ASTM D6602-13(2022)e1

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.
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Designation: D6602 − 13 (Reapproved 2022)
Standard Practice for
Sampling and Testing of Possible Carbon Black Fugitive
Emissions or Other Environmental Particulate, or Both
This standard is issued under the fixed designation D6602; 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.
ε NOTE—Corrected 6.2.1 editorially in February 2023.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers sampling and testing for distin-
D1619 Test Methods for Carbon Black—Sulfur Content
guishing ASTM type carbon black, in the N100 to N900 series,
D3053 Terminology Relating to Carbon Black
from other environmental particulates.
D3849 Test Method for Carbon Black—Morphological
1.2 This practice requires some degree of expertise on the
Characterization of Carbon Black Using Electron Micros-
part of the microscopist. For this reason, the microscopist must
copy
have adequate training and on-the-job experience in identifying
the morphological parameters of carbon black and general 3. Terminology
knowledge of other particles that may be found in the envi-
3.1 Definitions of Terms Specific to This Standard:
ronment. In support of this analysis, Donnet’s book is highly
3.1.1 aciniform—shaped like a cluster of grapes.
recommended to be used as a technical reference for recogniz-
3.1.1.1 Discussion—The spheroidal primary particles of
ing and understanding the microstructure of carbon black.
carbon black are fused into aggregates of colloidal dimension
forming an acinoform morphology.
1.3 The values stated in SI units are to be regarded as
3.1.2 aciniform carbon—colloidal carbon having a mor-
standard. No other units of measurement are included in this
phology consisting of spheroidal primary particles (nodules)
standard.
fused together in aggregates of colloidal dimension in a shape
1.4 This standard may involve hazardous materials,
having grape-like clusters or open branch-like structures
operations, and equipment. This standard does not purport to
3.1.3 carbon black, n—an engineered material, primarily
address all of the safety concerns, if any, associated with its
composed of elemental carbon, obtained from the partial
use. It is the responsibility of the user of this standard to
combustion or thermal decomposition of hydrocarbons, exist-
establish appropriate safety, health, and environmental prac-
ing in the form of aggregates of aciniform morphology which
tices and determine the applicability of regulatory limitations
are composed of spheroidal primary particles characterized by
prior to use.
uniformity of primary particle sizes within a given aggregate
1.5 This international standard was developed in accor- and turbostratic layering within the primary particles.
3.1.3.1 Discussion—Particle size and aggregate size (num-
dance with internationally recognized principles on standard-
ber of particles per aggregate) are distributional properties and
ization established in the Decision on Principles for the
vary depending on the carbon black grade. Transmission
Development of International Standards, Guides and Recom-
electron micrographs shown in Annex A2 demonstrate that
mendations issued by the World Trade Organization Technical
while particle and aggregate sizes vary greatly within a given
Barriers to Trade (TBT) Committee.
grade of carbon black, the primary particle size is essentially
uniform within an individual aggregate.
3.1.4 chain of custody—a document describing the condi-
This practice is under the jurisdiction of ASTM Committee D24 on Carbon
tion of a sample during its collection, analysis, and disposal.
Black and is the direct responsibility of Subcommittee D24.66 on Environment,
Health, and Safety.
Current edition approved June 1, 2022. Published July 2022. Originally approved
in 2000. Last previous edition approved in 2018 as D6602 – 13 (2018). DOI:
10.1520/D6602-13R22E01. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Hess, W.M. and Herd, C.R., Carbon Black Science and Technology, Edited by contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Donnet, J.B., Bansal, R.C., and Wang, M.J., Marcel Dekker, Inc., New York, NY, Standards volume information, refer to the standard’s Document Summary page on
1993, pp. 89–173. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D6602 − 13 (2022)
3.1.5 char—a particulate larger than 1 μm made by incom- samples and identify the classes of particulate present includ-
plete combustion which may not deagglomerate or disperse by ing materials consistent or inconsistent with manufactured
ordinary techniques, may contain material which is not black, carbon black (referred to simply as carbon black). A semi-
and may contain some of the original material’s cell structure, quantitative estimate of the percentage of each type of surface
minerals, ash, cinders, and so forth. particulate component is determined using polarized light
microscopy (PLM). However, PLM analysis cannot differen-
3.1.6 fugitive dust—transitory, fleeting material comprised
tiate between carbon black and soots (black carbons) that may
of particulates foreign to the surface of deposition.
come from many sources in the environment. Therefore,
3.1.7 fungus, sooty mold, mildew, biofilm—particulates from
transmission electron microscopy (TEM) analysis is mandatory
a superficial growth that grows on living and decaying organic
in determining whether a sample contains carbon black.
matter.
