Update: Unknown Substance Removed From Fortanasce Building Identified

Update 3:30 p.m. spokeswoman Beth Stogner said investigators have identified the substance removed from the Fortanasce Physical Therapy building as potash bentonite, a chemical frequently used in water softeners.

The substance, while otherwise generally harmless, could trigger allergies or an asthma attack in people prone to them, Stogner said, adding no injuries or illness were reported.

Stogner said Fortanasce received a threat "related to recently resolved litigation proceedings" prior to Thursday's incident. The investigation has been turned over to the .

Police Lt. Roy Nakamura said the Department will soon assign an investigator to the case. Authorities have reopened the building and allowed employees and patients back inside, Stogner said.

Update 1:00 p.m.: The Hazmat team removed a bag filled with a white substance from the building. It will be taken for testing. We'll fill you in as soon as we know anything.

Update 11:45 a.m.: Hazmat officials could be seen entering the building to assess the threat of the mysterious white substance discovered inside.

Previously: The building is being evacuated while firefighters work to identify a mysterious white substance, officials said Thursday.

The substance appeared on the desks of several employees.

Firefighters received the call around 9:15 a.m., said an official at the Verdugo Fire Communications Center. are working to block off West Naomi Avenue at South Baldwin Avenue and Lovel Avenue, according to scanner reports.

What form the white substance is in is unclear.

Burbank Hazmat is reportedly on scene and have requested the Los Angeles County Sheriff's Hazmat team as well, according to scanner reports.

No other information is available.

This story will continue to be updated as information becomes available.