| Emission levels in the U.S. are regulated by the Environmental Protection Agency (EPA) through The Clean Air Act. On Jan. 1, 2010, the EPA set a new limit on nitrogen oxide (NOx) emissions at 0.20 g/bhp-hr for new diesel vehicles. | Selective Catalytic Reduction (SCR) is the leading method of controlling NOx emissions available today. Using an SCR-equipped engine, along with reliable, high-quality DEF, is an efficient way to meet the EPA’s NOx regulations. |