytical blank concentration must average less than 18 s/mm2 in an area of 0.057 mm2 (nominally 10 200-mesh grid openings) and a single preparation with a maximum of 53 s/mm2 for that same area. 4. Preparation areas for air samples must not only be separated from preparation areas for bulk samples, but they must be prepared in separate rooms. 5. Direct preparation techniques are required. The object is to produce an intact film containing the particulates of the filter surface which is sufficiently clear for TEM analysis. a. TEM Grid Opening Area measurement must be done as follows: i. The filter portion being used for sample preparation must have the surface collapsed using an acetone vapor technique. ii. Measure 20 grid openings on each of 20 random 200-mesh copper grids by placing a grid on a glass and examining it under the PCM. Use a calibrated graticule to measure the average field diameters. From the data, calculate the field area for an average grid opening. iii. Measurements can also be made on the TEM at a properly calibrated low magnification or on an optical microscope at a magnification of approximately 400X by using an eyepiece fitted with a scale that has been calibrated against a stage micrometer. Optical microscopy utilizing manual or automated procedures may be used providing instrument calibration can be verified. b. TEM specimen preparation from polycarbonate (PC) filters. Procedures as described in Unit III.G. or other equivalent methods may be used. c. TEM specimen preparation from mixed cellulose ester (MCE) filters. i. Filter portion being used for sample preparation must have the surface collapsed using an acetone vapor technique or the Burdette procedure (Ref. 7 of Unit II.J.) ii. Plasma etching of the collapsed filter is required. The microscope slide to which the collapsed filter pieces are attached is placed in a plasma asher. Because plasma ashers vary greatly in their performance, both from unit to unit and between different positions in the asher chamber, it is difficult to specify the conditions that should be used. Insufficient etching will result in a failure to expose embedded filters, and too much etching may result in loss of particulate from the surface. As an interim measure, it is recommended that the time for ashing of a Environmental Protection Agency Pt. 763, Subpt. E, App. A known weight of a collapsed filter be established and that the etching rate be calculated in terms of micrometers per second. The actual etching time used for the particulate asher and operating conditions will then be set such that a 1–2 µm (10 percent) layer of collapsed surface will be removed. iii. Procedures as described in Unit III. or other equivalent methods may be used to prepare samples. F. TEM Method rfrederick on PROD1PC67 with CFR 1. An 80–120 kV TEM capable of performing electron diffraction with a fluorescent screen inscribed with calibrated gradations is required. If the TEM is equipped with EDXA it must either have a STEM attachment or be capable of producing a spot less than 250 nm in diameter at crossover. The microscope shall be calibrated routinely for magnification and camera constant. 2. Determination of Camera Constant and ED Pattern Analysis. The camera length of the TEM in ED operating mode must be calibrated before ED patterns on unknown samples are observed. This can be achieved by using a carbon-coated grid on which a thin film of gold has been sputtered or evaporated. A thin film of gold is evaporated on the specimen TEM grid to obtain zone-axis ED patterns superimposed with a ring pattern from the polycrystalline gold film. In practice, it is desirable to optimize the thickness of the gold film so that only one or two sharp rings are obtained on the superimposed ED pattern. Thicker gold film would normally give multiple gold rings, but it will tend to mask weaker diffraction spots from the unknown fibrous particulate. Since the unknown d-spacings of most interest in asbestos analysis are those which lie closest to the transmitted beam, multiple gold rings are unnecessary on zone-axis ED patterns. An average camera constant using multiple gold rings can be determined. The camera constant is one-half the diameter of the rings times the interplanar spacing of the ring being measured. 