The former head of the New South Wales Rural Fire Service (RFS), Phil Koperberg, has hit out at the new 'catastrophic' fire danger rating, saying he thinks it is inappropriate.

The category was introduced last year in the wake of Victoria's Black Saturday bushfires.

Large areas of Victoria and South Australia were under a catastrophic warning yesterday but no major fires broke out. Today the catastrophic conditions have shifted to north-east Victoria and parts of southern New South Wales.

Mr Koperberg told ABC Local Radio that 'extreme' used to be the highest level of warning for fire danger, and that was strong enough.

"The Oxford English Dictionary defines extreme as 'to the highest degree possible,'" he said.

"Catastrophe... signals a disastrous end, an event causing much damage or suffering.

"To use that as a predictor is, in my view, inappropriate."

Mr Koperberg says he acknowledges that New South Wales is following national guidelines and that the RFS uses the term very judiciously.

But he says he would not be surprised if the 'catastrophic' category is scrapped in the future.

"It may well be that in the fullness of time, once these issues have been fully analysed and dissected, that there will be a re-configuration of the fire danger index," he said.

"It may well be that the uppermost of that scale will be 'extreme' and the terminology is like 'if a fire occurs in these extreme conditions the consequence could well be catastrophic'."

However, the current New South Wales Fire Commissioner, Shane Fitzsimmons, says the 'catastrophic' threat level is both necessary and effective.

The Commissioner says 'catastrophic' is only used when the fire danger is off the scale and that it is different to 'extreme'.

"The research and the history has shown that there is a demonstrable difference and effect in fire behaviour," he said.

The Commissioner says the feedback from the public on the issue has been positive.

Largely ignored

There are reports that the code red catastrophic warnings have been largely ignored by visitors to affected regions this week.

David Kennedy, who runs a tourist park in Victoria's north-east, says the warning system is ineffective.

He says most guests did not know what a code red was, or chose to ignore it.

"We've warned all the guests that were in the park at the time and we've been telling guests that are arriving that there is a code red," he said.

"But generally speaking ... the reaction from our guests has been, well, we'll wait and see. No one has actually left and no-one has decided not to arrive.

"There's a feeling that code red may mean that, but it might not happen."

There is also concern from some tourism operators, who say the new warning system will have a devastating effect on business.

While the dire warning has had little impact on some tourists who have already set up camp, Mr Kennedy says the industry is worried about the deterrent effect.

"We've had a fire every three years here in Bright, but we could have a code red every three or four weeks," he said.

"We don't know just what impact that's going to have on the tourism industry, and we think probably it could end up having a significant impact on the tourism industry."

Mr Kennedy says the government has dropped the ball when it comes to alerting tourists to possible dangers.

"We feel in a way that the government has passed the responsibility of warning people on to the industry, and we're going to suffer for it," he said.