ASTM D6877-13(2018)

Standard Test Method for Monitoring Diesel Particulate Exhaust in the Workplace

SIGNIFICANCE AND USE
5.1 The test method supports previously proposed occupational exposure standards (7, 8) for DPM. A DPM exposure limit has since been promulgated for metal and nonmetal mines, but there currently are no limits for general occupational settings (a proposed limit (7) was withdrawn from the ACGIH Notice of Intended Changes (NIC) list in 2003). In the United States alone, over a million workers are occupationally exposed (9). An exposure standard for mines is especially important because miners’ exposures are often quite high. NIOSH (9), the International Agency for Research on Cancer (10) (IARC), the World Health Organization (11) (WHO), the California Environmental Protection Agency (12), the U.S. Environmental Protection Agency (13) (EPA), and the National Toxicology Program (14) reviewed the animal and human evidence on DPM and all classified diesel exhaust as a probable human carcinogen or similar designation. In 2012, the WHO reclassified diesel exhaust as carcinogenic to humans (Group 1) (15). In addition, in a study of miners, the National Cancer Institute (NCI) and NIOSH reported increased risk of death from lung cancer in exposed workers (16, 17).  
5.2 The test method provides a measure of occupational exposure to DPM. Given the economic and public health impact of epidemiological studies, accurate risk assessment is critical. The NIOSH/NCI study of miners exposed to diesel exhaust provides quantitative estimates of lung cancer risk (16, 17). The test method was used for exposure monitoring. Since publication (in 1996) as NMAM 5040, the method has been routinely used for occupational monitoring (5).  
5.3 Studies indicate a positive association between airborne levels of fine particles and respiratory illness and mortality (18-26). The test method and others have been used for EPA air monitoring networks and air pollution studies. Because different methods produce different results, method standardization is essential for regulatory compliance determinations...
SCOPE
1.1 This test method covers determination of organic and elemental carbon (OC and EC) in the particulate fraction of diesel engine exhaust, hereafter referred to as diesel particulate matter (DPM). Samples of workplace atmospheres are collected on quartz-fiber filters. The method also is suitable for other types of carbonaceous aerosols and has been widely applied to environmental monitoring. It is not appropriate for sampling volatile or semi-volatile components. These components require sorbents for efficient collection.
Note 1: Sample collection and handling procedures for environmental samples differ from occupational samples. This standard addresses occupational monitoring of DPM in workplaces where diesel-powered equipment is used.  
1.2 The method is based on a thermal-optical technique (1, 2).2 Speciation of OC and EC is achieved through temperature and atmosphere control, and an optical feature that corrects for sample charring (carbonization).  
1.3 A portion of a 37-mm, quartz-fiber filter sample is analyzed. Results for the portion are used to calculate the total mass of OC and EC on the filter. The portion must be representative of the entire filter deposit. If the deposit is uneven, two or more representative portions should be analyzed for an average. Alternatively, the entire filter can be analyzed, in multiple portions, to determine the total mass. Open-faced cassettes give even deposits but may not be practical. At 2 L/min, closed-face cassettes generally give results equivalent to open-face cassettes if other dusts are absent. Higher flow rates may be employed, but closed-faced cassettes operated at higher flow rates (for example, 5 L/min) sometimes have uneven deposits due to particle impaction at the center of the filter. Other samplers may be required, depending on the sampling environment (2-5).  
1.4 The calculated limit of detection (LOD) depends on the level of contamination of the media bl...

General Information

• Status: Published
• Publication Date: 30-Sep-2018
• ICS: 13.040.50 - Transport exhaust emissions
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.04 - Workplace Air Quality

Relations

• Replaces: ASTM D6877-13e1 - Standard Test Method for Monitoring Diesel Particulate Exhaust in the Workplace
• Effective Date: 01-Oct-2018
• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM D1356-14b - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Dec-2014
• Refers: ASTM D1356-14a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Jan-2014
• Refers: ASTM D1356-05(2010) - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Apr-2010
• Refers: ASTM D1356-05 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2005
• Refers: ASTM D1356-00a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 10-Nov-2000

Overview

ASTM D6877-13(2018) is the Standard Test Method for Monitoring Diesel Particulate Exhaust in the Workplace, developed by ASTM International. This standard outlines procedures to determine concentrations of organic and elemental carbon (OC and EC) in diesel particulate matter (DPM) within workplace atmospheres using thermal-optical analysis of particulate collected on quartz-fiber filters. As diesel exhaust is recognized as a carcinogenic agent, monitoring DPM is critical for occupational health, especially in industries with frequent diesel-powered equipment operation, such as mining.

