Crews from both the Shoalhaven and Nowra brigades and Manildra’s own fire personnel tackled the fire in the substation on the second level of the complex, which controls one of the gluten driers.

Fire crews and NSW Ambulance were called to the Bolong Road location just after 10am.

Firefighters donned breathing apparatus and once the electricity was shut off to the substation, the fire was extinguished using CO2 extinguishers.

Shoalhaven station officer Gavin Bell said crews were onsite for two hours fighting the fire and also ventilating the room.

At the height of the emergency, four staff working in a lower level laboratory were evacuated, while other staff also met at evacuation points at the front of the factory.

Manildra personnel were assessing the damage, with the substation expected to be off-line for a period of time.