The U.S. Environmental Protection Agency is temporarily adjusting the sulfur tolerance test to smooth the transition to ultra-low-sulfur diesel fuel. The agency announced Thursday, April 20 it would make the change until better tests are developed to reliably measure low sulfur in the fuel distribution system.
The tolerance will rise from 2 parts per million to 3 parts per million through Oct. 14, 2008. The temporary measure is to guarantee that fuel actually meeting the 15 ppm sulfur cap, effective June 1, is not falsely rejected. The cap itself and its deadline are unaffected by the announcement, designed only to give labs more time to improve measurements.
The agency also is adjusting the designate-and-track provisions to account for nonpetroleum diesel fuels, such as biodiesel. The provisions require the industry to record information such as the sulfur content of the distillates the industry produces, imports and distributes.