ABOUT ASBESTOS MINERALOGY
Asbestos is a family of crystalline hydrated silicates with a fibrous geometry and unique physical and chemical properties. Asbestos fibre is classified into two groups, serpentine and amphibole. Chrysotile (or “white asbestos”) is the only member of the serpentine group. Crocidolite (“blue asbestos”), amosite (“brown asbestos”), tremolite, anthophyllite and actinolite are amphiboles. The amphiboles are characterised by long rigid fibres. Chrysotile fibres are wavy and tend to break into smaller fragments.
INDUSTRIAL USE OF ASBESTOS
Asbestos has been used widely throughout history because of its strength, flexibility, durability and its resistance to heat, acids and alkalies. The majority of asbestos used in Australia was incorporated into asbestos cement (“AC”), i.e. cement reinforced with asbestos fibres. There were two main categories of AC product, building materials and pressure and sewerage pipes. The building materials included corrugated sheeting, flat sheeting, roof tiles and moulded products such as gutters and telecom pits. High density AC was used for thermal and electrical insulation, such as in furnaces, bench tops, fume cupboard linings and switch gear. AC poses fewer health risks than certain other types of asbestos-containing products because the asbestos fibres are firmly bound into a cement matrix.
The second largest category of asbestos use was as a filler or reinforcement. The main products within this category included asbestos-containing paper and millboard which were used in the manufacture of products such as roofing felts, clutch facings, brakes and gaskets. Fibres were added to paint to give various textured finishes, strength, heat resistance and opaqueness. Many plastic sheets and tile flooring products contained asbestos. Asbestos packings and seats were used in a wide range of products, for example, gaskets. Asbestos reinforced plastics were incorporated in automotive components, small machine parts, road signs and bearings.
Asbestos is an excellent insulation material. Fire resistant insulation boards were similar to asbestos cement products but had a much higher asbestos content, 25% to 40% versus 10% to 15% by weight. They were widely used for partitions and suspended ceilings as a barrier to fire or to protect structural steelwork. Asbestos lagging for thermal insulation was made in the form of rigid pipes, slabs, pre-formed sections or sprayed coatings. Sprayed on asbestos insulation was easier to apply, particularly on uneven or hard to get at surfaces. Pipe and boiler lagging was commonly used in ships, engineering works, power stations, factories, hospitals and other large buildings. Woven asbestos was used to manufacture asbestos quilts, mattresses, and blankets for thermal insulation. These were often used on ships. Asbestos cloths were made into protective clothing and safety curtains. Asbestos cord or rope was used for thermal insulation on small domestic and industrial pipe work. Asbestos yarns and fabrics had a high asbestos content, up to 100%.
Currently world usage of asbestos is confined to chrysotile and to four principal product categories; asbestos cement, friction materials, roof coatings and cements, and gaskets. Approximately 85% of chrysotile used worldwide is for production of asbestos-cement products (pipes and sheets), mainly in developing countries. In 1992, approximately 28 million tonnes of asbestos-cement products were produced in about 100 countries. About 10,000 tonnes of chrysotile asbestos is imported in Australia annually for use in friction products. The use of asbestos is being progressively phased out across the world.
ABOUT ASBESTOS MINING INDUSTRY IN AUSTRALIA
For much of the 20th Century, with the exception of the early 1980s, most of the asbestos fibre used in Australia was imported.3 Until the re-opening of the Woodsreef mine at Barraba in 1970, the only mine of note was the Wittenoom mine in Western Australia which produced blue asbestos from about 1937 until 1967. The Woodsreef mine produced white asbestos and approximately half of its production was exported. Asbestos mines were operating around 1918 in Tasmania and at Baryulgil in NSW. Small mines produced crocidolite in South Australia from as early as 1916 until the 1950s but never in large amounts.
Australian Blue Asbestos Pty Limited (a subsidiary of CSR) started production at Wittenoom in the Pilbara region of Western Australia in 1938. The mine ceased production in 1966 as it was unprofitable. In 1997 to 1983, Woodsreef operated at Barraba, NSW, the largest chrysotile mine in Australia. Australia was never a large producer of fibre; in 1952 it produced only 0.2% of world production.
