Background
Asbestos-containing material (ACM) is any material or thing, that as part of its design, contains asbestos. Asbestos occurs naturally in some rocks and ore deposits and can therefore be encountered through mining processes (e.g. drilling, blasting, processing). However, this bulletin deals with the management of manufactured products that contain asbestos.
The term asbestos refers to six types of naturally occurring, fibrous, silicate minerals. Amosite (brown asbestos), chrysotile (white asbestos) and crocidolite (blue asbestos) were used in manufactured ACM products found in Australia. However, there are no known applications in this country for the other three forms of asbestos (actinolite, anthophyllite and tremolite) in manufactured
ACM products.
ACMs were used extensively in Australian buildings, structures, plant, equipment and motor vehicles. Buildings and structures constructed or renovated between 1945 and the late 1980s may contain asbestos in areas such as ceilings, internal walls, roofs, eaves, external cladding, wet areas and vinyl floor tiles. Asbestos may also be present in brake pads, gaskets and seals, pipes and
pipe lagging.
From 1985 the manufacture, importation and installation of products containing crocidolite and amosite was banned. This was followed in the late 1980s by the ban of their use in building products. On 31 December 2003, a national ban on all uses of chrysotile asbestos came into effect.
Summary of hazard
If not effectively managed, asbestos can pose a significant hazard on mine sites and in mine-site provided accommodation. Workers can be exposed to airborne asbestos fibres if ACMs are in a poor condition and/or disturbed. Asbestos poses a risk to health when fibres are inhaled. Most fibres are removed from the respiratory system by the body’s natural defences (e.g. coughing). However, fibres that remain in the lungs may lead to asbestos-related diseases such as pleural disease, asbestosis, lung cancer and mesothelioma.
There have been several incidents on Western Australian mining operations where ACMs have only been discovered during the course of work activities, while workers were not wearing appropriate personal protective equipment (PPE). These include:
- pipes encased in black asphalt wrapping that contained asbestos were disturbed by construction equipment (including an elevated work platform and welding leads) during installation of a new pipeline
- asbestos tape, originally used to join steel plates, was disturbed by workers while replacing the roof of a thickener
- a gasket containing asbestos was removed from a filter pump by workers using an angle grinder during decommissioning works
- a coating containing asbestos (i.e. Coro-Kote) which had been painted on several walkways, was removed by a worker using a blow torch
- white, friable lagging containing asbestos was disturbed by workers maintaining a heat exchanger.
Contributory factors
- Disturbance of ACM by failure to:
- identify asbestos hazards at the mining operation
- prevent the potential release of airborne asbestos fibres
- display appropriate signage and labelling warning of the asbestos hazard
- remove ACM from site following advice from competent persons.
- Failure to use a respirator that was correctly fitted and of an appropriate type.