UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2000 TRAVERWOOD DRIVE

ANN ARBOR, MI 48105-2498

 OFFICE OF

AIR AND RADIATION

April 30, 2013

MEMORANDUM

SUBJECT: Meeting with American Petroleum Institute (API) Test Methodologies Workgroup

FROM: Joe Sopata, Chemist

USEPA/OAR/OTAQ/CD/FCC

THROUGH: John Weihrauch, Center Director

USEPA/OAR/OTAQ/CD/FCC

TO: EPA Docket # EPA-HQ-OAR-2011-0135

This memo documents a meeting held on April 18, 2013 between representatives of API Test Methodologies Workgroup and the 

United States Environmental Protection Agency (EPA) to discuss EPA’s Performance Based Analytical Test Method Approach

(PBATMA) included in the proposed rule entitled, “Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission 

and Fuel Standards” (Tier 3). The meeting attendees from API Test Methodologies Workgroup included David Lax (API), Frank 

Disanzo, (Exxonmobil), Kathryn Brtko (BP), Janice Raburn (BP), Kishore Nadkarni, Barbara Schroeder (Shell), Richard Stanley

(RMS Statistics), Al Verstuyft (Al Verstuyft Consulting), Alex Lau (TCL-Consulting), John Rizzo (Marathon Petroleum), Peg 

Broughton (Marathon Petroleum), and from EPA included Joe Sopata and John Weihrauch.

The PBATMA discussion topics included background, proposed qualification criterion, statistical quality control requirements, 

implementation dates and Agency approval options which are presented in detail the preamble and regulations of the Tier 3 proposal. 

The API Test Methodologies Workgroup requested that EPA provide flow chart examples of qualification requirements for Absolute 

Fuel Parameters and Method Defined Fuel Parameters. These flowcharts are attached. These flow charts are not intended to cover all 
aspects of the Performance Based Analytical Test Method Approach proposed requirements. EPA encourages review of both the

preamble and regulations for details on the PBATMA proposal not covered in these flow charts. 
Flow Chart Example: Absolute Fuel Parameter (Absolute) - Sulfur in Gasoline 

Note: EPA proposes that fuel parameters categorized as “Absolute” are sulfur in gasoline 

and sulfur in butane (VCSB – Voluntary Consensus Standards Body)

YES YES

NO

 NO 

 NO

YES

Is Alternative Test 

Method a Voluntary

Consensus Standard 

Body (VCSB Method)?

Precision - the maximum allowable standard 

deviation of 20 test results on a 10 ppm gasoline 

would be 0.95 ppm.

Accuracy – the average of 10 consecutive results 

on a 1-10 ppm gravimetric sulfur standard cannot 

be more than 0.71 ppm and the average of 10 

consecutive results on a 10-20 ppm gravimetric 

sulfur standard cannot more than 1.00 ppm

Method Qualified

Lab determines if 

ASTM D6708 

reveals that 

sample-specific 

biases cannot be 

determined as 

random?

Method 

Disqualified.

Method 

Disqualified
Flow Chart Example: Method-Defined Fuel Parameter (Method-Defined) 

Aromatics in Gasoline: Note: EPA proposes that all other fuel parameters besides 

sulfur in gasoline and sulfur in butane currently designated in our gasoline and diesel 

fuel programs are Method-Defined 

(VCSB – Voluntary Consensus Standards Body)

YES NO

YES NO YES NO

Obtain use of a Reference Installation of 

Designated Test Method (DM):

1) DM near middle distribution of industry

monthly inter-laboratory crosscheck 

program.

2) DM has been shown to be in statistical 

control. 

(Both for 5 months)

Precision - the maximum 

allowable standard deviation of 

20 test results on a 32 volume 

percent aromatics gasoline 

would be 0.70 volume percent

Is Alternative Test 

Method a Voluntary

Consensus Standard 

Body (VCSB) Method?

VCSB determines if use of ASTM 

D6708 yields a null result compared 

to designated test method (DM)?(**)

Lab determines if ASTM 

D6708 reveals that samplespecific biases cannot be 

determined as random?

Use 

Alternative 

Test Method 

result w/o 

correlation.

VCSB uses 

ASTM D6708 

to determine 

correlation 

equation to 

DM.

Method 

Disqualified

.

Same as ** but 

Lab also 

determines if 

the cross 

method 

reproducibility

(Rcm) is ≤ 70% 

of published R 

of DM.