United States
Environmental Protection
Agency
Atmospheric Research and
Exposure Assessment Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S3-89/023 Sept. 1989
f/EPA Project Summary
Annual Report on Performance
Audit Results for POHC Testing
During RCRA Trial Burns
R. K. M. Jayanty, S. B. Tompkins, and G. B. Howe
Audit material containing Principal
Organic Hazardous Constituents
(POHCs) have been developed by the
U.S. Environmental Protection Agency
(EPA) for use by federal, state, and
local agencies or their contractors to
assess the accuracy of measurement
methods during RCRA trial burn
tests. Audit materials are currently
available for 27 gaseous organics in
five, six, seven and nine component
mixtures at parts-per-billion levels (7
to 10,000 ppb) in compressed gas
cylinders in a balance gas of
nitrogen. The criteria used for the
selection of 28 gaseous organic
compounds is described.
Stability studies indicate that all of
the organics tested (with the excep-
tion of ethylene oxide and propylene
oxide below 10 ppb levels) are stable
enough to be used as reliable audit
materials.
Subsequent to completion of the
stability studies, 129 performance
audits have been conducted with the
audit materials to assess the accu-
racy of the Volatile Organic Sampling
Train (VOST) and bag measurement
methods during or prior to RCRA trial
burn tests. The results of those
audits and a summary table of the
audits conducted for each POHC and
the measurement system audited is
described in this report. The audit
results obtained with the audit gases
during or prior to RCRA trial burn
tests are generally within ±50 per-
cent of the audit concentrations
measured by Research Triangle
Institute.
This Project Summary was devel-
oped by EPA's Atmospheric Research
and Exposure Assessment Laboratory,
Research Triangle Park, NC, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The determination of POHC at trace
levels (<50 ppb levels) during hazardous
waste trial burn tests requires
sophisticated sampling and analysis sys-
tems. Agency personnel responsible for
trial burn tests need to be concerned
about the accuracy of POHC measure-
ments. Accuracy of such measurements
may be assessed by conducting a
performance audit. A performance audit
is a quantitative assessment of the accu-
racy of a measurement system. When a
performance audit is conducted during or
prior to a hazardous waste trial burn test,
it provides an assessment of the meas-
urement accuracy and indicates the
presence of any bias for the combined
sampling and analysis system.
The Quality Assurance Division of US
EPA's Atmospheric Research and Expo-
sure Assessment Laboratory has initiated
a program to supply audit materials for
use during hazardous waste trial burn
tests. The Research Triangle Institute
(RTI), under contract with US EPA, is the
principal organization for development of
audit gases and coordinating subsequent
audits using these gases. The main
objectives of this program are: (1) to
evaluate the quality of measurements
made by federal/state/local agencies, or
their contractors, by using ppb gas
cylinders for performance audits to
assess the relative accuracy of source
measurement systems during hazardous
waste trial burn tests; (2) to verify the
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manufacturer's certified analysis of the
multicomponent gas mixtures; (3) to
determine the stability of the gas
mixtures over time; and (4) to develop
new audit materials as requested by
EPA.
Currently, 28 gaseous compounds
selected on the basis of the anticipated
needs of US EPA's Office of Solid Waste
and Office of Air Quality Planning and
Standards have been investigated for
suitability as audit materials. Table 1 lists
the 28 organic compounds and the
concentration ranges currently available
in the ppb level cylinder gases. The
balance gas for all gas mixtures is
nitrogen and the cylinder construction
material is aluminum. A summary of the
performance audits conducted during or
prior to RCRA trial burn tests has been
described in this paper.
Criteria Used for Selection of
Organic Compounds
In I983, EPA initiated a program to
develop ppb cylinder gas standards con-
taining hazardous organic compounds
that could be used to audit volatile POHC
measurement systems during trial burn
tests. Through 1985, three mixtures of
ppb cylinder gases were developed
which are shown in Table 1. The criteria
used by EPA for selecting various
organic compounds in the three mixtures
(Group's I, II and III) are described in a
separate publication1. On the basis of the
experience of EPA's Air and Energy
Engineering Research Laboratory
(AEERL) with RCRA trial burn testing,
five, nine, and seven compound gas
standards were developed during 1983 to
1985. Several compounds were included
Table 1. Auditing POHC Measurements"
Group II
Group 1 Compounds Compounds
Group III
Compounds
Group IV
Compounds
Carbon tetrachloride Trichloroethylene
Chloroform i ,2-dichloroethane
Perchloroethylene 1,2-dibromoethane
Vinyl Chloride
Benzene
Acetonitrile
Trichloro-
flouromethane
(F-11)
Dichloro-
diflouromethane
(F-12)
Bromomethane
Vinylidene chloride
1,1,2-tnchloro-
1,2,2-tnflouro-ethane
(F-113)
1,2-dichloro-
1,1,2,2-tetra-
flouroethane
(F-114)
Acetone
1,4-Dioxane
Chlorobenzene
Toluene
Acrylomtrile
1,3-Butadiene
Ethylene oxide"
Methylene chloride
Propylene oxide""
Ortho-xytene
Methyl ethyl ketone Pyndine"
1,1,1 -trichloro-ethane
Group I Ranges
7 to 90 ppb
90 to 430 ppb
430 to 10,000 ppb
Group II Ranges
7 to 90 ppb
90 to 430 ppb
Group III Ranges
7 to 90 ppb
90 to 430 ppb
Group IV Ranges
7 to 90 ppb
430 to 10,000 ppb
'All gas standards are in a balance gas of nitrogen.