Because the preparation steps for the TEM analysis eliminates
3.1.8 mineral dust—naturally occurring inorganic particu-
certain types of particles and concentrates only the fine (small)
lates inherent to the area such as soil minerals.
particles from the sample, the TEM analysis alone cannot be
3.1.9 pollen—particulates from a mass of microspores in a used to estimate the amount of carbon black or other particle
seed plant. type in the whole sample. Either the PLM or TEM analysis
may be done first.
3.1.10 rubber dust—finely divided soft particulates abraded
from rubber.
4.2 Section 6 provides guidelines for proper sampling and
handling of fugitive emission/environmental samples. Sections
3.1.11 sample—a small fractional part of a material or a
8 and 9 describe the analysis of the sample using polarized
specified number of objects that are selected for testing,
light microscopy (PLM) and transmission electron microscopy
inspection, or specific observations of particular characteris-
(TEM). The TEM analysis is critical in determining if the
tics.
collected sample is consistent or inconsistent with carbon
3.1.12 soot—a submicron black powder generally produced
black. Use of the TEM analysis is mandatory in determining
as an unwanted by-product of combustion or pyrolysis. It
whether a sample is positive for carbon black. The use of the
consists of various quantities of carbonaceous and inorganic
PLM analysis is not mandatory when the TEM analysis finds
solids in conjunction with adsorbed and occluded organic tars
no aciniform aggregates resembling carbon black. Section 9
and resins.
describes additional ancillary techniques that may be included
3.1.12.1 Discussion—The carbonaceous portion also is col-
in a sample analysis for purposes of providing supporting
loidal and often has the aciniform morphology. Soot may have
information as to the nature of the sample material. These are
several carbon morphologies. Examples of soot are carbon
situation-dependent methods and can provide critical identifi-
residues from diesel and gasoline engines, industrial flares,
cation information in certain cases.
sludge pits, burning tires, and so forth.
4.3 A block diagram is presented in Fig. 1 to give a possible
3.1.13 sticky tape—a section of tape with a sticky, solvent-
scheme to follow in performing this analysis. However, it
soluble adhesive used in the collection of particles from
should be noted that this diagram is a suggestion, not a
surfaces.
requirement. Either the PLM or TEM analysis may be per-
3.1.14 surface—the outer surface, facing, or exterior bound-
formed first.
ary of an object capable of supporting carbon and other fugitive
and natural occurring dusts and particulates.
5. Significance and Use
3.1.15 turbostratic—a type of graphitic crystallographic
5.1 There are a variety of darkening agents that contribute to
structure in which there is no symmetry along the z-axis.
air and surface contamination in industrial, urban and rural
3.2 Acronyms:
environments. Biofilms (fungal and algal), soil minerals, plant
3.2.1 EDS—energy dispersive spectroscopy associated with
fragments, rubber fragments, metal corrosion and soot are
SEM and TEM for the identification of elemental composition,
common darkening agents. Soot is formed as an unwanted
by-product of combustion and consequently varies widely with
3.2.2 LM—light microscope,
the type of fuel and combustion conditions. Carbon black, on
3.2.3 PLM—polarizing light microscope,
the other hand, is purposely produced under a controlled set of
3.2.4 SEM—scanning electron microscope,
conditions. Therefore, it is important to be able to distinguish
3.2.5 TEM—transmission electron microscope.
carbon black from soot, as well as other environmental
contaminants.
3.2.6 WDS—wavelength dispersive spectroscopy associated
with SEM and TEM for the identification of elemental com-
6. Sampling
position.
6.1 The area to be sampled should be representative of the
NOTE 1—Standard terminology relating to carbon black can be found in
contaminated area. For sampling, choose an area that appears
Terminology D3053.
to contain black particulates. In some situations, the same
4. Summary of Practice general surface can be used for gathering all test samples for
each property site location or area.
