ASTM D6877-03(2008)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6877 − 03(Reapproved 2008)
Standard Test Method for
Monitoring Diesel Particulate Exhaust in the Workplace
This standard is issued under the fixed designation D6877; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 OC-EC methods are operational, which means the
analyticalproceduredefinestheanalyte.Thetestmethodoffers
1.1 This test method covers determination of organic and
greater selectivity and precision than thermal techniques that
elemental carbon in the particulate fraction of diesel engine
donotcorrectforcharringoforganiccomponents.Theanalysis
exhaust,hereafterreferredtoasdieselparticulatematter(DPM
method is simple and relatively quick (about 15 min). The
). Samples of workplace atmospheres are collected on quartz-
analysis and data reduction are automated, and the instrument
fiber filters. The method also is suitable for other types of
is programmable (different methods can be saved as methods
carbonaceous aerosols, but it is not appropriate for sampling
for other applications).
volatile or semi-volatile components. These components re-
quire sorbents for efficient collection. 1.6 A method (5040) for DPM based on thermal-optical
NOTE1—Samplecollectionandhandlingproceduresforenvironmental
analysis has been published by the National Institute for
samples differ from occupational samples. This standard addresses occu-
Occupational Safety and Health (NIOSH). Method updates (3,
pational monitoring of DPM in workplaces where diesel-powered equip-
4)havebeenpublishedsinceitsinitial(1996)publicationinthe
ment is used.
NIOSHManualofAnalyticalMethods(NMAM).Both OCand
1.2 The method is based on a thermal-optical technique (1,
EC are determined by NMAM 5040. An EC exposure marker
2) . Speciation of organic and elemental carbon is achieved
was recommended because EC is a more selective measure of
through temperature and atmosphere control, and an optical
exposure.Acomprehensivereviewofthemethodandrationale
feature that corrects for sample charring.
for selection of an EC marker are provided in a recent Chapter
1.3 A portion of a 37-mm, quartz-fiber filter sample is of NMAM (5).
analyzed. Results for the portion are used to calculate the total
1.7 The thermal-optical instrument required for the analysis
massoforganicandelementalcarbononthefilter.Theportion 3
is manufactured by a private laboratory. As with most
mustberepresentativeoftheentirefilterdeposit.Ifthedeposit
instrumentation, design improvements continue to be made.
is uneven, two or more representative portions should be
Different laboratories may be using different instrument mod-
analyzed for an average. Open-faced cassettes give even
els.
deposits but are often not practical. Closed-face cassettes give
1.8 This standard does not purport to address all of the
equivalentresultsifotherdustsareabsent.Othersamplersmay
safety concerns, if any, associated with its use. It is the
be required, depending on the sampling environment (2-5).
responsibility of the user of this standard to establish appro-
1.4 The calculated limit of detection (LOD) depends on the
priate safety and health practices and determine the applica-
level of contamination of the media blanks (5). A LOD of
bility of regulatory limitations prior to use. Specific precau-
approximately 0.2 µg carbon per cm of filter was estimated
tionary statements are given in 7.1.5, 8.3, and 12.12.2.
when analyzing a sucrose standard solution applied to filter
portions cleaned immediately before analysis. LODs based on
2. Referenced Documents
media blanks stored after cleaning are usually higher. LODs
2.1 ASTM Standards:
based on a set of media blanks from a commercial laboratory
2 2 2
were OC=1.2µg/cm , EC=0.4µg/cm ,and TC=1.3µg/cm ,
where OC, EC, and TC refer to organic, elemental, and total
The carbon analyzer used in the development and performance evaluation of
carbon, respectively.
th
this test method was manufactured by Sunset Laboratory, 2017 19 Avenue, Forest
Grove, Oregon 97116, which is the sole source of supply of the instrument known
This test method is under the jurisdiction of ASTM Committee D22 on Air to the committee at this time. If you are aware of alternative suppliers, please
Qualityand is the direct responsibility of Subcommittee D22.04 on Workplace Air provide this information to ASTM Headquarters. Your comments will receive
Quality. carefulconsiderationatameetingoftheresponsibletechnicalcommitteewhichyou
Current edition approved Aug. 1, 2008. Published September 2008. Originally may attend.
approved in 2003. Last previous edition approved in 2003 as D6877–03. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D6877-03R08. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The boldface numbers in parentheses refer to references at the end of this test Standards volume information, refer to the standard’s Document Summary page on
method. the ASTM website.
