Mr Corbell said it had cost the government between $2 million and $3 million to demolish and clear the Downer Mr Fluffy house which was missed in the 1990s clean-up, and with 1050 homes known to have contained the loose insulation, demolition was unaffordable.

He was speaking in response to a call from the head of the federal Asbestos Safety and Eradication Agency, Peter Tighe. Mr Tighe described the houses as a time- bomb and said no amount of cleaning could make them safe.

But Mr Corbell told 2CC radio that demolition was "simply not possible". "We're looking at a very extensive remediation. The government undertook that in relation to the Downer property, where we purchased the home, we completely deconstructed the home. Removed the soil from the property as well. It cost the government between $2 million and $3 million for that one property.

''We've got over 1000 properties across the ACT … we have to be sensible about this."

Mr Corbell said that about 100 homes in Queanbeyan still contained the deadly Mr Fluffy insulation, with no remediation program at all.

"I'm not going to accept that everyone's going to come at the ACT government on this issue - where we have taken a proactive approach, where we have provided constant information, where we have been part of a clean-up program, and other governments are doing nothing …There are homes in Queanbeyan that have Mr Fluffy in them that have never been cleaned, never been remediated in any way."

Robson Environmental's manager of hazardous materials, Ged Keane, said a Queanbeyan resident had walked into his office before Christmas with a bag of loose insulation from his home, which turned out to be Mr Fluffy asbestos.

He had just bought the house and the building inspector had not identified it, Mr Keane said, pointing to NSW as a much bigger problem than in Canberra.

Mr Keane's company has been assessing Canberra houses in the past few months, after homeowners were warned their homes were part of the Mr Fluffy clean-up program. About 90 per cent contained residual asbestos fibres, he said, but in most cases it was confined to the sub-floor and was safe.

In some cases, cornices were damaged and fibres had migrated to surfaces below, such as the tops of fridges. But Mr Keane said when the fibres were contained in wall cavities and sub-floors, and if garages and storage areas under the houses were sealed, the houses were "perfectly safe" to live in.

People could not, however, do any work on the walls, including replacing electrical sockets or switches.

Workplace Safety Commissioner Mark McCabe also rejected the suggestion houses needed to be demolished. None of the assessments suggested that was necessary, he said, other than the rare cases of houses missed by the clean-up.

If the ceilings were sealed and the walls in good shape and the houses monitored to ensure they stayed that way, the risk was extremely small.

Mr Corbel is considering more measures to ensure tenants and tradespeople are made aware of the Mr Fluffy homes.