PRODUCTION AND USE OF ASBESTOS FIBRE IN AUSTRALIA
The bulk of asbestos used in Australia during the 20th Century (perhaps over 90%) was used to produce asbestos cement (“AC”). AC refers to cement that has been reinforced with asbestos fibres to produce a much stronger and more useful product. The presence of asbestos can also render the product harder and more fire resistant. Prior to 1916 AC products were imported from England and Europe. In 1916 the Wunderlich company (later part of CSR) opened a factory in Cabarita, a Sydney suburb. Other factories (including those operated by James Hardie) soon followed. The peak period for the industry was following World War II when demand outstripped supply. For example, it became necessary to order pipe for large civil projects many years in advance and State Governments rationed supply.
Asbestos cement (“AC”) sheeting was liberally used in housing during this time. Between 1945 and 1954 more than 70,000 homes were built using AC cladding in NSW, 57% of the homes built in the State. In Australia as a whole 25% of new houses were built with AC. The bulk of fibre used was chrysotile from Canada. The addition of amphiboles helped speed up the rate of production and strengthen the product. Amosite was the major amphibole used and was imported from South Africa, some crocidolite from the Wittenoom mine (operated by a CSR subsidiary) in Western Australia was also used. Crocidolite’s use was limited as it was more expensive and added a blue discolouration to the product.
CONSUMPTION OF ASBESTOS PRODUCTS AND MATERIALS
Australia has been one of the largest consumers of asbestos in the world. During the 1950s Australia was the fourth largest consumer of asbestos cement products and the highest per capita user of asbestos in the world (predominantly chrysotile). There was a rapid increase in the use of asbestos in Australia for the 30 years from 1940 to 1970, followed by a relatively stable volume during the 1970s. The decline in usage was even more rapid than the increase, with consumption dropping to relatively small amounts by 1985 and to very small amounts by the end of the 1980’s. The use of asbestos in Australia was effectively banned from the end of 2003.
Because industrial and commercial use of asbestos was widespread in Australia to up to the 1980s, recipients of claims have included government bodies (e.g. the Royal Australia Navy, State Rail Authority, Land & Housing Commission, Pacific Power), manufacturers (e.g. JHIL, Coy and Jsekarb, CSR Limited through its subsidiary Seltsam), employers (e.g. major construction companies) and occupiers of sites where asbestos was used (e.g. power station operators).
Asbestos fibres can cause various diseases when inhaled. The risk of disease depends on the type of fibre the concentration of asbestos in the inhaled air and the period of time over which the person was exposed. Long thin fibres (typical of amphiboles like crocidolite) are generally more carcinogenic than shorter thicker ones (typical of chrysotile), possibly because amphibole fibres are not cleared as quickly from the lungs. Fibres less than 5 um in length are mostly removed by the lungs’ own clearance mechanism. Fibres longer than 5 um are mostly deposited in the respiratory and terminal bronchioles and it is these fibres that may subsequently cause disease.
OCCUPATIONAL ASBESTOS EXPOSURE
Exposure to asbestos fibres from products or manufacturing processes is said to occur in various ways. Exposure usually occurred at work, although cases of domestic exposure (a wife washing her husband’s work clothes, for example) are not uncommon. Claims have also been received from waterside workers who allege exposure to raw asbestos while unloading or handling bags of asbestos fibre which has been imported or shipped.
Raw asbestos is used in asbestos cement manufacture. The asbestos dust levels generated in asbestos cement manufacturing factories was generally lower in comparison with other manufacturing processes involving asbestos. Progressive introduction of control measures from the late-1950s helped reduce dust levels in factories. A medical surveillance scheme for James Hardie workers was established in the 1960s and a full-time doctor was employed from 1967 to advise on all aspects of asbestos health related issues.
Most asbestos products destined for the construction industry did not undergo any further manufacturing operation between the factory and the construction site. However flat and corrugated asbestos cement sheets and asbestos cement pipes were cut, drilled or processed on site and these processes could release asbestos fibres and dust which were then inhaled by workers or bystanders. From 1978 Coy’s asbestos cement products carried warning labels. Prior to this Coy provided use instructions which recommended that users take steps to keep dust down (such as wetting the product while cutting it).
