There are six different types of asbestos that occur naturally throughout the world. Asbestos is actually the generic name given and is not a mineralogical definition. A mineral product that is flexible, possesses high tensile strength, is heat resistant, resistant to chemical degradation, and can be woven into fabric is commercially designated as “asbestos.”
Asbestos is divided into two groups: serpentine and amphibole which is determined by the chemical compounds the mineral. Overall, asbestos is made up of silicon, oxygen, hydrogen, and other various metals. Serpentine is a variety of asbestos thats structure is layered with curly fibers. Amphibole asbestos has long, chain like structures that has sharp fibers and can be inhaled easily. Chrysotile is the only type of asbestos in the serpentine category, while the remaining five types belong in the amphibole category.
Six Types of Asbestos –
Actinolite – Actinolite is classified under amphibole asbestos. Its chemical compound is mostly magnesium and is similar to tremolite asbestos. Its color ranges from white to dark brown and is usually found in metamorphic rocks. Its chemical composition makes it a common mineral found in rocks and soil, but actinolite asbestos has not been used as much in asbestos containing products. Its classification as amphibole asbestos means that it is more dangerous because it has sharper fibers that break off easily and subsequently are easier to inhale. However, it is important to note that some forms of actinolite are non-fibrous and are not life-threatening. Despite the differences of fibrous and non-fibrous actinolite, it is banned/regulated in many countries.
Amosite – Amosite asbestos or “brown” asbestos is typically identified by its brown color and straight fibers. Made up of iron and magnesium, it was largely used as insulation in factories and buildings, and was acoustical and anti-condensation material. Because if its use in many insulation products, the EPA classified amosite as the second most used type of asbestos in the United States. Amosite was mostly mined in South Africa.
Anthophyllite– Anthophyllite asbestos is usually brown and yellow in color and its make-up of long sharp fibers places it in the amphibole category of asbestos. As one of the least common types of asbestos that has been found and used, anthophyllite is mostly composed of magnesium and iron. Anthopyllite was typically found in talc mines throughout the United States, especially in Pennsylvania, New Hampshire, central Massachusetts, North Carolina, and Montana. Since this type of asbestos was rarer, it wasn’t used commercially. Rather, it was used in products that contained vermiculite and talc, since that was where anthophyllite originated.
Chrysotile – Chrysotile asbestos is the most common form of asbestos used and it the only kind that is categorized as serpentine asbestos because if its curly fibers. The curly fibers are not as easy to inhale and because of this, some think that chrysotile is “safer” than other types of asbestos. This is not the case because the fibers can still become lodged in a person’s lung or stomach. Additionally, because its use is the most wide-spread, more people suffer from asbestos related diseases from contact with chrysotile than any other form of asbestos. Chrysotile is more flexible that other types of asbestos and can be woven into fabrics. It was also used in brake linings, floor and ceiling tiles, and home products like hair dryers and toasters. Today it is still used in products like pipes, sheets, and shingles and mined in Canada, Russia, and Italy.
Crocidolite – Crocidolite or “blue asbestos” is part of the amphibole family. Its bluish fibers are the thinnest and finest fibers of all other asbestos types and usually are the sharpest and longest. These components make it the most deadly form of asbestos. Crocidolite was not as heat resistant as other forms of asbestos, so it was not as desirable. Crocidolite was typically mined in Western Australia, South Africa, and Bolivia. Even though this form of asbestos was not used as much as others, it caused an irreparable amount of damage to those who mined it. In towns like Wittenoom, Australia, almost 18 percent of those who mined the blue asbestos died from asbestos cancer, and its airborne fibers caused Wittenoom to be completely taken off the map.
Tremolite– Tremolite asbestos is also considered one of the most deadly forms of asbestos due to its very sharp, thin, needle-like fibers that can be easily inhaled. Tremolite is the type of asbestos that can be found in vermiculite, which is a type of magnesium aluminum silicate material that expands when heated and used in a construction and agriculture. The vermiculite that was contaminated with tremolite asbestos caused hundreds of deaths in the town of Libby, Montana – a town specifically known for its vermiculite mines.
According to the United States Geographical Survey, asbestos can be found in 20 states in the U.S. and had been mined in 17 of them. The products that contained asbestos had practical purposes and were seen as a material that made things much safer. Braking systems in cars were considered more dependable, water supply pipes remained inexpensive to build and maintain, and ships that were insulated with asbestos during World War II were considered to be much safer.
The asbestos industry today still maintains that some forms of asbestos carry little risk of developing into an asbestos related disease. However, the fact of the matter remains that there is truly, no safe amount of asbestos exposure, regardless of the type.
Sources
The Mesothelioma Cancer Alliance, “Types of Asbestos,” Mesothelioma.com (2016). [Link]
Abestosnetwork.com, “Types of Asbestos Fibers,” (2016). [Link]
U.S. Geological Survey, “Some Facts About Asbestos,” U.S. Department of the Interior (March 2001). [Link]
The Vermiculite Association, “What is Vermiculite.” [Link]
