Types of Asbestos
Asbestos refers to six naturally occurring minerals that have been used commercially in construction since the 19th century. Although there are well over one hundred minerals recognised as having asbestos-like fibres, there are only six types of asbestos recognised and regulated. Of the six types of asbestos recognised, one belongs to the serpentine class while the other five belong to the amphibole class of asbestos. This distinction is made because of the differences in the potency and chemical composition of the asbestos.
Chrysotile Asbestos
Chrysotile asbestos, also known as white asbestos, has silky, fine white fibres and belongs to the serpentine class of asbestos. This type of asbestos is obtained from serpentinite rocks and makes up about 95% of the asbestos found in most commercial buildings. Because it’s the most commonly used form of asbestos, white asbestos accounts for most of the asbestos-related health issues in the world.
Tremolite Asbestos
Tremolite asbestos is another one of the common types of asbestos that is found in metamorphic rocks. Tremolite asbestos ranges in colour from white to dark green and was used for many industrial purposes, such as household products. For example, tremolite asbestos has been identified as an ingredient in talcum powder.
Actinolite Asbestos
Also found in metamorphic rocks, actinolite asbestos is related to tremolite but contains much higher levels of iron. This form of asbestos comes in many colours, such as white, grey and green. Like all types of asbestos, actinolite asbestos poses a health risk, although not as high as exposure to other forms of commercially used asbestos.
Anthophyllite Asbestos
Of the six types of asbestos, this form is the most recognisable. Anthophyllite asbestos has white brittle fibres that are made up of crystals, taking on a distinctive chain appearance. This form of asbestos is created through the breakdown of talc in ultramafic rocks. Anthophyllite asbestos has little industrial use, although it is sometimes added to gardening soil.
Amosite Asbestos
Amosite, or brown asbestos, was used the longest for insulation in many countries. Once the second-most commonly used of the types of asbestos, brown asbestos is now largely banned. The name of this form comes from a mine in South Africa and it can be identified by light grey to brown straight fibres.
Crocidolite Asbestos
This form of asbestos, commonly known as blue asbestos, is made up of straight blue fibres. Occurring naturally all over the world, blue asbestos is considered the most lethal of all the types of asbestos.