Asbestos Materials
Asbestos is a strong durable non-combustible fibre, the unique properties of which make it ideal for reinforcing cement, vinyl and other materials used in making building products. It has the added property of providing insulation and protecting structure from the effects of fire. As a result asbestos containing materials have been used extensively in the building industry.

There are three main types of asbestos. The most common type is Chrysotile or white asbestos which accounts for some 95% of all asbestos used. The other two are Amosite or brown asbestos and Crocidolite, blue asbestos.

Chrysotile
Chrysotile (white) was in the past most commonly used type of asbestos in the manufacture of building materials. Chrysotile was used mainly in asbestos cement boards and also, to a lesser extent, in sprayed asbestos coatings and asbestos lagging.

Amosite
Amosite (brown) asbestos was used either as sprayed asbestos coatings, asbestos lagging or insulating board. The most important use of Amosite was in asbestos insulating board used for fire protection.

Crocidolite
Crocidolite (blue) asbestos was used mainly as sprayed asbestos coatings or insulating board. The use of Crocidolite in building applications was never extensive.

Risk
The risk of exposure to respirable asbestos dust for a building occupant is generally low. The risk when working with asbestos building materials depends on the nature of the fibre content of the material allied to the type of work being undertaken. Asbestos does not become a hazard until fibres are released into the atmosphere caused generally by some form of mechanical disturbance.

Products such as asbestos cement board have high density, low fibre content with a very low working dust level. Products such as asbestos insulating board have a medium density with medium fibre content and moderate working dust level. Products such as asbestos lagging or sprayed asbestos coating have a low density with high fibre content and high working dust level.