As it continues to look into a deadly hydrogen sulfide leak, the Chemical Safety Board is stressing the value of comprehensive risk assessments and emergency readiness.
After contract personnel opened the wrong flange, the release occurred. According to the most current update, CSB is also looking into hazard analyses, contractor management systems, energy isolation practices, and maintenance and training protocols at a refinery in Deer Park, Texas. About 27,000 pounds of hydrogen sulfide, a poisonous, colorless gas, were released during the incident, resulting in the deaths of two workers and the injuries of thirteen others.
The agency reports that one contract worker suffered fatal injuries during the chemical release and another from a different company died while working on equipment less than 250 feet away.
The work was intended to be performed on a “depressurized, purged and isolated” piping segment about 5 feet from the piping flange opened in error, per CSB.
The update cites a federal chemical database that states a concentration of hydrogen sulfide as low as 100 parts per million is considered immediately dangerous to life and health. Exposure to concentrations above 1,000 ppm can trigger a near-immediate fatality, according to OSHA.
“Hydrogen sulfide is a highly toxic substance that can result in serious injury and death even at low concentrations,” CSB Chair Steve Owens said in a press release. “This dangerous incident resulted in the death of two workers and put other workers and the surrounding communities at very serious risk.”
