CHARLESTON, W.Va. -- About 25 pounds of ammonia gas was released at Dupont's Belle plant late Thursday.

According to a Kanawha County Metro 911 electronic notification posted at 11:49 p.m., the leak occurred at 11:12 p.m. Firefighters from the Belle Volunteer Fire Department responded to the leak.

Kanawha County Emergency Services Director Dale Petry said the leak occurred in an ammonia unit at the plant as crews were getting ready to pump dimethylamine. Petry said crews had pressurized the system to check for leaks and found none prior to pumping the chemical.

Nevertheless, a leak occurred when the pressure in the system reached 220 pounds per square inch, Petry said. Plant officials estimated about 25 pounds of chemical was released, he said.

According to a Kanawha County Metro 911 electronic notification posted at 11:49 p.m., the leak occurred at 11:12 p.m. Firefighters from the Belle Volunteer Fire Department responded to the leak.

Kanawha County Emergency Services Director Dale Petry said the leak occurred in an ammonia unit at the plant as crews were getting ready to pump dimethylamine. Petry said crews had pressurized the system to check for leaks and found none prior to pumping the chemical.

Nevertheless, a leak occurred when the pressure in the system reached 220 pounds per square inch, Petry said. Plant officials estimated about 25 pounds of chemical was released, he said.