This method provides a reliable tool to assess workplace exposures to airborne carbonaceous particles, support regulatory compliance, and inform health risk assessments. The standard is widely referenced in occupational hygiene and environmental air quality monitoring.

Key Topics

• Occupational Exposure Monitoring: The method quantifies worker exposure to diesel particulate matter, a probable human carcinogen as designated by organizations including the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO).
• Thermal-Optical Analysis: By leveraging programmable instruments and rigorous temperature and atmospheric controls, the approach separates OC and EC, also correcting for any sample charring to ensure accurate carbon speciation.
• Quartz-Fiber Filter Sampling: Workplace atmospheric samples are collected onto pre-cleaned quartz-fiber filters, which are essential for withstanding the high temperatures required for proper analysis.
• Standardization and Compliance: Standardized methods such as this are needed for consistent regulatory enforcement and interlaboratory data comparison, particularly in industries subject to air quality regulations.
• Detection and Sensitivity: The method achieves low limits of detection, ensuring reliable measurement of even small amounts of diesel particulate in workplace air.

Applications

ASTM D6877-13(2018) is applied in several critical contexts:

• Mining Industry: Regulated environments such as metal and nonmetal mines use this standard to assess worker exposure to DPM according to official exposure limits.
• Industrial Workplaces: Facilities operating diesel-powered vehicles or equipment rely on this method for routine air quality monitoring to protect worker health and support corporate occupational hygiene programs.
• Environmental Monitoring: Though designed for occupational exposure, the method is also applied to general air quality studies and environmental monitoring, with procedural adaptations for different sampling scenarios.
• Epidemiological Research: Accurate exposure assessments provided by this standard underpin studies linking DPM exposure to health outcomes such as increased lung cancer risk and respiratory illnesses.
• Regulatory Reporting: Organizations use this method to generate standardized data supporting compliance with workplace air quality regulations and to benchmark control measures.

Related Standards

Several other standards and guidelines intersect with the scope of ASTM D6877-13(2018):

• NIOSH Method 5040: A closely related method published by the National Institute for Occupational Safety and Health for analyzing OC and EC in DPM, forming the basis for much of the ASTM standard’s approach.
• ASTM D1356: Provides terminology for sampling and analysis of atmospheres, referenced within D6877 for definition clarity.
• MSHA Guidelines: The Mine Safety and Health Administration endorses similar impactor-based methods for DPM collection and analysis in mining operations.
• International Guidelines: WHO, IARC, and other agencies reference similar techniques when developing recommendations for occupational and public health exposure limits.

Keywords: diesel particulate matter, DPM monitoring, occupational exposure, thermal-optical analysis, organic carbon, elemental carbon, workplace air quality, ASTM D6877, diesel exhaust carcinogen, environmental monitoring, mining industry air sampling, regulatory compliance, carbon analysis.

Standards Content (Sample)