3. Magnification Calibration. The magnification calibration must be done at the fluorescent screen. The TEM must be calibrated at the grid opening magnification (if used) and also at the magnification used for fiber counting. This is performed with a cross grating replica (e.g., one containing 2,160 lines/mm). Define a field of view on the fluorescent screen either by markings or physical boundaries. The field of view must be measurable or previously inscribed with a scale or concentric circles (all scales should be metric). A logbook must be maintained, and the dates of calibration and the values obtained must be recorded. The frequency of calibration depends on the past history of the particular microscope. After any maintenance of the microscope that involved adjustment of the power supplied to the lenses or the high-voltage system or the mechanical disassembly of the electron optical column apart from filament exchange, the magnification must be recalibrated. Before the TEM calibration is performed, the analyst must ensure that the cross grating replica is placed at the same distance from the objective lens as the specimens are. For instruments that incorporate a eucentric tilting specimen stage, all specimens and the cross grating replica must be placed at the eucentric position. 4. While not required on every microscope in the laboratory, the laboratory must have either one microscope equipped with energy dispersive X-ray analysis or access to an equivalent system on a TEM in another laboratory. 5. Microscope settings: 80–120 kV, grid assessment 250–1,000X, then 15,000–20,000X screen magnification for analysis. 6. Approximately one-half (0.5) of the predetermined sample area to be analyzed shall be performed on one sample grid preparation and the remaining half on a second sample grid preparation. 7. Individual grid openings with greater than 5 percent openings (holes) or covered with greater than 25 percent particulate matter or obviously having nonuniform loading must not be analyzed. 8. Reject the grid if: a. Less than 50 percent of the grid openings covered by the replica are intact. b. The replica is doubled or folded. c. The replica is too dark because of incomplete dissolution of the filter. 9. Recording Rules. a. Any continuous grouping of particles in which an asbestos fiber with an aspect ratio greater than or equal to 5:1 and a length greater than or equal to 0.5 µm is detected shall be recorded on the count sheet. These will be designated asbestos structures and will be classified as fibers, bundles, clusters, or matrices. Record as individual fibers any contiguous grouping having 0, 1, or 2 definable intersections. Groupings having more than 2 intersections are to be described as cluster or matrix. An intersection is a nonparallel touching or crossing of fibers, with the projection having an aspect ratio of 5:1 or greater. See the following Figure 2: 787 VerDate Aug<31>2005 14:36 Aug 06, 2007 Jkt 211171 PO 00000 Frm 00797 Fmt 8010 Sfmt 8002 Y:\SGML\211171.XXX 211171 40 CFR Ch. I (7–1–07 Edition) 788 VerDate Aug<31>2005 14:36 Aug 06, 2007 Jkt 211171 PO 00000 Frm 00798 Fmt 8010 Sfmt 8006 Y:\SGML\211171.XXX 211171 EC01AP92.004</GPH> rfrederick on PROD1PC67 with CFR Pt. 763, Subpt. E, App. A Pt. 763, Subpt. E, App. A i. Fiber. A structure having a minimum length greater than or equal to 0.5 µm and an aspect ratio (length to width) of 5:1 or greater and substantially parallel sides. Note the appearance of the end of the fiber, i.e., whether it is flat, rounded or dovetailed. ii. Bundle. A structure composed of three or more fibers in a parallel arrangement with each fiber closer than one fiber diameter. iii. Cluster. A structure with fibers in a random arrangement such that all fibers are intermixed and no single fiber is isolated from the group. Groupings must have more than two intersections. iv. Matrix. Fiber or fibers with one end free and the other end embedded in or hidden by a particulate. The exposed fiber must meet the fiber definition. b. Separate categories will be maintained for fibers less than 5 µm and for fibers equal to or greater than 5 µm in length. c. Record NSD when no structures are detected in the field. d. Visual identification of electron diffraction (ED) patterns is required for each asbestos structure counted which would cause the 789 VerDate Aug<31>2005 14:36 Aug 06, 2007 Jkt 211171 PO 00000 Frm 00799 Fmt 8010 Sfmt 8002 Y:\SGML\211171.XXX 211171 EC01AP92.005</GPH> rfrederick on PROD1PC67 with CFR Environmental Protection Agency rfrederick on PROD1PC67 with CFR Pt. 763, Subpt. E, App. A 40 CFR Ch. I (7–1–07 Edition) analysis to exceed the 70 s/mm2 concentration. (Generally this means the first four fibers identified as asbestos must exhibit an identifiable diffraction pattern for chrysotile or amphibole.) e. The micrograph number of the recorded diffraction patterns must be reported to the client and maintained in the laboratory’s quality assurance