CSB: 27,000 Pounds of Toxic Gas Released in Texas Hydrogen Sulfide Release

The U.S. Chemical Safety Board released an investigation update into a fatal hydrogen sulfide release at PEMEX Deer Park Refinery in Texas. The incident occurred on October 10, 2024, and killed two workers and injured 13 others.

CSB’s investigation found that during a maintenance activity at 4:23 p.m., approximately 27,000 pounds of toxic hydrogen sulfide gas were released.

In addition to the two fatalities and other serious injuries, the release resulted in shelter-in-place orders issued by officials in the nearby cities of Deer Park and Pasadena, lasting for several hours, and a portion of Texas State Highway 225 was closed temporarily.

The CSB’s update states that on the day of the incident two contract workers at the refinery partially opened a flanged connection on piping containing hydrogen sulfide gas, which caused the release. One of these workers was fatally injured.

The work was supposed to be done on a different, isolated piping segment located about five feet away from the flange that was opened. Two other contract workers from a separate company, who were working on equipment less than 250 feet away and downwind from the release, were also affected, with one fatally injured from the hydrogen sulfide exposure.

The CSB’s investigation is ongoing, and the CSB will provide complete findings, analyses, and recommendations in its final investigation report.

Source: CSB