A TRUCK driver has managed to escape moments before his B-double burst into flames on the Bruce Highway.

The Chronicle understands the truck, carrying fertiliser and engine parts, crashed into a gully near Bauple about 3pm.

The driver got out of the cab and ran before the truck caught fire, igniting the surrounding grassland.

Speaking to reporters at the scene, Gympie Fire Station Officer Adrian Bond said conditions were made more difficult due to the lack of water and distance from both Gympie and Maryborough.

He said there had been concerns about toxic smoke in the area but the fertiliser was mineral- based which meant it didn't fan the flames.

He described the driver as "extremely fortunate".

"Fortunately the driver was able to hop out of the cab relatively quickly and was essentially uninjured.

"Just after that the prime mover caught alight."

Nineteen fire fighting crews fought the blaze. 12 remain on scene tonight.

The highway is expected to remain closed for several hours.