The U.S. Occupational Safety and Health Administration said on May 5 that it has proposed a $55,000 fine against Mollenberg-Betz Inc., a Buffalo, N.Y., mechanical contractor, for eight serious violations of workplace safety standards following a fatal explosion last November at a Tonawanda, N.Y., chemical plant. The blast killed Richard Folaron, a welder who worked for Mollenberg-Betz. OSHA also proposed a $61,000 fine against DuPont Corp., the plant's owner, for nine serious violations. It says Folaron was welding atop a 10,000-gallon slurry tank when sparks ignited vapors, causing the blast that killed him and injured another employee. OSHA cited Mollenberg-Betz for not verifying that the tank was empty before welding began and for not having specific hazardous energy control procedures. Dupont was cited for failing to notify its contractor of explosion hazards and safety procedures, among other things. The contractor could not be reached. However, in a published report, its attorney said the firm disputes OSHA's findings and that the event was the first serious workplace accident in the company's 100-year history.