On June 3, 2019, EPA and Photofabrication Engineering, Inc. (PEI), a facility that photo etches precision metal parts in Milford, Massachusetts, reached a Clean Air Act administrative order on consent. In January 2019, the facility had a spill of hydrofluoric acid, an extremely hazardous substance. EPA sent PEI an information request to determine the company's compliance with several statutes, including the hazard identification requirements of the Clean Air Act's General Duty Clause. Through the company's response, an EPCRA Tier II form, and a 2018 Clean Water Act inspection report, EPA learned that the company was storing incompatible acids together. If mixed, these acids could be explosive and create toxic fumes. As part of the Order, the company has agreed to perform a process hazard review of its chemical storage practices. The Clean Air Act?s 112(r) program is not delegated to Massachusetts, but EPA has notified MassDEP about our action.