records. In the event that examination of the pattern by a qualified individual indicates that the pattern has been misidentified visually, the client shall be contacted. f. Energy Dispersive X-ray Analysis (EDXA) is required of all amphiboles which would cause the analysis results to exceed the 70 s/mm2 concentration. (Generally speaking, the first 4 amphiboles would require EDXA.) g. If the number of fibers in the nonasbestos class would cause the analysis to exceed the 70 s/mm2 concentration, the fact that they are not asbestos must be confirmed by EDXA or measurement of a zone axis diffraction pattern. h. Fibers classified as chrysotile must be identified by diffraction or X-ray analysis and recorded on a count sheet. X-ray analysis alone can be used only after 70 s/mm2 have been exceeded for a particular sample. i. Fibers classified as amphiboles must be identified by X-ray analysis and electron diffraction and recorded on the count sheet. (Xray analysis alone can be used only after 70 s/mm2 have been exceeded for a particular sample.) j. If a diffraction pattern was recorded on film, record the micrograph number on the count sheet. k. If an electron diffraction was attempted but no pattern was observed, record N on the count sheet. l. If an EDXA spectrum was attempted but not observed, record N on the count sheet. m. If an X-ray analysis spectrum is stored, record the file and disk number on the count sheet. 10. Classification Rules. a. Fiber. A structure having a minimum length greater than or equal to 0.5 µm and an aspect ratio (length to width) of 5:1 or greater and substantially parallel sides. Note the appearance of the end of the fiber, i.e., whether it is flat, rounded or dovetailed. b. Bundle. A structure composed of three or more fibers in a parallel arrangement with each fiber closer than one fiber diameter. c. Cluster. A structure with fibers in a random arrangement such that all fibers are intermixed and no single fiber is isolated from the group. Groupings must have more than two intersections. d. Matrix. Fiber or fibers with one end free and the other end embedded in or hidden by a particulate. The exposed fiber must meet the fiber definition. 11. After finishing with a grid, remove it from the microscope, and replace it in the appropriate grid holder. Sample grids must be stored for a minimum of 1 year from the date of the analysis; the sample cassette must be retained for a minimum of 30 days by the laboratory or returned at the client’s request. G. Sample Analytical Sequence 1. Under the present sampling requirements a minimum of 13 samples is to be collected for the clearance testing of an abatement site. These include five abatement area samples, five ambient samples, two field blanks, and one sealed blank. 2. Carry out visual inspection of work site prior to air monitoring. 3. Collect a minimum of 5 air samples inside the work site and 5 samples outside the work site. The indoor and outdoor samples shall be taken during the same time period. 4. Remaining steps in the analytical sequence are contained in Unit IV of this Appendix. H. Reporting 1. The following information must be reported to the client for each sample analyzed: a. Concentration in structures per square millimeter and structures per cubic centimeter. b. Analytical sensitivity used for the analysis. c. Number of asbestos structures. d. Area analyzed. e. Volume of air sampled (which must be initially supplied to lab by client). f. Copy of the count sheet must be included with the report. g. Signature of laboratory official to indicate that the laboratory met specifications of the method. h. Report form must contain official laboratory identification (e.g., letterhead). i. Type of asbestos. I. Quality Control/Quality Assurance Procedures (Data Quality Indicators) Monitoring the environment for airborne asbestos requires the use of sensitive sampling and analysis procedures. Because the test is sensitive, it may be influenced by a variety of factors. These include the supplies used in the sampling operation, the performance of the sampling, the preparation of the grid from the filter and the actual examination of this grid in the microscope. Each of these unit operations must produce a product of defined quality if the analytical result is to be a reliable and meaningful test result. Accordingly, a series of control checks and reference standards are to be performed along with the sample analysis as indicators that the materials used are adequate and the 790 VerDate Aug<31>2005 14:36 Aug 06, 2007 Jkt 211171 PO 00000 Frm 00800 Fmt 8010 Sfmt 8002 Y:\SGML\211171.XXX 211171