The concentration of pyridine is not certified due to severe analytical difficulties.
"" The concentration of this compound in the 7 to 90 ppb range cylinders is not certified due to
stability problems.
in the same cylinder with the idea the
the same gas cylinders could be used t
audit more than one POHC during trie
burn tests.
In 1986, a six-compound Group IV ga
standard was developed, The selection c
the six organic compounds for Group I'
was based on EPA health ris
assessment studies plus input from
state agency. The compounds include
in Group IV are also shown in Table 1.
Selection of Compound
Concentrations for Audit
Materials
The gas standards were initially deve
oped at two concentration ranges to aud
the two prevalent test methods for volatil
POHCs. The 7 to 90 ppb and 90 to 43
ppb concentration ranges were selecte
for the Groups I, II, III and IV gas stanc
ards to audit POHC measurement
during RCRA trial burn tests; the (owe
range standard is used to audit VOS1
measurements, and the higher ga:
standard is used to audit bag sampling
measurements. Later, Group I and l\
standards in the 430 to 10,000 ppl
concentration range were added. Thes<
standards were added because th<
RCRA regulation requires a Destructioi
and Removal Efficiency (ORE) of at leas
99.99 percent but does not regulate <
maximum emission rate for the POHCs
Therefore, some source testers hav<
received approval to conduct the tria
burn test in such a manner that POHC
concentrations in stack emissions arc
about 1000 ppb. Trial burn tests of thii
higher concentration (i.e., 1000 ppb
reduces considerably the effect o
atmospheric POHC contamination on th<
VOST measurement system, compare*
to trial burn test where the POHC stacl
emissions are on the order of 10 to 51
ppb concentrations.
Performance Audit Procedure
As stated previously, the EPA (througl
RTI) supplies cylinder gases containini
selected POHCs for audit upon reques
from federal, state, or local agencies o
their contractors. The contractors must
however, be performing hazardous wast
trial burn tests on behalf of EPA or on<
of these other agencies to qualify for th<
performance audit. In fact, the VOS'
method described in the EPA manua
SW-846 specifically requires an audi
during the trial burn2. A performano
audit must be conducted simultaneous!
with the actual planned test. A pei
formance audit prior to a trial burn test t
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ssess the proficiency of the measure-
ent system (including the sampling and
analytical personnel) is recommended
but not required.
When a request is received, the
cylinder pressures are measured and the
cylinders are shipped by overland carrier.
When a cylinder gas is used to audit the
VOST system for a trial burn test, an
aluminum suitcase is also sent. The
aluminum suitcase contains a gas regu-
lator, glass manifold with heating tape,
and necessary tubing and fittings to draw
the cylinder gas sample into the glass
manifold. The audit gas is then drawn at
atmospheric pressure from the manifold
into the VOST system. A letter is
included with the audit cylinder which
gives general instructions for conducting
the audit. The audit results are reported
to the agency (federal, state, or local)
coordinator requesting the audit. There is
no charge to the user except the cost of
returning the audit cylinder and aluminum
suitcase.
Performance Audit Results and
Discussion
As of September, 1988, 268 perform-
ance audits have been initiated using ppb
audit gases. Of these 268 ppb audits, 129
audits have been initiated to assess the
accuracy of measurement methods
(VOST or bag for sampling and GC/MS
or GC with specific detector for analysis)
during or prior to hazardous waste trial
burn tests. Of the 129 RCRA audits, 122
are complete and the results are sum-
marized in this report. For the 122
completed audits, the frequency each
compound was selected for audits is
shown. The frequency of audits con-
ducted at RCRA trial burn tests on a
quarter/calendar year basis since 1984, is
shown in Figure 1. It appears from Figure
1 that the frequency of audits has
increased since October 1986, due to the
mandatory audit requirement included in
the VOST method published in SW 8462.
