The Occupational Safety and Health Administration is proposing a combined $50,000 fine against two companies for safety violations related to an explosion at a south Augusta biodiesel plant that killed a 35-year-old welder in August.

Jason Karstedt, an employee of Advance Industrial Maintenance & Machine, was welding a steel tank at Farmers & Truckers Biodiesel, 4207 Mike Padgett Highway, at the time of the Aug. 21 blast.

"The hazards associated with welding near flammable and combustible chemicals are well known, yet these two companies failed to take the basic procedures that could have prevented this tragedy," said Gei-Thae Breezley, the director of OSHA's Atlanta-East Area Office.

OSHA reported Friday that it cited Farmers & Truckers Biodiesel for 12 safety violations carrying a proposed penalty of $29,450. Advance Industrial was cited for five safety violations carrying $20,850 in proposed penalties.

The citations are for not taking precautions for employees working in a confined space, not providing proper training, not having a lockout-tagout program and not developing a hazard communications program.

The companies have 15 business days to contest the citations.