ASBESTOS

Asbestos minerals are naturally occurring fibrous silicates. From the structural chemistry point of view they belong to two different classe s: The group of serpentines, to which the primarily used chrysotil (wh ite asbestos) belongs, consists of curled up layer silicates. On the o ther hand in the amphiboles (for example blue asbestos (crocidolite)), which belong to the band silicates, the fibrous form is pre-formed in their silicon-oxygen partial structure. The characteristic properties of asbestos (its fibrous form, thermal and chemical inertness, good e lectric and thermal insulation, spinability...) led to extensive appli cation of the mineral fibers in nearly all fields of engineering and e veryday life. Because of the health effects of asbestos dust - fibroge ne and cancerogene diseases - the application of asbestos containing p roducts will cease with the end of this century. The search for substi tute materials (especially fibers) is currently an area of interest in material sciences.