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)

Standard No.

ASTM D7201-06(2020)

Release Date

2020

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM D7201-06(2020)

Scope

1.1 This practice2 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),3 the National Institute for Occupational and Health (NIOSH) Manual of Analytical Methods, NIOSH 7400 (2), and the Occupational Safety and Health Administration (OSHA) 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 calibration) and use of sample results for asbestos abatement projects is provided in a standard Practice for Air Monitoring for Management of Asbestos-Containing Materials (WK 8951) currently being considered by ASTM subcommittee E06.24. A further practice has been approved for the specific purpose of sampling and counting airborne fibers in mines and quarries (Practice D7200), although the practice herein may also be used for this purpose. The current practice may be used as a means of monitoring occupational exposure to asbestos fibers when asbestos fibers are known a priori to be present in the airborne dust. The practice gives an index of airborne fiber concentration. This practice may be used in conjunction with electron microscopy (see Appendix X1) for assistance in identification of fibers. This practice may be used for other materials such as fibrous glass, or man-made mineral fibers by using alternate counting rules (see Annex A4). 1.3 This practice specifies the equipment and procedures for sampling the atmosphere in the breathing zone of an individual and for determining the number of fibers accumulated on a filter membrane during the course of an appropriately-selected sampling period. The practice may also be used to sample the atmosphere in a specific location or room of a building (area sampling), where this may be helpful in assessing exposure to workers handling fiber-containing products. 1.4 The ideal working range of this test practice extends from 100 fibers/mm2 to 1300 fibers/mm2 of filter area. For a 1000-L air sample, this corresponds to a concentration range from approximately 0.04 to 0.5 fiber/mL (or fiber/cm3 ). Lower and higher ranges of fiber concentration can be measured by reducing or increasing the volume of air collected. However, when this practice is applied to sampling the presence of other, non-asbestos dust, the level of total suspended particulate may impose an upper limit to the volume of air that can be sampled if the filters produced are to be of appropriate fiber loading for fiber counting. 1.5 Users should determine their own limit of detection using the procedure in Practice D6620. For Reference the NIOSH 7400 method gives the limit of detection as 7 fibers/ mm2 of filter area. For a 1000 L air sample, this corresponds to a limit of detection of 0.0027 fiber/mL (or fiber/cm3 ). For OSHA ID 160 the limit of detection is given as 5.5 fibers/mm2 of filter area. For a 1000 L air sample, this corresponds to a limit of detection of 0.0022 fiber/mL (or fiber/cm3 ). 1 This practice is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.07 on Sampling, Analysis, Management of Asbestos, and Other Microscopic Particles. Current edition approved April 15, 2020. Published April 2020. Originally approved in 2006. Last previous edition approved in 2011 as D7201 – 06 (2011). DOI: 10.1520/D7201-06R20. 2 This practice is based on NIOSH 7400, OSHA ID 160, and ISO 8672. Users of this ASTM standard are cautioned that if they wish to comply with one of these specific procedures exactly they should follow that procedure, otherwise they should document the modification 3 The boldface numbers in parentheses refer to a list of references at the end of this standard. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. 1.6 If this practice yields a fiber concentration that does not exceed the occupational limit value for the particular regulated fiber variety, no further action may be necessary. If the fiber concentration exceeds the occupational limit value for a specific fiber variety, and there is reason to suspect that the specific fiber variety is mixed with other fibers not covered under the same standard or regulation, the optional method specified in Appendix X1 may be used to measure the concentration or proportion of the fibers counted that are of the regulated variety. 1.7 The mounting medium used in this practice has a refractive index of approximately 1.45. Fibers with refractive indices in the range of 1.4 to 1.5 will exhibit reduced contrast, and may be difficult to detect. 1.8 Fibers less than approximately 0.2 µm in diameter will not be detected by this practice (4). 1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section 7. 1.11 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM D7201-06(2020) Referenced Document

• ASTM D1356 Standard Terminology Relating to Sampling and Analysis of Atmospheres*， 2024-04-21 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*， 2022-09-01 Update
• 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*， 2024-04-21 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(2020) 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)