Composition of asbestos
Asbestos, also called asbestos, refers to certain silicates with a fibrous texture. There are different categories of asbestos, the main ones being:
- The chrysolite, or white asbestos, which is part of the serpentine group
- Crocidolite, or blue asbestos, which is part of the amphibole group
The chemical composition of asbestos is not harmful, but it is its physical properties that carry serious dangers: asbestos fibers have the property of being able to separate into extremely fine fibers and easily inhalable to humans.
Use of asbestos
Thanks to its physical properties, asbestos is perfect for many applications.
Asbestos and insulation
Asbestos is fireproof and therefore has been extensively used as fire protection.
It is also a very good thermal and sound insulation: hence the presence of asbestos in many buildings and industrial installations.
The building industry and asbestos
Asbestos is used in the form of flocking as an insulating material.
Plates containing 15 to 60% asbestos are also used to insulate roofs.
In addition, fibro-cement, which is made up of asbestos in part (less than 15%), is used in the composition of certain pipes or corrugated sheets for roofing.
The dangers of asbestos
The dangers of asbestos have been known for more than two millennia.
Health risks due to asbestos
Asbestos fibers have the particularity of being able to disintegrate very easily under the effect of friction, vibrations, shocks or movements of air. The microfibers thus released are invisible to the naked eye and can be inhaled deep down the lungs by people nearby.
This exposure to asbestos causes many pathologies:
- Asbestosis: fibrosis of the lung that gradually decreases the respiratory capacity
- Pleural plaques: thickening of the lung envelope
- Bronchopulmonary or mesothelioma cancer (pleural cancer) that can appear long after exposure (20 to 30 years). It was the duration of this latency that made it difficult to detect the link between exposure to asbestos and the various pathologies it causes.
Asbestos and environment
Due to its volatility, asbestos is dangerous for the environment.
For this reason, the treatment of asbestos waste is very strictly regulated by French legislation. They must be packed in sealed containers before being discharged. The transport of this waste is also highly regulated and falls within the dual framework of the transport of hazardous materials and the transport of waste.
Waste disposal is carried out either by vitrification or by storage facilities. The second alternative is more developed because of its lower cost. Storage facilities are classified and controlled by the State.