The U.S. Environmental Protection Agency announced Friday that it will extend the transition period for retail diesel outlets to provide ultra-low sulfur diesel (ULSD) from Sept. 1 to Oct. 15, 2006. During this period, on-highway diesel fuel will be required to contain 22 parts per million (ppm) of sulfur before the 15 ppm requirement takes effect.

The extension addresses concerns raised by refiners, suppliers and stakeholders that diesel sulfur levels may rise above the 15 ppm threshold because of mingling with earlier batches of higher sulfur fuels, EPA told Fleet Owner in an emailed statement.

This will have no effect on the planned introduction of clean diesel vehicles and engines slated for Fall 2006, EPA said.

The American Trucking Assns. told Fleet Owner that it supports the action taken by EPA.

"We are hopeful that by Oct. 15 ULSD is capable of being distributed without sulfur contamination," ATA said in an emailed statement. "But should there be a need for a further extension, we would be concerned that engine and truck manufacturers may not honor warranty obligations."