COLUMBIA — Researchers were allowed to go back to work Tuesday in MU's Schweitzer Hall a day after a lab explosion injured four people, one seriously.
One graduate student, two postdoctoral students and a lab technician were burned and received shrapnel and impact injuries in the incident. One remained in the hospital in "good" condition, a news release said.
The university said it would not be releasing the names of those involved in the incident. MU spokesman Christian Basi cited the Family Educational Rights and Privacy Act, a federal law that governs the release of information about students.
In a news release, Columbia Fire Capt. Eric Hartman said the explosion was caused by the ignition of hydrogen gas in an anaerobic hood — an oxygen-free chamber used for working with bacteria that can't survive in oxygen. A flammable combination of gases used for the device came into contact with an ignition source, the release said, resulting in an explosion. The source of the ignition remains unknown.
On Tuesday morning, Columbia Battalion Chief Steven Sapp said investigators were still looking into the possibility of technical failure and that the department might need to send the lab equipment to independent investigators for evaluation.
The department withdrew a previous statement Monday night that said human error led to the explosion, a conclusion Sapp called "premature." He blamed a mix-up at the department for the claim.
The university is looking into whether additional precautions are necessary, the MU News Bureau release said.
“I’m concerned about those injured and all affected by this incident,” MU Chancellor Brady Deaton said in the release. “One of our campus priorities is the safety of our faculty, staff and students.”
As of Tuesday afternoon, according to the news release, work was under way by MU Campus Facilities and Environmental Health and Safety crews to clean up after the explosion. Both the fire department and the university declared the rest of the building structurally sound.
The lab belongs to MU biochemistry professor Judy Wall, Basi said. Wall declined to comment on the incident or on the specific details of the experiment being conducted at the time of the explosion. Wall's lab was used for experiments with bacteria.
Hartman said the number of injuries was "certainly reduced" because of MU being on summer break, which meant fewer people working in the facility.
After Monday's explosion, the fire alarm was triggered and the building's fire sprinklers activated, extinguishing most of the fire, Hartman said in a release. The building was evacuated, and Hartman said the fire was contained in about 10 minutes. Fire crews then began working to ventilate chemicals.
Seventeen windows were blown out in the third-floor explosion.
Explosions in anaerobic chambers are not unprecedented, according to a research paper written by Mike Cox of Anaerobe Systems in San Jose, Calif.
Cox — who previously experienced two small anaerobic chamber explosions — wrote that when a chamber is transitioning to an oxygen-free state, specific combinations of oxygen and hydrogen can become flammable, making an explosion possible if something ignites the gas.
Similar explosions have occurred at the University of Michigan and the University of Oklahoma in years past.