SYDNEY - Fire crews and a team of specialist experts are working on a strategy to tackle a dangerous smouldering silo fire in southern NSW.
About 1,500 Cootamundra residents were urgently evacuated from their homes on Friday after a fire in a near-empty grain silo prompted fears of
a massive explosion.
An 800-metre exclusion zone was established around the silo, which forced the closure of one-third of the grain-belt town's streets.
The residential exclusion was lifted yesterday after fire crews successfully nullified volatile gases inside the silo, but authorities warned further evacuations may be necessary.
NSW Fire Brigades Superintendent Craig Brierley said the silo's two hatches were opened overnight, and gases allowed to escape, decreasing pressure in the 10,000-tonne concrete structure.
A team of hazardous materials experts, flown to Sydney, had examined the gases to ensure they were not harmful.
A small fire is still smouldering through about 275 tonnes of grain, causing fears a combustible dust cloud could trigger an explosion.
"There's a fire in the grain at the moment smouldering," Supt Brierley said.
"The problem is you can't disturb the grain because it will create a dust cloud which will ignite and spark a very violent fire that creates an explosion."
The very fine particles of dust would rapidly ignite and act like gunpowder, creating great heat and pressure, he said.
If the silo did explode it would shower giant chunks of concrete across the exclusion area and would obliterate adjacent silos.
A petrol station is inside the exclusion zone.
Supt Brierley said Hazmat and firefighting specialists were this morning working on a plan.
If the fire is allowed to burn through all the grain it could be weeks before the silo was declared safe, he said.
The exclusion zone had been reduced to the industrial area and rail yards near the silo, and no longer contained any homes.
- AAP
