EPA proposes tougher SCR guidelines

Says most pollution control systems have been effective

June 20, 2011

The U.S. Environmental Protection Agency has updated its guidance for certification of diesel truck engines using selective catalytic reduction (SCR) to reduce emissions.

The pollution control systems most engine manufacturers used to meet 2010 emission standards have been effective, but technical developments justify tougher guidelines, said EPA.

The proposed guidance specifies requirements for:

• Warning drivers when they are running low on diesel exhaust fluid (DEF). • Slowing the truck down to 5 mph if the DEF tank runs down to empty or the SCR dosing is not working. • Identifying and responding to poor-quality DEF. • Better tamper resistance.

The EPA is accepting comments its Control of Emissions From New Highway Vehicles and Engines; Guidance on EPA's Certification Requirements for Heavy-Duty Diesel Engines Using Selective Catalytic Reduction Technology until July 7, 2011.

For more information, visit: www.gpo.gov/fdsys/pkg/FR-2011-06-07/html/2011-13851.htm.