Minnesota is the first state to mandate the sale of biodiesel.

The requirement took effect Sept. 29. The state Legislature approved the requirement in 2002, but it could not take effect until the state verified that sufficient quantities of B2 biodiesel would be available to meet the state´s needs.

"Today, Minnesota takes another step toward reducing our dependence on foreign oil while improving our environment and our rural economy," Gov. Tim Pawlenty said during a press conference with state Agriculture Commissioner Gene Hugoson.

Biodiesel is made from renewable oils and fats. In Minnesota, it is made primarily from soybean oil, and state officials have stressed the benefit to farmers by increasing demand for soybean crops.

Minnesota has three biodiesel plants. They have a combined annual production capacity of nearly 63 million gallons, making Minnesota the leading producer of biodiesel in the United States.

"It will also benefit the state´s natural resources and public health through a reduction in harmful vehicle emissions," Hugoson said.

Independent tests have shown that biodiesel reduces harmful emissions including unburned hydrocarbons, carbon monoxide and particulate matter.

B2 can be used in conventional diesel-engine vehicles without modifications.

Railroad locomotives, off-road taconite and copper mining equipment and heating equipment would be exempt from the B2 requirement.