A tainted shipment of ethanol made its way to some Midwestern gas stations, and may cause problems for some drivers. The corn alcohol was produced at a plant in Clinton, Iowa. Archer Daniels Midland says 100 times the usual amount of a rust-inhibiting chemical was accidentally mixed into the ethanol, which was shipped out Wednesday night for blending with gasoline at terminals in Bettendorf, Milwaukee, Chicago and Rockford, Illinois. After fuel mixed with the ethanol went to gas stations in Milwaukee, customers started reporting car problems, and by Thursday night about fifty Milwaukee gas stations were closed. A-D-M says 120-thousand gallons of ethanol were overtreated with the additive at the Clinton plant, though it’s not yet clear whether any made it to retail stations in Iowa.