More than 30 FRV firefighters responded to a hazardous material incident in South Melbourne on Monday afternoon.
Crews arrived at the York Street business at 3.50pm, following reports of an envelope containing a white powder.
Wearing personal protective equipment, firefighters entered the building.
Inside, crews located two occupants who were required to decontaminate using the internal shower, before being assessed by Ambulance Victoria paramedics.
Firefighters cordoned off the building to prevent community exposure to the substance.
FRV's scientific advisor also attended the scene.
FRV has handed the scene to Victoria Police.
Reviewed 22 March 2021