California Air Resources Board

SACRAMENTO – The California Air Resources Board (ARB) today applauded a decision by the Superior Court of California, Fresno County that affirms the legality of the 1998 identification of diesel particulate as a toxic air contaminant (TAC).

"We are pleased the court has confirmed that the ARB acted within its authority and used appropriate scientific procedures. This ruling allows us to continue our vigorous efforts to reduce the public's exposure to diesel particulate," said Catherine Witherspoon, ARB Executive Officer.

In 1998, the state's Scientific Review Panel and staffs of the Office of Environmental Health Hazard Assessment (OEHHA) and the ARB presented the Board with evidence on the health impacts of supporting the identification of diesel particulate as toxic. After hearing more than six hours of testimony the Board identified diesel particulate as a toxic air contaminant. Once a compound has been identified as toxic, California state law then requires the ARB to reduce public exposure.

In 2000, the ARB developed its Diesel Risk Reduction Plan that set the goal of cutting diesel emissions by 85 percent by 2020. The plan includes a series of measures designed to achieve that goal. As part of that plan the Board has adopted measures that require the use of low sulfur diesel fuel in most applications statewide, tighter tailpipe limits on in-use diesel trucks and buses and to control emissions from port equipment and ships operating in California waters.

"Since the Board's 1998 identification further evidence of the potential health damage from fine particles has been found, making that decision an even more important step in protecting public health," Witherspoon added.