UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
OFFICE OF AIR QUALITY PLANNING AND STANDARDS
Technical Note -Pb Monitoring Implementation Strategy Analysis Method
Issues
BACKGROUND
On November 12, 2008 EPA substantially strengthened the national ambient air quality standards
(NAAQS) for lead (see 73 FR 66934). EPA revised the level of the primary (health-based) standard
from 1.5 micrograms per cubic meter (|ig/m3) to 0.15|ig/m3, measured as total suspended particles
(TSP) and revised the secondary (welfare-based) standard to be identical in all respects to the
primary standard. In conjunction with strengthening the lead (Pb) NAAQS, EPA identified the
need for states to improve existing lead monitoring networks by requiring monitors to be placed in
areas with sources that emit one ton per year (tpy) or more of lead and in urban areas with more
than 500,000 people. Depending on specific circumstances, States may have the option of using
monitoring for either lead in TSP (Pb-TSP) or lead in PMio (Pb-PMio) using approved Federal
Reference Methods (FRMs) or Federal Equivalent Methods (FEMs) to meet monitoring
requirements.1 This document provides guidance in the form of questions and answers related to
analyzing for Pb-TSP and Pb-PMio and analysis method issues as they relate to implementation of
Pb monitors in support of the strengthened primary standard for Pb.
1. What analysis methods can be used for the revised Pb-TSP NAAQS monitoring
requirements?
For required monitoring you may use the Atomic Absorption (AA) FRM described in 40 CFR 50
Appendix G or any of the 21 approved equivalent Pb methods on the list posted at
http://www.epa.gov/ttn/amtic/files/ambient/criteria/reference-equivalent-methods-list.pdf.
As noted in the November 12th Pb final rule, EPA maintained the current FRM and FEMs for Pb-
TSP sampling and analysis method for monitoring of the Pb NAAQS. No substantive changes were
made to the Pb-TSP method (73 FR 67020).
2. Is EPA planning any further revisions to existing or approved Pb-TSP methods?
EPA recognizes that significant advances in measurement technology have been made since the
promulgation of Appendix G in 1978 and approval of the current Pb-TSP FEMs. Therefore, EPA
encourages the development of new FEMs using the revised part 53.33 requirements and also
intends to establish a new FRM through the rulemaking process (expected to begin late in 2009).
1 Refer to the Technical Note on network design for guidance regarding Pb-TSP and Pb-PM10 monitors in support of the
NAAQS; www.epa.gov/ttn/amtic/pb-monitoring.html
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3. Once a new Pb-TSP FRM is promulgated and new FEMs approved, can I continue to use
one of the 21 FEMs currently approved or must I switch to one of the new methods?
Once the new Pb-TSP FRM is promulgated in 40 CFR part 50, EPA intends to take the actions
specified in Part 53.16 paragraph (e). Appendix G will be revised and EPA will take the necessary
steps to address the use of existing FEMs moving forward. This may result in a future deadline to
stop using all or some currently approved FEMs. States should continue to use existing, approved
methods until such time as new methods are finalized and approved.
4. What is EPA doing to support the process for approval of new Pb-TSP FEMs?
EPA is taking action to expedite the process, including: (1) working with States to identify suitable
archived TSP filters that can be utilized for the evaluation of candidate methods; (2) engaging in
discussions with Regions, States, and contract laboratories to identify motivated partners for
development of universally-applicable FEM applications; and (3) development of a new FRM
through the rulemaking process.
5. What method is currently required as the reference method for approving new FEMs?
For Pb in TSP, the FRM in Appendix G (AA) must be used as the reference method to demonstrate
the approvability of new FEMs.
6.1 am collecting data with one of the current Pb-TSP FEMs. Since new FEMs have not yet
been approved, can my data be used to compare to the NAAQS?
As noted in Appendix R (73 FR 67055) of the rule, all valid FRM/FEM Pb-TSP data submitted to
AQS or otherwise available to EPA that meet the requirements of 40 CFR part 58 shall be used in
design value calculations. Pb-TSP data collected prior to January 1, 2009 will also be considered
valid for NAAQS comparisons if the sampling and analysis methods that were utilized to collect
those data were consistent with the provisions of 40 CFR Part 58 that were in effect at the time of
original sampling or that are in effect at the time of anttainment/nonattainment determination, and if
such data are submitted to AQS prior to September 1, 2009.
