Firefighters have been forced to retreat back from the fire following multiple explosions and are now reassessing firefighting options.
ACT Fire Brigade has issued an EMERGENCY ALERT about the presence of a potentially toxic smoke plume to the suburb of Mitchell between Flemington Road and Gungahlin Drive and the Barton Highway and Wells Station Drive.
The ACT Fire Brigade has confirmed the fire is burning within an amount of mineral oil within the building.
Firefighters are now re-commencing firefighting operations using water and foam.
The ACT Fire Brigade has now ordered the evacuation of the whole suburb of Mitchell including a number of campers at Exhibition Park.
There is still a localised smoke plume but there is no threat to nearby residential suburbs of Harrison and Franklin.
Residents are advised to remain indoors.
The building is located in the newer industrial estate of Mitchell off Hoskins Street.
Firefighters have been forced to move a few hundred metres back from the premises while working with the business operator to identify what substances are inside the building.
The business, Energy Service International (ESI), works with materials including oil from electricity transformers.
The fire has produced a thick smoke plume in the immediate area.
A 300 metre exclusion zone has now been put in place.
Three fire pumpers, bronto, hazmat, BA unit and command crews are all on scene.
The ACT Fire Brigade is working with the business operator to identify the contents of the building.
The fire has now burned through the roof of the premises as firefighters work to extinguish it.
The ACT Ambulance Service also in attendance as a precaution.