EPA and CARB Sets Emission Standards for USA
The Environmental Protection Agency (EPA) sets the emission standards in USA, for all pollution sources. Due to its unique climate conditions, the state of California requires more stringent emissions standards. Therefore, it was allowed under the Federal Clean Air Act to draft its own emission standards.
In the year 2000 another 13 American states followed California and supported the standards from the Californian Air Resource Board (CARB) to be introduced in 2004. The PM levels in USA will remain high as compared to Europe until 2007, when the levels are required to be even lower than the European levels for 2008.
Off-Road Machinery
Emission standards for off-road machinery with diesel engines have been in force in the United States since January 1996. Sweden followed an EU-directive and introduced such standards during 1998. The introduction of these standards was a two-step process. The step 1 limited values was enforced during 1998-2000, and the step 2 values - introduced during the 2001-04 timeframe. This standard applies to new machinery.