ASTM D7201-06(2011)
Standard Practice for Sampling and Counting Airborne Fibers, Including Asbestos Fibers, in the Workplace, by Phase Contrast Microscopy (with an Option of Transmission Electron Microscopy)
- Standard No.
- ASTM D7201-06(2011)
- Release Date
- 2006
- Published By
- American Society for Testing and Materials (ASTM)
- Status
- Replace By
- ASTM D7201-06(2020)
- Latest
- ASTM D7201-06(2020)
- Scope
Users of this practice must determine for themselves whether the practices described meet the requirements of local or national authorities regulating asbestos or other fibrous hazards.
Variations of this practice have been described by the Asbestos Research Council in Great Britain (8), the Asbestos International Association (AIA) RTM 1 (9), NIOSH 7400, OSHA (Reference Method ID 160), and ISO 8672. Where the counting rules of the latter three methods differ, this is noted in the text.
Advantages
The technique is specific for fibers. PCM is a fiber counting technique that excludes non-fibrous particles from the analysis.
The technique is inexpensive, but requires specialized knowledge to carry out the analysis for total fiber counts, at least in so far as the analyst is often required under regulations to have taken a specific training course (for example, NIOSH 582, or equivalent).
The analysis is quick and can be performed on-site for rapid determination of the concentrations of airborne fibers.
Limitations
The main limitation of PCM is that fibers are not identified. All fibers within the specified dimensional range are counted. Differential fiber counting may sometimes be used to discriminate between asbestos fibers and fibers of obviously different morphology, such as cellulose and glass fiber. In most situations, differential fiber counting cannot be used to adequately differentiate asbestos from non-asbestos fibers for purposes of compliance with regulations without additional positive identification. If positive identification of asbestos is required, this must be performed by polarized light or electron microscopy techniques, using a different portion of the filter.
A further limitation is that the smallest fibers visible by PCM are about 0.2 μm in diameter, while the finest asbestos fibers may be as small as 0.02 μm in diameter.
Where calculation of fiber concentration provides a result exceeding the regulatory standard, non-compliance is assumed unless it can be proven that the fibers counted do not belong to a member or members of the group of fibers regulated by that standard.
1.1 This practice describes the determination of the concentration of fibers, expressed as the number of such fibers per millilitre of air, using phase contrast microscopy and optionally transmission electron microscopy to evaluate particulate material collected on a membrane filter in the breathing zone of an individual or by area sampling in a specific location. This practice is based on the core procedures provided in the International Organization for Standardization (ISO) Standard ISO 8672 (1) , the National Institute for Occupational and Health (NIOSH) Manual of Analytical Methods, NIOSH 7400 (2), and the Occupational Safety and Health Administration (OSHA) Method ID 160 (3). This practice indicates the important points where these methods differ, and provides information regarding the differences, which will allow the user to select the most appropriate procedure for a particular application. However, selecting portions of procedures from different published methods generally requires a user to report that they have used a modification to a method rather than claim they have used the method as written.
1.2 The practice is used for routine determination of an index of occupational exposure to airborne fibers in workplaces. Workplaces are considered those places where workers are exposed to airborne fibers including asbestos. Additional information on sampling strategies, sample collection (including ......
ASTM D7201-06(2011) Referenced Document
- ASTM D1356 Standard Terminology Relating to Sampling and Analysis of Atmospheres*， 2024-04-19 Update
- ASTM D1357 Standard Practice for Planning the Sampling of the Ambient Atmosphere
- ASTM D257 Standard Test Methods for DC Resistance or Conductance of Insulating Materials
- ASTM D3670 Standard Guide for Determination of Precision and Bias of Methods of Committee D22
- ASTM D5337 Standard Practice for Flow Rate for Calibration of Personal Sampling Pumps
- ASTM D6620 Standard Practice for Asbestos Detection Limit Based on Counts
- ASTM D7200 Standard Practice for Sampling and Counting Airborne Fibers, Including Asbestos Fibers, in Mines and Quarries, by Phase Contrast Microscopy and Transmission Electron Microscopy*， 2024-04-19 Update
- ISO 8672 Air quality - Determination of the number concentration of airborne inorganic fibres by phase contrast optical microscopy - Membrane filter method
ASTM D7201-06(2011) history
- 2020 ASTM D7201-06(2020) Standard Practice for Sampling and Counting Airborne Fibers, Including Asbestos Fibers, in the Workplace, by Phase Contrast Microscopy (with an Option of Transmission Electron Microscopy)
- 2006 ASTM D7201-06(2011) Standard Practice for Sampling and Counting Airborne Fibers, Including Asbestos Fibers, in the Workplace, by Phase Contrast Microscopy (with an Option of Transmission Electron Microscopy)
- 2006 ASTM D7201-06 Standard Practice for Sampling and Counting Airborne Fibers, Including Asbestos Fibers, in the Workplace, by Phase Contrast Microscopy (with and Option of Transmission Electron Microscopy)