4.1 This practice describes the procedures and protocols to
follow in order to collect fugitive emission/environmental 6.2 Equipment:
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D6602 − 13 (2022)
6.3 Samples are to be collected by the following two
techniques (wipe and tape) in accordance with 6.3.1 and 6.3.2.
Precautions should be taken to carefully collect, handle, and
transport samples in a manner that will not cause further
contamination.
6.3.1 Technique I: Wipe Sampling—Collect the wipe sample
by wiping the surface to be sampled with a polyester wipe to
remove surface particulates and solids. Light pressure on the
wipe should be sufficient. Make sure that enough of an area has
been wiped to load the surface of the wipe. Place the exposed
wipe in a ziploc bag and label.
6.3.2 Technique II: Tape Sampling—Prepare a tape-lift slide
by applying an appropriate length of tape to a clean glass
microscope slide, leaving a tab for easy removal of the tape.
Remove particulates and solids from surfaces by removing the
tape from the prepared slide and applying it to the surface to be
sampled. Carefully remove the tape and place back across the
glass microscope slide. Take care not to overload the tape.
6.3.3 All collected samples must be clearly identified at the
time of collection.
6.4 At the time of sample collection, complete a sampling
record (Table 1) and also complete a chain of custody record
(Table 2).
6.5 This practice does not preclude examination of samples
collected by other means than the preceding, such as polyeth-
ylene glove wipes, filter paper, samples of clothing, material
scraped directly from the surface of interest, and so forth, or a
large sample taken in other containers at a spill site. However,
these samples always require thorough identification taken at
the time of sample collection.
FIG. 1 Block Diagram of Suggested Analysis Scheme for
6.6 It is advisable in the case of repeated incidents to clean
Samples
the surface between sampling.
7. Examination by Light Microscopy
6.2.1 Polyester Wipes (Texwipe Alphasat synthetic fiber 7.1 Summary of Test Method—This method of examination
wipes in 70 % alcohol/30 % DI water or equivalent). is a screening test method that provides an overview of the bulk
6.2.2 Sticky tape (Scotch Crystal Clear Tape, No. 25 or composition of the sample through examination under a light
equivalent). microscope. This portion of the method is mandatory except in
6.2.3 Polyethylene Ziploc Bags. cases where TEM examination gives no positive results for
6.2.4 Standard Glass Microscope Slides. aciniform aggregates resembling carbon black and there is no
TABLE 1 Example Sampling Record
Sample Identification Number: ___________________________________________________________
Sample Location: _________________________________________________________________________
Date of Sampling: ____________________________________________________________________
Comments:
.
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D6602 − 13 (2022)
TABLE 2 Example Chain of Custody Record
Sample ID Date Sampled Sampled By Comments
1.
2.
3.
4.
5.
Sample
Relinquished By Received By Time Date Reason for Change:
Number
1.
2.
3.
4.
5.
Comments:
request for a semi-quantitative analysis of the other compo- preserves the integrity of the particle aggregates without the
nents in the sample. In addition, there are special situations smearing that tends to occur when using the wipe sampler.
where other information such as a torn bag near a carbon black 7.3.3 Inspect the wipe sample with a stereobinocular micro-
manufacturing site strongly suggests that the black particulate scope. With a clean razor blade, cut out a small square section
being sampled is carbon black. In this case, a TEM analysis (~1 cm) of a representative portion of the wipe, including an
may be sufficient to confirm the presence of carbon black area of black staining if present. Using two clean tweezers,
without the mandatory PLM analysis. It is important to note agitate, twist, and scrape the square section of the wipe over a
that the results obtained by the light microscopy technique clean microscope slide to dislodge particle from the wipe and
cannot be considered as conclusive for identifying the presence on to the slide. If fine black particles coat some of the fibers of
of carbon black. the wipe, pull some of them out and mount them separately. It
may also be possible to transfer dark particulate from the wipe
7.2 Apparatus:
to a microscope slide using a tungsten needle. Add a drop of
7.2.1 Light Stereomicroscope, capable of at least 40× mag-
immersion oil to the preparation (oil having a refractive index
nification.
of 1.55 works well) and place a cover slip over it.
