The U.S. Chemical Safety and Hazard Investigation Board (CSB) recently released final reports on two concluded investigations and updates on four ongoing investigations.

The CSB's October 11 final report on a June 2019 fire and explosion at the Philadelphia Energy Solutions (PES) Refinery in Philadelphia, Pennsylvania, identified several safety issues. Flange Bolts

During the incident, a corroded pipe elbow ruptured, releasing process fluid into the refinery’s hydrofluoric acid alkylation unit. Over 5,000 pounds of highly toxic hydrofluoric acid was released, and a 38,000-pound vessel fragment launched off-site and landed on the other side of the Schuylkill River. Issues identified in the CSB’s report included the following:

The U.S. Occupational Safety and Health Administration (OSHA) also investigated the accident in Philadelphia. The agency cited PES in 2020 for serious violations of the process safety management (PSM) standard and proposed $132,600 in penalties.

OSHA inspectors determined there were deficiencies in PES’s PSM program, including failing to establish or implement written procedures, insufficient hazard analysis, and inadequate inspection of process equipment for highly hazardous chemicals used in the process.

The CSB also issued its final report on the 2016 flash fire and explosion at the Sunoco Nederland, Texas, crude oil terminal, which resulted in burn injuries to seven workers. CSB investigators identified deficiencies in the company’s hot work policies and procedures, as well as the contractors hired to execute the work.

On August 12, 2016, hot work was being conducted by a Sunoco contractor on a section of pipe that contained residual crude oil. The pipe segment was plugged on both ends by another contractor using an isolation device. During the welding operation on the inside surface of a flange, vapor inside the pipe gathered between two of the installed isolation tools and ignited. The ignition caused a buildup in pressure, leading to an explosion at both ends of the isolated pipe.

The CSB concluded that Sunoco’s hot workprocedure did not adequately state that hot work on equipment that currently or previously contained flammable material was not permitted by OSHA or the National Fire Protection Association’s (NFPA) 51B standard.

The CSB also released updates on four ongoing investigations:

Stainless Steel Weld Elbows OSHA also investigated the liquid nitrogen release at Foundation Food Group and, in July 2021, cited 4 employers at the facility with 59 violations and proposed penalties totaling $998,637.