The US Chemical Safety and Hazard Investigation Board has called on the US Environmental Protection Agency to review its regulation of hydrofluoric acid. One-third of the nation’s 150 petrochemical refineries use HF to produce high-octane gasoline. The CSB’s April 24 statement urges the EPA to reexamine and update a 1993 study to determine the effectiveness of existing risk management program requirements as well as the viability of using inherently safer alkylation technologies in refineries. “In the last 4 years, the CSB has investigated two refinery incidents where an explosion elevated the threat of a release of HF,” CSB interim executive Kristen Kulinowski says. “Refinery workers and surrounding community residents are rightly concerned about the adequacy of risk management for the use of hazardous chemicals like HF.” HF is a highly toxic chemical that can seriously injure or cause death at concentrations as low as 30 ppm, the CSB says. The CSB’s recommendation follows its accident investigations at an ExxonMobil refinery in California and a Husky Energy refinery in Wisconsin. After the California accident, the South Coast Air Quality Management District began examining HF regulations and alternatives. That effort is ongoing, a South Coast AQMD spokesperson says. EPA officials say it is reviewing the CSB’s request.