The different types of asbestos: explained

The different types of asbestos: explained

There are more different types of asbestos than you may have realised, and we’re often asked about them. If you’re not sure what it is, asbestos was widely used as a building material for decades pre-2000, due to its cheapness, strength and fireprotection and insulating qualities, not to mention its easy and wide availability. It also offered excellent resistance to chemicals and water, among other properties, which made it massively popular in construction.

Why and When Does Asbestos Become a Problem?

Asbestos poses a potentially deadly threat to human health, and it still kills some 5,000 workers annually – more than the yearly death toll on the UK’s roads. It remains relatively low-risk if left untouched. But if disturbed or handled without due care, damaged asbestos-containing materials release tiny fibres into the air, which can lead to several serious diseases – these often develop over decades. They include mesothelioma, an increasingly common type of cancer affecting the lung lining and the lower digestive tract lining, alongside asbestos-related lung cancer and asbestosis, an irreversible and potentially fatal progressive scarring of the lung causing the patient to experience progressive breathing difficulties. Pleural thickening and asbestos warts are among the other health problems which can arise.  

Where is Asbestos Typically Found?

Asbestos is found in so many different products and places, and with many non-asbestos containing items looking very similar to those which do contain the substance, making it fiendishly difficult to spot the potentially dangerous products unless you’re trained to know what you are looking for.  

That’s why you need to draw on the expertise of a team of specialist asbestos surveyors from an organisation such as Core Surveys, which has an in-depth knowledge of where asbestos may be lurking 

What Are The Different Types of Asbestos?

Essentially, there are six basic varieties of asbestos, all unique minerals which fall into two broad categories of mineral familyUnfortunately, all are highly toxic and can cause serious and life-threatening illness. Here, we look at each one in turn. 


Amphibole asbestos has brittle needle-like fibres which break down into much smaller ones than those constituting Serpentine asbestos (described below). This makes them more aerodynamic and penetrative, so they pose the gravest health risk, either when inhaled or when embedded in the skin.  

Amphibole asbestos is blue and brown. And it was less commonly used than other varieties, before all asbestos was banned in the UK at the turn of the millennium.  

Crocidolite (blue asbestos)

Traditionally, this has been the most commonly used type of amphibole asbestos. It’s also one of the most potentially deadly 

Because of its thin and brittle fibres, which are short and sharp, if it’s inhaled, it easily becomes lodged in the lungs. Equally, the fibres’ crystalline shape makes them hard to exhale, and they quickly break down, leading to serious asbestos exposure. It’s often contaminated with traces of tremolite.  

Commonly found in pipe insulation, spray-on coatings, and types of cement wallboard and so on, it was actually banned in the UK as long ago as 1970. With strong heat resistance, it was also widely used in cement and roofing materials, as well as brakepads.  

Amosite (brown asbestos)

Most of this type of asbestos is mined in Africa, and it’s an especially strong and heat-resistant mineral often found in cement sheets, ceiling tiles, plumbing and electrical insulation. Clearly, all asbestos varieties are toxic, but exposure to amosite carries a relatively higher cancer risk.  

It’s often found mixed with chrysotile in insulation boarding. But brown asbestos has coarser, tougher fibres which are brittle, sharp and readily inhaled. Its crystals can puncture human tissue and stick to it like little spikes. The use of amosite was voluntarily banned in 1980. 

Anthophyllite, Actinolite and Tremolite

These are three minor asbestos varieties:  


Tremolite is often encountered as a contaminant in chrysotile asbestos. It’s found in some talc products, sealants, paints and insulating products. You’ll see it in various colours, including green, white and grey. It forms short, needle-like prisms.  


Actinolite is found in similar places and is not unlike tremolite in its chemical make-up and colours. Again, it’s made up of needle-like crystals. Fibres are lightweight, generally dark and it can present as brittle and fibrous or densely compact. It’s worth noting that it’s less common than many other asbestos forms. But it expands on heating, making it a popular choice for fire-proofing and insulating materials.  


Anthophyllite is again grey, green or white. Often found as a contaminant in composite flooring, it’s not one of the more commercial types of asbestos, but can be encountered in things like talc-based products. And while it’s relatively lower-risk, there’s still a clear link with mesothelioma.  


Serpentine  is distinguished by its curtly-looking fibres, and there is only one type of this kind of asbestos, which comes from serpentine rocks, found around the world and made of minerals with a snakeskin-like texture:


With a white appearance, this flexible mineral has been more widely used than other types of asbestos, most frequently in cement roof sheets as well as ceiling sheets or panels and occasionally in floors and walls, plus some wall plaster and also in brake pads. The fibres are fine and heat-resistant, and their curly shape does mean they can be breathed out more easily so there is less potential risk to human health.  

That said, using chrysotile was forbidden in the UK from 1999, the last asbestos variant to be banned here.  

Avoiding Asbestos-Related Diseases Caused by Exposure

 To ensure those occupying or working in a building are not exposed to asbestos fibres, identification, risk assessment and asbestos management are vital tools.  

 At Core Surveys, we have the experience and industry expertise to understand all varieties of this mineral, and know how to manage the associated risks. Contact us to book an asbestos survey or find out more about asbestos testing and we’ll take it from there.