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Knowledge Base » Health and Safety » What is Asbestos?

What is Asbestos?

Last updated on 20th December 2023

Asbestos used to be known as the miracle mineral, as it had a wide range of uses and was renowned for its unique properties, such as fire and heat resistance. It was used in thousands of products, even in cigarettes and baby clothing. It wasn’t until the 20th century that the dangers of asbestos started to come to light. Regardless of the increased awareness, asbestos manufacture and use continued, despite its association with ill health and deaths in the early 1900s. The first recorded asbestos-related death was in 1906.

Further research into asbestos-related diseases eventually led to a ban on asbestos in the UK in 1999. It meant that all types of asbestos were no longer legally permitted to be manufactured, imported, supplied and used in the UK. However, it was used extensively between the 19th and 20th centuries, particularly in building materials and transport after the Second World War. Therefore, regardless of the ban in the 1990s, people (particularly workers) can still be exposed to asbestos, and it remains a risk to this day.

Unfortunately, asbestos is still responsible for many diseases and deaths in the UK, even though it was banned. According to the Health and Safety Executive (HSE), asbestos is the single greatest cause of work-related deaths in the UK, and asbestos-related diseases currently kill around 4,500 people a year in Great Britain. Hence, why it is so crucial to prevent exposure to this “hidden killer”.

This article will look at what asbestos is, the dangers, the types and how it can be detected.

What is asbestos?

Asbestos refers to a group of naturally occurring fibrous materials known as silicate minerals. In the past, different types of asbestos were mined, extracted and imported globally.

Asbestos was used in many different products throughout the centuries, but mainly in construction materials used in residential, commercial and industrial buildings. These materials are known as Asbestos Containing Materials (ACMs).

Some examples include:

  • Asbestos Insulating Board (AIB), e.g. ceiling tiles, walls and linings, fireproofing, plasterboard and soffits.
  • Sprayed coatings, e.g. fireproofing on steelwork, soundproofing, fillers, roof sheeting and coated panels.
  • Textiles, e.g. gaskets and fuse boxes, rope seals and fire blankets.
  • Plastics (composites), e.g. toilet seats, cisterns and vinyl flooring.
  • Loose filled asbestos, e.g. insulation in lofts, cavity walls and under floors.
  • Lagging, e.g. pipework, boilers and heating systems.
  • Cement, e.g. flat or corrugated roof sheeting, downpipes and gutters, wall cladding and cement flues.
  • Decorative coatings, e.g. Artex on ceilings.
  • Roofing felts, e.g. garage and outbuilding roofs.
  • Paper and millboard, e.g. linings and wrapping and heat insulation for electrical equipment.

As long as asbestos is in good condition and is not disturbed or damaged, the risk is low. However, if it is disturbed or damaged, it can become a danger to health, as the asbestos fibres become airborne, which can be inhaled by people in the area.

Asbestos fibers detected in roof

What are the dangers of asbestos?

There is a risk of asbestos exposure if it is disturbed, as fibres and dust become airborne.

Activities that increase the risk of asbestos exposure are:

  • Maintenance and repair.
  • Demolition and refurbishment.
  • Accidental damage to ACMs.

Those at a higher risk of asbestos exposure are (this list is not exhaustive):

  • Heating engineers.
  • Builders.
  • Maintenance workers.
  • Plumbers.
  • Carpenters and joiners.
  • Painters and decorators.
  • Construction workers.
  • Plasterers.
  • Roofers.
  • Electricians.

Asbestos fibres are so tiny that they are not visible to the human eye and cannot be detected by smell. Tens of thousands can be present in a sample equivalent to the width of a human hair.

If the fibres are disturbed and become airborne, they can be easily inhaled through the nose and mouth and deep into the lungs. Once the fibres are in the lungs, they penetrate the tissue and cause scarring over time. This can make it difficult for a person to breathe and causes other unpleasant symptoms.

The damage asbestos fibres cause is a result of repeated exposure over some time. The harm is not immediately obvious to those exposed, as it takes many years for symptoms to show.

Being exposed to asbestos can increase the risk of the following diseases:



  • This is cancer of the lining of the lungs.
  • 2,369 mesothelioma deaths due to past asbestos exposures (2019) (HSE).

