What Are Asbestos Exposure Limits — and Why Do They Matter More Than Ever?
Asbestos is still present in hundreds of thousands of buildings across the UK, and the health risks it poses have not diminished with time. Understanding asbestos exposure limits is not just a regulatory box-ticking exercise — it is the difference between a safe workplace and one that could cost workers their lives. With over 5,000 asbestos-related deaths recorded in Britain each year, this remains the country’s single largest cause of work-related fatality.
Whether you manage a school, an office block, a hospital, or an industrial site, the rules around asbestos exposure apply to you. Here is what every duty holder, facilities manager, and employer needs to know.
The Current Asbestos Exposure Limits in the UK
The UK’s legal asbestos exposure limits are set out under the Control of Asbestos Regulations and are enforced by the Health and Safety Executive (HSE). These are not guidelines or suggestions — they are hard legal thresholds.
There are two limits you need to be aware of:
- Control limit (long-term): 0.1 fibres per cubic centimetre of air (f/cm³), averaged over a four-hour period
- Short-term exposure limit: 0.6 f/cm³, averaged over any 10-minute period — this applies to non-licensed work
These figures apply to all types of asbestos fibres, including chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). There is no ‘safe’ level of asbestos exposure — these limits represent the maximum permissible level, not a safe target to aim for.
The HSE is explicit: the control limit is not a safe level. Employers must reduce exposure to as low as reasonably practicable, and only then use the control limit as an absolute ceiling that must never be breached.
How Are Asbestos Fibres Measured?
Airborne asbestos fibres are measured using specialist air sampling equipment. A pump draws air through a filter membrane, which is then analysed under a phase contrast microscope by an accredited laboratory. Results are expressed in fibres per cubic centimetre (f/cm³).
Background levels in outdoor air are typically around 0.0001 f/cm³ or lower. Any reading approaching the control limit of 0.1 f/cm³ should trigger immediate investigation and remedial action.
Legal Duties Under the Control of Asbestos Regulations
The Control of Asbestos Regulations place clear, enforceable duties on employers, building owners, and those who manage premises. The core obligation is the duty to manage asbestos — set out in Regulation 4 — which requires duty holders to:
- Identify the location and condition of all asbestos-containing materials (ACMs) in their premises
- Assess the risk of fibres being released
- Prepare and implement an asbestos management plan
- Provide information about the location and condition of ACMs to anyone who may disturb them
- Review and monitor the plan and ACMs regularly
Failure to comply is a criminal offence. The HSE can issue improvement notices, prohibition notices, and prosecute duty holders — with unlimited fines possible in the Crown Court.
Licensed, Notifiable Non-Licensed, and Non-Licensed Work
Not all asbestos work carries the same level of risk, and the regulations reflect this with three distinct categories:
- Licensed work: The highest-risk activities — such as removing sprayed coatings or lagging — require a licence from the HSE, prior notification to the relevant enforcing authority, health surveillance, and detailed record-keeping. Health records for licensed work must be retained for 40 years.
- Notifiable Non-Licensed Work (NNLW): Lower-risk than licensed work but still requires notification to the enforcing authority, medical surveillance, and written records. Medical examinations became mandatory for NNLW workers following regulatory changes — employers must ensure these are in place.
- Non-licensed work: The lowest-risk category, but still subject to risk assessment, appropriate controls, and the short-term exposure limit of 0.6 f/cm³ over 10 minutes.
Understanding which category applies to a task is critical before any work begins. When in doubt, treat the work as higher-risk until a competent assessment confirms otherwise.
HSG264 and the Role of Asbestos Surveys
The HSE’s guidance document HSG264 sets out the standard for asbestos surveying in non-domestic premises. It defines two main types of survey:
- Management survey: Used during normal occupation and operation of a building. It identifies ACMs that could be disturbed during routine maintenance and everyday activities.
- Refurbishment and demolition survey: Required before any refurbishment or demolition work. It is more intrusive and must locate all ACMs in the relevant areas, including those that may be hidden.
Choosing the right type of survey is not optional — using a management survey when a refurbishment survey is required puts workers at serious risk and leaves duty holders legally exposed.
