Police and paramedics were also called to the scene during the fire amid reports of multiple explosions at the site.
More than 120 firefighters and 40 trucks fought the massive blaze for hours before it was brought under control.
Advice - Industrial Fire at Superior Dr, Dandenong South. Threat is Reduced. For more info: — VicEmergency (@vicemergency) https://t.co/uX31QorwZY #vicfiresDecember 8, 2023
One factory worker remains unaccounted for.
Firefighters were unable to enter the building to conduct a primary search as the structure was fully engulfed in flames, Fire Rescue Victoria said in a statement.
A man in his 60s was taken to The Alfred Hospital in a stable condition with upper body injuries, while two other men in their 30s and 40s were taken to Dandenong Hospital.Both were in a stable condition with upper body injuries, Ambulance Victoria said.Another person was transported to The Alfred.
Smoke remains visible several kilometres away from the blaze. (HANDOUT/SES VICTORIA/FACEBOOK)
Smoke was visible several kilometres away from the blaze with strong winds blowing it across multiple suburbs.
Fire Rescue Victoria assistant chief fire officer Greg Christison said the wind conditions were quite extreme.
"It's presenting a number of challenges for us in suppression activities," he told reporters.
Authorities downgraded a watch and act warning to advice for local residents after the fire threat was reduced.Several roads in the area were closed and drivers were warned to avoid the area.