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.
Designation: D6877 − 13 (Reapproved 2018)
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 approximately 0.2-µg carbon per cm of filter was estimated
when analyzing a sucrose standard solution applied to filter
1.1 This test method covers determination of organic and
portions cleaned immediately before analysis. LODs based on
elemental carbon (OC and EC) in the particulate fraction of
media blanks stored after cleaning are usually higher. LODs
dieselengineexhaust,hereafterreferredtoasdieselparticulate
based on a set of media blanks analyzed over a six month
matter (DPM). Samples of workplace atmospheres are col-
period at a commercial laboratory were OC = 1.2 µg/cm , EC
lected on quartz-fiber filters. The method also is suitable for
2 2
= 0.4 µg/cm , and TC = 1.3 µg/cm , where TC refers to total
other types of carbonaceous aerosols and has been widely
carbon (TC = OC + EC). In practice, the LOD estimate
applied to environmental monitoring. It is not appropriate for
provided by a laboratory is based on results for a set of media
sampling volatile or semi-volatile components. These compo-
blanks submitted with the samples.To reduce blank variability
nents require sorbents for efficient collection.
(due to lack of loading), a manual OC-EC split is assigned at
NOTE1—Samplecollectionandhandlingproceduresforenvironmental
the time when oxygen is introduced. With manual splits, the
samples differ from occupational samples. This standard addresses occu-
pational monitoring of DPM in workplaces where diesel-powered equip-
SD for media blanks is typically about 0.02–0.03 µg EC/cm ,
ment is used.
givingLODs(3×SDblank)fromabout0.06–0.09µgEC/cm .
1.2 The method is based on a thermal-optical technique (1, The corresponding air concentration depends on the deposit
2). Speciation of OC and EC is achieved through temperature area (filter size) and air volume.
andatmospherecontrol,andanopticalfeaturethatcorrectsfor
1.5 OC-EC methods are operational, which means the
sample charring (carbonization).
analyticalproceduredefinestheanalyte.Thetestmethodoffers
1.3 A portion of a 37-mm, quartz-fiber filter sample is greater selectivity and precision than thermal techniques that
analyzed. Results for the portion are used to calculate the total donotcorrectforcharringoforganiccomponents.Theanalysis
mass of OC and EC on the filter. The portion must be method is simple and relatively quick (about 15 min). The
representative of the entire filter deposit. If the deposit is analysis and data reduction are automated, and the instrument
uneven, two or more representative portions should be ana- is programmable (different methods can be saved as methods
lyzed for an average. Alternatively, the entire filter can be for other applications).
analyzed, in multiple portions, to determine the total mass.
1.6 A method (5040) for DPM based on thermal-optical
Open-faced cassettes give even deposits but may not be
analysis has been published by the National Institute for
practical. At 2 L/min, closed-face cassettes generally give
Occupational Safety and Health (NIOSH). Method updates (3,
results equivalent to open-face cassettes if other dusts are
4)havebeenpublishedsinceitsinitial(1996)publicationinthe
absent. Higher flow rates may be employed, but closed-faced
NIOSHManualofAnalyticalMethods(NMAM).Both OCand
cassettes operated at higher flow rates (for example, 5 L/min)
EC are determined by NMAM 5040. An EC exposure marker
sometimes have uneven deposits due to particle impaction at
(for DPM) was recommended because EC is a more selective
the center of the filter. Other samplers may be required,
measure of exposure. A comprehensive review of the method
depending on the sampling environment (2-5).
and rationale for selection of an EC marker are provided in a
1.4 The calculated limit of detection (LOD) depends on the Chapter of NMAM (5).
level of contamination of the media blanks (5).A LOD of
1.7 The thermal-optical instrument required for the analysis
is manufactured by a private laboratory. As with most
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.04 on WorkplaceAir The carbon analyzer used in the development and performance evaluation of
Quality. this test method was manufactured by Sunset Laboratory, 2017 19thAvenue, Forest
Current edition approved Oct. 1, 2018. Published October 2018. Originally Grove, Oregon 97116, which is the sole source of supply of the instrument known
ɛ1
approved in 2003. Last previous edition approved in 2013 as D6877–13 . DOI: to the committee at this time. If you are aware of alternative suppliers, please
