A fluorine gas leak in Engineering II forced authorities to evacuate students, faculty and staff from the building Wednesday afternoon while a hazardous material team inspected the laboratory where the leak originated.

Officer Mark Signa, UC Police Dept. public information officer, said the fluorine gas leak came from a cylinder in a research facility on the second floor of Engineering II. Three graduate students working in the lab found that the tube attached to the container was not properly connected, he said. The students saw a small cloud of the pale, yellowish-green gas and tried to turn off the valve controlling the gas’ flow before setting off the building’s fire alarm, Signa said. He said they called the UCPD at 1:24 p.m.

No one was injured by the leak, and faculty and students were allowed re-entry into the building about an hour after the Santa Barbara Hazmat Team examined the room, he said.

The hazmat team — wearing oxygen tanks and dressed in full body, airtight suites — entered the building around 6 p.m. and determined there was no serious concern that the chemical was still present, Signa said. A ventilation system in the room where the fluorine gas is stored sucks air from the lab and disperses it into the outside air, where it becomes diluted and non-hazardous, he said.

“They went into the room and they tested the air, and it appears that the chemical dissipated and had basically been vented away,” he said. “Basically the systems worked like they were supposed to and there wasn’t too much chemical in there, so they were able to get everything cleared from the room automatically.”

Although a UCSB hazmat team was geared up and ready to enter the building earlier, the city of Santa Barbara’s crew was called in as a safety precaution, Signa said. The UCSB team has Level B training while the Santa Barbara Hazmat Team has Level A training, the highest rating.

Police did not know Wednesday evening why the tube was incorrectly connected, but the UCSB Environmental Health and Safety Dept. will investigate the incident today, Signa said.

The container was filled with a mixture of gases, 5 percent of which was fluorine, Signa said.

Materials professor David Clarke, who is in charge of the lab where the leak came from, said he was not on campus when the incident happened, but he was promptly notified of the situation. The three graduate students who discovered the leak worked under Clarke.

“The students responded properly and correctly,” he said.

When the toxic gas comes into contact with water, it forms hydrofluoric acid, Clarke said. Inhaling the fluorine gas is potentially fatal, as it creates hydrofluoric acid from the water in a person’s throat, he said.

Clarke said his research team uses fluorine gas to develop film that can be used for new optical and electronic applications.

Katie Whitehead, a graduate student in chemical engineering, said she was in the building holding her office hours when she heard the fire alarm.

“It’s an inconvenience to the scientific community, but in the concern of safety, this is the appropriate thing to do,” she said.

Some graduate students and researchers said the building’s evacuation inconvenienced them because they were working on experiments at the time. Dmitri Vainchtein, a postdoctoratal researcher in mechanical engineering, said he was running a simulation on his laptop computer

“I have some simulations on my computer and its power is not connected,” he said. “I’m afraid if it’s not saved, it will disappear.”

Vainchtein said he would not lose any major data if he were not allowed into the building in time to reconnect his laptop’s power cord.

“It’s more annoying than bad,” he said.

Daniel Trahan, a Rice University student visiting friends at UCSB, said he had a flight at 6 p.m. Wednesday, but he left his luggage in one of the offices in Engineering II.

“We heard the alarm go off and we came down the stairs,” he said.

Paul Desruisseaux, associate vice chancellor of public affairs, said the chancellor and the dean of engineering were both out of town when the leak occurred, but both were being kept aware of the situation. He said authorities handled the situation well.

“Obviously the response has been tremendous with our police, fire and environmental safety departments,” he said. “No one has been injured.”