An oil refinery worker died after suffering from exposure to propane and acid at a Valero plant in Memphis, TN.
He is the second person to die this year from an on-the-job injury at the plant.
The plant earned citations for violations related to the safe handling and control of hazardous energy and chemicals.
Fire Department spokesman Wayne Cooke said two workers suffered injuries when a sight glass on a pump ruptured, exposing them to a mixture of propane and hydrofluoric acid. A sight glass is a transparent tube or window that allows workers to monitor fluid levels within a tank, pipe, pump or boiler.
One of the workers died at the hospital. The second worker and two firefighters have non-critical injuries. The names of the victims were not immediately available.
Company spokesman Bill Day says Valero is investigating the incident and that safety is its most important concern.