10.1520/D6877-13R18. provide this information toASTM International Headquarters.Your comments will
2 1
The boldface numbers in parentheses refer to references at the end of this test receive careful consideration at a meeting of the responsible technical committee,
method. which you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6877 − 13 (2018)
instrumentation, design improvements continue to be made. 3.3.4 σ (µg/cm )—standard deviation in collected mass
w
Different laboratories may be using different instrument mod- loading determination
els. 2
3.3.5 OC, EC, TC (µg/cm or µg)—organic, elemental, and
total carbon
1.8 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.3.6 RSD—relative standard deviation
standard.
3.3.7 V (L)—sampled volume
1.9 This standard does not purport to address all of the
3.3.8 W (µg)—field blank filter’s EC mass reading
b
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.3.9 W (µg)—active filter’s EC mass reading
EC
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 4. Summary of Test Method
Specific precautionary statements are given in 7.1.5, 8.3, and
4.1 The thermal-optical analyzer has been described previ-
12.12.2.
ously (1-5). Design improvements have been made over time,
1.10 This international standard was developed in accor-
but the operation principle remains unchanged. OC-EC quan-
dance with internationally recognized principles on standard-
tificationisaccomplishedthroughtemperatureandatmosphere
ization established in the Decision on Principles for the
control. In addition, the analyzer is equipped with an optical
Development of International Standards, Guides and Recom-
feature that corrects for the char formed during the analysis of
mendations issued by the World Trade Organization Technical
somematerials.Opticalcorrectionismadewithapulseddiode
Barriers to Trade (TBT) Committee.
laser and photodetector that permit continuous monitoring of
the filter transmittance/reflectance.
2. Referenced Documents
4.2 The main instrument components (transmittance instru-
2.1 ASTM Standards:
ment) are illustrated in Fig. 1. The instrument output, called a
D1356Terminology Relating to Sampling and Analysis of
thermogram, is shown in Fig. 2. For analysis, a known area
Atmospheres
(normally 1.5 cm ) of the quartz-fiber filter sample is removed
with a sharp metal punch. Quartz-fiber filters are required
3. Terminology
because temperatures in excess of 850°C are employed. The
3.1 Definitions—For definitions of terms used in this test
portionisinsertedintothesampleoven,andtheovenistightly
method, refer to Terminology D1356.
sealed. The analysis proceeds in inert and oxidizing atmo-
3.1.1 limit of detection (LOD), n—a value for which ex-
spheres. First, OC (and carbonate, if present) is removed in
ceedence by measured mass indicates the presence of a
helium as the temperature is stepped to a preset maximum
substance at given false-positive rate: 3 × estimated standard
(usually ≥850°C in NMAM 5040; see 4.4). Evolved carbon is
deviation of estimated mass of a blank.
catalytically oxidized to CO in a bed of granular MnO . The
2 2
CO is then reduced to CH in a Ni/firebrick methanator, and
3.2 Definitions of Terms Specific to This Standard: 2 4
CH isquantifiedbya FID.Next,thesampleoventemperature
3.2.1 elemental carbon (EC), n—excluding char, light- 4
is lowered, an oxygen-helium mix (2% oxygen after dilution
absorbing carbon that is not removed from a filter sample
of the 10% oxygen in helium supply) is introduced, and the
heated to 870°C in an inert atmosphere.
temperature is increased to 900°C (or higher) to remove
3.2.2 organic carbon (OC), n—carbon volatilized in helium
(oxidize) the remaining carbon, some or all of which is EC,
while heating a quartz-fiber filter sample to 870°C. Includes
dependingonwhethercharisformedduringthefirstpartofthe
carbonates, if present, unless quantified separately. Also in-
analysis (a char correction is made if so). At the end of each
cludes char formed during pyrolysis of some materials.
analysis, calibration is made through automatic injection of a
3.2.3 thermogram, n—digitized output signal of thermal-
fixed volume of methane.
optical instrument. Shows detector and filter transmittance
4.3 Some samples contain components (for example, ciga-
signals at different temperatures in nonoxidizing and oxidizing
rette and wood smokes) that carbonize (convert to carbon) to
atmospheres.
form char in helium during the first part of the analysis. Like
