Tennessee’s two U.S. Senators are asking the Environmental Protection Agency to temporarily relax rules over what kind of fuel gas stations can sell in Shelby County. That’s after a fire damaged the Valero oil refinery in Memphis, threatening the city with a fuel shortage.

In a letter to the EPA, the two senators say all 427 gas stations in the county are reporting low supplies of ‘summer blend’ fuel, a type the law normally requires this time of year.

To ease the pinch, Senators Lamar Alexander and Bob Corker want the EPA to allow sale of different blends of gasoline for the next few weeks.