The Environmental Protection Agency is celebrating the 40th anniversary of the Clean Air Act, and clean diesel has been a part of that success, said Allen Schaeffer, the executive director of the Diesel Technology Forum, after attending anniversary activities in Washington, D.C.

"The diesel industry is proud to have been a part of the history of the Act, its implementation, and most importantly, the results in making America's air cleaner while growing the economy," Schaeffer said in a statement.

"Diesel has been the primary power in America's economic growth and a major part of the clean air success story. Because of the Clean Air Act and the cooperative working relationship of the EPA, environmental and health organizations, the diesel industry, and local government agencies, remarkable improvements have been achieved that has resulted in today's clean diesel technology. It powers the nation's trucks, construction equipment, farm equipment, ships, locomotives and buses, which today meet the most stringent emissions standards in the world."

Along with taking lead out of gasoline, Schaeffer said, "a hallmark success story of the Act has been the introduction of new ultra-low sulfur diesel fuel that has enabled the development of more efficient engines and emissions control technologies. Taken together, clean diesel fuel and the emissions control improvements and advanced engine technologies today allow diesel engines to be near zero in emissions."

In fact, he pointed out, in some parts of the United States, the air that goes into the diesel engines will be dirtier than the exhaust that comes out.

Schaeffer said the industry is continuing to phase in new cleaner diesel fuels and emissions standards in off-road machines and equipment, while also moving to meet the next challenge to reduce carbon dioxide emissions.