Early reports had said a 150-tonne sand storage hopper was at risk of collapsing at the height of the fire.

Fire crews from Camden and Picton initially attended the blaze when it broke out about 11am, but were forced to call for back-up.

At the peak of the fire, there were five Fire and Rescue NSW and three Rural Fire Service crews battling flames and thick black smoke.

Police and paramedics also attended.

FRNSW duty commander Chris Wilson said that although the fire was fast burning, crews were able to bring it under control quickly.

"It looked very spectacular - there was lots of black smoke and flame, but it was extinguished very quickly," he said.

"There was no real danger of anything collapsing or exploding."

Mr Wilson said it was believed friction from the conveyor belt had started the fire.

There were no suspicious circumstances, and no-one was injured.

Fire and Rescue crews were also called to a house fire in Whittaker Street in Flinders about 8am on Monday.

Fire and Rescue NSW Inspector Don Pescud said two people had been inside the house when the fire broke out but both were able to escape unharmed.

The blaze caused severe damage to the property's garage and smoke damage to the rest of the building, Inspector Pescud said.

It took about an hour for crews to bring the flames under control.