1 8 August 2014

1 

### “Control of Air Pollution f rom Motor Vehicles:
Tier 3 Motor Vehicle Emissions

A nd Fuel Standards”

§ 80.47 Performance

- based Analytical Test Method Approach 79 Federal Register 23633

– 23640 (April 28, 2014)

API Identification of items in need of either
technical correction or further clarification

Precision criteria : all fuel properties

- §80.47 ( b )(1 )

, §80.47 (c )(1 ), §80.47 (d )(1 ), §80.47 (e )(1 ), §80.47 (f )(1 ), §80.47 (g )(1 ), §80.47 (h )(1 ), §80.47 (i )(1 ), §80.47 (j )(1 )

“ The 20 results must be a series of tests with a sequential rec ord of analysis and no emissions
omissions .”

The reference to emissions (shown in red strikeout) is incorrect and should be corrected as
illustrated by the red underlined text

.

Precision criteria: sulfur in gasoline

- §80.47(b )(1)

“Beginning January 1, 2016...the maximum allowable standard deviation computed from the results of a minimum of 20 tests made over 20 days ( seven or fewer tests per week and two or fewer tests per day tests may be arranged into no fewer than five batches of four or fewer tests each, with only one such batch allowed per day over the minimum of 20 days ) on samples...”

The instructions shown in red strikeout are inconsistent with discussion in the Preamble and the clause, “five batches or fewer tests each” is confusing to the reader. (Perhaps it is missing some text?) We suggest that it be corrected as illustrated

.

Precision criteria: sulfur in butane

- §80.47(c)(1)

“Beginning January 1, 2016...the maximum allowable standard deviation computed from the results of a minimum of 20 tests made over 20 days (tests may be arranged into no fewer than five batches of f

our or fewer tests each, with only one such batch allowed per day over the minimum of 20 days) on samples...”

The wording shown in red underline font should be added as illustrated to be consistent with §80.47(b)(1)

.1 8 August 2014

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Precision criteria: fuel properties specified in §80.47(d)(1), §80.47(e)(1), §80.47(f)(1), §80.47(g)(1), §80.47(h)(1), §80.47(i)(1), §80.47(j)(1)

“Beginning January 1, 2016...the maximum allowable standard deviation computed from the results of a minimum of 20 tests made over 20 days (tests may be arranged into no fewer than five batches of four or fewer tests each, with only one such batch allowed per day over the minimum of 20 days) on samples...”

The wording shown in red underline font should be added as illustrated to be consistent with the wording suggested above for the same text which appears in §80.47(c)(1).

Precision criteria: RVP

- §80.47(g)(1)

“ (Ex ample: A gasoline having a RVP of 6.8psi: Maximum allowable standard deviation of 20

test s withdrawn from a 250 mL container ≤0.3*(0.40psi) = 0.12 psi ” ).

The example reference s the reproducibility of 0.40psi for a 250 mL co ntainer and should be
clarified as illustrated by the additional text in red underline font

.

Precision criteria: gasoline distillation

- §80.47 (h )(1)

“(Example: A gasoline having an in itial boiling point of 26 °C .... maximum allowable standard deviation of 20 tests for E90t E90 ≤0.3*(2.0+2.53*Sc) °C ... where Sc is the average slope (or rate of change) of the gasoline distillation curve as calculated in accordance with section 13.5 13.2 of ASTM D86

- 07 .”

