(TULSA) - Investigators tested the air at the site of a toxic release Thursday, as hospitals began discharging dozens of people who got a whiff of the harmful gas.
The rupture Wednesday of an arsine gas cylinder at Solkatronic Chemical sent 143 people to area emergency rooms. But at least 89 had been discharged by Thursday afternoon, and the majority of others were in good condition and expected to be released later Thursday or Friday.
The conditions of four people admitted to St. John Medical Center ranged from fair to good.
Many of those admitted to hospitals showed no ill effects, but doctors warned that the symptoms might not show up for hours and kept patients for observation.
Breathing just small quantities of arsine, a form of arsenic, can be dangerous.
``It's strange. I feel fine, but I'm lying around in a hospital bed,'' said John Clanton, who was waiting to be released almost 24 hours after the incident.
Clanton, a Tulsa World photographer, was the first member of the media on the scene. He said he smelled the garlic-like odor associated with arsine once and later felt dizzy.
Arsine destroys red blood cells, which can lead to kidney failure. Clanton has only one kidney and said he was glad he opted to go to the hospital.
Environmental Protection Agency investigators were taking air samples at the site near the river Port of Catoosa to determine if there was any residual contamination, EPA spokesman David Bary said.
The agency also would be meeting with company officials to pinpoint what caused the leak. The Occupational Safety and Health Administration also is investigating, company officials said.
Officials with Solkatronic's parent, Allentown, Pa.-based Air Products and Chemicals, expressed regret for the accident.
The release took place around 1:30 p.m. Wednesday when employees heard a loud pop and discovered a tank of arsine had blown a valve on an outdoor loading dock. Each roughly 4-foot high tank holds 50 to 60 pounds of gas, said Howard Kuritzky, operations manager.
Several other nearby tanks of arsine were not affected.
``The cause of the release is currently under investigation,'' he said. ``All appropriate regulatory agencies have been notified and company experts are onsite investigating the release.''
The 10 Solkatronic employees and contractors who were admitted to a Claremore hospital as a precaution were released Thursday morning without ever showing symptoms, he said.
Solkatronic makes about 4,000 pounds of arsine gas each month at the port plant. The gas is used in the manufacture of semiconductor chips for cell phones, light emitting diodes for signs, vehicle tail and stop lights and in communications lasers and fiber optic cable.
Company officials said they know of no other releases at the 3-year-old plant, which is targeted for expansion.
Patients who felt fine were beginning to grow frustrated as hospitals held them for observation and took blood and urine tests, officials said.
``Our emergency room established a protocol they would hold for observation for at least 24 hours,'' said St. Francis Hospital spokesman Jeremy Burton. ``People don't necessarily feel sick or have symptoms.''
Only four people remained hospitalized at St. John Medical Center late Thursday. Three were in good condition and one was in fair condition, spokeswoman Tina Wells said.
Emergency officials said the incident was handled smoothly, in part because of large scale training during the past year.
Two local companies with their own emergency response teams, Sunoco and Boeing, aided in the decontamination process at St. John, Wells said. The incoming patients had to remove their clothing and were sprayed with water.
``In the midst of all this, we had a motorcycle accident victim come in,'' she said. ``I thought it was going to be nuts. It wasn't because we had trained for this.''