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D6877 − 03 (2008)
D1356Terminology Relating to Sampling and Analysis of 3.4.8 W (µg)—field blank filter’s EC mass reading
b
Atmospheres
3.4.9 W (µg)—active filter’s EC mass reading
EC
3. Terminology
4. Summary of Test Method
3.1 For definitions of terms used in this practice, refer to
4.1 The thermal-optical analyzer has been described previ-
Terminology D1356.
ously (1-5). Design improvements have been made over time,
3.2 Definitions:
but the operation principle remains unchanged. OC-EC quan-
3.2.1 limit of detection, LOD—A value for which ex-
tificationisaccomplishedthroughtemperatureandatmosphere
ceedence by measured mass indicates the presence of a
control. In addition, the analyzer is equipped with an optical
substance at given false-positive rate: 3 × estimated standard
feature that corrects for the char formed during the analysis of
deviation of estimated mass.
somematerials.Opticalcorrectionismadewithapulseddiode
3.3 Definitions of Terms Specific to This Standard: laser and photodetector that permit continuous monitoring of
the filter transmittance.
3.3.1 organic carbon (OC)—Carbon volatilized in helium
while heating a quartz-fiber filter sample to 870°C. Includes
4.2 The main instrument components are illustrated in Fig.
carbonates, if present, unless quantified separately. Also in-
1. The instrument output, called a thermogram, is shown in
cludes char formed during pyrolysis of some materials.
Fig. 2. For analysis, a known area (normally 1.5 cm)ofthe
3.3.2 elemental carbon (EC)—Excluding char, light- quartz-fiberfiltersampleisremovedwithasharpmetalpunch.
absorbing carbon that is not removed from a filter sample
Quartz-fiberfiltersarerequiredbecausetemperaturesinexcess
heated to 870°C in an inert atmosphere.
of850°Careemployed.Theportionisinsertedintothesample
oven, and the oven is tightly sealed. The analysis proceeds in
3.3.3 total carbon (TC)—Sum of organic and elemental
inert and oxidizing atmospheres. First, OC (and carbonate, if
carbon.
present) is removed in helium as the temperature is stepped to
3.3.4 thermogram—Digitized output signal of thermal-
a preset maximum (about 870°C in NMAM 5040). Evolved
optical instrument. Shows detector and filter transmittance
carbon is catalytically oxidized to CO in a bed of granular
signals at different temperatures in nonoxidizing and oxidizing
MnO . The CO is then reduced to CH in a Ni/firebrick
2 2 4
atmospheres.
methanator, and CH is quantified by a FID. Next, the sample
3.4 Symbols and Abbreviations:
oven temperature is lowered, an oxygen-helium mix (2%
3.4.1 DPM—diesel particulate matter
oxygen after dilution of the 10% oxygen in helium supply) is
introduced, and the temperature is increased to 900°C (or
3.4.2 LOD (µg/cm )—limit of detection:3×s
w
2 higher) to remove the residual carbon. At the end of each
3.4.3 s (µg/cm )—estimate of σw
w
analysis, calibration is made through automatic injection of a
3.4.4 σ (µg/cm )—standard deviation in collected mass
w
fixed volume of methane.
loading determination
4.3 Some samples contain components (for example, ciga-
3.4.5 OC, EC, TC (µg/cm or µg)—organic, elemental, and
rette and wood smokes) that carbonize (convert to carbon) or
total carbon
char in helium during the first part of the analysis. Like EC
3.4.6 RSD—relative standard deviation
initially present in the sample, char strongly absorbs light,
3.4.7 V (L)—sampled volume particularlyinthered/infraredregion.Thecharformedthrough
FIG. 1 Schematic of Thermal-Optical Instrument (V = valve) for Determination of Organic and Elemental Carbon in DPM and Other Car-
bonaceous Aerosols.
D6877 − 03 (2008)
NOTE 1—PC is pyrolytically generated carbon (char). Final peak is methane calibration peak. Carbon sources: pulverized beet pulp, rock dust
(carbonate), and diesel particulate.
NOTE2—InthecomparativetestreportedbyBirch(28),participantsuseddifferentmaximumtemperaturesinhelium(5).Theactualmaximumranged
from about 850-900°C. NMAM 5040 specifies 870°C, which is near the middle of the range.
