The prohibition of heavy metals in RFG means that heavy metals may not be added, nor may it contain more than trace levels that may be picked up from the transportation/distribution system. In fact, no substantially similar unleaded gasoline may contain any elements purposely added outside of carbon, hydrogen, oxygen, nitrogen, and sulfur. Refiners are not required to test for heavy metals; however, quality control measures should be in place to ensure that heavy metals are not being added.(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)