A federal appeals court said ConAgra Foods Inc was not liable for a 2010 fire and explosion at an Illinois flour mill that burned three workers, and overturned much of a nearly $180 million jury award against the packaged foods company and a contractor. The 7th U.S. Circuit Court of Appeals in Chicago on Tuesday said a lower court judge should have granted judgment as a matter of law to ConAgra, whose products include Chef Boyardee pasta, Hunt's ketchup and Peter Pan peanut butter.