Performance-Based Test Method/Lab Qualification

EPA420-B-05-015

Guidance and Form Instructions to

Parties Submitting Diesel Sulfur

Accuracy and Precision Information for

Approval of Test Methods by Facility

May 11, 2005

(minor revisions: September 22, 2005)

Transportation and Regional Programs Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency

OMB Control Number: 2060-0566
Expiration Date: September 30, 2005

Disclaimer
The discussion in this document is intended solely as guidance. The statutory provisions and EPA
regulations described in this document contain legally binding requirements. This document is not a
regulation itself, nor does it change or substitute for those provisions and regulations. Thus, it does not
impose legally binding requirements on EPA, States, or the regulated community. This guidance does not
confer legal rights or impose legal obligations upon any member of the public.
While EPA has made every effort to ensure the accuracy of the discussion in this guidance, the obligations
of the regulated community are determined by statutes, regulations, or other legally binding requirements.
In the event of a conflict between the discussion in this document and any statute or regulation, this
document would not be controlling.
The general description of the application process provided here may not apply to a particular situation.
Interested parties are free to raise questions about the substance of this guidance and its applicability to a
particular situation. EPA may adopt approaches on a case-by-case basis that differ from those described
in this guidance.
Mention of trade names or commercial products does not constitute endorsement or recommendation for
their use.
This is a living document and may be revised periodically without public notice. EPA welcomes public
input on this document at any time.

Introduction: On May, 2004, EPA promulgated new requirements for non-road diesel fuel. One of the
provisions of this final rule, explained in Subpart I of 40 CFR Part 80, requires that each test facility must
meet specified accuracy and precision criteria with their chosen test method for sulfur in on-road or nonroad diesel fuel additives and/or diesel fuel. Evidence of having met these requirements must be
submitted to and approved by the Agency before using the method to make measurements for
demonstrating compliance. There are separate accuracy and precision criteria for diesel fuels and
additives subject to the two sulfur standards --15 ppm and 500 ppm.
Depending on your test facility situation, you may be required just to meet the 15 ppm diesel sulfur
accuracy and precision criteria, you may choose to meet the 500 ppm diesel sulfur accuracy and precision
criteria, or may be required to meet both of these accuracy and precision criteria. For diesel fuel at the
500 ppm sulfur level, if your test facility has chosen to use the designated test method, ASTM D 2622-03,
or any of the following alternative test methods, ASTM D 4294-03, ASTM D 5453-03a, or ASTM D 3120
03a with correlation to the designated test method, it is not necessary for your test facility to qualify these
methods for precision or accuracy.
40 CFR § 80.520(a)(1) explains the 15 ppm sulfur standard for motor vehicle diesel fuel and fuel additives.
40CFR § 80.510(b)(1)(i) and § 80.510(c) explains the 15 ppm sulfur standard for Non-road Locomotive
Marine(NRLM) diesel fuel and fuel additives. 40 CFR § 80.520(c) explains the 500 ppm sulfur standard
for motor vehicle diesel fuel. 40 CFR § 80.510(a) explains the 500 ppm sulfur standard for NRLM diesel
fuel. 40 CFR § 80.584 explains the actual accuracy and precision criteria for the applicable standards
above. 40 CFR § 80.585 explains both the requirement that the criteria must be met on a facility-specific
basis and a description of the process by which methods may be approved. The following guidance
applies to any party applying to EPA for such approval of their test method at their testing facility. This
guidance deals only with the approval of test methods at a testing facility for measuring sulfur in diesel fuel
additives or sulfur in diesel fuel.
The discussions of the applicable regulations in this document are not verbatim. The reader is
encouraged to read and become familiar with the applicable regulations of Subpart I of 40 CFR Part 80.
These instructions are intended to help a test facility qualify a method for the measurement of sulfur in
diesel motor fuel or diesel motor fuel additives, as well as, to help facilitate the timely review and approval
of each test facility’s method.
Applicable Dates: These requirements for method qualification under § 80.585 become effective on
December 27, 2004.
Note: Please see Part I for instructions on use of a spreadsheet template provided by the Agency for
determining compliance with the accuracy and precision criteria of § 80.584. We encourage parties to use
this spreadsheet to structure their development of the information and data needed for a method
qualification application and to submit it to the Agency in order to expedite the review and approval
process. Please see Part II for submission instructions.

