Callers to Triple Zero (000) reported thick smoke coming from the warehouse on Assembly Drive just before 2pm.
Firefighters arrived on scene in eight minutes to find the factory well alight.
Wearing breathing apparatus, FRV crews attacked the blaze and brought it under control just after 3:30pm.
Ten FRV appliances responded to the scene, along with three aerial appliances, a rescue appliance and support units.
Two people were transferred into the care of Ambulance Victoria paramedics.
FRV crews worked alongside Victoria Police, Airservices Australia and SES crews at the scene.
An advice message has been issued for Airport West, Keilor Park, Melbourne Airport and Tullamarine to avoid the area.
Reviewed 23 June 2021