The California Air Resources Board has certified Engelhard Corp.'s DPX catalytic particulate filter for use in diesel retrofits.

CARB verified that DPX filters reduce diesel particulate matter, or soot, by 85 % when used in combination with low-sulfur fuel (15 parts per million) on certain trucks and buses. The verification opens the door for use of DPX filters under the State's "In-Use Diesel Retrofit Plan."
The action follows approval of DPX filters by the U.S. Environmental Protection Agency for use in the federal Voluntary Diesel Retrofit Program.
"This technology gives bus and truck operators the opportunity to make existing vehicles run far cleaner," said Ed Stanczak, group vice president and general manager of Environmental Technologies at Engelhard. "Diesel vehicles have a well-deserved reputation for fuel efficiency and durability. Unfortunately, they also have a reputation for soot and pollution. Now the technology is in place to change that negative side of the diesel."
CARB developed the In-Use Diesel Retrofit Plan to dramatically reduce emissions levels of diesel particulate matter. Under the plan, CARB is working to identify diesel vehicle and engine types used in California, demonstrate and verify the capabilities of retrofit devices and implement retrofit programs. Retrofit programs are based on regulatory requirements, incentives and voluntary participation.
Engelhard's DPX filters are verified for use with Cummins M-11 and ISM heavy-duty diesel engines model years 1995 -2001. Verified applications include refuse haulers, school buses, urban buses, fuel tanker trucks and long-haul trucks and buses. DPX filters also are approved in California under Executive Order D-385-6 for installation on vehicles powered by Caterpillar, Cummins, DDC, International, Mack and Volvo engines. Engelhard is working to expand verification of DPX filters under the In- Use Diesel Retrofit Plan to these engines, as well.