Asbestos was widely used in the past for insulation, in building materials in the form of asbestos cement, and in brake linings.In the home it was used in asbestos mats for gas stoves, oven mitts and stands for electric irons, and sometimes for thermal insulation. All these uses have now been banned and substitute fibres are used. Often there are no records of where asbestos was used, but one must assume that any fibrocement sheets, roofs or pipes installed before 1981 contain asbestos. If it is in a place where nobody touches it, such material should be quite safe. If it is inside a house, it should be painted so that no fibres can be rubbed off it. Do NOT sand first.

If asbestos cement sheets are to be removed, drilled or sawn, they should be thoroughly wetted beforehand and protective clothing and a good quality respirator worn (see Protective clothing). Power tools should not be used as they produce more dust than handsaws or drills. Old asbestos sheets should not be re-used. The local council or state environment protection authority should be consulted about where and how to dispose of old asbestos cement.

If asbestos insulation is to be removed from a building, a specialist licensed firm must be employed. Complete, positive-pressure 'spacesuits' have to be worn during the work to protect the workers from asbestos dust and fibres.

Health effects
Asbestos fibres are smaller than other common industrial fibres and are invisible to the naked eye. They become airborne easily and can be inhaled deep into the lungs. Exposure to even a small amount of asbestos may lead to diseases such as asbestosis, lung cancer or mesothelioma, a form of cancer, often after a delay of 20 to 40 years. All types of asbestos can lead to these illnesses although the blue variety seems to be the worst. Smokers are especially vulnerable.

Under national occupational health and safety regulations, the permitted maximum concentration in the workplace of airborne asbestos fibres is 100 fibres per litre for brown and blue asbestos and 1,000 fibres per litre for white asbestos (500 fibres per litre in New South Wales). If these levels are exceeded measures have to be taken to remove the asbestos.

Environmental effects
In the past the families of people working with asbestos or asbestos products (e.g. miners, mechanics working on brakes, plumbers insulating pipes and building workers using asbestos sheets or insulation) were as much at risk as the workers themselves, for fibres easily contaminate clothing and homes. Factories using asbestos could also spread contamination over a wide area. The use of blue and brown asbestos is prohibited in Australia and chrysotile (white) asbestos will be phased out by the end of 2003. Waste dumps containing asbestos products which are inadequately covered still present a danger.

Alternatives
Many different fibres are now used to replace asbestos. In brake linings, fibreglass, rockwool and even organic polymer fibres are used to give strength to the material. Fibrocement has been made with cellulose fibres since 1981, and insulating material now mostly consists of fibreglass wool or rock-wool/synthetic mineral fibres (see also Insulating materials). The fibres of these are of much larger diameter than those of asbestos, but their dust can also irritate the skin and the lungs. Insulation made of cellulose, wool, polyester and foil with a cellular fill are also available.

Related sites

www.diysafe.nsw.gov.au