SANTA ROSA, Calif. --
Phosphorus gas was being blamed for an explosion Tuesday that forced the evacuation of a high-tech company in Sonoma County and critically injured one worker, according to Santa Rosa fire officials.
The industrial accident happened at Agilent Technologies in Santa Rosa. Hazmat crews were at the site most of the afternoon.
The chemical explosion set off fire alarms at about 10:30 a.m. Tuesday morning. Approximately 100 employees inside the building had to be cleared out. Many workers heard the blast.
Agilent taped off building one where the explosion happened. Through the building’s exterior windows, people's purses and lunches were visible right where they had to drop them when the building was evacuated.
Workers told KTVU it was a frightening experience.
"It was really loud. Like something really heavy fell down on the floor," said Agilent employee Mingwei Li.
Agilent officials said the explosion happened while two maintenance workers were cleaning lab equipment, a process involving some eight chemicals.
The equipment involved is used for production of integrated circuits, said Agilent spokesman Jeff Weber. And that equipment needs to be maintained and cleaned occasionally."
One worker – a man identified as Patrick Colbus -- received severe burns on his face and torso. Fire crews had to rescue him because he couldn't make it out of the building on his own.
The other worker had mild injuries. A Santa Rosa firefighter who was one of the first to respond to the incident was also injured and was taken to Santa Rosa Memorial Hospital, Fire Inspector Marita Petersen said.
Those evacuated were taken to another part of the campus and checked for chemical contamination.
"It's like taking a shower. You take your clothes off, and get a new set of clothes," Weber said.
All of the employees who were evacuated were asked to stay at the facility for a period of time as a precautionary measure to determine if they had suffered any effects from the explosion, Weber said.
Some workers said maintenance crews do clean machines that have dangerous materials. Fire officials believed a combination of red phosphorus, white phosphorus and heavy metals likely sparked the blast.
"I'm kind of shocked that something happened really," said Agilent employee Kent McComber. "It's an MBE -- molecular beam epitaxy -- so they go in in oxygen suits and they try to be real careful."
The worker with the burns was in critical condition at UC Davis Medical Center Tuesday night. Other employees were sent home. It was not clear whether the building would be cleared for staff to return on Wednesday.
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