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Part I - Instructions for use of spreadsheet for evaluating method precision and accuracy.
I.

Precision demonstration for motor vehicle diesel fuel and diesel fuel additives subject to
the 15 ppm sulfur standard.

Precision Criteria, § 80.584(a)(1) - a standard deviation less than 0.72 ppm, computed from the results of
a minimum of 20 repeat tests made over 20 days on samples taken from a single homogeneous
commercially available diesel fuel with a sulfur content in the range of 5-15 ppm. The 20 results must be a
series of tests with a sequential record of analyses and no omissions.1
A.

In the workbook entitled “Sulfur Test Method Template”, locate the worksheet entitled, “15 ppm S
Precision”. Enter data in the light shaded green areas of the worksheet. For an example of the
“15 ppm S Precision” worksheet with data completely entered, please see the worksheet entitled,
“EX - 15 ppm S Precision”.
Notes:
1.
Test results must be reported in parts per million (ppm) to the number of significant digits
specified in the method description or, if no such precision is indicated, to as many digits
to the right of the decimal point as appear on the instrument readout up to three.
2.
The date and time of each test measurement must be reported.
3.
Please include the laboratory test identification number for each test result.

B.

After entering the data into the light shaded green area of the “15 ppm S Precision” worksheet, go
to the “File” menu at the top of the screen and select “Save” to save your data. Once all the data
are entered into the “15 ppm S Precision” worksheet, the standard deviation of the data set
(located in cell B18), and an indication as to whether the 15 ppm sulfur precision criterion are met
will be determined by the worksheet. The indication of “PASSED” or “FAILED” is located in cell
B17 in the worksheet, after the question, “Is 15 ppm Sulfur Precision Criterion Met?”. If the
worksheet is missing required data, an indication of “REQUIRED DATA MISSING” will appear
after this question. There is a QC data entry check for each test result in column E (i.e., if data is
entered in a test result cell, an indication of “OK” will appear next to that cell, but if no data is
entered in a test result cell, an indication of “DATA REQUIRED IN CELL #” will appear next to that
cell). Note: If the applicant wishes to include more than the 20 minimum tests, please report the
additional data by adding rows to the spreadsheet.2

1

A laboratory may exclude a given sample or test result only if the exclusion is for a valid reason
under good laboratory practices and it maintains records regarding the sample and test results and the
reason for excluding them.
2

Additional rows may be inserted to accommodate the extra data points. If these rows are added
in the middle (say around row 25), the equations that analyze the data will be automatically adjusted. If
difficulties are encountered in doing this, please call for help.

2

II.

Accuracy demonstration for motor vehicle diesel fuel and diesel fuel additives subject to
the 15 ppm sulfur standard.

Accuracy Criterion -

1.

The arithmetic average of a continuous series of at least 10 tests
performed on a commercially available gravimetric sulfur standard
(CAGSS) in the range of 1-10 ppm sulfur shall not differ from the
accepted reference value of that standard by more than 0.54 ppm sulfur.3

2.

The arithmetic average of a continuous series of at least 10 tests
performed on a CAGSS in the range of 10-20 ppm sulfur shall not differ
from the accepted reference value of that standard by more than 0.54
ppm sulfur.4

A.

