The explosion happened at about 10:30 a.m. in Building One at the facility, located at 1400 Fountaingrove Parkway. It occurred in a ground-floor laboratory, in an area where integrated circuits are made using molecular beam epitaxy, Agilent spokesman Jeff Weber said.
The explosion injured two employees - a man who was taken to Santa Rosa Memorial Hospital with critical injuries and a woman with minor injuries who was later taken by private car to Kaiser Hospital, Weber said.
The man was cleaning a machine when there was a chemical flash, Weber said. He said cleaning the machine generally involves wearing a protective body suit, but he did not know whether the man was wearing one this morning.
The woman, a contract employee from Volt, was injured when something fell and hit her on the head outside of the laboratory, he said.
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. She did not know his condition.
About six engines from the Santa Rosa Fire Department were dispatched to the scene. Rincon Valley Fire Department offered mutual aid, with four fire engines, one truck and two chief officers.
Agilent's own chemical emergency response team also responded.
No flames were found, but there was some damage to laboratory, Weber said.
The cause of the explosion is under investigation. There were about eight chemicals involved, Petersen said. She did not know what those chemicals were.
Employees will be told later this afternoon whether they can return to work. People working in the company's other three buildings at the facility were unaffected.
