Batch numbers should be assigned in numerical and chronological order of production (not shipment). If a batch of gasoline must be re-blended because it is out of specification, and an independent laboratory has already sampled the batch, the resulting batch must be assigned a new ID.

The volume of the original batch ID should then be reported to EPA as zero. If an independent lab has not sampled the original batch, the refiner may retain the original batch number. In either case, the refiner should ensure that records are kept on the nature of the contamination, corrective measures and original and subsequent sampling and testing.(7/1/94)

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)