A hazardous materials crew responded to a federal building in Santa Ana to investigate a substance people were exposed to Tuesday afternoon, officials said.
Officials were called around 2 p.m. after several employees were exposed to an unknown powdery substance inside the federal building at 701 W. Santa Ana Blvd., the Orange County Fire Authority said.
Around 4:30 p.m., fire officials said they'd determined the substance wasn't dangerous, but they were still working to identify what it was.
The building, with an official address of 34 Civic Center Plaza, houses offices for several agencies including U.S. Department of Housing and Urban Development, U.S. Citizenship and Immigration Services and U.S. Immigration and Customs Enforcement.
The exposure occurred on the third floor, which was subsequently evacuated, firefighters said.
None of the people identified as patients were exhibiting symptoms, but as a precaution they were undergoing decontamination procedures and being transported for evaluation.
"They were completely asymptomatic showing no symptoms, but again until we can identify the substance we wanted to make sure they went to the appropriate facility to be evaluated in the meantime," Orange County Fire Authority Capt. Tony Bommarito told KTLA.
It was the second hazmat incident in Santa Ana Tuesday, after crews responded to handle illegally dumped mercury in a residential area.