Lung cancer

  • Similar to cancer caused by smoking.
  • 260 new cases of asbestos-related lung cancer each year, with 240 reported in 2019 (HSE).



  • Results in scarring to the lungs.
  • There were 490 deaths in 2019 that mentioned asbestosis on the death certificate (HSE).


  • This is the thickening of the lung lining.
  • There were 510 new cases of pleural thickening assessed for Industrial Injuries Disablement Benefit in 2019 (HSE).

Further information on the statistics for asbestos-related diseases can be found on the HSE statistics webpage and in their latest report.

Symptoms of asbestos-related diseases will differ depending on the type, but some that are common to all are:

  • Breathlessness, particularly with exertion.
  • Coughing and wheezing.
  • Fatigue and tiredness.
  • Appetite loss leading to weight loss.
  • Chest pain and tightness.

These diseases develop over time through repeated exposure to asbestos. It takes many years (typically between 15 and 60 years) for symptoms to develop and, once they do, they are severely disabling.

There is no cure, which means that once a person has the condition, there is no way of reversing the effects. Asbestos-related diseases are progressive and are fatal.

Several risk factors can worsen the symptoms of asbestos-related diseases and can speed up the onset.

For example:

  • If a person is older, a smoker or has a pre-existing health condition.
  • Higher frequency and longer duration of exposure to asbestos fibres.
  • A high concentration of asbestos fibres in the air.
  • The type of asbestos.

As asbestos fibres are not visible, the risks are often not appreciated. These fibres can be airborne for several hours, and a person would be unaware of the damage caused as the effects of exposure are not immediately seen.

Woman coughing after being exposed to asbestos for years

Types of asbestos

Asbestos does not only refer to one type of silicate mineral; there are many different types.

There are two groups of asbestos and six types, which are:

Amphiboles group

  • Actinolite
  • Anthophyllite
  • Tremolite
  • Crocidolite
  • Amosite.

Serpentine group

  • Chrysotile.

Out of these six, three types were more commonly used in the UK. These are:


  • Also known as blue asbestos.
  • Discovered in 1805 in South Africa.
  • Fibres are sharp and straight.


  • Also known as brown asbestos.
  • Discovered in 1870 in South Africa.
  • Fibres are needle-like.


  • Also known as white asbestos.
  • Discovered in 1850 in Canada.
  • Fibres are fluffy and curly.

Chrysotile is more common and was used more commercially than the two other types of asbestos.

All asbestos should be considered dangerous. However, blue and brown are considered to be more hazardous than white. This is due to the nature of the fibres, i.e. blue and brown asbestos fibres are straight, sharp and brittle.

There are two forms of asbestos: friable and non-friable.

  • Friable asbestos – is a higher risk than non-friable, as it is not bound. Therefore, the release of fibres is more likely if it is damaged. It can be crushed by hand and be turned into a powder when dry. Examples of friable asbestos are insulating boards and sprayed coatings.
  • Non-friable asbestos – usually bound in a matrix and is deemed to be lower risk. The fibres are not released as readily as friable asbestos, and it is more resistant to damage. However, fibre release can still occur from cutting or sanding. Examples of non-friable asbestos are cement and Artex.

How to detect asbestos

Asbestos cannot be identified as present (or the type) unless a sample is taken and analysed in a laboratory. The reasons for this are:

  • Asbestos fibres are microscopic and are not visible to the naked eye.
  • Asbestos is often mixed with other materials and can be confused with those that do not contain asbestos.
  • The colour cannot be relied upon, as asbestos is often not blue, brown or white.

There are some things to look out for that may indicate the presence of asbestos, for example:

  • It is a general rule that if the building was built before the year 2000, it can be assumed that it will contain asbestos.
  • The common places and materials where asbestos was used in buildings in the past, e.g. insulated boards and sprayed coatings. The HSE’s asbestos image gallery has some examples.

A risk assessment must always be completed before any work starts, which may include an asbestos survey if the building was built before the year 2000 and/or if premises are going to be upgraded, refurbished or demolished. Businesses have a legal duty to identify whether any asbestos is present and manage it accordingly.

