Types and Properties

Asbestos is a group of naturally occurring fibrous silicate minerals. It is strong, cheap, chemically resistant, and an excellent thermal and acoustic insulator — which is why it was used in enormous quantities in buildings, ships, plant and vehicles for most of the twentieth century.

The main types

Type	Common name	Typical use
Chrysotile	White asbestos	Cement products, floor tiles, gaskets, brake linings, textiles
Amosite	Brown asbestos	Insulating board, pipe insulation, sprayed coatings
Crocidolite	Blue asbestos	Sprayed coatings, pipe lagging, some cement products

Colour cannot be used for identification — the fibres are microscopic and materials are mixed, coated and painted. Only laboratory analysis of a sample can identify asbestos, and only a competent surveyor should take that sample.

Why the fibres are dangerous

Asbestos fibres are extremely fine and split lengthways into finer fibres still. They penetrate deep into the lung, where the body cannot clear or dissolve them, and they remain for life. Damage accumulates from cumulative exposure, and there is no known safe level.