Locate the worksheet entitled, “15 ppm S Accuracy”. Enter data in the light shaded green areas of
the worksheet. For an example of the “15 ppm S Accuracy” worksheet with data completely
entered, please see the worksheet entitled, “EX - 15 ppm S Accuracy”.
Notes:
1.
Test results must be reported in parts per million (ppm) to the number of digits specified in
the method description or, if no such precision is indicated, to as many digits to the right of
the decimal point as appear on the instrument readout up to three.
2.
It is recommended that the date and time of each test measurement be reported.
3.
Please include the laboratory test identification number for each test result.
4.
In the appropriate rows, enter the “Vendor Name of Gravimetric Standard”, “Lot
Identification Number of Gravimetric Standard”, and “Accepted Reference Value of the
Gravimetric Standard (ppm)” in parts per million for both the 1-10 ppm and 10-20 ppm
sulfur gravimetric standards.
5.
Since the Test Method and Laboratory Identification information for this demonstration are
the same as the Test Method and Laboratory Identification information in the “15 ppm S
precision” worksheet, for your convenience, this information is automatically referenced
from the “15 ppm S Precision” worksheet.

B.

After entering the data into the light shaded green area of the worksheet as described above, go
to the “File” menu at the top of the screen and select “Save” to save all of the entered data. Once
all data are entered into the “15 ppm S Accuracy” worksheet, this worksheet will calculate the
arithmetic average for both the 1-10 ppm sulfur data set (located in cell B20) and the 10-20 ppm
sulfur data set (located in cell I20). This worksheet will also calculate the difference between the
arithmetic average of the data set and the accepted reference value of each respective
gravimetric standard (located in cell B24 for the 1-10 ppm accuracy demonstration & located in
cell I24 for the 10-20 ppm accuracy demonstration). This worksheet will indicate whether the 15
ppm sulfur accuracy criteria are met for the candidate test method by saying “PASSED” or
“FAILED” in the cell after the questions, “Is 1-10 ppm Sulfur Accuracy Criterion Met?” (located in
cell B19) and “Is 10-20 ppm Sulfur Accuracy Criterion Met?” (located in cell I19). Both of these
accuracy criteria must be met in order for the test method to be considered to have met the 15
ppm accuracy criteria. If the worksheet is missing required data, an indication of “REQUIRED
DATA MISSING” will appear after the applicable question. There is a QC data entry check for
each test result in column E and column L (i.e., if data is entered in a test result cell, an indication
of “OK” will appear next to that cell, but if no data is entered in a test result cell, an indication of
“DATA REQUIRED IN CELL #” will appear next to that cell). There is also a QC data entry check

3

Individual test results shall be compensated for any known chemical interferences.

4

Individual test results shall be compensated for any known chemical interferences.

3

on the concentration of the gravimetric standard in cell E23 and cell L23 (i.e., for either the 1 to 10
ppm sulfur accuracy demonstration or 10 to 20 ppm sulfur accuracy demonstration, if the
concentration of gravimetric standard falls within the applicable concentration range, an indication
of “OK” will appear in the respective cell, if the concentration of the gravimetric standard falls
below the applicable concentration range, an indication of “ARV TOO LOW IN
CONCENTRATION” will appear in the respective cell, if the concentration of the gravimetric
standard is above the applicable concentration range, an indication of “ARV TOO HIGH IN
CONCENTRATION” will appear in the respective cell). Note: If the applicant wishes to include
more than the 10 minimum tests, please report the additional data by inserting rows into the
spreadsheet.5
III.

Precision demonstration for motor vehicle diesel fuel subject to the 500 ppm sulfur
standard.

Precision Criterion, § 80.584(a)(2) - a standard deviation less than 9.68 ppm, computed from the results
of a minimum of 20 repeat tests made over 20 days on samples taken from a single homogeneous
commercially available diesel fuel (SHCADF) with a sulfur content in the range of 200-500 ppm. The 20
results must be a series of tests with a sequential record of analyses and no omissions.6
A.

Locate the worksheet entitled, “500 ppm S Precision”. Follow the instructions for Section I above,
but enter the data for the 500ppm precision demonstration rather than that for the 15ppm
demonstration. For an example of the “500 ppm S Precision” worksheet with data completely
entered, please see the worksheet entitled, “EX - 500 ppm S Precision”.

