The mineral asbestos consists of microscopically small fibres. There are different types of asbestos, divided into two mineral groups: serpentine and amphibole. Serpentines have curled fibres, whereas the fibres of amphiboles are rod-shaped and more dangerous.
The different types of asbestos are often distinguished by colour. White asbestos (chrysotile), a serpentine, is the most common type of asbestos. It makes up approximately 85% of all asbestos found in the Netherlands.
Asbestos types from the amphibole group, such as blue asbestos (crocidolite) and brown asbestos (amosite) are less common.
Serpentines (curled fibres)
Chrysotile = white asbestos
The microscopically small asbestos fibres have been used in a broad variety of applications. Sometimes as a loose fibrous mixture, sometimes bonded with another material. Different types of asbestos may be combined in an application.
Only an electron microscope can reveal if something contains asbestos, and what type of asbestos it is.
In firmly-bound asbestos, the asbestos fibres are bonded with another material, usually cement or glue. The best-known examples are corrugated sheets and Eternit wall panels. It also was a popular material for making flower boxes, sewer pipes, gas pipes and water pipes. If firmly-bound asbestos is undamaged, it poses little health risk.
Loosely-bound (friable) asbestos
In loosely-bound asbestos, the likelihood of fibre release is much greater, because the fibres are not encased in another material. Therefore, loosely-bound asbestos always needs to be enclosed, encapsulated or removed. It has been applied in e.g. vinyl sheet flooring, heat-resistant clothing, sealant, isolation plates and as spray asbestos.