7.1 am using an existing approved FEM for Pb-TSP, should I submit a new FEM application
for Pb-TSP right away?
If you are using an approved FEM as written, you do not need to submit a new FEM application. If
you wish to submit a new FEM application, we are encouraging agencies to work together and with
their EPA Regions and OAQPS in a coordinated effort to submit applications for universally-
applicable FEMs that other agencies can use. We do not encourage individual monitoring agencies
to expend the resources and time necessary to develop and submit a new application when one of
the new "generic" FEMs that become approved by EPA/ORD may be used. If you are interested in
being part of this coordinated effort, please contact your regional EPA representative to express
interest.
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8. Will the collection of new field samples be needed for the preparation of new FEM
applications?
The FEM test requirements in Part 53.33 specify the analysis of field samples in the 0.045 to 0.375
|ig/m3 concentration range. Previously collected field samples in this range can be analyzed as long
as they are not more than one year old.
9. If the application for an FEM is approved for my method, can other laboratories use it as
an FEM?
Yes, we encourage those applicants submitting FEM applications to make the standard operating
procedures (SOPs) universally-applicable (or generic) and non-proprietary to allow EPA to post the
SOPs on our http://www.epa.gov/ttn/amtic/ web site for other labs to use.
10. How will the approved FEMs be distributed? Will there be a Federal Register notice?
Yes, there will be a Federal Register notice for approved FEMs. The list of designated Reference
and Equivalent Methods will be updated on the http://www.epa.gov/ttn/amtic/ website. The
approved, non-proprietary FEM SOPs will be posted on the EPA monitoring website at:
http ://www. epa. gov/ttn/amtic/pb-monitoring.html.
11. If my laboratory uses the Inorganic (IO) Compendium methods 3.1, "Selection,
Preparation and Extraction of Filter Material" and 3.5, "Determination of Metals in Ambient
Particulate Matter Using ICP/MS", would this be considered an FEM for Pb-TSP or Pb-
PM10?
At this time, neither compendium method has been approved as an FEM for Pb-TSP or Pb-PMio. A
new FEM application would need to be submitted and approved.
12. If an application for a new FEM is submitted, what information must be provided to EPA
for review?
For general application information, refer to 40 CFR Part 53.4. For the FEM test requirements,
please refer to 40 CFR Part 53.33 (Attachment to this document) and the flow chart in Figure 1.
This applies to new FEMs for both Pb-TSP and Pb-PMio. For additional questions or clarifications,
you may contact Surender Kaushik (kaushik. surender@epa. gov).
13. If an application for a new FEM is submitted, how long will it take for EPA review?
The required application review period is within 120 days after receipt, if the submitted information
is complete. A longer period of time may be required if EPA needs to request additional information
from the applicant.
14. Where do I submit my application for a new FEM?
Submit applications by mail to: Director, National Exposure Research Laboratory (MD-205-03), US
EPA, Research Triangle Park, NC 27711. Refer to Section 53.4 of 40 CFR for additional
information.
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15. What analysis methods can be used for the new Pb-PMi0 monitoring requirements?
For now, Pb-PMi0 must be analyzed by the FRM specified in 40 CFR Part 50, appendix Q
(EDXRF) or by an FEM designated in accordance with part 53.33. At the present time, no FEM
has yet been approved for Pb-PMi0. EPA is in the process of developing new FEMs for Pb-PMi0
using ICP-MS and ICP-AES/OES and expects to complete the application process by fall 2009.
16. Can I use the same FEM analysis methods approved for Pb-TSP for Pb-PMi0?
FEMs approved for Pb-TSP cannot be used for Pb in PMi0. The FRMs for Pb-TSP and Pb-PMi0 are
not the same, so separate demonstrations and applications are needed.
17. Can Pb-PMio data from National Air Toxics Trends Stations (NATTS) be used to meet
requirements for Pb monitoring under the new NAAQS?
In order for Pb-PMio data to be used, it must be collected with a low-volume (16.7 Lpm) PMi0c
sampler (see 40 CFR part 50 Appendix O) and analyzed by the XRF FRM (see 40 CFR part 50
Appendix Q). The Pb-PMio site must also be sited in accordance with the revised methodological
and network design requirements for Pb that are described in 40 CFR Part 58 Appendices C and D.
