A four-person team of the US Chemical Safety and Hazard Investigation Board (CSB) is investigating an explosion and fire at Philadelphia Energy Solutions (PES), a refining complex in southwest Philadelphia.
The accident occurred during the early-morning hours of June 21 and injured four workers. It started in the alkylation unit where hydrofluoric acid (HF) is used to raise the octane of gasoline produced by the refinery, the company says.
HF is used in about one-third of the 150 US refineries. Fears of release of HF in a dense, lethal, acidic cloud have led people living near such facilities and members of Congress to call for better controls or substitution. PES reports no HF release from the incident.
The US Environmental Protection Agency’s most recent analysis of HF use and risk management provisions was in 1993. Earlier this year, the CSB called on the EPA to review that work to determine if the provisions are sufficient to protect refinery workers and nearby communities and if HF substitutes are available. The board notes that two technologies—a solid-state approach and an ionic liquid technology—are being developed to replace HF in at least two refineries.
The PES accident comes on the heels of incidents at a Husky Energy refinery in Superior, Wisconsin, in 2018 and a former ExxonMobil refinery in Torrance, California, in 2015. Like PES, those facilities use HF, operate near residential neighborhoods, and were investigated by the CSB.
PES is one of the world’s oldest oil-related facilities and is the largest refinery on the US East Coast, operating along the Schuylkill River for over 150 years. The refinery, which emerged from bankruptcy proceedings less than a year ago when investment firms took it over, will be shuttered in July and sold, PES announced June 26.