Minnesota is the first state to require that diesel fuel contain a 5 percent blend of biodiesel.

It was the first state to require diesel sold in the state contain biodiesel, but the previous standard was 2 percent. There were initially concerns about cold-weather performance and quality issues, but supporters say those issues have been addressed.

Some early concerns with the Minnesota B2 requirement were overcome through enhanced quality control.

According to the biodiesel industry, it is safe to use up to a 20 percent blend of high quality biodiesel year-round, in even the coldest of climates. Biodiesel will gel in cold weather, just like regular diesel fuel. But biodiesel blends can be treated for winter use in similar ways that No. 2 diesel is treated. Cold weather concerns are greatly diminished with lower blends like B5.

According to analysis from the Minnesota Department of Agriculture, the state's B2 Fuel Standard added an average of 4/10 of a penny to the cost of a gallon of diesel during the last three years.

Washington, Oregon, Pennsylvania, Louisiana, New Mexico and Massachusetts have also passed biodiesel requirements.