What is Asbestos?
Asbestos is mined from rock and it is the loose fibre broken down from the mined rock material that is used in the manufacture of numerous products. Asbestos is invariably mixed with another material and is rarely encountered in its raw form.
There are three identified types of asbestos:
Chrysotile (white asbestos), Amosite (brown asbestos), and Crocidolite (blue asbestos).
When Asbestos was being used extensively, it was due mainly to its properties as a fire and moisture resistant material. Asbestos has been found to cause major health issues such as Asbestosis (a respiratory disease) and in some forms it is also carcinogenic (cancer forming).
Although the NZ OSH guidelines and controls cam into affect at the end of 1982, asbestos products were still available for use. Asbestos was still mined and used overseas. We have come across asbestos has been used in NZ since 1982.
Asbestos containing materials are referred to as either friable or bonded. Friable asbestos is in the form of powder, or can be crumbled, pulverised or reduced to powder by hand pressure when dry. Friable asbestos includes materials such as sprayed and thermal insulation, pipe lagging and millboard, and can release fibres with only minimal disturbance.
Bonded asbestos products are ones in which the asbestos fibres are bound within the matrix of the material. Bonded asbestos is more difficult to damage and cause the release of fibres by hand and includes materials such as asbestos cement sheeting (fibre cement or fibro). However, bonded asbestos containing materials that have been subjected to weathering, physical damage, water damage, fire or other conditions may contain exposed fibres which could be released upon disturbance.
Inhalation of asbestos fibre has been shown to pose a potentially fatal health risk.
Exposure to asbestos fibre may occur when materials containing asbestos are in poor condition, are flaking or crumbling. Consequently exposure to asbestos fibre may occur when materials containing asbestos are sanded, sawn, drilled, or handled in maintenance and/or removal tasks.
Three main disease states have been associated with the inhalation of asbestos fibre: asbestosis, lung cancer and mesothelioma. Inhalation of high concentrations of all forms of asbestos may result in asbestosis, a progressive fibrosis of lung tissue. The two forms of cancer associated with the inhalation of asbestos are lung cancer and mesothelioma.
Asbestos exposure is considered to account for at least 80% of mesotheliomas that develop with Crocidolite (blue asbestos) and Amosite (brown asbestos) providing the greatest hazard.
Professional Asbestos Removal
Given the risks associated with asbestos fibre, removing asbestos containing materials from your home or business is best left to a professional asbestos removal contractor. It is also why there are such strict guidelines around removal as well as disposal of asbestos products. In NZ dealing with asbestos is covered in the Guidelines for the Management and Removal of Asbestos Revised January 1999; Published by Occupational Safety and Health Service, Department of Labour ISBN 0-477-03560-4.