OSHA fined U.S. Steel $118,214 and issued 10 citations for blast
The U.S. Chemical Safety and Hazard Investigation Board issued a final report on the August 2025 explosion at the Clairton Coke Works, recommending that U.S. Steel develop written policies and procedures for flushing gas valves. The blast killed two workers and injured 11 others, including contractors.
The board issued its report a year after the accident at the sprawling riverside industrial facility near Pittsburgh, the largest of its kind in the Western Hemisphere.
U.S. Steel has said the explosion happened when workers were flushing a gas valve with pressurized water in preparation for routine planned maintenance. The valve ruptured under intense pressure and released combustible coke oven gas.
The recommendation targets the maintenance step under way when the valve failed, according to the company’s account of the accident. The final report calls on U.S. Steel to put in writing the policies and procedures governing gas valve flushing.
The Occupational Safety and Health Administration previously fined the company a total of $118,214 and issued 10 citations over the incident.
OSHA said U.S. Steel’s written procedures, practices and training to safely maintain equipment and flush the gas valve were incomplete, outdated or inadequate.