On March 6, the U.S. Chemical Safety and Hazard Investigation Board (CSB) issued a new Safety Alert titled “Hazards Posed by Discharges from Emergency Pressure-Relief Systems.” The CSB’s alert highlights hazards identified with emergency pressure-relief systems from four CSB investigations.
The alert advises facilities that while a discharge from emergency pressure-relief systems can help protect equipment from unexpected and undesired high-pressure events, it can also seriously harm or fatally injure workers and cause extensive damage to a facility if the discharge is not made to a safe location.
CSB Chairperson Steve Owens said, “All four of the incidents highlighted in the CSB’s safety alert underscore the importance of thoroughly evaluating emergency pressure-relief systems to ensure they discharge to a safe location where they will not harm people.”
Of the four incidents cited, the most recent includes an event from May 2018 in which an ethylene release ignited, injuring 23 workers at the Kuraray America, Inc. ethylene and vinyl alcohol copolymer plant in Pasadena, Texas.
Using findings from the four incidents, the CSB’s safety alert issues three key lessons for facilities: follow existing good practice guidance; evaluate whether the atmosphere is the appropriate discharge location or if there are safer alternatives; and ensure hazardous chemicals vented into the atmosphere discharge to a safe location.
The alert also calls on companies to evaluate and, when appropriate, update their emergency pressure relief systems to prevent future incidents and protect workers and surrounding communities from harm.
