Federal safety officials have cited science-based products company DuPont and a New York contractor for 17 safety violations after the explosion of a 10,000-gallon chemical tank that left one worker dead and injured another. The U.S. Department of Labors Occupational Safety and Health Administration recommended $61,500 in fines for DuPont and $55,440 in fines for contractor Mollenberg-Betz Inc. (WCxKit) A Mollenberg-Betz welder died last November while attaching a bracket to the storage tank at DuPonts plant in Tonawanda, close to Buffalo. OSHA cited both companies for not taking steps to prevent welding in an explosive environment.