A party who produces RFG by combining blendstocks is a refiner under the RFG regulations, and is subject to all RFG standards and requirements. See the answer to Question 7, Section IX.B., of the July 1, 1994 Question and Answer document.

As a result, a party who combines normal butane and natural gasoline could certify the resulting product as RFG, provided the gasoline meets all RFG standards and the party meets the other refiner requirements, including those involving sampling and testing, independent sampling and testing, recordkeeping, reporting, and independent audits.(10/17/94)

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)