CSB Report Urges Building Design Protections After 2025 Coke Plant Blast

Washington — A Chemical Safety Board final report on a fatal August 2025 explosion at a coking plant emphasizes the importance of ensuring that facility buildings are designed to protect people and contents during incidents, according to Safety+Health Magazine.

The report details the incident at the U.S. Steel Clairton (PA) Coke Works Facility. CSB investigators found that the explosion occurred inside the Battery 13/14 transfer room after coke gas was released from process piping.

Incident Details

The blast killed two workers and injured 11 others, including five who sustained serious injuries. Both deceased workers and two of those seriously injured were inside or near buildings in the area where the explosion occurred. None of the buildings were designed or constructed to withstand an explosion, the agency says. U.S. Steel did not perform a facility siting evaluation of its coke oven batteries before the incident.

CSB Recommendations

To protect facilities from fires, explosions or toxic releases, CSB recommends that companies conduct facility siting analyses of normally occupied spaces, such as control rooms, and involve workers who occupy the buildings in the process, according to Safety+Health Magazine.

Additional Lessons

CSB also notes that companies should always consider and properly control the potential for overpressure when connecting an external pressure source to piping or equipment containing hazardous chemicals. Companies should develop and apply robust process safety management principles to all hazardous processes. Regulation establishes minimum expectations with no prohibition from exceeding minimum requirements.

“When buildings are occupied by personnel, they must be adequately designed or located to protect the personnel or equipment from fires, explosions or toxic releases,” Drew Sahli, agency investigator in charge, said in a press release. “Had these buildings been located in a different area of the facility, away from coke batteries, this incident could have been far less severe.”

The report was published by the Chemical Safety Board and covered by Safety+Health Magazine.