NFPA diamond for hydrogen flouride.

Hydrogen fluoride is an acid used as a catalyst in the alkylation unit in the refinery to produce high-octane petroleum. It carries an NFPA 704 (“fire diamond”) health rating of 4: “very short exposure could cause death or major residual injury.” The chemical turns into hydrofluoric acid when it is in contact with moisture and becomes an extremely corrosive liquid and contact poison that burns skin, tissue and eyes. It rapidly penetrates tissues and can cause systemic toxicity, damaging the heart and lungs and causing death. Under the right conditions, a large release could form a lethal plume of acid vapors that could extend for miles downwind, putting thousands of people at risk.

One-third of refineries use hydrogen fluoride, according to the USW. The other two-thirds use sulfuric acid as a catalyst, which also can burn skin, tissue and lungs but is somewhat less toxic. Most important, sulfuric acid has much less potential to form a deadly vapor plume extending outside the refinery.

Solid-state catalysts offer promise as an even safer alternative but are currently at the pilot plant stage and have not been used commercially yet for the alkylation process.

The USW says it will discuss other alternatives to the use of hydrogen fluoride with the industry and if necessary will work through the regulatory agencies and Congress to get the issue resolved.

Hydrogen fluoride is such a deadly component, and there are new and safer technologies available...We intend to pursue every avenue till we have safer units that don’t endanger our refinery workers or the communities surrounding these facilities.

—USW Vice President Gary Beevers

There have been three reported hydrogen fluoride release incidents in the past five months.

• On 11 March at the Sunoco refinery in Philadelphia, 10 contractors were exposed to hydrogen fluoride and sent to the hospital after the chemical’s release from the alkylation unit
• On 19 July, hydrogen fluoride was released during a fire at Citgo’s east refinery in Corpus Christi, Texas. One USW-represented employee remains in an intensive care unit as a result of thermal burns from the fire.
• On 6 Aug, at the non-union ExxonMobil refinery in Joliet, Ill., hydrogen fluoride was released from the alkylation unit and resulted in one operator suffering from hydrogen fluoride-related chemical burns.

In a 13 Aug. final report to the Texas Commission on Environmental Quality (TCEQ), Citgo estimated that nearly 4,000 pounds of hydrogen fluoride had been released in its event. According to Citizens for Environmental Justice, the TCEQ records show that this quantity was the largest hydrogen fluoride release in 20 years. The group said the company did not tell citizens the dangerous nature of the fire or that potentially deadly gas had escaped. Reportedly there were citizens who experienced adverse health effects, according to the USW.

The USW plans to work with local community environmental groups to end the use of hydrogen fluoride. A mid-September meeting between the local and international union, the Sierra Club and Citizens for Environmental Justice in Corpus Christi is planned.