Seven of the 26 compounds have been
found to be more popular for perform-
ance audits. These seven compounds
are: carbon tetrachloride, chloroform, per-
chloroethylene, vinyl chloride, trichloro-
ethylene, benzene, and toluene. Of the
122 audits completed, 100 are by the
VOST method, 14 with Tedlar bags, 1 with
glass bulbs, 6 by direct injection, and 1
audit is unknown. The majority of the
audits employed GC/MS for analysis and
only a few used GC with a specific
detector, It is very interesting to note that
the auditee results for the VOST method
are usually within the ± 50 percent
accuracy limit stated in the VOST
protocol.
Stability Studies
An ideal calibration standard or audit
material should be stable over its total
time of usage. Such standards or mate-
rials may be considered stable if the
results of reanalyses over time fall within
the 95% confidence limits of the com-
bined uncertainty for the preparation and
analysis of the analyte concentrations.
To ensure that the concentration of
each standard is periodically analyzed for
stability, a two-tier stability assessment is
conducted. In the first tier, on each
standard, the commercial gas manufac-
turer conducts a minimum of two anal-
yses that are separated by at least 30
days. These analyses were performed to
verify that the components in the cylinder
were stable at the manufacturing facility
before shipment to RTI. The second tier
stability assessment involves the periodic
reanalysis at RTI. Once a gas standard is
received from the gas manufacturer, it is
Number
of
Audits
15-
14 —
13 —
12-
11 —
10-
9 —
7 —
s
2-
0 —
; 2
3 4
1984
1
2
3
*!
4
1985
/
Ma
ludil
ndatory
1
1234
1986
1234
1987
1234
1988
Quarter/Calendar Year Audit Initialed
Figure 1. Audits conducted in RCRA trial burns.
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analyzed as soon as possible, then
reanalyzed at 2, 6, and 12 months and
annually thereafter to determine any
change in the gas mixtures. All analyses
are performed by gas chromatography
(GC) with flame ionization (FID) and/or
electron capture detector (ECD), The
analysis procedures and the stability
data obtained to date for all of the ppb
level organic cylinder gases are sum-
marized and published in the project
report3. An examination of the stability
data for many of the organics in the ppb
level cylinder gases show the results
varied by less than 10 percent over a
one to five year period. A gas standard
is not available for auditing purposes
until the 2-month RTI analysis is com-
pleted. If the compounds are not stable
during that period, those compounds are
not recommended for audits. It appears
from the long term stability study, that
all the organics tested (with the
exception of ethylene oxide and propy-
lene oxide at 10 ppb level) are stable
enough to be used as reliable audit
materials.
Summary and Conclusions References
Compressed gas cylinders containing 1.
27 gaseous volatile organic compounds
at ppb levels have been used success-
fully in audits to assess the accuracy of
measurement systems, especially those
used during hazardous waste trial burn
tests. The 28 gaseous volatile organic
compounds were selected on the basis
of the anticipated needs of EPA's Office 2.
of Solid Waste and Office of Air Quality
Planning and Standards.
Stability studies indicate that all of the
organic compounds tested (with the
exception of ethylene oxide and pro-
pylene oxide at the 10 ppb level) are
stable enough to be used as reliable
audit materials. One hundred twenty-
nine performance audits have been 3.
initiated (through September 1988) to
assess the accuracy of POHC measure-
ment systems used during hazardous
waste trial burn tests. Audit results have
generally been wtthin ± 50 percent of
the RTI measured concentrations.
D. J. von Lehmden, "Program Stra-
tegies for Standards Development
for Hazardous Waste Incineration",
presented at the ASTM Conference
on Recent Developments in Monit-
oring Methods for Toxics in the
Atmosphere, July 27-31, 1987,
Boulder, Colorado.
Volatile Organic Sampling Train,
Method 0030, SW-846 Manual (Test
Methods for Evaluating Solid Waste,
Physical/Chemical Methods), 3rd
Edition, available from the Superin-
tendent of Documents, U.S. Govern-
ment Printing Office, Washington,
DC 20402, Document Number 955-
001-00000-1.
V. R. Bryant, G. B. Howe, S. B.
Tompkins, and R. K. M. Jayanty,
"Stability of Parts-Per-Billion Haz-
ardous Organic Cylinder Gases and
Performance Audit Results of
Source Test and Ambient Air Meas-
urement Systems" Status Report #5,
Research Triangle Institute, October,
1988.
R. K. M. Jayanty, S. B. Tompkins, and G. B. Howe are with Research Triangle
Institute, Research Triangle Park, NC 27709.
D. J. von Lehmden is the EPA Project Officer (see below).
The complete report, entitled "Annual Report on Performance Audit Results for
POHC Testing During RCRA Trial Burns ," (Order No. PB 89-161 970/AS; Cost:
$15.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Atmospheric Research and Exposure Assessment Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S3-89/023
000085833 *|«c«0» M'*1
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