What is Asbestos?

Asbestos is a collection of naturally occurring crystalline fibrous silicate minerals, which can resist heat and chemicals. This mineral occurs in many parts of the world, although the main sites of commercial mining and production are: Canada, the Soviet Union and Southern Africa. Asbestos containing rock is crushed and milled at the mining site to produce raw asbestos of various grades.

Asbestos has a number of valuable properties including:

• physical strength
• resistance to chemicals
• non-combustibility
• good thermal insulation
• good electrical insulation

This has meant that asbestos was widely used in building and other materials for a range of applications, such as lagging of pipes and boilers; loose insulation often between floors, in ceilings and within partitions; sprayed insulation on beams and girders; and as a component in other products such as decorative ceilings, floor tiles, fireplaces, fire blankets and brake linings.

However, when asbestos becomes damaged, it releases asbestos dust, which is made up of microscopic fibres which, if breathed in, are harmful and can cause eventual damage to the lungs even many years after the first exposure (15-60 years). The level of exposure at which asbestos fibres cause ill health is not known, although what is known is that the more asbestos dust a person is exposed to the greater the risk.