Tyson Foods confirmed an ammonia leak in Madison, Neb. forced a plant evacuation and sent 40 workers to the hospital Thursday evening, May 24.
"We're investigating the cause of an ammonia leak. The plant was not in full production at the time, however, there were about 150 people present, and most of them were working in our second shift ham boning operation," said Tyson spokesman Gary Mickelson.
He said following the evacuation, 40 workers were taken to local hospitals for evaluation as a precautionary measure and all have been released.
Mickelson said Tyson maintenance workers repaired the ammonia line involved in the leak. Ammonia is used as a part of the plant's refrigeration system.
The Tyson Foods pork processing plant, which employs about 1,100 people, was not damaged and remains operational.