18. Will EPA provide a national laboratory contract for analysis of Pb-TSP and Pb-PMio
samples collected by state/local monitoring agencies?
EPA is not planning to organize large-scale laboratory support for routine Pb monitoring efforts at
the national level.
19. Are there other laboratory support options for Pb analysis that can be pursued
individually by monitoring agencies?
Monitoring agencies should be proactive in contacting their Regional offices regarding issues
related to Pb analysis. It may be possible for one state laboratory to do analysis for another state.
Some EPA Regional labs, or labs under contract to EPA Regional Offices, may be able to provide
occasional analysis of state/local filters, for example for quality assurance purposes. The PM2.5
speciation laboratory contract does not provide for the analysis of TSP filters (8x10 inch glass fiber
filters); however, Teflon PMio low-volume filters can be analyzed under this contract for 35
elements by XRF (the FRM for Pb-PMio) and multiple elements by ICP-MS (a likely FEM for Pb-
PMio). Due to the larger costs associated with the analysis of multiple elements, this contract
option should only be utilized for monitoring agencies leveraging multiple uses of the data (e.g.,
NATTS). In addition, there is at least one government General Services Administration (GSA)2
contract for laboratory analysis that does exist and line items are provided for single element
options for analysis by XRF, ICP-AES, and ICP-MS. State agencies may be able to get access to
these services through their EPA Regional Office, or the contract lab may be wiling to negotiate to
charge the GSA rates directly for state agencies. If a GSA schedule is used, monitoring agencies
using the GSA schedules must ensure that the contractor analyzes filters for Pb-TSP or Pb-PMio
using the approved FRM/FEM methods.
2 For example, see GSA contract GS-07F-5544R at
www.gsaadvantage.gov/ref_text/GS07F5544R/GS07F5544R_online.htm
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Attachment
53.33 Test Procedure for Methods for Lead (Pb).
(a) General. The reference method for Pb in TSP includes two parts, the reference method for high-
volume sampling of TSP as specified in 40 CFR 50, Appendix B and the analysis method for Pb in
TSP as specified in 40 CFR 50, Appendix G. Correspondingly, the reference method for Pb in
PMioincludes the reference method for low-volume sampling of PMioin 40 CFR 50, Appendix O
and the analysis method of Pb in PMio as specified in 40 CFR 50, Appendix Q. This section
explains the procedures for demonstrating the equivalence of either a candidate method for Pb in
TSP to the high-volume reference methods, or a candidate method for Pb in PMioto the low-volume
reference methods.
(1) Pb in TSP—A candidate method for Pb in TSP specifies reporting of Pb concentrations in terms
of standard temperature and pressure. Comparisons of candidate methods to the reference method in
40 CFR 50, Appendix G must be made in a consistent manner with regard to temperature and
pressure.
(2) Pb in PMio—A candidate method for Pb in PMiomust specify reporting of Pb concentrations in
terms of local conditions of temperature and pressure, which will be compared to similarly reported
concentrations from the reference method in 40 CFR 50 Appendix Q.
(b) Comparability. Comparability is shown for Pb methods when the differences between:
(1) Measurements made by a candidate method, and
(2) Measurements made by the reference method on simultaneously collected Pb samples (or the
same sample, if applicable), are less than or equal to the values specified in table C-3 of this
subpart.
(c) Test measurements. Test measurements may be made at any number of test sites. Augmentation
of pollutant concentrations is not permitted, hence an appropriate test site or sites must be selected
to provide Pb concentrations in the specified range.
(d) Collocated samplers. The ambient air intake points of all the candidate and reference method
collocated samplers shall be positioned at the same height above the ground level, and between 2
meters (1 meter for samplers with flow rates less than 200 liters per minute (L/min)) and 4 meters
apart. The samplers shall be oriented in a manner that will minimize spatial and wind directional
effects on sample collection.
(e) Sample collection. Collect simultaneous 24-hour samples of Pb at the test site or sites with both
the reference and candidate methods until at least 10 sample pairs have been obtained.
Revised June 2009 5
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(1) A candidate method for Pb in TSP which employs a sampler and sample collection procedure
that are identical to the sampler and sample collection procedure specified in the reference method
in 40 CFR part 50, Appendix B, but uses a different analytical procedure than specified in 40 CFR
Appendix G, may be tested by analyzing pairs of filter strips taken from a single TSP reference
sampler operated according to the procedures specified by that reference method.
