Asbestos Glossary: Key Terms Explained
Last updated 12 July 2026·Written and checked against current HSE guidance
This glossary defines the key asbestos terms used across UK surveys, removal and regulation, from the three main asbestos types to survey types, licensing categories and clearance procedures. Each definition stands alone. Remember that no term lets you judge a material by eye: only a laboratory test confirms asbestos.
Types of asbestos
Three types of asbestos were used in UK construction. The colour names describe the raw mineral as it comes out of the ground, not the finished product, so colour never identifies a material. Only laboratory analysis can confirm which fibre, if any, is present.
- Chrysotile (white asbestos)
- The most widely used type of asbestos, made of curly serpentine fibres and often called white asbestos. It was blended into cement products, artex and floor tiles, and was the last type banned in the UK, in 1999. The colour name describes the raw mineral, not the finished product, so only a laboratory test can confirm it. See our guide on how to identify asbestos.
- Amosite (brown asbestos)
- An amphibole asbestos with straight, needle-like fibres, commonly called brown asbestos. It was used heavily in asbestos insulating board and thermal insulation, is regarded as more hazardous than white asbestos, and was banned in the UK in 1985. The colour name refers to the mineral, so only laboratory analysis can confirm it in a material.
- Crocidolite (blue asbestos)
- An amphibole asbestos with fine, straight fibres, commonly called blue asbestos and widely regarded as the most hazardous type. It was used in sprayed coatings, lagging and some cement, and was banned in the UK in 1985. Once it is mixed into a product the blue colour is hidden, so only a laboratory test can identify it.
Materials and product terms
These are the material and product terms you will see in surveys and reports. None of them can be confirmed by appearance alone, because asbestos and asbestos-free versions of the same product often look identical. Only a laboratory test on a sample settles it.
- ACM (asbestos-containing material)
- Short for asbestos-containing material. It is the umbrella term used in surveys and asbestos registers for any material or product found to contain asbestos, such as cement sheeting, insulating board, artex, floor tiles or lagging.
- AIB (asbestos insulating board)
- Short for asbestos insulating board, a board made from asbestos fibres and a binder. It was used for fire protection, ceiling tiles, soffits and partition walls. AIB is friable and higher-risk, so working with it is often licensable. It looks like ordinary building board, so only a laboratory test can confirm it. See where asbestos is found in UK homes.
- Asbestos cement
- A bonded material combining asbestos, usually white, with cement. It was used for corrugated roofing, garage and shed sheets, gutters, pipes and cold water tanks. The fibres are locked into a hard cement matrix, so it is lower-risk while intact, but it must never be cut or broken.
- Artex / textured coating
- A textured decorative coating applied to ceilings and walls in swirls, stipples and fan patterns, named after a well-known brand. Older coatings often contained a small amount of white asbestos. The pattern proves nothing on its own, so only a laboratory test can confirm whether a coating contains asbestos.
- Sprayed coating / limpet
- Asbestos sprayed onto ceilings, walls and structural steel for fire protection and insulation, often known by the trade name Limpet. It is highly friable and among the most hazardous asbestos materials, and work on it is licensable.
- Black mastic / bitumen adhesive
- The dark, tar-like adhesive used to stick down old floor tiles, also called bitumen adhesive. It frequently contained asbestos and can do so even where the tile above it does not, so both the tile and the adhesive should be tested rather than assumed safe.
- Friable
- Describes asbestos material that is soft, loosely bound and easily crumbled by hand, releasing fibres readily. Lagging, sprayed coatings and insulating board are friable and high-risk. Friable materials are the reason much asbestos work is licensable.
- Non-friable / bonded
- Describes asbestos material whose fibres are locked into a hard matrix, such as asbestos cement, floor tiles and textured coatings. Bonded material is lower-risk while intact and undisturbed, but cutting, drilling or breaking it releases fibres and turns it into a hazard.
- Encapsulation
- Sealing or coating an asbestos-containing material in place so its fibres cannot be released, leaving it where it is rather than removing it. It is a recognised way to manage asbestos that is in good condition and unlikely to be disturbed. See encapsulation vs removal.
Health conditions
These are the main diseases linked to breathing in asbestos fibres. They usually develop many years after exposure, which is why disturbing asbestos is treated so seriously. For the wider picture, see whether asbestos is dangerous.
- Mesothelioma
- A cancer of the lining of the lungs or abdomen that is almost always caused by breathing in asbestos fibres. It usually develops decades after exposure and is the disease most closely associated with asbestos.
- Asbestosis
- A long-term scarring of the lung tissue caused by breathing in asbestos fibres over time, which makes breathing progressively harder. It is typically linked to heavy or prolonged exposure.
