Section 80.78(a)(7)(i) requires that RBOB may be blended only with oxygenate of the type and amount (or within the range of amounts) specified by the RBOB refiner, and recited in the RBOB product transfer documents. Nevertheless, there is no adverse environmental consequence if a party blends a quantity of oxygenate with RBOB that exceeds the specified amount, provided that the resulting RFG meets the oxygen maximum and substantially similar requirements. Note that under certain circumstances there is an adverse environmental consequence if the oxygenate type which is blended is different than the specified type. In addition, there almost always is an adverse environmental consequence if the amount of oxygenate which is blended is less than the specified amount.
In consequence, EPA will allow parties to view the oxygenate amount specification for RBOB as a minimum, and add oxygenate amounts in excess of that minimum up to the applicable oxygen maximum under § 80.41(g) in the case of simple model RFG, or up to the substantially similar maximum in the case of all RFG. In no case, however, may a party add an oxygen amount which is less than the specified amount, or an oxygenate type which is different than the specified type. For example, if an oxygenate blender obtains non-VOC-controlled any-oxygenate RBOB for which 7.7 vol% ethanol (2.9 wt% oxygen) is specified, the oxygenate blender may blend up to 10 vol% ethanol (4.0 wt% oxygen). The oxygenate blender in this example could not, however, blend less than 7.7 vol% ethanol. EPA intends to modify § 80.78(a)(7)(i) in a future rulemaking to reflect this answer. (4/18/95)
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)