If anyone detects asbestos unexpectedly during work, they should always stop what they are doing immediately and assume it is asbestos until confirmed otherwise. A risk assessment and an asbestos survey will help determine what actions are needed and whether the work is licensable. The HSE asbestos essentials EM1 provides instructions on what to do if asbestos is discovered or accidentally disturbed during work.

If a person believes they have been exposed to asbestos and have symptoms, they may have understandable concerns about their health. The HSE states that “any cases of inadvertent, short-term exposure to asbestos will most likely have led to minimal exposure to fibres, with little likelihood of any long-term ill health effects”. However, the effects will depend on many factors, e.g. the type of asbestos, duration of exposure and the work activity.

Individuals should consult with their GP if they have concerns and provide them with all relevant information regarding the exposure. The GP may place a note on an individual’s record and/or they may refer them to a respiratory specialist. X-rays may be taken if an individual has symptoms, which can show asbestos-related damage to the lungs. However, it is important to note that X-rays will not be able to show whether asbestos fibres have been inhaled.

One type of asbestos

The Control of Asbestos Regulations 2012

Asbestos comes under the Control of Asbestos Regulations 2012, which places duties on employers, the self-employed and those who manage non-domestic premises. The main requirements are:

  • An asbestos survey must be completed by a competent person to identify the asbestos in the building.
  • A risk assessment is required where there is a risk of asbestos exposure. The assessment should look at the location, likelihood of disturbance and the monitoring of the condition of ACMs.
  • A written plan must be in place before work starts on asbestos.
  • A licence must be obtained from the HSE, and they must be notified of certain types of work with asbestos. Removal of asbestos should only be done by a licensed contractor.
  • Information, instruction and training should be provided to employees. Asbestos awareness training is required for those who are likely to disturb asbestos. For those who remove asbestos, specialist training will be necessary.
  • Employees should be prevented from being exposed to asbestos, or exposure should be reduced to a low level (where exposure cannot be prevented). Control measures that are used by employees must be maintained.
  • PPE should be provided, and there should be arrangements for cleaning and disposing of contaminated clothing.
  • There should be arrangements for dealing with accidents, incidents and emergencies, e.g. accidental release of asbestos.
  • When working on ACMs (or removing), workers should prevent the spread of asbestos, clean up, have designated areas, monitor the air and clear the site.
  • Medicals and health surveillance should be provided for those at risk of exposure.

Even though the law won’t apply to homeowners carrying out DIY, they still need to take stringent precautions and dispose of asbestos legally.

They should always seek advice from local authority environmental health officers if they suspect asbestos is present or have accidentally found it in their home. The regulations will still apply to the self-employed and those who work on domestic projects for customers and clients.

The HSE has guidance on the regulations and what duty holders are legally required to do on their asbestos webpage and in the Approved Code of Practice.


Asbestos is a hidden danger, and it is not just a problem of the past. According to think tank ResPublica, an estimated six million tonnes of asbestos are still inside 1.5 million buildings in the UK, including hospitals and eight out of 10 schools.

If there are tens of thousands of fibres present in a sample equivalent to the width of a human hair, then you can appreciate the staggering number of fibres in six million tonnes.

The amount of asbestos still present in buildings may seem a frightening prospect, and you may wonder why it has not all been removed. Remember, it is only dangerous if asbestos-containing materials are disturbed and the fibres are released into the air and inhaled.

Asbestos is still in many buildings across the country. Therefore, it wouldn’t be economically viable to remove it and dispose of it all. Also, asbestos removal increases the risk of fibre inhalation, which means it is better to leave it and manage the risk if it is in good condition. A risk-based approach is used for the asbestos that remains.

Asbestos must not be disturbed unless the work requires sampling and removal. If disturbance of asbestos is likely, the risk should be assessed and managed accordingly in line with the asbestos regulations. 

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About the author

Michelle Putter

Michelle Putter

Michelle graduated with an MSc in wildlife biology and conservation in 2012, but her career has taken quite a different turn to the one expected. She started in health and safety in 2009 and has worked in several industries such as electrical engineering, aviation and manufacturing. She has been working with CPD Online College since 2018 and became NEBOSH Diploma qualified in 2020. In her spare time, Michelle's passions are wildlife and her garden. She has volunteered for many conservation organisations and particularly enjoys biological recording. Michelle also likes hiking, jogging and cycling.

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