- Pleural thickening
- A thickening and hardening of the lining around the lungs, known as the pleura, caused by asbestos exposure. It can reduce lung capacity and cause breathlessness, and it is one of several conditions linked to inhaling asbestos fibres.
Surveys, testing and clearance
These terms cover how asbestos is found, tested and signed off. Surveys are carried out to the HSE standard, and the confirmation you can rely on is always a written laboratory result. Our guide to the types of asbestos survey explains which one you need.
- Management survey
- A minimally intrusive asbestos survey that locates and assesses asbestos so it can be managed safely while a building stays in normal use. It underpins the asbestos register and management plan required by the duty to manage.
- Refurbishment & demolition survey
- A fully intrusive, destructive asbestos survey required before any refurbishment or demolition work, to locate all asbestos that the work could disturb. It is more thorough and disruptive than a management survey.
- Re-inspection survey
- A follow-up survey that monitors the condition of known asbestos materials over time, checking whether any have deteriorated or been damaged. It keeps the asbestos register and management plan up to date.
- HSG264
- HSE guidance titled Asbestos: The survey guide, published in 2010. It sets the UK standard for how asbestos surveys are carried out and defines the management survey and the refurbishment and demolition survey.
- HSG248
- HSE guidance titled Asbestos: The analysts' guide. It sets the UK standard for the analytical work that supports asbestos removal, including air monitoring and the four-stage clearance.
- UKAS-accredited laboratory
- A laboratory accredited by the United Kingdom Accreditation Service (UKAS) to analyse asbestos samples. UKAS accreditation is the recognised standard for reliable analysis, and confirmation of asbestos should come from a UKAS-accredited laboratory through asbestos testing.
- Air monitoring
- Measuring the concentration of asbestos fibres in the air, expressed in fibres per millilitre of air, to check exposure and confirm an area is safe. It is used during and after removal work and forms part of the four-stage clearance.
- Four-stage clearance / certificate of reoccupation
- The independent procedure an accredited analyst carries out after licensed asbestos removal, before an area is reoccupied. Its four stages are a preliminary check of the site and paperwork, a thorough visual inspection, air monitoring against the clearance indicator of 0.01 fibres per cubic centimetre, and a final assessment after the enclosure is removed. Passing it results in a certificate of reoccupation.
Regulation and compliance
These are the legal and compliance terms that govern how asbestos is managed and worked with in the UK. Landlords and businesses in particular need to understand the duty to manage. For a fuller walkthrough, see our guide on asbestos compliance for landlords and businesses.
- Control of Asbestos Regulations 2012
- The current UK law governing how asbestos is managed and worked with, often shortened to CAR 2012. It sets out duties for employers, licensing requirements, exposure limits and the duty to manage asbestos in non-domestic premises.
- Duty to manage (Regulation 4)
- The legal duty under Regulation 4 of the Control of Asbestos Regulations 2012 requiring those responsible for non-domestic premises, and the common parts of residential buildings, to find, record, assess, manage and monitor any asbestos present.
- Licensable work
- Higher-risk asbestos work, typically on friable materials such as lagging, sprayed coatings and much insulating board, that legally requires an HSE-licensed contractor, enclosures and specific controls under the Control of Asbestos Regulations 2012.
- Non-licensed work
- Lower-risk asbestos work, usually on bonded materials such as asbestos cement and textured coatings, that does not require an HSE licence. It must still be carried out with proper training, precautions and safe disposal.
- NNLW (notifiable non-licensed work)
- Short for notifiable non-licensed work, a category between licensed and non-licensed work. It does not need a licence but must be notified to the enforcing authority, with extra requirements for medical surveillance and record-keeping under the Control of Asbestos Regulations 2012.
- HSE-licensed contractor
- A contractor holding a licence from the Health and Safety Executive (HSE) to carry out higher-risk, licensable asbestos work such as removing lagging, sprayed coatings and insulating board.
- Control limit
- The maximum concentration of asbestos fibres in the air a worker may be exposed to, set by the Control of Asbestos Regulations 2012 at 0.1 fibres per cubic centimetre of air averaged over a four-hour period. Exposure must be kept as far below this limit as possible.
- Clearance indicator
- The air-test figure used during a four-stage clearance to judge whether an area is safe to reoccupy after asbestos removal, set at 0.01 fibres per cubic centimetre of air. It is a clearance benchmark, not a safe level of exposure.
- Consignment note
- The document that accompanies asbestos waste from the site where it is removed to the licensed facility where it is disposed of, recording what the waste is and tracking its safe disposal.
- Asbestos register
- A record of the location, type and condition of all known or presumed asbestos in a building. It is a core part of meeting the duty to manage and is kept up to date through re-inspection.
- Asbestos management plan
- A written plan setting out how the asbestos recorded in a building's register will be managed, monitored and controlled, including who is responsible and what to do if material is disturbed. It is required under the duty to manage.