5

Additional rows may be inserted to accommodate the extra data points. If these rows are
inserted in the middle of the range (say after row 30) the equations for the average and other functions will
be automatically adjusted. Extra rows inserted for one of the two standard levels, while appearing in the
range for the other standard level, will not affect the calculations for the level where no data were added.
6

A laboratory may exclude a given sample or test result only if the exclusion is for a valid reason
under good laboratory practices and it maintains records regarding the sample and test results and the
reason for excluding them.

4

IV.

Accuracy demonstration for motor vehicle diesel fuel subject to the 500 ppm sulfur
standard.

Accuracy Criterion -

A.

1.

The arithmetic average of a continuous series of at least 10 tests
performed on a commercially available gravimetric sulfur standard
(CAGSS) in the range of 100-200 ppm sulfur shall not differ from the
accepted reference value of that standard by more than 7.26 ppm sulfur.7

2.

The arithmetic average of a continuous series of at least 10 tests
performed on a CAGSS in the range of 400-500 ppm sulfur shall not
differ from the accepted reference value of that standard by more than
7.26 ppm sulfur.8

Locate the worksheet entitled, “500 ppm S Accuracy”. Follow the instructions for section II above,
but enter the data for the 500ppm accuracy demonstration rather than that for the 15ppm
demonstration. For an example of the “500 ppm S Accuracy” worksheet with data completely
entered, please see the worksheet entitled, “EX - 500 ppm S Accuracy”.

7

Individual test results shall be compensated for any known chemical interferences.

8

Individual test results shall be compensated for any known chemical interferences.

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PART II - Instructions for submission of Accuracy and Precision data to Agency for Approval
I.

For each test facility that wishes to have a test method approved, the following information
must be submitted to the Agency for approval:

A.

40 CFR 80.585(a). For methods that are approved by a voluntary consensus-based organization
standards body (VCSB), such as the American Society for Testing and Materials (ASTM) or
International Standards Organization (ISO), each individual test facility must submit the
information for accuracy and precision criteria specified under § 80.584 (Please use instructions in
Part I of this guidance). The approval of the test method is limited to the single test facility that
performed the testing for accuracy and precision. The individual facility must submit the accuracy
and precision results for each method, including information on the date and time of each test
measurement to demonstrate precision, following procedures established by the Administrator.

B.

40 CFR 80.585(b). For methods that are not approved by a VCSB, for such a method to be
approved, the following information must be submitted to the Administrator by each test facility for
each test method that it wishes to have approved:
1.
2.
3.
4.

Full test method documentation, including a description of the technology and/or
instrumentation that makes the method functional.
Information demonstrating that the test method meets the applicable accuracy and
precision criteria of § 80.584, including information on the date and time of each test
measurement to demonstrate precision (Please use instructions in Part I of this guidance).
If requested by EPA, test results from use of the test method to analyze samples of
commercially available fuel provided by EPA.
Any additional information requested by the Administrator and considered necessary for
deciding whether to approve the test method.

C.

40 CFR 80.585(c). Sample Retention. Samples used for precision and accuracy determination
must be retained for 90 days.

D.

Confidential Business Information Claim. You may claim the information you submit as
confidential business information (CBI) by clearly marking your submission. Please be sure to
indicate your CBI claim where asked on the spreadsheet and clearly indicate that your submission
contains information claimed as CBI in your cover letter. If no such written claim is made, then the
information you submit may be made available to the public by EPA without further notice. EPA’s
regulations regarding CBI are at 40 CFR Part 2.

E.

Please send one paper hard copy of your applicable information described above that includes a
cover memo with your signature, along with a 3.5 inch floppy disk or compact disk containing the
accuracy and precision data in the spreadsheet described above by overnight mail or courier
service to the address below.
Joe Sopata, Chemist

United States Environmental Protection Agency

Fuels Program Support Group

Transportation and Regional Programs Division

1310 L Street, N.W, (6406J), 6th Floor, Room 627Q

Washington, D.C. 20005

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F.

G.

40 CFR 585(d). EPA Approval.
1.

Within 90 days of receipt of all materials required to be submitted under 40 CFR 80.585(a)
or (b), the Administrator shall determine whether the test method is approved.

