What is Asbestos?
Asbestos is a generic term applied to some mineral silicates of the serpentine and amphibole groups, whose characteristic feature is to crystallise in fibrous form.
Asbestos is a physical paradox it is described as having the “Combined properties of silk and rock”
- Fibres can be spun into strands that can be woven into cloth
- Tensile strength similar to steel
- Good flexibility
- Almost indestructible- will not burn, rot or corrode
- The word “asbestos” comes from Greek word “amiantus” meaning ”inextinguishable” or “indestructible”
There are many members of the family – common among these are blue asbestos (crocidolite), white (chrysotile) and brown or grey asbestos (amosite). Other forms of asbestos include anthophyllite which was used mainly in Finland. However tremolite, said to be part of the amphibole asbestos group, was used in some commercial talcs in small quantities and is also a contaminant of other asbestos types, e.g. chrysotile (white asbestos).
The three most common types of asbestos that were mainly used in a wide range of products are:
- Chrysotile (white asbestos)
- Crocidolite (blue asbestos)
- Amosite (brown or grey asbestos)
Until the late 1960s, the Australian industry used both serpentine (75%) and amphibole (25%) asbestos. Subsequently, the use of chrysotile increased to approximately 95% whilst blue and grey asbestos declined to 5%.
Asbestos is one of the most useful and versatile minerals known to man mainly because of its unique properties, flexibility, tensile strength, insulation (from heat and electricity) and chemical inertness. It is the only natural mineral that can be spun and woven like cotton or wool into useful fibres and fabrics.
The importation of Asbestos ceased at the end of 2003 however, there will be limited exceptions for the approved use of asbestos products in highly specialized industries.
SOURCES OF ASBESTOS
Large deposits of asbestos were discovered in the Ural Mountains in the Soviet, in the Alps of Northern Italy, Canada, USA, South Africa and Rhodesia. In Australia, large deposits of crocidolite were found in the North of Western Australia at Wittenoom Gorge and some deposits of white asbestos were mined in Northern New South Wales (Barraba and Baryulgil).
The versatility of Asbestos enabled it to used across a variety of industries these include
Asbestos is contained in some 3000 products manufactured world wide
- Construction Industry – used 2/3 of all asbestos
- Car Manufacturing
- Textile Industry
- Aerospace Industry
- Marine and Rail Transport industries
Some Deteriorating Asbestos Products (below)
Asbestos at Home
Most homes built before the mid 1970’s contain asbestos in some form, and in fact asbestos building products continued to be used up until the early 1980’s. Asbestos was easy to work with, was affordable and had the added quality of being heat resistant.
There are more than 3000 applications of asbestos use – the result is that workers have and are exposed in virtually every occupation, and most homes contain asbestos in some form.
Asbestos was often sprayed onto ceilings and walls for a variety of purposes, i.e. decorative, etc. It was also used as a form of insulation around the pipes behind radiators or wood-burning stoves. Asbestos was also used in Vinyl floor tiles and their backings, roofing, eaves, shingles, some plaster and paint. Many routine repairs, renovation and maintenance activities – even putting in a new heating system – can disrupt asbestos, releasing millions of fibres into your home, school or office.
Asbestos cement products such as roofs and cladding contain as much as 11% to 20% of chrysotile and 5% to 10% amphibole asbestos (crocidolite or amosite). As a result of the continuing exposure to meteorologic influences such as rain, sunshine, wind and frost, as well as to industrial atmospheric pollutants, the surface of asbestos cement products corrodes and weathers.
Thus, cement particles and asbestos fibres are released from the surface and disperse in air and rainwater.
Residential housing and schools were often clad with fibro cement sheeting (commonly known as fibro) and roofed with corrugated asbestos cement products.
Common Domestic Applications of Asbestos are:
- Vinyl Tiles
- Hessian sacks used to carry asbestos used as lining under carpet and tiles
- Insulation on Hot Water Pipes
- Millboard behind heaters and stoves
- Asbestos cement sheeting in various forms and styles on walls and eaves
- Insulation inside fuse boxes
- Asbestos Ceiling insulation in either a dry form or as a roofing felt
- Asbestos corrugated roofing and fencing
- Asbestos plasters
- Asbestos being mixed into paint to give walls and ceilings a textured look.
Please seek professional advice on handling Asbestos around the home from your Local Authority or Department of Health or ring the ADSA on 1800 646 690.