Exposure to asbestos in friction products occurred in the manufacture and maintenance of those products, particularly amongst motor mechanics. However, the risk of contracting an asbestos-related disease from exposure to brake linings is not high due to the fact that friction products only contained chrysotile and because of the low and intermittent exposure to asbestos experienced by mechanics.
ENVIRONMENTAL EXPOSURE TO ASBESTOS
Due to the widespread use of asbestos in industrialised countries some exposure to asbestos is probably universal, particularly in urban areas. Asbestos fibres have been found in water supplies and food products. Asbestos fibres are commonly found in the lungs of city dwellers. Whether asbestos exposure in the general population at these low levels causes disease is contentious and, on present scientific evidence, is most unlikely. That is, exposure to a greater than background level of asbestos is necessary to develop disease.
WHEN ARE YOU MOST AT RISK?
All types of asbestos can break into fibres so small that once they get into the air, they can remain airborne and be inhaled into the lungs, making it difficult for the body to remove them. In some people, this can lead to asbestos-related disease.Asbestos-related diseases are mainly cancers of the lungs, cancers of the chest lining (mesothelioma) and asbestosis, which is a non-cancerous condition. The lower the level of exposure to asbestos the lower the level of risk. Therefore, the aim should be to minimise exposure to asbestos in the air.
Diseases caused by asbestos may not become evident for up to 50 years, and there is no known cure. Research has shown that smoking significantly increases the risk of lung cancer in people who have been exposed to asbestos. Materials containing asbestos do not pose a risk to health if they are left undisturbed and are in good condition. Asbestos is only a risk to health if asbestos fibres are released into the air and breathed in. DIY renovators and tradespeople are the ones most at risk of exposure to asbestos fibres as they are more likely to frequently undertake repairs, renovations and other work such as using power tools, sawing or sanding, which can generate the release of asbestos fibres into the air. So, watch out for asbestos and take care.You are mostly at risk when:
- You are working on an unfamiliar site;
- The building you are working on was built before the year 1990;
- Asbestos-containing materials and other hazardous materials were not identified before the job was started;
- Asbestos-containing materials and other hazardous materials were identified but this information was not passed on by the people in charge to the people doing the work;
- You don’t know how to recognise and work safely with asbestos and hazardous materials; and/or
- You know how to work safely with asbestos and hazardous materials but you choose to put yourself at risk by not following proper precautions, perhaps to save time or because no one else is following proper procedures.
Remember, as long as the asbestos and/or hazardous materials are not damaged or located somewhere where they can be easily damaged, they won’t be a risk to you.
- You can’t see or smell asbestos fibres in the air;
- The effects of asbestos take many years to show up – avoid breathing it in now;
- Smoking increases the risk many times; and
- Asbestos is only a danger when fibres are made airborne
ASBESTOS RELATED DISEASES
There are four principal asbestos-related diseases:
(a) Mesothelioma – a disease in which cancer (malignant) cells are found in the sac lining the chest (the pleura) or abdomen (the peritoneum);
(b) Asbestosis – a progressive scarring of the lungs which is potentially fatal;
(c) Lung Cancer – which may in certain circumstances be caused by exposure to asbestos; and
(d) Asbestos-related Pleural Disease – a range of non-malignant conditions similar to asbestosis which are caused by inhalation of asbestos fibres.
ARPD can range from asymptomatic pleural plaques to extensive pleural fibrosis causing severe breathlessness.
Further details can be found at http://www.asbestosdiseases.org.au/
Malignant mesothelioma is the most serious asbestos-related disease. The typical life expectancy from diagnosis is six to nine months. It is a diffuse malignant tumour usually of the pleura or peritoneum. Although it can take 30 years or more to manifest itself from the person’s first exposure to asbestos, once the tumour starts growing it is unusually aggressive.
The connection between asbestos exposure (crocidolite) and mesothelioma was first established by Wagner in South Africa in 1960. The relative risk for developing mesothelioma is dependant on fibre type, dose and time since first exposed. Thus, those exposed at younger ages are at higher lifetime risk. However, mesothelioma is associated with a wide range of exposure duration and pulmonary asbestos burdens, including sometimes seemingly small exposures. Families of asbestos workers exposed to asbestos on hair and clothing have been found to be at risk, as are employees who worked in the same vicinity as asbestos workers. The risk of mesothelioma in workers exposed to chrysotile is much lower than the risk in workers exposed to amphiboles (especially crocidolite) or to mixtures of fibres containing amphiboles.
