There are fears that Australian soldiers could have been exposed to deadly particles by firing dummy charges which contained asbestos during artillery training drills.

An internal investigation has been launched after one of the charges broke and spread asbestos dust in a small room of people at the Puckapunyal training base last October.

The Australian Defence Force (ADF) has been importing dummy charge bags containing white chrysotile asbestos from the United States for the last 46 years.

It was thought the material was safe for soldiers to use, but that view has now changed.

Lindsay Kranz, the director general Occupational Health and Safety for Defence, says the dummy charges come as part of a training kit for the Army's 105mm howitzer.

He says the charge bags were recently removed from use after the Puckapunyal incident.

"In October last year one broke and a couple of people in close proximity were exposed and that's when there was an internal investigation of that scenario," he said.

"Then that went further into the whole use of those dummy bags and at that point they were all withdrawn from service."

Mr Cranz says the chances of artillerymen being exposed to deadly fibres are slim.

But he is asking for personnel to come forward if they are experiencing breathing difficulties.

"It appears that in the main they were used outside," he said.

"If they had broken and asbestos had been released ... it was in the open air and therefore not in concentration ... we think that the risk even to the people dealing with the bags all the time is probably very low."

Kevin Reed, who trained with the howitzers for nearly 12 years, says soldiers were asked to destroy the bags after use.

"Any charge bags that were left over at the end of the live firing period, we burnt off," he said.

Dangerous substance

Kevin Reed knows the dangers of asbestos exposure but he says he is not concerned about the threat of contracting mesothelioma.

"We're talking about people who grew up post-war," he said.

"We lived in fibro houses, asbestos was everywhere, and some small amount in a charge bag probably didn't worry the great majority of us."

But Barry Robson, from the Asbestos Disease Foundation, says it could take up to 30 years before an exposed soldier starts showing symptoms.

"The whole gun crew would have been affected and anybody else standing around near them when the charges were let off," he said.

Mr Robson says the Defence Force is responsible for whatever ill effects the soldiers may face in the future.

"They should be held very accountable, especially if they knew that these charge bags contain asbestos fibres and then they still used them up until just recently," he said.

"I find it borders on criminal."