2.

If the Administrator denies approval of the test method, within 90 days of receipt of all
materials required to be submitted under 40 CFR 80.585(a) or (b), the Administrator will
notify the applicant of the reasons for not approving the method. If the Administrator does
not notify the applicant within 90 days of receipt of the application, that the test method is
not approved, then the test method shall be deemed approved.

3.

If the Administrator finds that and individual test facility has provided false or inaccurate
information under 40 CFR 80.585, upon notice from the Administrator the approval shall
be void ab initio.

4.

Non-VCSB test method/test facility approval shall be valid for five years from the date of
approval by the Administrator and shall not be extended. If the method is later approved
by a VCSB, the approval shall remain valid so long as the conditions of 40 CFR 80.585(a)
are met.

40 CFR 80.585(e). Quality Assurance procedures for sulfur measurement instrumentation. A test
method shall not be considered a test using an approved test method unless the following quality
control procedures are performed separately for each instrument to make measurements:
1.

Follow all mandatory provisions of ASTM D 6299-02 and construct control charts from the
mandatory quality control testing prescribed in paragraph 7.1 of the reference method,
following guidelines under A 1.5.1 for individual observation charts and A 1.5.2 for moving
range charts.9

2.

Follow paragraph 7.3.1 of ASTM D 6299-02 to check standards using a reference material
at least monthly or following any major change to the laboratory equipment or test
procedure. Any deviation from the accepted reference value of a check standard greater
than 1.44 ppm (for diesel fuel subject to the 15 ppm sulfur standard) or 19.36 ppm (for
diesel fuel subject to the 500 ppm sulfur standard) must be investigated.

3.

Samples of test batches must be retained for 30 days or the period equal to the interval
between quality control sample tests, whichever is longer.

9

The Director of the Federal Register approved the incorporation by reference of ASTM D 6299
02, Standard Practice for Applying Statistical Quality Assurance Techniques to Evaluate Analytical
Measurement System Performance, as prescribed in 5 U.S.C. 552(a) and 1 CFR Part 51. Anyone may
purchase copies of this standard from the American Society for Testing and Materials, 100 Barr Harbor
Dr., West Conshohocken, PA 19428. Anyone may inspect copies at the U.S. EPA, Air and Radiation
Docket and Information Center, 1301 Constitution Ave., N.W., Room B102, EPA West Building,
Washington, D.C. 20460 or at the National Archives and Records Administration (NARA). For information
on the availability of this material at NARA, call 202-741-6030 or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

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4.

H.

Upon discovery of any quality control testing violation of paragraph A 1.5.1.3 or A 1.5.2.1
of ASTM D 6299-02, or any check standard deviation greater than 1.44 ppm (for diesel
fuel subject to the 15 ppm sulfur standard) or 19.36 ppm (for diesel fuel subject to the 500
ppm sulfur standard), conduct an investigation into the cause or such violation or
deviation and, after restoring method performance to statistical control, retest retained
samples from batches originally tested since the last satisfactory quality control material
or check standard testing occasion.

40 CFR 80.586. Record retention requirements for approved test methods. Each individual test
facility must retain records related to the establishment of accuracy and precision values, all test
method documentation, and any quality control test and analysis under title 40 CFR sections
80.584 and 80.585 for five years.

EPA Contact:
Joe Sopata
(202) 343-9034
Fax: (202) 343-2801
Email: [email protected]

OMB Control No. 2060-0566

Approval expires: 9/30/05

The public reporting and recordkeeping burden for this collection of information is estimated to average
180 hours per response. Send comments on the Agency’s need for this information, the accuracy of
the providing burden estimates, and any suggested methods for minimizing respondent burden,
including through the use of automated collection techniques to the Director, Collection Strategies
Division, U.S. Environmental Protection Agency (2822T), 1200 Pennsylvania Ave., NW, Washington,
D.C. 20460. Include the OMB control number in any correspondence. Do not send the completed form
to this address.

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