Abstract: Employee #1 was asked to perform a chemical etching procedure using propanol and concentrated hydrofluoric and nitric acids. The acids and the propanol were accidentally mixed, resulting in an exothermic reaction. Employee #1 suffered chemical burns on her the face, neck, and arms. Employee #3 suffered chemical burns on his arms while helping Employee #1 into the emergency shower and eye- and face wash facility. Approximately 2 hours later, Employee #2 poured the same waste acid/propanol mixture into a 5-gallon waste container, again producing an exothermic reaction. He suffered chemical burns on his face, neck, and arm.