Asbestosis refers to interstitial pulmonary fibrosis resulting from asbestos exposure. The more intense the dose, the earlier and ultimately more severe the fibrosis. During the 1920s and 1930s asbestosis was common and often took as little as seven to eight years to develop in a worker. Regulation of the industry and voluntary dust suppression measures lowered exposure levels and decreased the incidence of the disease. The diagnosis of asbestosis requires sufficient past exposure to asbestos to place the individual at substantial risk. Asbestosis is unlikely to occur unless there has been exposure to at least moderate concentrations of asbestos for more than a few years. Chrysotile can cause asbestosis, and again the disease may take 20 or more years from exposure to manifest.
Asbestos is a known carcinogen and the incidence of lung cancer is higher among asbestos workers. All lung cancer types occur in asbestos workers. An estimated 5.7% of all lung cancers in men in the West of Scotland (an area which had a large shipbuilding industry) are asbestos related. The latency from first exposure is in excess of 20 years.
The relative risk for developing lung cancer depends on a number of factors, dose, fibre type, job type, smoking history and presence of pulmonary fibrosis. The general view is that there is approximately a multiplicative effect of smoking and asbestos exposure. That is, although both asbestos and smoking in their own right increase the risk of lung cancer, asbestos and smoking together increase that risk many-fold. At present, the Courts require evidence of asbestosis, or of exposure to asbestosis sufficient to cause asbestosis, before attributing a lung cancer to asbestos exposure.
Asbestos-related Pleural Disease
Pleural plaques are the most common manifestation of asbestos exposure. Macroscopically, pleural plaques appear as shiny, white, slightly raised areas on the parietal thoracic wall and diaphragmatic pleura. Microscopically they consist of fibrous tissue. Asbestos fibres are rarely found in pleural plaques. Pleural plaques are probably not, per se, associated with an increased risk of lung cancer or any other disease. Rather, they are a marker of asbestos exposure. They occur some 15 years after exposure, and are associated with the duration and amount of exposure. Generally pleural plaques are asymptomatic (and are therefore non-compensable), but occasionally a person with plaques will claim damages for pain or for the fear of contracting a more serious disease.
Benign Pleural Effusions
Benign pleural effusions occur in a small percentage of asbestos workers, usually less than 20 years after initial exposure to high concentrations of asbestos.
Diffuse Pleural Thickening
Diffuse pleural thickening can severely impair ventilation and cause significant restrictions on lung function. Restricted lung function with a preserved diffusing capacity is the expected pattern.
Rounded atelectasis refers to a peculiar infolding of the pleura. These lesions can occur many years after exposure to asbestos and are probably sequelae of benign pleural effusions. The peripheral infolding of the lung is the result of the associated pleural thickening and can be mistaken for a tumour. They have a characteristic appearance on computed tomography of a ‘comet tail’ of vessels and bronchi leading into the lesion and associated pleural thickening, maximal adjacent to the lesion. Once formed they tend to persist relatively unchanged.
ASBESTOS AND JAMES HARDIE
James Hardie was the dominant consumer of asbestos in Australia, averaging approximately 70% (60,000 tonnes) of all asbestos fibre consumed annually. James Hardie’s primary business was the manufacture of asbestos cement products. These came in the form of building products and asbestos cement pipes. Prior to the mid-1980s, James Hardie manufactured asbestos cement flat and corrugated sheets for internal and external wall cladding in buildings and for roofs, asbestos cement water and sewer pipes. Building products were originally imported from Italy but by the 1920s local production started at the Camellia factory in NSW. Production started soon after at factories in Victoria (Brooklyn) and at Newstead in Queensland. At a later stage the Rivervale plant in Western Australia was built and a joint operation in association with Wunderlich was established in Adelaide in the 1950s. In 1960 James Hardie became the sole operator of the South Australian business when it bought out Wunderlich’s interest. Prior to 1974 James Hardie also manufactured asbestos insulation materials in a joint venture with CSR Limited, and also in its own right prior to 1964.
