Over 200 pounds of anhydrous ammonia was released into the air Sunday at the Perdue poultry plant in Georgetown.

The incident occurred on Sunday, July 23, at about 5 p.m. at the 20621 Savannah Road facility. The Delaware Department of Natural Resources and Environmental Control is investigating.

According to Perdue Farms’ Environmental Manager Tanya Rogers-Vickers, about 243 pounds of ammonia was released over a period of 20 to 30 minutes.

“It was contained pretty fast,” she said. “We believe the pressure valve popped on the condenser. We think it was low on water.”

The U.S. Environmental Protection Agency considers ammonia a hazardous substance, but it is widely used as an industrial refrigerant. Condensers, which typically sit on the roof of a facility, are used to compress and vaporize the ammonia in the refrigeration process.