Basics

Asbestos is a family of natural minerals that have attracted a lot of research and controversy. According to various sources, the French word "amiante" (asbestos) comes from the Greek word "amiantos" which means incombustible, incorruptible or designates quicklime. Asbestos fibres are distinguished from other natural fibres because they are nonflammable, will not rot, are resistant to most chemical products, are flexible and have higher tensile strength than steel.

Asbestos may be classified into two groups : Serpentine and amphiboles.

Chrysotile is the only kind of asbestos in the serpentine group. It is the only kind of asbestos used in the world today. We can distinguish it from the amphiboles by its structure and its composition. When compared to amphiboles fibres, chrysotile fibres are flexible and will dissolve in acid. They are therefore easier to eliminate from the human body. It is for this reason that chrysotile fibres have little effect on organic tissues.

Until recently, the most highly exploited minerals of the amphibole group were amosite (brown asbestos) and crocidolite (blue asbestos). They were mostly useful for making insulation materials. However, these fibres are more rigid and are resistant to acids. They are more difficult to eliminate from the human body. That is why they have ceased to be used. As far as anthophyllite, tremolite and actinolite are concerned. These is no significant known usage.