Section 80.2 of the regulations defines a "batch" as "a quantity of reformulated gasoline which is homogeneous with regard to those properties which are specified for reformulated gasoline certification." For refiners who are exempt from the independent sampling and testing requirements, the batch identification number should be assigned at the point the refiner begins producing a stream of gasoline with a given set of parameters, which are representative of the composite sample. In some cases, where a large volume of gasoline is produced to the same specification, the refiner may wish to sample, test and report batches based on smaller quantities of gasoline as it is being shipped out.

However, refiners who in-line blend, and who have not been exempted from the independent sampling and testing requirements, must blend to a storage tank and meet the independent sampling and testing requirements for certifying RFG as specified in § 80.65(f).(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)