White asbestos (chrysotile) was by far the most common type of asbestos used by James Hardie, which at the time was thought to pose less risk of inducing mesothelioma than did crocidolite. Recent medical thinking suggests the conclusions about toxicity may not be correct. Chrysotile was mainly sourced its supplies from Canadian mines in Quebec and British Columbia. A James Hardie subsidiary, Asbestos Mines Pty Limited, owned and operated the small chrysotile mine at Baryulgil until its sale in 1975. However the total output of the mine was very limited. The major fibre used in the manufacture of asbestos cement products was chrysotile Brown asbestos (amosite) was not used in James Hardie products until the 1950s when new sources of the fibre were opened up in South Africa. The use of small quantities of amosite in asbestos cement products continued until about 1980. James Hardie used blue asbestos (crocidolite) in certain products from the mid-1950s until about 1968. The crocidolite was sourced from the CSR mine at Wittenoom. Because of its colour it was not able to be used for all products; its main use was in pressure pipes and building products that were not able to be seen in detail, such as roofing products. The use of blue asbestos was discontinued on the recommendation of James Hardie’s medical officer, Dr S.F. McCullagh, in 1967-68.
The asbestos content of James Hardie asbestos cement sheet and pipes ranged from 8% to 15%, and was predominantly chrysotile with small amounts of crocidolite (to 1968) and amosite. Production of asbestos cement pipes began in 1926 but the use of asbestos cement pressure pipe for water and sewerage use did not become widespread until autoclaving of pipes was introduced in the early 1950s. Asbestos content of pipes was approximately 15% of which about 12% was white asbestos and the remainder amosite. During the period 1956-1968 crocidolite was also used (about 2%).
Asbestos containing insulation products were first manufactured by James Hardie in the 1930s and by the 1950s James Hardie had established itself in the market with a product called 85% magnesia. In 1964 James Hardie formed a joint venture with CSR and Bradford Insulation known as Hardie-BI Company to make and market insulation products. Major products produced were 85% Magnesia and K-Lite. Both products contained about 15% amosite. The partnership was dissolved in 1974 and James Hardie ceased production of asbestos thermal insulation products.
Jsekarb manufactured brake linings for motor vehicles, railway wagons and locomotives. James Hardie had initially entered the brakes and friction products market in the early 1930s and had a well established business by 1950 under the brand name “Five Star”. In 1963 James Hardie entered into the Hardie-Ferodo joint venture with Ferodo of the UK. Hardie-Ferodo carried out considerable product development work, particularly with regard to railway rolling stock brakes. With the withdrawal of Ferodo from the partnership in 1978, the business was renamed Better Brakes (later known as Jsekarb) and was ultimately sold to Futuris Corporation Limited in 1987. The only asbestos used in asbestos-containing friction products was chrysotile.
ASBESTOS & HAZARDOUS MATERIALS MANAGEMENT
Asbestos and Hazardous Materials must be properly managed to prevent people dying from asbestos and other associated diseases in the future. Workers who carry out building maintenance and repair are particularly at risk. Each year thousands people who worked in such trades die from past exposures to asbestos fibres and hazardous materials such as Lead and PCB’s. And these workers are still at risk. Millions of commercial buildings worldwide still contain asbestos and hazardous materials.
If you are responsible for managing the maintenance and repair of a building, plant, construction site, parcel of land, you must manage any asbestos and or hazardous materials. As well as protecting people from exposure, you have a legal duty to manage asbestos and hazardous materials.
YOUR DUTY TO MANAGE ASBESTOS AND HAZARDOUS MATERIALS
Yes, if you are responsible for maintenance and repairs. You are a dutyholder if:
- You own the building or structure;
- You are responsible through a contract or tenancy agreement;
- There is no formal contract or agreement but you have control of the building;
- In a multi-occupied building, you are the owner and have taken responsibility for maintenance and repairs for the whole building.
If you are unsure whether you are a dutyholder – seek professional advice.
If you are not the dutyholder, but have information about the building, you must co-operate with the dutyholder, eg landlords must pass on relevant information to new tenants, and leaseholders must allow access for inspection by managing agents.
WHAT BUILDINGS ARE AFFECTED?
- All non-domestic buildings, whatever the type of workplace or business;
- Domestic premises; and
- The common areas of residential rented buildings and holiday apartments;
For more information on where asbestos is likely to be found please visit www.yourasbestos.com.au or contact your nearest OCTIEF office on 1800 628 433.