Asbestos fibres are strong and durable, and they resist the influence of acids and high temperatures. Moreover, asbestos insulates well and it is cheap. Therefore, it used to be an extremely popular material for a wide variety of applications. Because of this, and because asbestos is a naturally and frequently occurring mineral,
asbestos fibres are omni-present in the air. Normally, these are such small amounts that they do not pose any health risks. In the case of long-term exposure to high concentrations of airborne fibres, however, all types of asbestos are hazardous via inhalation.