What is asbestos?
Asbestos is a group of naturally forming minerals that are widely distributed in nature. It was widely used in the production of insulation and construction materials due to its strength, flexibility, heat resistance and relatively cheap cost for mining and processing. Asbestos was also used as an additive in paint and sealants, vehicle brake pads and clutches, and outdoor furniture.
Unfortunately, asbestos is a highly toxic, insidious, and environmentally persistent material that has affected thousands of Australians, and is likely to affect thousands more this century.
Types of asbestos
The three most widely used types of asbestos were:
- Crocidolite: blue asbestos
- Amosite: brown or grey asbestos
- Chrysotile: white asbestos.
In the past, Australia was one of the largest consumers of asbestos in the world. Australia only began regulating the use of asbestos products in the late 1970s and a ban on asbestos was introduced in 2003.
Asbestos-containing building products
Asbestos-containing building products are classified under two categories:
Friable (soft, crumbly): These asbestos products are generally quite soft and loose and can be crumbled into fine dust with very light pressure, such as crushing in your hand. Friable asbestos products contain high levels of asbestos (up to 100%) loosely held in the product so that the asbestos fibres are easily released into the air. Thermal insulation around pipes is an example of a friable asbestos product. Friable asbestos products are dangerous because the asbestos fibres can get into the air very easily, and may be inhaled by people living or working in the vicinity.
Bonded (solid, rigid, non-friable): These asbestos products are made from a bonding compound (such as cement) mixed with a small proportion of asbestos (usually less than 15%). Fibro Sheeting is an example of a bonded asbestos product. Although bonded asbestos products do not normally release any asbestos fibres into the air and are considered a very low risk, there is potential for damaged or weathered (including hail damage) products to become friable thereby creating the risk of releasing asbestos fibres into the air.
Why is asbestos dangerous?
Small airborne asbestos fibres carry the greatest risk as they can be inhaled into the respiratory system via the nose and mouth. Asbestos fibres can also be swallowed and then enter the digestive system.
Asbestos fibres that are inhaled into the lungs can become lodged or embedded into the lung tissue. These fibres can irritate lung tissue surrounding them and may cause a number of health concerns including a number of asbestos related lung diseases.
Asbestos related diseases
Asbestos related diseases can take many years to develop in some cases up to 20 – 40 years after exposure. However it is important to note that exposure to asbestos fibres does not always result in an asbestos related disease. While some asbestos related diseases affect the inside of the lungs the majority affect the pleura. The pleura is a thin membrane that lines the surface of the lungs and the inside of the chest wall outside the lungs. Embedded asbestos fibres can irritate the lung tissue that’s surrounding them and may cause a number of diseases. Asbestos related diseases include: Mesothelioma, Lung cancer and Asbestosis.
Where you might find asbestos
The versatility of asbestos made it attractive to many industries and it is thought to have been used in more than 3,000 different applications worldwide, with Australia being one of the highest users of asbestos. This same versatility now poses a problem for identifying areas that still contain asbestos products and the potential for people to be exposed to asbestos and its associated health risks.
Approximately one third of all homes built in Australia contain asbestos products and any home built prior to 1991 could possibly contain asbestos products.
As a general rule if your house was built:
- Before the mid-1980s: It is highly likely that it has asbestos-containing products.
- Between the mid-1980s and 1990: It is likely that it has asbestos-containing products.
- After 1990: It is unlikely that it has asbestos-containing products. However, some houses built in the 1990s and early 2000s may have still used asbestos cement materials until the total ban on any activities involving asbestos products became effective from December 2003.
If you are thinking about renovating, you must be aware of asbestos. It is important for home owners and renovators to be aware of how to safely manage asbestos in and around the home.
You cannot determine whether a material contains asbestos by simply looking at it. The only way to be sure is to get a sample tested by a National Association of Testing Authorities (NATA) accredited laboratory.
In fact, there are many areas in the home where asbestos-containing materials can be found including (but not limited to):
- roof sheeting and capping
- gables, eaves/soffits water pipes and flues
- wall sheeting (flat or a weatherboard style)
- vinyl sheet flooring
- carpet and tile underlays
- zelemite backing boards to the switchboards
- flexible building boards
- imitation brick cladding
- carports and sheds
- waterproof membrane
- telecommunications pits
- some window putty
- expansion joints
- packing under beams
- concrete form-work
Steps for reducing your risk
- Know where asbestos-containing products could be in your home. If in doubt, get the product tested, or assume it is asbestos.
- Maintain asbestos-containing products in good condition (e.g. use paint, surface finishes, enclosures, or capping).
- Replace asbestos cement materials if they are damaged. Ensure all friable asbestos is removed by a licensed asbestos removalist.
- Plan ahead to prevent disturbing and releasing asbestos fibres, especially when renovating.
- Get advice from your local or State/Territory government on safe handling and disposal of asbestos-containing products.
- Engage a licensed asbestos removalist when undertaking major home renovations or demolitions where asbestos might be present.