The reference to E90t (shown in red strikeout) is incorrect and should be corrected as
illustrated. In addition, there is no section 13.5 in ASTM D86

- 12 . In earlier revisions such as

D86

- 07, section 13.5 covers information on b ias

. The slop e calculation is given in section 13.2. Since the precision calculation is from an earlier re v is ion of ASTM D86, it should be specifically
referenced as shown . Alternatives include :

 as calculate d in accordance with section A4.10.1 of D86

- 12 OR

 as calculate d in accordance with D8 6

Precision criteria: aromatics in diesel

- §80.47(j)(1)

“ Beginning January 1, 2016, for motor vehicle gasoline, gasoline blendstock, and gasoline fuel
additives motor diesel fuel subject to the motor vehicle diesel standards at §80.520 the maximum allowable standard deviation computed from the results of a minimum of 20 tests made over 20 days (tests may be arranged into no fewer than five batches or fewer tests each, with only one such batch allowed per day over the minimum of 20 days) on samples using good laboratory practices taken from a single homogeneous commercially available gasoline diesel fuel

.. ”1 8 August 2014

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The references to gasoline (shown above in red strikeout) are incorrect and should be corrected
as illustrated.

“( Example: A diesel fuel containing 35 Vol% aromatics: maximum allowable standard deviation of 20 tests ≤0.3*(

3.7 3.3 Vol%) = 1.11 0.99 Vol%). ”

Note: 3.7 (shown above in red strikeout) pertains to the reproducibility of oxygenated gasoline

sam ples. The value should be 3.3 V ol% for diesel fuel.

Criteria for designated test method reference installations

- §80.47(k)(2)

“ The reference installation of the method

- defined fuel parameter for the applicable designated test method must be shown to stay within the middle 50% of the distribution of an industry or commercially available monthly inter

- laboratory crosscheck program for 3 out of 5 successive exchanges for at least a period of five months using good laboratory practices. Specifically, compute the difference between the instrument's average measurement of the fuel closest to the applicable fuel standard (or to the average value for the fuel parameter in the complex model) and the mean for that fuel ob tained by all of the non

- outlier labs in the monthly inter

laboratory crosscheck program. Standardize this difference by expressing it in standard
deviation units. These standardized inter

- laboratory crosscheck differences should be placed in a moving aver age with a minimum span of five months. The instrument's moving average in standard deviation units cannot be outside the central 50% of the distribution of all laboratories that participated in the inter

- laboratory crosscheck program.”

Please provide clarification and/or guidance on the process to be followed because the regulatory t ext in this section appears to be contradictory. For instance, should one use the 1 st

and 3 rd quartile s to demonstrate that the reference installation stays “within the middle 50%” ? If yes, this appears to be contradictory with the later requirement to : ”s pecifically, compute the difference between the instrument's average measurement

... and the mean ...obtained in the monthly inter

- laboratory crosscheck program.”

.

Qualification Criteria for Non

- VCSB Method

- Defined Parameter Test Methods

- §80.47( m )( 6 )

“The candidate method

- defined non

- VCSB test method precision qualification must be conducted in the form of “cross

- method reproducibility” (Rcm) of the candidate method and applicable designated test method as required recommended 1 in ASTM D6708, where the Rcm must be equal to or less than 70 percent of the published reproducibility of the applicable designated test method using good laboratory practices”.

1 Note: Per the language stated in Section 6.6.3 of ASTM D6708

- 13, this practice is “recommended” not “required.”1 8 August 2014

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Cross

- method reproducibility is a measure of accuracy as well as precision. This requirement would pose significant hurdles for a non

- VCSB as Rcm represents an average of the designated and alternative test methods. Additional clarification and guidance is requested.

Accuracy SQC

- - §80.47(o)(1)

“Every facility shall conduct tests of every instrument wit h a commercially available check standard as defined in the ASTM D6299 at least three times a year using good laboratory practices.”

Please clarify that participation in the ASTM RFG (reformulated gasoline) ILCP (Inter L aboratory Crosscheck Program) or AS TM MG (motor gasoline) ILCP a minimum of three times per year satisfies this Accuracy SQC requirement for method

- defined parameters (i.e. vapor pressure, oxygenates, olefins, aromatics, boiling point and benzene) and plot accordingly

.

Accuracy SQC

- § 80.47(o)(1), § 80.47(p)(1)

“ The Accepted Reference Value of the check standard must be determined by the respective designated test method for the fuel parameter following the guidelines of ASTM D6299.”