3.2.4 total carbon (TC), n—sum of organic and elemental
EC typical of fine particle pollution, char strongly absorbs
carbon.
light, particularly in the red/infrared region. The char formed
3.3 Symbols and Abbreviations:
through pyrolysis (thermal decomposition) of these compo-
3.3.1 DPM—diesel particulate matter
nents causes the filter transmittance/reflectance to decrease.
Charring can begin at 300°C; the process may continue until
3.3.2 LOD (µg/cm )—limit of detection:3×s
w
the maximum temperature is reached. After OC removal, an
3.3.3 s (µg/cm )—estimate of σ
w w
oxygen-helium mix is introduced to effect combustion of
residual carbon, which includes char and any EC originally
present. As oxygen enters the oven, light-absorbing carbon is
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
oxidized and a concurrent increase in filter transmittance
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
occurs. The split (vertical line prior to EC peak in Fig. 2)
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. between OC and EC is assigned when the initial (baseline)
D6877 − 13 (2018)
FIG. 1 Schematic of Thermal-Optical Instrument (V = Valve) for Determination of Organic and Elemental Carbon in DPM and Other Car-
bonaceous Aerosols
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 matter.
NOTE 2—In the comparative test reported by Birch (6), participants used different maximum temperatures in helium (5). The actual maximum ranged
from about 850–900°C. NMAM 5040 specifies 870°C, which is near the middle of this range.
FIG. 2 Thermogram for Filter Sample Containing OC, Carbonate (CC), and EC
valueofthefiltertransmittanceisreached.Allcarbonremoved initial (baseline) value during the first part of the analysis (in
before the OC-EC split is considered organic; that removed helium), the OC-EC split is automatically assigned earlier, in
afterthesplitisconsideredelemental.Ifnocharisformed,the helium mode (5). A lower preset maximum (for example,
split is assigned prior to removal of EC. Ordinarily, the split is 650°C)canbeusedtoreduceEC/charlossinheliumsothatthe
assigned in the oxidative mode of the analysis. split occurs during the oxidative mode (5).
4.4 Occasionally, the sample EC (along with any char 4.5 OC and EC results are reported in units µg per cm of
formed) is lost during the fourth temperature step in helium. filter deposit. The total OC and EC on the filter are calculated
Loss of EC in helium is uncommon but sometimes occurs, bymultiplyingthereportedvaluesbythe depositarea(slightly
possiblyduetooxidantsinthesample.Incaseswhenlossisto less than the filter area). A homogeneous deposit is assumed.
an extent where the filter transmittance reaches/exceeds its The TC in the sample is the sum of OC and EC. If carbonate
D6877 − 13 (2018)
ispresent,thecarboninitisquantifiedas OCunlesscorrection selective measure of the diesel-source OC. It also provides a
is made. Additional details about carbonates are given in a better measure of the diesel-source EC if the dust contains EC
following section. (for example, carbon black, coal), which is less common. A
finely ground sample of the bulk material can be analyzed to
5. Significance and Use
determinewhetheradustposespotentialinterference.Depend-
ing on the dust concentration, size distribution, and target
5.1 The test method supports previously proposed occupa-
analyte (EC or TC), an impactor/cyclone may be required.
tional exposure standards (7, 8) for DPM.A DPM exposure
Additional details can be found elsewhere (5). Some OC
limit has since been promulgated for metal and nonmetal
interferences cannot be excluded on the basis of size (for
mines, but there currently are no limits for general occupa-
example, cigarette smoke and other combustion aerosols,
tional settings (a proposed limit (7) was withdrawn from the
condensation aerosol).
ACGIHNoticeofIntendedChanges(NIC)listin2003).Inthe
United States alone, over a million workers are occupationally
6.3 In metal and nonmetal mines, the Mine Safety and
exposed (9). An exposure standard for mines is especially
Health Administration (MSHA) recommended use of a spe-
important because miners’ exposures are often quite high.
cialized impactor (with cyclone) to minimize collection of
NIOSH (9), the International Agency for Research on Cancer
carbonates and other carbonaceous dusts (6, 8, 27-31).
(10) (IARC), the World Health Organization (11) (WHO), the
6.4 For measurement of diesel-source EC in coal mines, an
California Environmental Protection Agency (12), the U.S.