(2) A candidate method for Pb in PMio which employs a sampler and sample collection procedure
that are identical to the sampler and sample collection procedure specified in the reference method
in 40 CFR part 50, Appendix O, but uses a different analytical procedure than specified in 40 CFR
Appendix Q, requires the use of two PMi0reference samplers because a single 46.2-mm filter from a
reference sampler may not be divided prior to analysis. It is possible to analyze a 46.2-mm filter
first with the non-destructive X-ray Fluorescence (XRF) FRM and subsequently extract the filter for
other analytical techniques. If the filter is subject to XRF with subsequent extraction for other
analyses, then a single PMi0 reference sampler may be used for sample collection.
(3) A candidate method for Pb in TSP or Pb in PMiowhich employs a direct reading (e.g.,
continuous or semi-continuous sampling) method that uses the same sampling inlet and flow rate as
the FRM and the same or different analytical procedure may be tested. The direct measurements are
then aggregated to 24-hour equivalent concentrations for comparison with the FRM. For
determining precision in section (k), two collocated direct reading devices must be used.
(f) Audit samples . Three audit samples must be obtained from the address given in §53.4(a). For Pb
in TSP collected by the high-volume sampling method, the audit samples are3/4x 8-inch glass fiber
strips containing known amounts of Pb in micrograms per strip (jig/strip) equivalent to the
following nominal percentages of the National Ambient Air Quality Standard (NAAQS): 30%,
100%, and 250%. For Pb in PMi0collected by the low-volume sampling method, the audit samples
are 46.2-mm polytetrafluorethylene (PTFE) filters containing known amounts of Pb in micrograms
per filter (ng/filter) equivalent to the same percentages of the NAAQS: 30%, 100%, and 250%. The
true amount of Pb (Tqi), in total jig/strip (for TSP) or total jig/filter (for PMio), will be provided for
each audit sample.
(g) Filter analysis .
(1) For both the reference method samples (e) and the audit samples (f), analyze each filter or filter
extract three times in accordance with the reference method analytical procedure. This applies to
both the Pb in TSP and Pb in PMi0methods. The analysis of replicates should not be performed
sequentially, i.e., a single sample should not be analyzed three times in sequence. Calculate the
indicated Pb concentrations for the reference method samples in micrograms per cubic meter
(|ig/m3) for each analysis of each filter. Calculate the indicated total Pb amount for the audit
samples in jig/strip for each analysis of each strip or jig/filter for each analysis of each audit filter.
Label these test results as RIA, RIB, RIC, R2A, R2B, etc., QIA, QIB, QIC, etc., where R denotes results
from the reference method samples; Q denotes results from the audit samples; 1, 2, 3 indicate the
filter number, and A, B, C indicate the first, second, and third analysis of each filter, respectively.
Revised June 2009
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(2) For the candidate method samples, analyze each sample filter or filter extract three times and
calculate, in accordance with the candidate method, the indicated Pb concentration in |ig/m3 for
each analysis of each filter. The analysis of replicates should not be performed sequentially. Label
these test results as CIA, CIB, C2C, etc., where C denotes results from the candidate method. For
candidate methods which provide a direct reading or measurement of Pb concentrations without a
separable procedure, CIA=CIB=CIC, C2A=C2B=C2c, etc.
(h) Average Pb concentration . For the reference method, calculate the average Pb concentration for
each filter by averaging the concentrations calculated from the three analyses as described in (g)(l)
using equation 1 of this section:
Equation 1
Where, i is the filter number.
(i) Analytical Bias.
(1) For the audit samples, calculate the average Pb concentration for each strip or filter analyzed by
the reference method by averaging the concentrations calculated from the three analyses as
described in (g)(l) using equation 2 of this section:
Equation 2
Where, i is audit sample number.
(2) Calculate the percent difference (Dq) between the average Pb concentration for each audit
sample and the true Pb concentration (Tq) using equation 3 of this section:
Equation3
D = ±!^ - 1 x 100
f j
if
(3) If any difference value (Dqi) exceeds ±5 percent, the bias of the reference method analytical
procedure is out-of-control. Corrective action must be taken to determine the source of the error(s)
(e.g., calibration standard discrepancies, extraction problems, etc.) and the reference method and
audit sample determinations must be repeated according to paragraph (g) of this section, or the
entire test procedure (starting with paragraph (e) of this section) must be repeated.
