ASTM D6058-96(2006)
(Practice)Standard Practice for Determining Concentration of Airborne Single-Crystal Ceramic Whiskers in the Workplace Environment
Standard Practice for Determining Concentration of Airborne Single-Crystal Ceramic Whiskers in the Workplace Environment
SIGNIFICANCE AND USE
The SCCW may be present in the workplace atmosphere where these materials are manufactured, processed, transported, or used. The test methods discussed in this practice can be used to provide guidance when monitoring airborne concentrations of SCCW in these environments.
Because of their visibility limitations, a significant fraction of the very small thin fibers that are present in some samples may not be detected by PCM or SEM. Therefore, TEM is considered to be the reference technique for the analysis of airborne SCCW. The TEM must be used to determine both fiber count and morphology when samples are from previously uncharacterized workplaces or materials.
Although TEM is the reference technique, PCM or SEM are considered to be the primary screening methods for the analysis of airborne SCCW.
Parallel TEM measurements shall be carried out, at least initially, to provide an index or relative measure of the fraction of total fibers that are seen by PCM or SEM. Only in instances when this percentage has been shown to be at a high and reproducible level may the lower resolution techniques (that is, PCM or SEM) be relied on exclusively.
SCOPE
1.1 This practice is intended to assist individuals in the sampling and analysis of single-crystal ceramic whiskers (SCCW), such as silicon carbide and silicon nitride, in the workplace environment. It describes sampling and analytical techniques used to assess the airborne concentration and size distribution of SCCW, which may occur in and around the workplace where these materials are manufactured, processed, transported, or used.
1.2 The protocols currently in use for asbestos and other fibrous materials have been used as a guide in developing sampling and analytical procedures for characterizing fibers produced from the manufacture and use of SCCW. The sampling and analysis protocols described here have been written specifically for SCCW, however, they may be appropriate for other man-made mineral fibers (MMMF).
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation:D6058–96 (Reapproved 2006)
Standard Practice for
Determining Concentration of Airborne Single-Crystal
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Ceramic Whiskers in the Workplace Environment
This standard is issued under the fixed designation D6058; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Environment by Phase Contrast Microscopy
D6059 Test Method for Determining Concentration of Air-
1.1 This practice is intended to assist individuals in the
borne Single-Crystal Ceramic Whiskers in the Workplace
sampling and analysis of single-crystal ceramic whiskers
Environment by Scanning Electron Microscopy
(SCCW), such as silicon carbide and silicon nitride, in the
workplace environment. It describes sampling and analytical
3. Terminology
techniques used to assess the airborne concentration and size
3.1 For definitions of terms used in this practice, refer to
distribution of SCCW, which may occur in and around the
Terminology D1356.
workplace where these materials are manufactured, processed,
3.2 Definitions:
transported, or used.
3.2.1 man-made mineral fiber, n—any inorganic fibrous
1.2 The protocols currently in use for asbestos and other
material produced by chemical or physical processes.
fibrous materials have been used as a guide in developing
3.2.2 single-crystal ceramic whisker, n—a man-made min-
sampling and analytical procedures for characterizing fibers
eral fiber that has a single-crystal structure.
produced from the manufacture and use of SCCW. The
3.2.2.1 Discussion—Although the terms fiber and whisker
sampling and analysis protocols described here have been
are, for convenience, used interchangeably in this practice,
written specifically for SCCW, however, they may be appro-
whisker is correctly applied only to single-crystal fibers
priate for other man-made mineral fibers (MMMF).
whereas a fiber may be single- or poly-crystalline or may be
1.3 The values stated in SI units are to be regarded as the
noncrystalline.
standard. The values given in parentheses are for information
only.
4. Summary of Practice
1.4 This standard does not purport to address all of the
4.1 This practice is based on a three-tier approach to the
safety concerns, if any, associated with its use. It is the
quantitative assessment of airborne SCCW levels. It includes
responsibility of the user of this standard to establish appro-
detailed procedures to analyze standard air sampling cassettes
priate safety and health practices and determine the applica-
by phase contrast microscopy (PCM), scanning electron mi-
bility of regulatory limitations prior to use.
croscopy (SEM), and transmission electron microscopy
2. Referenced Documents (TEM).
2 4.2 The choice of a particular analytical method shall be
2.1 ASTM Standards:
based on the visibility limitation of each instrument and an
D1356 Terminology Relating to Sampling and Analysis of
understanding of the actual size distribution of the fibers being
Atmospheres
analyzed.
D6056 Test Method for Determining Concentration of Air-
4.3 In general, PCM is suitable for the analysis of fibers that
borne Single-Crystal Ceramic Whiskers in the Workplace
aregreaterthanapproximately0.25µmindiameter.Depending
Environment by Transmission Electron Microscopy
on the instrument and the sample preparation method used, the
D6057 Test Method for Determining Concentration of Air-
SEM may be capable of examining fibers as small as 0.10 µm
borne Single-Crystal Ceramic Whiskers in the Workplace
in diameter. TEM has been shown to be suitable for the study
of even finer fibers. The high resolution of this instrument
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This practice is under the jurisdiction ofASTM Committee D22 onAir Quality
makes it well suited for the determination of the fraction of a
andisthedirectresponsibilityofSubcommitteeD22.04onWorkplaceAtmospheres.
fiber population with diameters#0.10 to 0.25 µm.
Current edition approved Oct. 1, 2006. Published October 2006. Originally
4.4 In addition to an enhanced image resolution, SEM and
approved in 1996. Last previous edition approved in 2001 as D6058 - 96 (2001).
DOI: 10.1520/D6058-96R06.
TEM have the further advantage of providing elemental
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
composition information on a single fiber. Furthermore, TEM
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
may also be used to ascertain crystallographic data on the fiber.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
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