impactor with sub-micrometer cutpoint (6, 8, 27-31) must be
EnvironmentalProtectionAgency (13)(EPA),andtheNational
usedtominimizecollectionofcoaldust.OnlylowlevelsofEC
Toxicology Program (14) reviewed the animal and human
were found in non-dieselized coal mines when an impactor
evidence on DPM and all classified diesel exhaust as a
with a sub-micrometer cutpoint was used (6).
probablehumancarcinogenorsimilardesignation.In2012,the
6.5 Environmental samples usually contain little (if any)
WHO reclassified diesel exhaust as carcinogenic to humans
carbonate. Levels in some occupational settings (for example,
(Group 1) (15). In addition, in a study of miners, the National
trona mines) may be quite high. Depending on the carbonate
Cancer Institute (NCI) and NIOSH reported increased risk of
type, a carbonate-subtracted value for OC (and TC) can be
death from lung cancer in exposed workers (16, 17).
obtained through acidification of the sample or separate inte-
5.2 The test method provides a measure of occupational
grationofthecarbonatepeak(see12.12).Ifcarbonateisnotof
exposure to DPM. Given the economic and public health
interest but present, a size-selective sampler can be used to
impact of epidemiological studies, accurate risk assessment is
exclude carbonate-containing dusts (see 6.3, 6.4, and 12.12).
critical. The NIOSH/NCI study of miners exposed to diesel
exhaustprovidesquantitativeestimatesoflungcancerrisk (16,
7. Apparatus
17). The test method was used for exposure monitoring. Since
7.1 The main components of the thermal-optical analyzer
publication (in 1996) as NMAM 5040, the method has been
(transmittance instrument) used in the test method are illus-
routinely used for occupational monitoring (5).
trated in Fig. 1. The principal components are:
5.3 Studies indicate a positive association between airborne
7.1.1 Sample oven, temperature programmable.
levels of fine particles and respiratory illness and mortality
7.1.2 Oxidizer oven, packed with MnO and heated to
(18-26).ThetestmethodandothershavebeenusedforEPAair
860°C.
monitoring networks and air pollution studies. Because differ-
7.1.3 Methanator,packedwithcatalyst(Ni-coatedfirebrick)
ent methods produce different results, method standardization
and heated to 500°C.
isessentialforregulatorycompliancedeterminationsandvalid
7.1.4 Flame ionization detector (FID).
comparisons of interlaboratory data.
7.1.5 Pulsed diode laser and photo detector, for continuous
5.4 The test method is being applied for emission-control
monitoring of filter transmittance. (Warning—In accordance
testing.
with the manufacturer, the instrument is a Class I Laser
Product. Weakly scattered laser light is visible during
6. Interferences
operation,butdoesnotposeahazard.Theinternallasersource
6.1 EC is a more selective marker of occupational exposure isaClassIIIbproduct,whichposesapossiblehazardtotheeye
if viewed directly or from a mirror-like surface (that is,
than other measures of DPM (for example, particulate mass,
total carbon).As defined by the test method, EC is the carbon specularreflections).ClassIIIblasersnormallydonotproduce
a hazardous diffuse reflection. Repairs to the optical system,
determined during the second stage of the analysis (after
pyrolysis correction). If the sample contains no pyrolyzable and other repairs requiring removal of the instrument housing,
should be performed only by a qualified service technician.)
material, all carbon evolved during this stage is considered
elemental. Inorganic dusts, carbonates, and wood and cigarette 7.1.6 Valve box/calibration loop,forcontrolofgasflowand
automatic injection of methane internal standard.
smokes ordinarily do not interfere in the EC determination
(2-5). OC can be contributed by smokes, fumes and other
sources. 8. Reagents and Materials
6.2 If high levels of other dusts are present, a size classifier 8.1 Organic Carbon (OC) Standards—Sucrose stock solu-
(for example, impactor, or cyclone, or both) should be used. If tion having carbon concentration of 25 mg/mL. Working
the dust is carbonaceous, a size classifier provides a more standards (dilutions of stock) with concentrations of 0.1 to 3
D6877 − 13 (2018)
mg C per mL solution. Ensure carbon loadings of standards 9. Sampling
spiked onto filter punches bracket the range of the samples.
9.1 Calibrate each personal sampling pump at 1–4 L/min
with a representative sampler in line.
8.2 Ultrapure water, Type I, (for preparation of sucrose
standard solution).
9.2 Use tweezers to insert filter supports (a second quartz
filter, cellulose pads or clean stainless steel screens) and
