January 26, 2023

OSHA Publication Revisits Fatal Hydrogen Sulfide Release

An accidental release of hydrogen sulfide that killed a worker and his wife in 2019 is examined in a new OSHA publication that clarifies employers’ obligations to protect workers who may be exposed to the colorless, flammable gas. The incident occurred at an oil and gas facility near Odessa, Texas, that was operated by Aghorn Operating Inc. During the incident, a lone worker who was responding to an alarm on a water pump entered the pump house to close valves and isolate the pump. But the pump suddenly reactivated, releasing water that contained hydrogen sulfide into the pump house. Hydrogen sulfide monitors around the facility were not functioning, and the worker was not wearing a personal hydrogen sulfide gas detector. He died from exposure to the gas. Sometime later, his wife accessed the facility to look for him, and she too was killed by hydrogen sulfide exposure.

The incident revealed several deficiencies at the facility. According to the OSHA publication, none of the facility’s hydrogen sulfide detectors communicated with the alarm system. Some of the detectors were in a testing mode, and others had been set up incorrectly. The employer had provided personal hydrogen sulfide detectors to its workers but did not have a formal written policy requiring their use. Workers had not been trained on lockout/tagout procedures, which would have prevented the pump from reenergizing. The facility also lacked procedures that would have prevented unauthorized visitors from accessing the pump house and other buildings at the site.

The Aghorn incident was the subject of a report (PDF) and safety video issued in 2021 by the Chemical Safety and Hazard Investigation Board. OSHA cited Aghorn for five serious violations and assessed penalties totaling $75,000.

The OSHA publication (PDF) is part of the agency’s “fatal facts” series, which describes instances in which workplace fatalities resulted from employers’ failure to identify and correct hazards, offers ideas on correcting the hazards, and educates workers about safe work practices.