EPA's importer definition is found at 40 CFR § 80.2(r), which states that an importer is "a person who imports gasoline, gasoline blending stocks or components, or diesel fuel from a foreign country into the United States (including the Commonwealth of Puerto Rico, the Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands)."
U.S. Customs Service regulations at 19 CFR § 101.1(l) define an importer as the "person primarily liable for the payment of any duties on the merchandise, or an authorized agent acting on his behalf."
To keep operations for EPA and the Customs Service consistent, the person who is the importer of record for the gasoline with the Customs Service should be the importer for purposes of EPA's RFG and anti-dumping programs. Normally this is the person who owns the gasoline when the import vessel arrives at the U.S. port of entry, or the person who owns the gasoline after it has been discharged by the import vessel into a shore tank, but sometimes it is a licensed customs house broker.
The Customs importer of record, whether it is the person who owns the gasoline when it enters the U.S port of entry, the purchaser of the gasoline or the customs house broker, is always responsible for compliance with the RFG and anti-dumping standards and requirements, however.(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)