US Chemical Safety Board faults Pemex in 2024 fatal accident

By Erwin Seba

HOUSTON, Feb 23 (Reuters) - The lack of a standard system for correctly identifying idled equipment at Pemex's Deer Park, Texas, refinery led to a poison gas release that killed two workers, the U.S. Chemical Safety and Hazard Investigation Board (CSB) said in a report released on Monday.

Workers were preparing an idled, de-inventoried unit for upcoming work on October 10, 2024 when they opened a flange on a nearby pipe of an operating unit, the report said.

A total of 27,000 pounds of deadly hydrogen sulfide was released, killing one of the workers who opened the flange. As the gas drifted downwind, it overcame a worker who was unable to escape. He also died, the report said.

A Pemex spokesperson was not immediately available to discuss the report.

"The CSB concludes that PEMEX Deer Park had written procedures that standardize pipe marking for pipe cutting but did not have a standardized process for flange opening and blind removal activities," the board wrote. "Had PEMEX Deer Park required clear standardized markings for all line opening activities, this incident may have been prevented."

Hydrogen sulfide concentrations during the release reached at least 500 parts per million at the Deer Park refinery, the board said. Thirteen other workers were taken to medical facilities for evaluation. The Houston suburbs of Pasadena and Deer Park issued shelter-in-place orders during the release.

Since the release, the Pemex refinery has adopted a system for identifying equipment to be opened for work, the report said.