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Asbestos |
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Exposure |
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Determinations of employee exposure shall be made from
breathing zone air samples that are representative of the 8-hour TWA and
30-minute short-term exposures of each employee.
Medical surveillance
Medical surveillance guidance is provided in the appendices to the OSHA
Standards:
- Medical questionnaires
- Interpretation and classification of chest roentgenograms
- Medical surveillance guidelines for asbestos
Exposure monitoring
Exposure monitoring samples must be analyzed by Phase Contrast Microscopy
(PCM) for OSHA purposes. PCM methods accurately assess fiber exposure levels, but PCM can
not differentiate between asbestos and non-asbestos fibers. Transmission Electron
Microscopy (TEM) methods may be used to identify fibers, but may not be used to quantify
air concentrations for occupational exposure.
- OSHA (Sampling) Reference Method
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Asbestos in Air. OSHA Analytical Method
ID-160,
(1997).
- Detailed procedure for asbestos sampling and analysis
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NIOSH Manual of Analytical Methods (NMAM). National Institute for Occupational Safety and
Health (NIOSH), (1994, August). Includes asbestos methods 7400 and
7402. Method No. 7400 is a PCM procedure, equivalent to the OSHA methods. Method
No. 7402 uses TEM to identify
fibers (OSHA will accept this TEM procedure, as it uses PCM to determine exposure).
Includes indices to 3rd and 4th edition.
- Asbestos fibers by TEM. NIOSH
Method No. 7402, (1994, August),
40 KB PDF, 7 pages.
Bulk sample analysis
Bulk sample analysis should be done by Polarized Light Microscopy
(PLM). Bulk
analysis results will likely apply to both OSHA and EPA regulations.
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Polarized Light Microscopy of Asbestos. OSHA Method
ID-191 (1992). Ddescribes the collection and analysis of asbestos bulk materials by light microscopy techniques including phase-polar illumination and central-stop dispersion microscopy.
- Polarized Light Microscopy of Asbestos
- 1910.1001,
Asbestos. OSHA Standard.
- Appendix J,
Polarized light microscopy of asbestos; Non-mandatory
- 1915.1001,
Asbestos. OSHA Standard.
- Appendix K,
Polarized light microscopy of asbestos; Non-mandatory analytical
methods
- National Institute for Occupational Safety and Health (NIOSH) has published two methods for the determination of asbestos in bulk materials.
- Asbestos, Chrysotile by XRD. NIOSH
Method No. 9000, (1994, August), 44 KB PDF, 6 pages.
- Asbestos (bulk) by PLM. NIOSH
Method No. 9002, (1994, August), 176 KB PDF, 9 pages.
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Directory of Accredited Laboratories. National Voluntary Laboratory Accreditation Program
(NVLAP), (2008). Includes online searchable directory. This accreditation is required for analyses being performed in compliance with AHERA regulations.
- Sampling and Analysis of Multi-Layered Materials
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