Water bombing aircraft are working to extinguish a fire on board a Canadian-owned freight ship docked in a NSW port amid warnings the blaze could evolve into a "hazardous material" incident.
All 20 crew members escaped uninjured from the Iron Chieftain shortly after the fire ignited in the cargo hold as it was unloading dolomite onto a conveyor belt at Port Kembla Harbour on Monday morning.
Up to 80 firefighters are now working to suffocate the fire with compressed air foam as they monitor the temperature of fuel tanks and the ship's ability to remain afloat, according to Fire and Rescue NSW.
NSW Fire and Rescue spokesman Paul McGuiggan says firefighting aircraft were dumping foam into the cargo hold.
"That's designed to starve the fire of oxygen," he told AAP.
The operation is expected to continue into the evening with firefighters to remain at the scene because of the risk posed by hazardous material in the fire's aftermath.
The NSW Environment Protection Authority also attended because firefighting materials entered the harbour from the vessel, a spokesperson said in a statement.
The Iron Chieftain is one of 56 ships owned by Canadian-based company CSL which transports cargo such as coal, iron ore, cement, gypsum, clinker, salt, sugar, alumina, limestone and heavy mineral concentrate.
The Australian-flagged ship docked in Port Kembla on Friday after sailing from Ardrossan in South Australia.
"CSL regrets any disruptions or inconveniences caused as a result of this incident," a CSL spokesman said in a statement.
"Once the fire has been extinguished, CSL will work with the authorities and conduct a full investigation to determine the cause of the fire and the extent of damages."
Booms have been put around the ship to help contain any oil or diesel spills.
Port Kembla closed at 4am shortly after the fire broke out but resumed operations about 11.30am, according to NSW Ports.
There's been no impact to any plant equipment or steel making operations where the Iron Chieftain is docked at a BlueScope berth, company spokesman Michael Reay told AAP on Monday.
