An anhydrous ammonia leak at a meat-packing plant forced 1,000 employees to evacuate and nearby residents to stay indoors for hours on Wednesday.
A faint ammonia odor was detectable a few blocks away from the JBS Swift plant east of downtown Louisville for more than an hour after the leak.
One worker, a 40-year-old man whose name was not released, was sent to the hospital after complaining of burning eyes, nausea and vomiting, Louisville Fire Department Capt. Salvador Melendez said. There were no other reported injuries, authorities said.
About 1,000 workers were evacuated at 11:30 a.m.
Sirens were set off about an hour after the accident in the plant's engine room to warn nearby residents when authorities determined the situation was serious enough that they could be at risk. Those living within a mile of the site were told to stay indoors and to avoid using air conditioning or heating.
The leak was stopped about 2 1/2 hours later and an all clear was issued to area residents, Melendez said.
Worker Shelia Jones, 42, said she had never seen an incident like this in her 19 years at the plant.
She said she was working in the rendering room near the scene of the leak when she smelled ammonia and began getting a headache. A plant safety inspector told her and about seven co-workers to get out immediately.
"Ooh, it's really strong. The ammonia would knock you down, take your breath away," Jones said.
She said she was among the first workers out and within five minutes, everyone else was running out the doors. She said the plant provides regular safety instruction.
"Everybody knows, you smell ammonia, you call the supervisor, everyone gets out," Jones said.
Workers dressed in white lab-style coats and hard hats could be seen outside sitting on the lawn and milling around while officials from the Fire Department and hazardous material teams conducted tests.
Anhydrous ammonia __a vapor__ is used for refrigeration at the plant, can cause chemical burns on the skin or lung injury if inhaled.
The plant is in a section of Louisville known as Butchertown because of its historic role in the meat-packing industry.
Officials with the plant's parent company, Golden, Colo.-based JBS, didn't immediately respond to calls seeking details on the accident.
In a November 2007 audit, the Louisville's Metro Air Pollution Control District determined that the plant's policies and risk management plans for such incidents were insufficient.
"It's still way too early to tell if procedures were followed properly," Matt Stull, APCD's spokesperson, said.
The accident was the second major incident involving a Louisville plant this week.
Two workers were killed in an explosion Monday at the Carbide Industries plant, which makes calcium carbide used in metalworking and is located in a petrochemical complex dubbed Rubbertown. A contained fire continued to burn there Wednesday.
Confusion after that incident over which agency is to alert the public about hazards from an industrial accident spurred the city to revamp its notification procedures.