7.2.2 Polarized Light Microscope, equipped with objectives
7.3.4 Place the glass slide sample on the polarized light
at least in the 10 to 40× range of magnification.
microscope and examine with transmitted (both directly and
7.2.3 Refractive Index Liquids including Meltmount, 1.662
with crossed polars) and reflected light. Aciniform soot will
or 1.55 RI Cargille liquid or equivalent.
appear as aggregates of jet black particles exhibiting dull
7.2.4 Scissors or Safety Razor Blades, or both.
reflection. While observing with the microscope, lightly press
7.2.5 Glass Slides.
the coverslip with a needle. If the aggregates are carbon soot or
7.2.6 Glass Cover Slips.
carbon black, they will likely deform inelastically or disperse,
7.2.7 Microscope Camera (Polaroid, 35 mm, or digital).
or both. If an aggregate deforms elastically, it is likely a rubber
7.2.8 Tungsten Needles.
7.2.9 Forceps.
TABLE 3 Particulate Work Sheet For Light Microscopy of
7.2.10 Reference Slides of Particles Found in Dust Samples.
Environmental Samples
7.2.11 Fiber-Optic Light Source, for reflected light exami-
Component Estimated Percentage
nation.
(by volume or area)
Pollen
7.3 Procedure:
Fungal, Mold, Biofilm
7.3.1 Inspect the tape-lift with a stereobinocular micro-
Soil Minerals
scope. Note regions of interest where either jet black or dark Soot (which may include aciniform
carbon, fine char & carbon black)
particles are visible.
Coal ash (Fly ash)
7.3.2 Inspect the tape-lift with a polarized light microscope
Plant Fragments
using both transmitted and reflected light. The tape lift will Paint
Insect Parts
preserve intact colonies of fungal material (biofilm) if present.
Rust/Metal Flakes
If the sampled surface is weathered paint, pigment lifted from
Rubber
the surface will not obscure or hinder identification of biofilm Coal/Coke
Other
constituents, as is often the case with wipe samples. Aciniform
soot will appear as opaque, jet black aggregates of particles
displaying a dull reflection in top light. The tape lift generally
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D6602 − 13 (2022)
used to ‘calibrate’ an analyst. Particles are examined by PLM
at magnifications ranging from 100 to 400×. Particles are
characterized and identified by PLM on the basis of their
optical properties, including, but not limited to: (1)
birefringence/bireflectance, (2) color, (3) morphology/surface
texture, (4) physical dispersal in mountant, and (5) refractive
index relative to mountant. Carbon black, as observed by PLM,
is typically black opaque aggregates or agglomerates that vary
in dimension based on the type or manufacturer. Various soots
may have a similar appearance by PLM. (Constituent particles
of aggregates are best observed with the TEM.) The
aggregates/agglomerates do not have a characteristic reflec-
tance but the aciniform morphology may be apparent. Perform
Kohler illumination for PLM periodically by the project
microscopist. Calibrate the graticule scale micrometer once
upon installation and again with the microscope if the micro-
scope is moved from its initial position.
7.3.5 It is highly recommended that the various types of
particles present be documented as needed with photomicro-
graphs (with the aid of the microscope camera).
7.3.6 Photographs of known samples of some or all of the
particulates listed in Table 3 should be made for reference and
comparison if needed. Collect these samples from the area in
question. Other environmental contaminants may be collected
for comparisons if desired.
7.3.7 There is no requirement on the least amount of
particles required for valid observation due to the variance in
population of particles.
FIG. 2 Comparison Chart Showing Known Percentages of Par-
ticles (3)
NOTE 2—An ancillary method may be used for PLM preparation that
includes the following:
(1) For examination by PLM, dissolve the tape-lift adhesive with organic
particle which contains carbon black as an additive. Estimate
solvents (for example, toluene, xylene, or chloroform).
the percentage of each component from Table 3 and record.
(2) Extract particles from the adhesive through mechanical shaking or
The identification of environmental particles and classification sonication.
