An office suite in Granite Bay was evacuated just before eleven o'clock this morning after an employee opened an envelope containing a white, powdery substance.

The Roseville Fire Department's hazmat team entered the law offices of Herrig & Vogt on Douglas Boulevard and determined the substance was calcium carbonate, a non-hazardous material that's used as a binder in everyday items like toothpaste, Comet cleanser and cement.

Employees were allowed to return to the building about two hours later.

The Placer County Sheriff's Office is investigating.