Introduction To Asbestos – A Brief Overview
Let’s start with a brief overview of asbestos.
Asbestos is a generic term used to describe a variety of fibrous silicate minerals. This building material, which was used from the 1940s to the 1980s, was prevalent among builders because of its durability, resistance to fire and beneficial insulation properties. However, once the building industry learnt of the umpteen health risks that are associated with the use of asbestos, its popularity gradually waned, before the manufacture and use of all asbestos products was finally banned across Australia on December 31, 2003.
While this nationwide ban was implemented on the manufacture, storage, supply, sale, installation, use, reuse and replacement of asbestos, owing to its durability and resistance to heat and chemicals, asbestos cement continues to be used in the manufacturing of certain building materials even today. Some of these products include fibro sheeting, guttering, corrugated roofing sheets, roofing shingles, downpipes as well as other pipes that are used for water.
Noteworthy Properties of Asbestos
Below are some key properties of asbestos which is why it was used as a popular building material prior to it being banned here in Australia.
- It is stable when heated
- It is strong and durable
- It is suitable for weaving and reinforcing
- It is resistant to chemicals
- It is resistant to electricity
- It is resistant to water and absorbency
The Queensland Government has detailed information on asbestos here.
Friable and Non Friable Asbestos
Asbestos products can be broadly classified as friable and non-friable.
The term friable’ is used to describe asbestos-containing materials that, when dry, can be easily reduced to powder by being crushed in the hands. These products usually contain a high percentage of asbestos fibres and are more likely to release them into the environment, when disturbed. This makes friable asbestos more hazardous to health in comparison to non-friable asbestos, which is why such products must be handled and removed only by a licensed asbestos removal company who have acquired an A-class licence.
Some products that contain friable asbestos include:
- Certain sprayed-on fire retardants
- Insulation and sound proofing
- The lining on some dated stoves, domestic heaters and hot water systems as well as the pipe lagging associated with these utilities
- Linoleum floor coverings and the backing of sheet vinyl
- Thermal lagging, like pipe insulation
Non Friable Asbestos
The term non-friable’ is used to describe asbestos-containing materials, in which the asbestos fibres are firmly bound to the matrix of the material. Also known as bonded asbestos, these products are less likely to release measurable levels of asbestos fibre into the environment, when disturbed. This makes non-friable asbestos less hazardous to health in comparison to friable asbestos. Such products, comprising of asbestos fibres that are held together with a bonding compound, like cement, typically contain less than 15 percent asbestos. Non-friable materials made from asbestos are solid, rigid and commonly found in domestic houses. They are also referred to as asbestos cement, fibro or AC sheeting.
Some products that contain non-friable asbestos include:
- Plaster patching compounds
- Vinyl floor coverings
- Textured paint
- Asbestos cement products
For more information on friable and non friable asbestos please click here.
Asbestos as a Health Hazard
Asbestos can prove to be health hazard if the fibres are suspended in the airborne environment and allowed to roam freely. Inhaling asbestos fibres can lead to a number of health problems.
As a matter of fact, every person is exposed to low levels of asbestos on a daily basis, with ambient air typically carrying 10 to 200 fibres per 1,000 litres. Whether a person eventually develops an asbestos-related disease depends on a number of factors, including the duration of exposure, degree of intake, period since first exposure, fibre types and concurrent exposure to other carcinogens.
When a person inhales asbestos fibres, the particulates tend to remain embedded in his or her lungs. They are known to cause inflammation and scarring in some cases though there are fewer instances of serious health problems emerging from the same.
- Pleural plaques
Often considered to be the earliest sign of exposure to asbestos, pleural plaques refer to areas of smooth, white, raised scar tissue that develop on the outer lining of the lungs, diaphragm and internal walls of the chest. Not every person that has been exposed to asbestos is likely to develop this condition, possibly because of the way in which different immune systems respond to asbestos fibres.
This is a chronic condition that results from the severe inflammation or scarring of the lungs. A person suffering from asbestosis will most likely have been exposed to asbestos for a long period and is expected to experience whooping cough and shortness of breath.
- Lung Cancer
Lung cancer is likely to develop if a person who has been exposed to asbestos fibres also happens to smoke or has a pre-existing lung problem. In this case, cancerous tumours develop along the lining of the tubes leading up to the lungs, the middle of the lungs or smaller air passages.
This rare form of cancer that develops in the tissue lining a person’s chest and abdominal cavities is often traced back to a confirmed history of significant exposure to asbestos. In Australia alone, approximately 90 percent of all patients diagnosed with mesothelioma have, at some point, been exposed to asbestos.
The removal of asbestos, including products from homes and workplaces, has varying obligations under different laws in Australia. For example, in Queensland, the practice of removing asbestos is legislated under the Workplace, Health and Safety Regulation of 2011 and strictly monitored by the Workplace, Health and Safety Licencing. In other words, if the asbestos that needs to be removed happens to be non-friable and exceeds 10m2, then only a licensed company can carry out the procedure. If the asbestos that needs to be removed happens to be friable, then also, only a licensed company must carry out the procedure and take necessary steps mandated under the Workplace, Health and Safety Regulation of 2011 that would ensure no asbestos fibres are released in the air.
Most people seem to think that asbestos materials are used only outside buildings, for instance, on wall sheeting, carport ceilings, eaves, corrugated roofing and fencing but the truth of the matter is that such products are used inside buildings as well. Being able to identify products that contain asbestos and assess whether they are safe or undsafe is important not only for homemakers but also those who regularly attend a workplace.
Safe work Australia has detailed information on asbestos which you can view here.
You can find out information on asbestos training courses here.