There are not one but MANY different types of asbestos fibers, divided into two main categories: serpentine and amphibole asbestos.
The serpentine variety is curly, included of chrysotile asbestos (or white asbestos), most commonly used for industrial purposes.
The chrysotile, CAS No. 12001-29-5, has the formula given: Mg3[Si2O5](OH)4. White asbestos is obtained from serpentine rocks which are common throughout the world. It is referred to safe group as well and being only one type of asbestos for exporting and use. The uniqueness of chrysotile asbestos is in complete absence of natural analogs and artificial substitutes having a combination of a lot useful properties: the large mechanical durability and elasticity, tensile strength, high factor of friction, the resistance and incombustibility, durability, alkali-resistance, high electric resistance, stability against decay, ability to detain bacteria and radiating emanation. Due to the specific characteristics, the chrysotile asbestos is an extremely useful material and has a wide application in asbestos cement production (especially within corrugated asbestos cement roof sheets typically used for developing countries), heat/electroesolation, automobile, air, chemical, petroleum and nuclear industry, manufacture of fireproof materials, textile and cloth products and others.
Nowadays, chrysotile is the only asbestos fibre that is approved to be exported. What we need to know is that 99% of the world’s current asbestos production is chrysotile, a fibre which, when inhaled in small quantities, poses no health threat.
Other asbestos fibers, from the amphibole family, are very straight and needle-like included of amosite, crocidolite, tremolite, actinolite, and anthophyllite.
The amphibole fibres used commercially (amosite, crocidolite, tremolite, actinolite, and anthophyllite) are extremely hazardous. Because of their chemical structure and straight, needlelike fibres, amphiboles are very dusty, as well as highly biopersistent. Once in the human body, they can remain indefinitely in the lung tissue, and may cause cancer and mesothelioma.
Why do we have to differentiate the white asbestos from blue and brown asbestos?
Asbestos is the commercial name for a group of naturally occurring fibrous silicate mineral. In fact, there are many types of asbestos fibre which are divided into two separated families: the serpentine and the amphiboles. Except for the similarity in the commercial name and fireproofing, the two groups of fibre a totally different in terms of physical/chemical properties, features and their negative impact on human health. This is also the conclusion made by scientists in the report of World Health Organization (WHO) in 2004. Lately, brown and blue asbestos groups have been banned worldwide, while chrysotile is the only type of asbestos approved to be mined and applied in industrial and residential products.
In the past, the poor working condition and wrong uses of asbestos such as spraying and outdated technologies lead to many lung cancer and mesothelioma cases caused by asbestos. However, since the 1980s, the mining and use of chrysotile have been heading towards a safe procedure. The negative effects of asbestos to human health and environment are being minimized thanks to the application of moist, automatic and closed technologies. Many countries are applying safe use programs for chrysotile which includes accidental risk assessment software, instruction guide set for preventing and controlling particles emitted in the production procedure and other training and monitoring community programs.
Besides, the asbestos containing products recently are completely different from the ones from the past – which usually used amphibole fibre (brown and blue asbestos), had low percentage of chrysotile, emitted lots of dust and were easy to be broken. Therefore, only products with high concentration of chrysotile are now allowed to be produced and commercialized. Moreover, they have to be durable using firm materials like cement so as to make sure no emission occurs.
The differences in the use of chrysotile in the past and present