A portion of Oakfield, Genesee County was shutdown Saturday afternoon due to an ammonia leak at a local food plant.

Genesee County sheriff's deputies said the leak occurred at Allen's Incorporated on Stevens Street around 12:30 p.m. It lasted for approximately two hours and was knocked down using water.

A voluntary evacuation was ordered for residents within a mile of the plant. Company officials said the leak occurred in the engine room. The ammonia was visible coming out of exhaust vents. It looks like steam.

Allens is a frozen food processing company open 24 hours a day, seven days a week. It uses ammonia refrigeration systems, which is standard operation. The company said approximately 70 people were in the building at the time, and Allens is prepared for emergencies such as this.

“We do what we call Hazmat drills several times a year. We trigger an alarm and evacuate the facility. We have meeting sites outside. The employees are directed to go to these meeting sites, and beyond that, we have a Hazmat team at our facility that's made up of mechanics and other people who work on the system,” said Jeff Clark, facility manager for Allens.

No one in or around the building suffered injuries. A firefighter was transported to the hospital for evaluation after suffering heat exhaustion. The Genesee County Fire Department said the Hazmat suits are hot inside and visibility is almost zero.

Crews are working to determine just how much ammonia escaped, and the cause of the leak is still under investigation.