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(j) Acceptable filter pairs. Disregard all filter pairs for which the Pb concentration, as determined in
paragraph (h) of this section by the average of the three reference method determinations, falls
outside the range of 30% to 250% of the Pb NAAQS level in |ig/m3 for Pb in both TSP and PMi0.
All remaining filter pairs must be subjected to the tests for precision and comparability in
paragraphs (k) and (1) of this section. At least five filter pairs must be within the specified
concentration range for the tests to be valid.
(k) Test for precision.
(1) Calculate the precision (P) of the analysis (in percent) for each filter and for each method, as the
maximum minus the minimum divided by the average of the three concentration values, using
equation 4 or equation 5 of this section:
Equation 4
p _ p
p = '"** _ iis. x i oo
or
Equation 5
p - Cjina, ~ l-imiii x j gg
n ~
U4tpe
Where, i indicates the filter number.
(2) If a direct reading candidate method is tested, the precision is determined from collocated
devices using equation 5 above.
(3) If any reference method precision value (PR;) exceeds 15 percent, the precision of the reference
method analytical procedure is out-of-control. Corrective action must be taken to determine the
source(s) of imprecision, and the reference method determinations must be repeated according to
paragraph (g) of this section, or the entire test procedure (starting with paragraph (e) of this section)
must be repeated.
(4) If any candidate method precision value (Pci) exceeds 15 percent, the candidate method fails the
precision test.
(5) The candidate method passes this test if all precision values ( i.e. , all PR;'S and all Pa's) are less
than 15 percent.
(1) Test for comparability.
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(1) For each filter or analytical sample pair, calculate all nine possible percent differences (D)
between the reference and candidate methods, using all nine possible combinations of the three
determinations (A, B, and C) for each method using equation 6 of this section:
Equation 6
CM ~~ *W
Where, i is the filter number, and n numbers from 1 to 9 for the nine possible difference
combinations for the three determinations for each method (j = A, B, C, candidate; k = A, B, C,
reference).
(2) If none of the percent differences (D) exceeds ±20 percent, the candidate method passes the test
for comparability.
(3) If one or more of the percent differences (D) exceed ±20 percent, the candidate method fails the
test for comparability.
(4) The candidate method must pass both the precision test (paragraph (k) of this section) and the
comparability test (paragraph (1) of this section) to qualify for designation as an equivalent method.
(m) Method Detection Limit (MDL). Calculate the estimated MDL using the guidance provided in
40 CFR, Part 136 Appendix B. It is essential that all sample processing steps of the analytical
method be included in the determination of the method detection limit. Take a minimum of seven
blank filters from each lot to be used and calculate the detection limit by processing each through
the entire candidate analytical method. Make all computations according to the defined method with
the final results in |ig/m3 . The MDL of the candidate method must be equal to, or less than 5% of
the level of the Pb NAAQS.
Table C-3 to Subpart C of Part 53— Test Specifications for Pb in TSP and Pb in PM10 Methods
Concentration range equivalent to percentage of NAAQS in (ig/m3
Minimum number of 24-hr measurements
Maximum reference method analytical bias, Dq
Maximum precision, Pr or PC
Maximum difference (D)
Estimated Method Detection Limit (MDL), (ig/m3
30% to 250%
5
±5%
<15%
±20 %
5% of NAAQS level
73 FR 67057, Nov. 12, 2008]
Revised June 2009
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FEM application process for methods used by Monitoring
Organizations for NAAQS
Reference Method
Flame AAFRL-001
1) Audit Samples
(53.33 f)
(3 Strips - triplicate analysis)
2) Precision & Comparability
(53.33/cS/)
1 strip (triplicate analysis) x 5 filters
(15 values)
c
Pb
Audit
Strips
(3 Strips)
Candidate FEM
3) Precision & Comparability
(53.33 k &!)
1 strip (triplicate analysis) x 5 filters
(15 values)
Reference/Candidate
Method Samples (53.33 j)
TSP Filters 0.045 - 0.375 ug/m3
4) MDL from Blanks
(53.33 m)
(7 Strips)
EPA/ORD
Approval
EPA/ORD
Evaluation
"Generic" FEM
application
Figure 1. Flow Chart for FEM process
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