"Asbestos" is the name given to a group of minerals that occur naturally as masses of strong, flexible fibres that can be separated into thin threads and woven. These fibres are not affected by heat or chemicals and do not conduct electricity. For these reasons, asbestos has been widely used in many industries. Four types of asbestos have been commonly used:

Asbestos is presented in two basic forms

Serpentine - 1 type

Chrysotile or white asbestos (curly, flexible white fibres), which account for about 90 percent of the asbestos currently used in industry

Chrysotile fibre

Amphibole - 5 types

Crocidolite or blue asbestos (straight blue fibres)
Amosite or brown asbestos (straight, brittle fibres that are light gray to pale brown colour)
Not so well known are:

Tremolite
Actinolite
Anthophyllite
Amphibole asbestos is the most dangerous form.

Asbestos fibres masses tend to break easily into a dust composed of tiny particles that can float in the air, breathed in and attach to clothes.

What harm can chrysotile do?
Chrysotile is classified by Europe as a category 1 carcinogen. It may cause mesothelioma (cancer of the lung lining) and asbestosis and has been linked with lung cancer. These diseases currently kill more people than any other single work-related illness.

Is its use currently prohibited?
Crocidolite (blue), amosite (brown) and some uses of chrysotile (white) asbestos have been prohibited in Great Britain by the Asbestos (Prohibitions) Regulations 1992.

What are the alternatives and are they safer?
There are many long-established alternatives to chrysotile, which do not rely on fibre technology. For example, corrugated polyvinylchloride (PVC) and steel sheeting can be used instead of asbestos cement sheets.

Several types of non-asbestos fibres can also be substituted for asbestos; they have been developed for use in a wide range of products. The main non-asbestos fibres in current use are polyvinyl alcohol (PVA), aramid and cellulose. A considered scientific view on their safety has recently become available. In July 1998,the UK's Department of Health Committee on Carcinogenicity (CoC) concluded that these three asbestos substitutes (PVA, cellulose and aramid) are safer than chrysotile. The European Commission Scientific Committee on Toxicity, Ecotoxicity and the Environment in September 1998 endorsed this view.