Please clarify the requirement to determine the ARV of the check standard by the respective designated test method.

The process of assessing accuracy based upon the designated EPA method result is
unreasonable if an a lternative VCSB method is used , particularly when matri x effect s are present and require a D6708 correlation bias correction to the designated method

. Therefore,

t he accuracy SQC should use the alternative VCSB ILCP consensus or ARV (accepted reference value) , without applying a bias correction

. If the alternative VCSB A RV isn’t provided in the ASTM ILCP, accuracy should be assessed based upon the designated EPA method using appropriate production or equivalent samples

.

A n example ( see figures below) of the issue presented by the presence of matrix effects for an altern ative VCSB method i s seen when correlating ASTM D1319 v ersu s the EPA

- designated

ASTM D 576 9 test method f o r total aromatics. This example s pecifically addresses the justification of the use of the alternative VCSB ILCP result without applying a bias correction(s) instead of the designated ILCP ARV value to assess accuracy

. T he correlation bias varies
between ASTM D1319 and ASTM D5769 depending on the 95% boiling point of the sample and cannot effectively be captured in a singl e correlation equation derived fro m ASTM D6708

. The underlying mechanism of this deviation is believed by an ASTM committee to be due to an underestimation of the C10+ aromatics in the gasoline samples when ASTM method D5769 is
used since not all C10+ sta ndards are available for the proper calibration of D5769

. The plot below illustrates the effect of the 95 % distillation temperature upon the average result
difference of A STM D5769 and D1319 (Figure 1). The sample matrix effects are even more pronounced if the alternative method ASTM D5580 is used instead of ASTM D5769 (Figure 2).1 8 August 2014

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In summary, the use of an I L CP sample with known designated method ASTM D5769 ARV may not yield an acceptable value that agrees with the reported ARV. In contrast any I L CP ARV’s reported value for the alternative method D1319 would yield an acceptable value when tested by ASTM D1319 in the laboratory.

Figure 1: Effect of the average result difference of ASTM D5769 and ASTM D1319 aromatics content versus the 95

% distillation temperature for ASTM ILCP data for RFG and MG from 2007 to current.

Figure 2: Effect of the average result difference of ASTM D5769 and ASTM D5580 aromatics content versus the 95 % distillation temperature for ASTM ILCP data for RFG and MG f rom 2007 to current.

“Mean of multiple back

- to

- back tests“

- § 8 0.47 (n)(1), § 80.47(o)(1) and § 80.47(p)(1)

“In circumstances where the absolute difference between the mean of multiple back

- to

- back

tests of the standard reference material and the accepted reference value of the standard reference material is greater than 0.75 times the published reproducibility of the test method must be investigated by the facility.”1 8 August 2014

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Is reference to the “mean” value corr ect? Or should the statement reference individual test
results ? Please clarify.

In addition, could EPA please clarify why this sentence is repeated in identical text in §80.47(p)(1) which focuses on non

- VCSB method

- defined parameters. It is our understan ding
that non

- VCSB alternative methods will rarely have published reproducibilities.

“ Precision SQC “

- § 80.47(n)(2)(i)

, § 80.47(o) (2)(i), § 80.47(p)(3)(i)

“Every facility shall conduct tests on every instrument with a quality control material as defined in paragraph 3.2.3 3.2.8 in ASTM D6299 either once per week or once per every 20 productions tests, whichever is more frequent. The facility must construct a nd maintain an “I” chart as
described in section 7 8 and section A1.5.1 and a “MR” chart as described in section A1.5. 2 4 .”

The references to the indicated sections in ASTM D6299

- 13 (shown in red strikeout) are
incorrect and should be corrected as illustr ated.

