An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Fuels Registration, Reporting, and Compliance Help

Will transmix processors be allowed to "stack" ethanol and exceed the maximum allowable oxygenate content without regard to VOC requirements?

Transmix processors who produce RFG are considered to be refiners and are required to meet all RFG standards and requirements that apply to refiners for the RFG produced, including the standards for oxygen and the renewable oxygenate. To the extent the RFG produced by a transmix processor contains oxygenate that was part of the transmix when received by the processor, this oxygenate may be used by the processor to meet the oxygen standard. If the oxygenate is renewable (e.g., ethanol in the case of non-VOC-controlled RFG, or ETBE in the case of VOC-controlled RFG), the oxygenate may be included in the transmix processor's compliance calculations for renewable oxygenate. If the amount or type of oxygenate in the transmix is inadequate to meet the oxygen or renewable oxygenate standards, the transmix processor has several options for meeting these standards. If the gasoline contains less than the 1.5 wt% minimum oxygen standard, the transmix processor must add sufficient oxygenate to meet this per-gallon standard. If the 1.5 wt% per gallon minimum is met, but not the 2.0 wt% per gallon oxygen standard, the transmix processor may add additional oxygenate. If the RFG will not be designated as VOC-controlled, then the maximum oxygen content standard is 3.5 wt%. If the RFG is VOC controlled, the maximum oxygen content standard is 2.7 wt%. Under the substantially similar requirements different oxygenates may be combined up to 2.7 wt% oxygen, which would allow the processor to add ethanol to the gasoline even if the gasoline contains some other oxygenate. If the 1.5 wt% oxygen minimum is met and the transmix processor meets the oxygen standard on average, oxygen credits may be obtained to meet 2.1 wt% oxygen average standard. Renewable oxygenate credits also may be obtained to meet that standard. Lastly, the transmix processor could designate the gasoline produced as conventional gasoline, in which case none of the RFG standards would apply. In all cases, the processor may not exceed the oxygen content maximum for RFG, and for VOC controlled RFG must meet the VOC requirements.(10/3/94)

This question and answer was posted at Consolidated List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (PDF)(333 pp, 18.17 MB, EPA420-R-03-009, July 2003, About PDF)