Q: What is Asbestos made of?
A: Asbestos is a Greek word meaning inextinguishable or indestructible. Asbestos is the name of a group of highly fibrous silicate minerals with separable, long and thin fibres. Separated Asbestos fibres are strong enough and flexible enough to be spun and woven. Asbestos fibres are heat resistant, making them useful in the past for many industrial purposes.
Q: What are the health concerns with Asbestos?
A: Asbestos becomes a health hazard only when the Asbestos containing materials become damaged or friable. “Friable” means Asbestos that under ordinary conditions can easily be crumbled. “Non Friable” means Asbestos that under ordinary conditions cannot be easily crumbled. Exposure to Asbestos fibre may occur when non friable Asbestos containing materials are sanded, sawn, drilled, water blasted, or handled in maintenance or removal tasks, and hence become “friable”.
Exposure to airborne friable Asbestos can result in health risks when fibres are inhaled.
Three main disease states have been associated with the inhalation of Asbestos fibre: Asbestosis, Lung Cancer and Mesothelioma.
Asbestosis in its various forms is a serious disease and there is a long latency period which, in the majority of cases, ranges from fifteen to fifty years between exposure and the development of mesothelioma and lung cancer. There is some suggestion that children exposed to Asbestos have a greater susceptibility to disease.
Q: What types of Asbestos containing materials exist in New Zealand?
A: The type of Asbestos containing materials which may be encountered in a dwelling or other building which are of most concern from a health perspective include:
Textured Coatings – a soft matrix of a variety of materials, including Asbestos, usually sprayed onto surfaces to provide a decorative effect.
Flooring – Some vinyls and linoleum may incorporate Asbestos, but Asbestos is more commonly found in the backing material.
Sprayed on Fire-proofing – Usually found on structural steel, or sometimes on the underside of roofing iron. May be both hard and impervious or soft and friable.
Acoustic Plaster Soundproofing – A firm, open pored, plaster like material. Usually exposed and not painted.
Insulation – Used to cover hot and cold water pipes, hot water reservoirs, pressure tanks and boilers, and generally covered with a fabric or metal jacket. Fire doors often contain laminates of Asbestos materials covered by wood, metal and vinyls.
Lagging – Usually found in industry to insulate boilers, condensate tanks, steam headers, hot pipes, steam pipes and condensate pipe work.
Asbestos Cement Products – In the form of roofing, exterior and interior wall claddings, interior wet area cladding, ceilings, pipes and spouting’s, fume cupboards, bench tops and sometimes found behind ovens.
These materials deteriorate with age. Very corroded materials may exhibit a breakdown of the matrix and become brittle and flaky.