What is asbestos:
Asbestos is a term used for six different types of naturally occurring silicate minerals. The base constitution of asbestos is usually fibrous crystals that are long and thin in nature, and the fibrous contains many microscopic fibrils. The main reason for the huge popularity of asbestos is its high level of heat resistance and its excellent electric insulator properties. During the 1960s to 1980s, asbestos was the most common material for building materials. However, the health and safety hazards associated with asbestos are well known, leading to its prohibition in many countries. Prolonged exposure to asbestos can lead to various lung conditions such as asbestosis and cancer.
Archeological studies:
Archeological studies have shown proof of the use of asbestos back in the stone age. However, large-scale mining started in the 19th century, and after a decade, people started to notice the health hazards and possible risks of using asbestos as a commercial material.
Types of Asbestos:
The Environmental Protection Agency (EPA) has recognized six minerals and divided them into two categories.
Amphibole:
The fibers of amphibole are long and straight. It is well known as brown or blue asbestos. There are five types of amphibole:
- Crocidolite: Crocidolite is a fiber form of amphibole and commonly known as blue asbestos. It has soft straight friable fibers and is primarily found in South Africa and Australia.
- Uses: It can be found mostly in engine insulators, spray-on paints, plastic, and cement products.
- Amosite: Amosite is also a fiber form of amphibole and commonly found in South Africa. Under the microscope, the fibers can be seen as brown long straight fibers.
- Uses: The most common usage of brown asbestos is in ceiling tiles, as a flame retardant in thermal insulators, and in insulating boards.
- Anthophyllite: Anthophyllite is one of the six recognized types of asbestos. It was first mined in Finland and then Japan. It typically occurs as a contaminant in chrysotile and is generally grey or white in color.
- Uses: Amphibole is not commonly used in commercial products. But it can still be found in some thermal insulators, talcs, and construction materials.
- Tremolite and Actinolite: Tremolite and actinolite are not commonly used in commercial products. They also occur as contaminants in chrysotile. These two types are very similar in nature, and their chemical structure is the same as well. The color of these asbestos can be brown, white, or transparent.
Serpentine:
The fibers of serpentine are curly, and chrysotile is the only member of this kind.
- Chrysotile: Under the microscope, chrysotile can be found as white fibers. It is the most common and can be found all over the world. Chrysotile asbestos is broadly available for commercial purposes and is more flexible in nature than amphibole type asbestos. It can be woven as fabric.
- Usage: The most common usage of chrysotile was in building construction, cement roofing, ceiling, floors, and walls. It was also used in fireplaces, fire barriers in fuse boxes, and gaskets of high-temperature equipment.
Industrial Usage:
Asbestos was used commercially in the 1970s to 1980s. For over a decade, it was the most common material in both residential and commercial buildings. Apart from that, asbestos has very high heat resistance, leading to its use in many products. Even in the 1940s, hospitals used asbestos blankets for patients.
Construction:
Construction was a huge market area for chrysotile asbestos. For over a decade, asbestos was the most common material for constructions, even in developed countries.
Developed Countries:
Prior to the ban, asbestos was widely used in thousands of materials, including cement sheets, roofing, and fire insulators. The use of asbestos in new construction projects is completely banned in many developed countries such as Australia, New Zealand, the United Kingdom, the European Union, and Japan. However, the United States still uses asbestos in building constructions.
Underdeveloped Countries:
Some countries such as India, Indonesia, China, and Brazil continue to use asbestos. Millions of houses, schools, and factories still have sheds and roofs made of asbestos. Asbestos-contaminated products:
Asbestos Contaminated products:
Talc:
Talc has a huge use in commercial bases, but it can be contaminated by asbestos. Therefore, regulations passed in 1973 stipulated that talc manufacturers should not market asbestos-contaminated talcs.