“ Validation of New QC Material ”

- § 8 0.47(n)(2)(ii), § 80.47(o)(2)(ii), § 80.47(p)(3)(ii)

“ When a test facility is making a transition from one batch of QC material to the next batch of QC material, the facility will either construct an “I” chart as described in section 7 8.7 and section A1.5.1 of ASTM D6299, or follow the “Q

- Procedure” in Annex 1.9 of ASTM D6299

. ”

The references to the indicated sections in ASTM D6299

- 13 (shown in red strikeout) are
incorrect and should be corrected as illustrated.

“ Expanded uncertainty of the accepted reference value”

- § 80.47(n)(2)(iv), § 80.47(o)(2)(iv), § 80 .47(p)(3)(iv)

“The expanded uncertainty of the accepted reference value of consensus named fuels shall have the following accuracy qualification criterion: Accuracy qualification criterion = square root [(0.75R)^2+(0.75R)^2/L], where L = the number of single results obtained from different labs
used to calculate the consensus ARV.”

This statement deals with accuracy, not precision. It should be moved to the relevant
subsections in § 80.47 that focus on Accuracy SQC

.

Need to conduct a D6708 Assessment for Non

- VCSB Alternative Test Methods for Absolute
Fuel Parameters

An EPA memorandum dated April 30, 2013 and submitted to the Tier 3 Docket (Docket ID: EPA

HQ

- OAR

- 2011

- 0135

- 1784) summarizes a meeting with the API TMWG. Page 3 of the
memorandum is a flow chart (reproduced below) that indicates that a D6708 assessment is required if an alternative test method for an absolute parameter is not a VCSB method.1 8 August 2014

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This requirement is , however, not specified in the regulatory text of the final Tier 3 rulemaking.

I t should be incorporated in to §80.47 (l) as shown in the suggested text in red underline and
strikeout font below :

“ (l) Qualification criteria for Voluntary Consensus Standard Based (V CSB) Method

- Defined
Parameter Test Methods and Non

- voluntary Con s ensus Standard Based (non

- VCSB) Absolute Fuel Parameter of Sulfur in Gasoline and Butane

.

( 1) Beginning January 1, 2016, include full test method documentation by the Voluntary

Consensus Standard Based (VCSB) organization , including a description of the technology and/or instrumentation that makes the method functional.

(2) Include information reported in the test method that demonstrates the test method meets the applicable precision inf ormation for the method

- defined fuel parameter as
described in this section.

(i) For the absolute fuel parameter of sulfur in gasoline and butane , include information reported in the test method that demonstrates the applicable accuracy criteria as described in §80.47 (b)(2) for gasoline and §80.47 (c)(2) for butane

.

(3) Include information reported in the test method that demonstrates the test method has been evaluated using ASTM D6708 and whether the comparison is a “null” result or
whether a correlation equation needs to be applied that predicts designated test method1 8 August 2014

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results from the applicable method

- defined alternative test method.

(4) The test methods specified at §§80.2(w) and 80.46(a)(1), (a)(2), (b)(1), (c)(1), (d)(1), (e)(1), (f)(1), and (g)(1) and in use prior to October 28, 2013 are exempt from the requirements of paragraphs (l)(1) through (3) of this section. ”1 8 August 2014

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### “Control of Air Pollution f rom Motor Vehicles:
Tier 3 Motor Vehicle Emissions

A nd Fuel Standards”

Preamble: Section VI. A.2. Performance Based Measurement Systems (PBMS)

79 Federal Register 23 577

- 23589 (April 28, 2014)

Items that Require Editorial Correction

VI. Technical Amendments and Regulatory Streamlining, A. 2.c.ii, Table VI

– 4, Table VI

- 5, Table

VI

- 6

The reference t o ASTM D6792 minimum TPI = (r/R’ ) (shown in yellow highlight) is incorrect and should be corrected to read R/R’.1 8 August 2014

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VI. Technical Amendments and Regulatory Streamlining, A. 2.c.ii, Table VI

– 9

The reference to ASTM D86

- 07, section 13.5 (shown in yellow highlight) is incorrect and should be corrected to read section 13.2. (Section 13.5 in ASTM D86

- 07 covers information on bias.)