A 100-metre exclusion zone was set up around 7pm to allow emergency crews to drain and then salvage the tanker which was holding around 8000 litres of LPG.

Wollongong Police Inspector Brian Wyver said the salvage operation was not expected to be complete until tomorrow morning. 

‘‘The truck driver was coming down the pass when he lost its brakes, it appears, and then he tried to go up the safety ramp but missed the safety ramp and has gone about 80 metres into the bush,’’ he said.

‘‘...It appears as if the truck driver was trying to go up the safety ramp and he’s clipped another car coming the other way.

‘‘No-one’s been injured in the accident.’’

Inspector Wyver said emergency services, including police, fire brigade and ambulance, were quickly on scene. The contents of the truck prompted the closure of the road.

‘‘As a result the fire brigade has declared it a hazard area so we’ve shut the pass, top and bottom,’’ he said.

‘‘There are no houses in the immediate area so no evacuations are required - it’s just a matter of retrieval.’’

Fire and Rescue NSW Wollongong duty commander Inspector Don Pescud said while there were no major injuries, the truck driver was treated for minor injuries by ambulance officers.

‘‘The fire brigade has stabilised the truck and is monitoring the air,’’ Inspector Pescud said at around 7pm.

The road is not expected to open again until tomorrow morning. 

Motorists are advised to use Mount Ousley Road or Lawrence Hargrave Drive as an alternative route.

Emergency services, RMS crews and a tow truck remain at the scene.