FIG. 2 Thermogram for Filter Sample Containing OC, Carbonate (CC), and EC.
pyrolysis (thermal decomposition) of these components causes 5. Significance and Use
the filter transmittance to decrease. Charring can begin at
5.1 The test method supports proposed, occupational expo-
300°C; the process may continue until the maximum tempera-
sure standards (6, 7) for DPM. In the United States alone, over
ture is reached. After OC removal, an oxygen-helium mix is
amillionworkersareoccupationallyexposed(8).Anexposure
introduced to effect combustion of residual carbon, which
standard for mines is especially important because miners’
includes char and any EC originally present.As oxygen enters
exposures are often quite high. NIOSH (8), the International
the oven, light-absorbing carbon is oxidized and a concurrent
Agency for Research on Cancer (9) (IARC), the World Health
increase in filter transmittance occurs. The split (vertical line
Organization (10) (WHO), the California Environmental Pro-
prior to EC peak in Fig. 2) between OC and EC is assigned
tection Agency (11), the U.S. Environmental Protection
when the initial (baseline) value of the filter transmittance is
Agency(12)(EPA),andtheNationalToxicologyProgram(13)
reached. All carbon removed before the OC-EC split is
have reviewed the animal and human evidence. All have
considered organic; that removed after the split is considered
classified diesel exhaust as a probable human carcinogen or
elemental. If no char is formed, the split is assigned prior to
similar designation.
removalof EC.Ordinarily,thesplitisassignedintheoxidative
mode of the analysis.
5.2 The test method provides a measure of occupational
exposure to DPM. Previous studies have produced equivocal
4.4 Occasionally, original EC (as opposed to char) is lost
results because exposure data are lacking. Given the economic
with the fourth temperature step in helium. Loss of EC in
and public health impact of epidemiological studies, accurate
helium is uncommon, but sometimes occurs, possibly due to
risk assessment is critical. An ongoing NIOSH/NCI study of
oxidants in the sample. The OC-EC split is automatically
miners exposed to diesel exhaust should provide a more
assigned earlier (in helium) in these cases (5).
quantitative estimate of the lung cancer risk. The test method
4.5 OC and EC results are reported in units µg per cm of
was used for exposure monitoring. Since publication (in 1996)
filter deposit. The total OC and EC on the filter are calculated
as NMAM 5040, the method has been routinely used for
bymultiplyingthereportedvaluesbythe depositarea(slightly
occupational monitoring (5).
less than the filter area). A homogeneous deposit is assumed.
The TC in the sample is the sum of OC and EC. If carbonate 5.3 The test method supports a proposed EPA air standard
ispresent,thecarboninitisquantifiedas OCunlesscorrection for fine particulate carbon. Recent studies indicate a positive
is made. Additional details about carbonates are given in a association between airborne levels of fine particles and
following section. respiratory illness and mortality (14-22). The test method and
D6877 − 03 (2008)
othershavebeenusedforEPAairmonitoringnetworksandair 7.1.3 Methanator—packed with catalyst (Ni-coated fire-
pollution studies. Because different methods produce different brick) and heated to 500°C.
results, method standardization is essential for regulatory 7.1.4 FID—flame ionization detector.
compliancedeterminationsandvalidcomparisonsofinterlabo- 7.1.5 Pulsed diode laser and photo detector—for continu-
ratory data. ous monitoring of filter transmittance. Warning—In accor-
dance with the manufacturer, the instrument is a Class I Laser
5.4 The test method is being applied for emission-control
Product. Weakly scattered laser light is visible during
testing.
operation,butdoesnotposeahazard.Theinternallasersource
isaClassIIIbproduct,whichposesapossiblehazardtotheeye
6. Interferences
if viewed directly or from a mirror-like surface (that is,
6.1 EC is a more selective marker of occupational exposure
specularreflections).ClassIIIblasersnormallydonotproduce
than other measures of DPM (for example, particulate mass,
a hazardous diffuse reflection. Repairs to the optical system,
total carbon).As defined by the test method, EC is the carbon
and other repairs requiring removal of the instrument housing,
determined during the second stage of the analysis (after
should be performed only by a qualified service technician.
pyrolysis correction). If the sample contains no pyrolyzable
7.1.6 Valve box/calibration loop—for control of gas flow
material, all carbon evolved during this stage is considered
and automatic injection of methane internal standard.
elemental. Inorganic dusts, carbonates, and wood and cigarette
smokes ordinarily do not interfere in the EC determination
8. Reagents and Materials
(2-5). OC can be contributed by smokes, fumes and other
8.1 Organic Carbon (OC) Standards—Sucrose stock solu-
sources.
tion having carbon concentration of 25 mg/mL. Working
6.2 If high levels of other dusts are present, a size classifier standards (dilutions of stock) with concentrations of 0.1 to 3
(for example, impactor, or cyclone, or both) should be used. If
mg C per mL solution. Ensure carbon loadings of standards
the dust is carbonaceous, a size classifier provides a more spik
...