If the downstream oxygenate blender is adding oxygenate in amounts other than that specified by the refiner of the RBOB, the blender would be liable for a violation of the regulations regardless of whether the gasoline meets the downstream standards. In such a case, the RBOB refiner would have to recalculate its batch values for the RBOB to reflect that actual level of blending that occurred (e.g., benzene and toxics emissions performance.)(11/28/94)

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)