Hundreds of Canberra families may have been exposed to a deadly form of asbestos believed to have been removed from homes in the early 1990s.
About 1000 houses in the ACT were insulated with loose-fill asbestos in the late 1960s and 1970s by a company trading as Mr Fluffy.
Amosite asbestos is considered to be one of the two most dangerous forms of the substance because it is easily crumbled or reduced to powder.
The microscopic amosite fibres require very little disturbance to become airborne.
A government-funded Loose Asbestos Insulation Removal program was conducted from 1988 to 1993 to remove the substance from houses. This followed a survey of all ACT homes built before 1980 to determine whether this insulation had been used.
The ACT government says at the time home owners were advised that some residual asbestos would remain in inaccessible areas and caution was needed when undertaking renovations and repairs.
Since 2004 residential sales in the territory must include a lease conveyance report advising buyers whether the house contained loose-fill asbestos.
But there have been calls for a mass public awareness campaign as this deadly form of asbestos has been found in the subfloors of five homes in the past four months.
And the ACT government will assist in the remediation this year of a house that missed the original clean-up two decades ago.
A Yarralumla family contacted The Canberra Times after they were exposed to amosite during a recent home renovation.
Mark and Sue Harradine want other ''Mr Fluffy'' home owners to be aware of the risks they could face and do not believe the message is made clear enough to potential buyers.
Robson Environmental, which conducted the testing on the Harradine home, has found amosite asbestos in the subfloors of five previously cleaned ''Mr Fluffy'' homes this year.
Robson's hazardous materials manager, Ged Keane, said most people had the perception that the asbestos had been entirely removed during the program.
But he said it was impossible to remove all the microscopic fibres. He said the company, which conducts tests for ACT Work Safe, had recently found the asbestos had migrated from the wall cavities from which it originally could not be removed.
They could not see the substance in clumps but had tested samples invisible to the eye.
''As long as people don't do any refurbishment, knock down walls, replace sockets, then it's contained within the walls - the removalists couldn't get at it to remove it,'' Mr Keane said.
''But if you've got areas where you've got a big subfloor where there's a garage and a workshop, and it's migrated down there, then there is the risk or the potential because you don't know.''
He said the paperwork home buyers received should be stamped in big print with a warning about the potential of loose-fill asbestos still proving a danger in the home.
''It's the worst, most dangerous kind. This type's probably a hundred times worse [than white asbestos].
''Now we know they couldn't clean down the wall cavity so the chances of it being down wall cavities in all [homes] is quite likely.''
ACT Work Safety commissioner Mark McCabe said while there was
an intensive awareness campaign done at the time of the clean-up it was hard to say how much knowledge home owners would have now.
He said problems probably arose when the homes changed hands, despite the requirement for the information to be presented to the potential buyers in the conveyancing report.
''Current owners may not realise the seriousness of it, or the need to take care,'' Mr McCabe said.
''The real problem with asbestos is it's an invisible health hazard so it's hard to get people to appreciate the seriousness of it.''
While he said there had been a recent spike in awareness of the dangerous nature of asbestos due to media reports and the government's public health website on the substance it was not specifically about amosite.
He said he would not necessarily support a new campaign on the substance because it was found quite rarely compared with the white bonded asbestos.
But Mr McCabe said it was likely that over such a long period of time the loose-fill asbestos would migrate.
A spokeswoman for Workplace Safety and Industrial Relations Minister Simon Corbell said the government had made efforts to advise people of the continuing presence of loose-fill asbestos in their homes since the clean-up more than two decades ago.
She said the program had been considered a success as the aim had been to remove asbestos from visible accessible areas in accordance with a code of practice still reflected in current regulations.
''It was always anticipated that most homes subject to the abatement program would continue to contain some residual loose-fill asbestos insulation,'' the spokeswoman said.
''It is important to understand that the clean-up program was never intended to remove all loose asbestos from homes.
''What it did was remove loose asbestos from visible and accessible areas, particularly the roof and accessible wall cavities.''
She said at the time owners of abated homes were ''expressly advised of the limitations of the program''.
In 2005 the ACT government sent a letter to all home owners recorded as being part of the program reminding them to take appropriate steps when undertaking renovations.
Mr Corbell's spokeswoman said the government was finalising a new comprehensive asbestos website and fact sheets on the program highlighting the presence and dangers of the loose-fill asbestos.
The Asbestos Regulators Forum, formed in 2011, is considering further measures that may be implemented to ensure the public is appropriately aware of the continued existence of the asbestos.
The ACT government has also assisted in the remediation of three homes - in Watson (1996), Lyons (2007) and Mawson (2009) - that missed the program.
A fourth home still subject to a confidentiality agreement will be cleaned this year.
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