(3) Transfer an aliquot onto a slide containing a drop of refractive index
into categories by PLM has been published (1). The micros-
liquid, for example, 1.55 or 1.660, on a microscope slide and cover with
copist relies on his/her training, experience and reference to
a coverslip.
various published articles and books about particle character-
The procedures used to prepare wipe samples for analysis include the
istics (2-8). Some representative PLM images of particles in
following:
the common darkening agent classes of soot, fungal growth (1) Roll a tungsten needle, wetted with organic solvent, (for example,
toluene, xylene, or chloroform), across surface of the wipe.
(biofilms), soil minerals, plant fragments and rubber particles
(2) Transfer a representative sampling of all particles from the needle to
are shown in Annex A1. Estimate the percentage of each type
a drop of refractive index liquid, that is 1.660, on a glass microscope slide
of component found from the list in Table 3 and record. It is
and cover with a coverslip.
helpful to observe the sample using different lighting
conditions, that is, top, bottom, and side lighting. This inspec- 8. Examination by Transmission Electron Microscopy
(TEM)
tion is performed in order to ascertain if carbon black, other
black particles, and nonblack particles are present.
8.1 Summary of Test Method:
7.3.4.1 The semi-quantitative visual estimate of percentages
8.1.1 This test method is a mandatory evaluation of the
of particles in a sample is a well known technique that has been
aciniform materials present in the sample to determine primar-
used for many years by geologists, paleontologists, and asbes-
ily if their morphology is consistent with grape-like or branch-
tos analysts (9-14). Analysts learn to perform calibrated visual
like structures typically associated with carbon black and soots.
estimates by studying comparison charts where a known
In order to discriminate discrete morphological parameters, the
percentage of the particles in the chart has been filled in with
resolving power of a TEM is required. In addition to TEM
dots or other dark figures. Fig. 2 shows a representative
examination, the ancillary methods in accordance with Section
comparison chart used for calibrating analysts in semi-
9 may provide supporting information as to the nature and
quantitative visual estimation. Samples of known composition
amount of the material.
made from known volumes of various components are also
8.1.2 The sample is extracted into element-free chloroform
or acetone by sonication. The resulting suspension is deposited
onto a prepared carbon substrate attached to a 200 or 300-mesh
The boldface numbers in parentheses refer to a list of references at the end of
this standard. copper grid. The grid is placed into the transmission electron
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D6602 − 13 (2022)
is found in the sample, it is advisable to also examine possible manufac-
microscope (TEM) and representative fields are examined. The
tured carbon blacks from the area to be used as controls versus the
aciniform materials are then evaluated for overall morphology.
environmental sample.
8.2 Apparatus and Chemicals:
8.4.2 If the aggregates are aciniform, then continue with the
8.2.1 Transmission Electron Microscope (TEM), equipped
identification process. Examine the overall morphology of the
with a suitable camera. Energy or wavelength dispersive
aggregate in the magnification range of 30 000× to 50 000×
analysis is highly recommended but not mandatory.
and examine the microstructure of the primary particles in the
8.2.2 Ultrasonic Bath or Ultrasonic Probe, of satisfactory
range of 100 000×. In support of the analysis, it is recom-
power to disperse the particles.
mended to generate photomicrographs of representative fields.
8.2.3 Copper TEM Grids, 3-mm 200 or 300-mesh, with
Refer to Annex A1 to aid in particle identification.
carbon substrate.
8.4.3 Elemental identification of the aciniform material is
8.2.4 Scissors.
highly recommended but not mandatory. It is accomplished
8.2.5 Glass 1 Dram Vials with Cap or Glass Test Tubes, 10
using an X-ray system associated with the electron microscope.
by 85 mm, or Glass Vial, 3 by 5 cm.
The aciniform particles of soot and carbon black are mostly
8.2.6 Pipettes, disposable.
carbonaceous but may contain small amounts of other ele-
8.2.7 Chloroform, spectrophotometric grade.
ments.
8.2.8 Acetone, spectrophotometric grade.
8.4.4 Morphology of Aggregates:
8.4.4.1 Assess how the primary particles are joined together
8.3 Procedure:
in the aggregates, that is, the dimensions (diameter and length)
8.3.1 Snip off an appropriate soiled portion of the polyester
of the necks between primary particles. In carbon black
wipe/cotton ball with a clean p
...