The U.S. Chemical Safety and Hazard Investigation Board (CSB) is looking into a tragic incident that took place at the PEMEX Deer Park Refinery in Texas on October 10, 2024. During the event, two contract workers lost their lives due to a release of hydrogen sulfide gas, a highly toxic substance.
On that day, maintenance contractors were working on a task involving the removal of piping isolation devices from one of the refinery’s Amine Regeneration Units. Unfortunately, while they were working, they accidentally opened a flange on a pipe connected to another unit that still contained pressurized hydrogen sulfide. This mistake led to a significant release of the toxic gas at around 4:23 p.m.
The situation quickly escalated. One of the workers at the scene was fatally injured almost immediately. The wind then carried the hydrogen sulfide gas to a nearby area where other contractors were working. Tragically, another worker downwind from the release also succumbed to hydrogen sulfide poisoning.
In response to the incident, local authorities issued shelter-in-place orders for the nearby cities of Deer Park and Pasadena. This precaution was taken to protect residents from exposure to the harmful gas. In total, over 27,000 pounds of hydrogen sulfide were released into the environment, raising serious safety concerns.
The PEMEX Deer Park Refinery, an indirect subsidiary of the Mexican government-owned company Pemex, employs around 1,000 staff and 1,200 contractors. The facility produces hydrogen sulfide as a byproduct, which poses significant health risks if not properly managed.
The CSB is currently investigating the incident and will focus on several key areas, including safety practices, maintenance policies, and emergency preparedness. Their final report will provide detailed findings and recommendations aimed at preventing similar incidents in the future.
The CSB is an independent federal agency dedicated to investigating hazardous substance releases and ensuring safety in chemical handling. As the investigation continues, the hope is that lessons learned will lead to improved safety measures in the industry.