THEODORE, Ala. (AP) — A coastal Alabama company was ordered to destroy some of the frozen chicken at its refrigeration plant after the ammonia leak that sent about 130 people to hospitals, but other meat was safe to eat, government regulators said Thursday.

Brian Mabry, a spokesman with the U.S. Agriculture Department's Food Safety and Inspection Service, said Millard Refrigerated Services was ordered to dispose of meat on a dock outside the plant and in the hold of a ship being loaded at the adjacent industrial canal leading to Mobile Bay.

Regulators determined that meat in four of the company's five massive coolers was safe and can be sold, he said. But due to lingering ammonia, inspectors have yet to be able to check the meat inside the fifth, a three-story cooler where the leak occurred.

"We don't know when they will be able to get in," he said.

Officials for the Nebraska-based company didn't immediately respond to questions seeking the amount of meat that had to be destroyed.

Ammonia leaked from a pipe atop a cooling building at Millard on Monday, resulting in a vapor cloud that wafted from the plant, which is located on the Theodore Industrial Canal. Only one worker at the plant was hurt, but scores reported breathing problems away from the plant, including many across the canal waters.

Mobile-area hospitals said about 130 people arrived at emergency rooms, and several were treated in intensive care units, but none of the injuries was life-threatening.

Investigators from the Occupational Safety and Health Administration are trying to determine what caused the pipe failure. Officials said the company could face fines both from OSHA and the Environmental Protection Agency.

The Millard plant uses ammonia as a refrigerant for chicken, which is frozen and shipped abroad.

In all, about 8,000 places in North America use ammonia to cool everything from ice rinks to meat coolers, said Bruce Badger, president of the International Institute of Ammonia Refrigeration, an industry group based in Washington.

The Alabama leak was different than most involving ammonia because the canal allowed vapors to spread further than normal, he said, but it appeared Millard Refrigerated Services "behaved responsibly here."

"We'd all like to know what happened here so we can prevent it from happening again," Badger said.

Records from the Bureau of Labor Statistics show that of the 38,124 people who died from workplace injuries in the United States from 2003 through last year, 15 were fatally injured by ammonia or ammonium compounds. It was unclear how many of those were linked to refrigeration plants, however.

Badger said ammonia is efficient, low-cost and "environmentally benign" in normal amounts.

"It is the concentration that is the concern," he said.