Response to Comments Document for Final Rule concerning the use of 
ASTM D6550-05 as an alternative test method for olefin content of gasoline

On January 31, 2011, EPA proposed to allow ASTM D6550-05 (SFC) as an alternative to the designated test method, ASTM D1319-03[ε1] (FIA), for measuring olefin content of gasoline, provided the results are correlated to ASTM D1319-03[ε1] using a site-specific correlation of FIA (volume percent) versus SFC (weight percent).  The Agency also proposed that correlation be completed on a site-specific basis.  To ensure a proper site-specific correlation, the gasoline fuel set used to develop the correlation shall span the range of the olefin properties representative of that refinery's or importer's gasoline production.  This gasoline fuel set would be analyzed by the test facility's laboratory using both ASTM D1319-03[ε1] (also known as FIA, or the designated test method) and ASTM D6550-05.   A resulting correlation equation would then be developed in terms of ASTM D1319-03[ε1] in volume percent and ASTM D6550-05 in weight percent.  Thus, the applicable range of the resulting correlation from a facility's site specific correlation would be consistent with that specific facility's olefin content range.  In response to this proposed rule, EPA received five comments from the American Petroleum Institute (API), BP America Incorporated (BP), the National Petroleum and Refiners Association (NPRA), Western States Petroleum Association (WSPA), and Shell Oil Products U.S. (SOPUS).  All comments were in support of the proposal.
       The following is a brief summary of additional comments provided by the American Petroleum Institute (API), the National Petroleum and Refiners Association (NPRA), Western States Petroleum Association (WSPA), and Shell Oil Products US (SOPUS) and EPA's responses to them. 
 Comments:
       API, NPRA and SOPUS also recommended that EPA update its regulations to incorporate by reference the 2010 year version of both ASTM D1319 and ASTM D6550.  
 Response:
       EPA will undertake this issue in a future rulemaking. 
 Comments:
       WSPA commented that a refinery may choose to have neither of the test methods (ASTM D1319 or ASTM D6550) in its laboratory if it is relying on a third party commercial laboratory to conduct 100 percent of its certification testing.  WSPA asked EPA for clarification that a third party laboratory may assist a refinery laboratory in its development and maintenance of the required correlation using samples from the specified refinery.  
 Response:
       EPA believes in the case where a refinery or importer may be relying on a third party commercial laboratory to conduct its certification testing, it would be acceptable for the third party commercial laboratory to assist the refinery or importer in the development and maintenance of the required correlation using samples from that specific refinery.  In addition, although not the subject of this rulemaking, EPA intends to establish a performance-based test method approach (PBTMA) rule which would provide criteria for the qualification of alternative test methods. 
