1. What is asbestos?

Asbestos is the name given to a group of naturally occurring minerals found in rock formations. Three types of asbestos were mined in Australia: white, blue and brown asbestos. Asbestos fibres are strong, heat resistant and have insulating properties. Asbestos fibres can be mixed with other materials, such as cement, to produce a variety of building products. Up to 90% of the asbestos produced in or imported into Australia was used for the manufacture of building products, especially asbestos cement materials, such as fibro-cement sheet.

The majority of asbestos (90%) used throughout the world, including Australia, was white asbestos. Australia banned the use or import of blue and brown asbestos or asbestos products in the mid-1980s, and banned all manufacture or import of white asbestos products in December 2003.

2. What is the difference between non-friable and friable asbestos materials?

Manufactured asbestos containing materials are classified as friable or non-friable. Non-friable is defined as not able to be crumbled, pulverised or reduced to powder by hand pressure. Non-friable asbestos materials are composed of asbestos fibres combined with a substrate such as cement or bitumen, where the asbestos fibres are encapsulated within a binding matrix.

Non-friable asbestos materials commonly used in domestic and industrial locations include asbestos fibro-cement sheet, asbestos cement moulded products, bitumen based water proofing and vinyl floor tiles.

Friable asbestos is defined as being able to be crumbled, pulverised or reduced to powder by hand pressure, for instance, pipe lagging, boiler insulation and sprayed insulation.

Non-friable asbestos materials can be made friable through damage or work processes, for example asbestos cement sheet that has been crushed, cut, drilled or sanded, or has degraded from long-term exposure to environmental factors such as acid rain.

3. Does my home need to be inspected for asbestos materials before I can start demolition or renovation work?

TV shows like 'The Block' depict contestants tearing down walls with a sledgehammer. However it is important to recognise that these properties have been audited for asbestos materials, and the materials safely removed before the show begins.

We always recommend that a pre-demolition (Division 6 audit) inspection is conducted on your home as soon demolition/renovation of any area of the building is proposed.

The majority of houses constructed or renovated between the late 1940’s and the late 1980’s contain asbestos materials. Sheds, garages and boundary fences are also often constructed of asbestos fibro-cement sheet. Asbestos containing material is most often located in bathrooms, kitchens, laundries and toilets.

Home improvements over the years since the house was built may have resulted in newer materials being laid over the top of older asbestos materials. For example, it is common to find new vinyl floor sheet installed over 1970’s patterned vinyl sheet in kitchens, bathrooms and laundries. Vinyl sheet from the 1970’s often has a white backing which is made almost entirely of asbestos fibre. Removal of the vinyl sheet and asbestos backing by a tradesperson can break-up the asbestos backing and result in contamination of large areas of the house with asbestos fibre.

The most likely cause of asbestos contamination in people’s houses occurs when a contractor starts demolition before the asbestos has been identified and removed. Breaking asbestos fibro-cement sheet asbestos with force or friction cutting the material, can release large quantities of asbestos fibres which remain suspended in the air for long periods before settling on surfaces in the house. Members of the household and family are then at risk from exposure to the asbestos fibres.

4. What happens if my house becomes contaminated by asbestos?

Where asbestos contamination of internal areas is suspected, a Licensed Asbestos Removalist (LAR) is required to undertake the clean-up. An occupational hygienist must be engaged to undertake a visual clearance inspection and air monitoring of the cleaned areas to confirm that the area is safe to be reoccupied.

Not all surfaces can be effectively cleaned however; carpets, rugs and fabric lounge suites have the potential to harbour asbestos fibres. Only hard surfaces that can be cleaned with a specialised vacuum cleaner and wet wiped can be completely decontaminated.

Decontamination of internal surfaces by an asbestos removal contractor can be a lengthy and expensive process. You may be faced with the prospect of not being able to return to your house until decontaminated and verified safe for occupation, recovering costs from the tradesperson for clean-up and decontamination, and unwanted delays to your project.

5. Can I clean-up asbestos contamination using a normal vacuum cleaner?

A domestic vacuum cleaner is not suitable for cleaning surfaces contaminated with asbestos dust. Use of a domestic vacuum cleaner and dry dusting of contaminated surfaces can disturb fibres so that they become airborne and are inhaled.

Hard impervious surfaces contaminated by asbestos dust can be effectively cleaned using a Class H vacuum cleaner with HEPA filter, that meets Australian Standard AS3544-1988, followed by wet wiping the surface. We recommend that asbestos decontamination is always undertaken by licensed asbestos removalist.

In the event that fabrics and carpet have been heavily contaminated by asbestos fibres, HEPA vacuuming may not be effective as the asbestos fibres can persist within the carpet and material even after cleaning. We recommend that any rugs, fabric upholstered chairs, curtains etc are covered with plastic sheeting and sealed with tape or removed from any area undergoing asbestos removal to an area that can be sealed, as a precaution against accidental asbestos contamination.

6. Who is at risk of developing asbestos related disease?

People living in large cities, particlarly residential areas bordering old industrial sites are exposed to low levels of airborne asbestos fibres each day. Industrial areas record higher levels of airborne asbestos, which is a legacy of the extensive use of asbestos materials in industry.

Ambient or background air usually contains between 10 and 200 fibres in every 1000 litres or 1 cubic metre of air (which is equivalent to 0.01 to 0.20 fibres per litre of air. At rest the average person breathes in 11 cubic metres of air a day and in that air there are approximately 110 asbestos fibres.

Most people are exposed to short incidents of higher levels of asbestos during their lives, resulting from accidental damage in the home, or as a result of tradespersons undertaking repair or renovation work in the home or in the workplace. For most people infrequent exposure is unlikely to result in disease.

Those most at risk are workers exposed to asbestos at work. Workplaces most at risk include demolition, roofing and construction contractors, engineers (heating, ventilation and telecommunications), electricians, painters and decorators, plumbers, plasterers and maintenance workers.

The risk of developing disease is dependent on the dose, which is the number of fibres breathed in each exposure and the number of times this occurs over a lifetime. Visible asbestos fibres are too large to become airborne and enter the lungs. Most large airborne fibres like any other particle that enters the airway are caught in the mucous of the respiratory system and expelled by coughing and sneezing.

Only fibres that can only be seen with a microscope that are small enough to enter the lower reaches of the lungs and have not been caught by the bodies natural defenses, have the potential to cause disease.