8.3 Sucrose, reagent grade (99+ %).
pre-cleaned, quartz-fiber filters into sampling cassettes. Seal
8.4 Helium-UHP (99.999%)—Scrubber also required for
cassettes.Asecondquartzfilterpermitscorrectionforadsorbed
removal of trace oxygen.
vapor (5, 30).
NOTE 3—Cellulose support pads give higher OC blanks than quartz
8.5 Hydrogen, purified (99.995%). Cylinder or hydrogen
filters or stainless steel screens. Filters are less expensive than screens.
generator source. (Warning—Hydrogen is a flammable gas.
9.3 Attach sampler outlet to personal sampling pump with
Users must be familiar with proper use of flammable and
flexible tubing. Remove plug from cassette inlet, if present.
nonflammable gases, cylinders, and regulators.)
9.4 Sample at an accurately known flow rate.
8.6 Air—Ultra zero (low hydrocarbon).
9.5 After sampling, replace top piece of cassette (or other-
8.7 Oxygen(10%)inhelium,bothgasesUHP,certifiedmix.
wise protect sample), if removed, and pack securely for
8.8 Methane(5%)inhelium,bothgasesUHP,certifiedmix.
shipment to laboratory.
NOTE 4—DPM samples from occupational settings generally do not
8.9 37-mm cassettes or alternative sampler.
require refrigerated shipment unless there is potential for exposure to
elevated temperatures (that is, well above collection temperature). DPM
8.10 Personal sampling pumps.
samples normally are stable under laboratory conditions. Some OC loss
8.11 High-purity, quartz-fiber filters, pre-cleaned. High-
may occur over time if samples contain OC from other sources (for
example, cigarette smoke). Sorption of OC vapor after sample collection
purity, binder-free, high efficiency filters must be used. Pre-
has not occurred, even with samples having high (for example, 80%) EC
cleaned filters are available from several laboratories. Filters
content.
also can be purchased and cleaned in-house. Filters should be
cleaned in a muffle furnace operated at 800–900°C for 1–2 10. Calibration and Standardization
hours. The filters should be checked (analyzed) to ensure that
10.1 Analyze aliquots of OC standard solution spiked onto
OC contaminants have been removed. A shorter cleaning
freshly cleaned filter portions. Remove portions from clean
periodmaybeeffective. OCresultsimmediatelyaftercleaning
filters with metal punch. Clean portions in sample oven before
should be below 0.1 µg/cm . OC vapors readily adsorb onto
spiking. Apply aliquots with syringe. Include carbon loadings
clean filters. Even when stored in closed containers, OC
representative of samples.
2 2
loadings may range from 0.5 µg/cm –0.8 µg/cm after several
10.2 When applying small aliquots (for example, 10 µL),
weeks.
disperse standard solution at one end of the 1.5 cm filter
8.12 Aluminum foil.
portiontoensureitcanbepositionedinlaserbeam.Toprevent
possible solution loss to surface, hold portion off the surface
8.13 10-µL syringe, (and other sizes, depending on volume
(largervolumescanpenetratetotheunderside).Allowwaterto
of standard applied).
evaporate before analyzing. A decrease in filter transmittance
8.14 Metal punch, for removal of 1.5 cm filter portions.
during the first temperature step of the analysis indicates water
NOTE2—Asmallerportion(forexample,takenwithcorkborer)maybe
loss. Allow samples to dry longer if this occurs. About 20
used,buttheareamustbelargeenoughtoaccommodatethelaser(thatis,
minutesshouldbeadequate.Filterportionsalsocanbedriedin
beam should pass through the sample, not around it). The area of the
the sample oven. For quick drying, the “clean oven” command
portion must be accurately known, and the sample must be carefully
positioned (filter transmittance will decrease dramatically when the onthemenucanbeselectedandcanceledafterabout4seconds
sample is properly aligned). A filter portion ≥0.5 cm with diameter or
(time may depend on instrument). The oven temperatures
width ≤1 cm is recommended.
should not exceed 100°C to avoid boiling the solution.As the
8.15 Tweezers, to handle filters. sampleisheated,arapiddecreaseinfiltertransmittanceshould
occur if the sample is properly aligned in the laser beam. The
8.16 Volumetric flasks—ClassA(for preparation of sucrose
sample is dry when the transmittance reaches a constant. This
stock solutions).
drying approach is convenient and prevents potential adsorp-
8.17 Analytical balance.
tion of organic vapors in laboratory air.
10.3 Analyze blanks with each sample set. Instrument
blanks are based on analysis of freshly cleaned filter portions.
Highfiltrationefficiencyandfilterpurityareessentialtotheperformanceofthe
11. Quality Control
...