If your building was constructed before the year 2000, you should assume asbestos is present until a survey proves otherwise. Asbestos was not fully banned in the UK until 1999, meaning it could be present in any structure built or refurbished before that date.
Our teams carry out asbestos survey London projects across the capital for commercial landlords, local authorities, and housing associations, helping duty holders meet their obligations under HSG264 and the Control of Asbestos Regulations.
Monitoring and Controlling Asbestos Exposure in Practice
Keeping asbestos exposure below the legal limits requires more than a one-off survey. It demands an ongoing, structured approach to monitoring and control. Here is what a robust asbestos management programme looks like in practice:
Regular Air Monitoring
Air monitoring should be carried out by an accredited hygienist whenever asbestos work is being undertaken, and as part of ongoing monitoring programmes in buildings where ACMs are present. Personal air sampling — where a monitor is worn by the worker — gives the most accurate picture of individual exposure.
Background monitoring of the wider work environment is also valuable, particularly in buildings where ACMs are in poor condition. Results should be logged and reviewed as part of the asbestos management plan.
Maintaining the Asbestos Register
Every premises with known or suspected ACMs should have an asbestos register — a document recording the location, type, condition, and risk rating of all identified materials. This register must be:
- Kept up to date — reviewed at least annually and updated after any work that affects ACMs
- Accessible to anyone who may disturb asbestos, including contractors and maintenance staff
- Reviewed before any maintenance, refurbishment, or construction work begins
An out-of-date or incomplete register is one of the most common failings found during HSE inspections. Do not let it be yours.
Training and Competency
Anyone who is liable to disturb asbestos in the course of their work must receive appropriate asbestos awareness training. This includes not just specialist asbestos workers, but also electricians, plumbers, joiners, and other tradespeople working in older buildings.
Training must be relevant to the type of work being carried out. Those undertaking licensed or NNLW work require more detailed instruction, and refresher training should be provided annually to keep knowledge current.
Waste Disposal
Asbestos waste is classified as hazardous waste and must be handled accordingly. All asbestos waste must be:
- Double-wrapped in heavy-duty polythene bags or sheeting
- Clearly labelled with hazard warnings
- Transported in a sealed, clearly marked vehicle
- Disposed of at a licensed hazardous waste facility
Fly-tipping asbestos waste is a serious criminal offence. Contractors who remove asbestos should provide a waste transfer note — always ask for one and keep it on file.
Asbestos Exposure Across Different Property Types
The risks associated with asbestos exposure limits vary depending on the type of property and how it is used. Commercial offices, schools, hospitals, and industrial premises each present different challenges.
In schools and public buildings, the priority is protecting occupants during normal use — management surveys and robust monitoring programmes are essential. In industrial settings, where maintenance work is frequent and more invasive, the risk of disturbing ACMs is higher and controls need to be proportionately stricter.
Our asbestos survey Manchester service covers a wide range of property types across Greater Manchester, from Victorian mill buildings to modern commercial premises — many of which contain asbestos in unexpected locations.
Similarly, our asbestos survey Birmingham team works with property managers across the West Midlands to identify and manage ACMs in everything from retail units to large industrial complexes.
What Happens If Exposure Limits Are Exceeded?
If air monitoring reveals that asbestos exposure limits have been breached, immediate action is required. Work must stop. The affected area should be evacuated and sealed off. A thorough investigation must establish how the breach occurred, and remedial measures must be put in place before work resumes.
Workers who have been exposed above the control limit must be informed. Their health records must be updated, and where licensed work is involved, the relevant enforcing authority must be notified. Depending on the circumstances, a review of the risk assessment and method statement will be necessary.
Ignoring a breach — or failing to investigate one properly — is not just dangerous. It is a criminal act that can result in prosecution, significant fines, and in serious cases, custodial sentences for individuals.
Practical Steps for Duty Holders
If you are responsible for a building constructed before 2000, here is a straightforward action plan to ensure you are managing asbestos exposure limits correctly:
- Commission an asbestos survey if you do not already have one — a management survey for occupied buildings, a refurbishment and demolition survey before any intrusive work
- Create or update your asbestos register based on the survey findings
- Develop an asbestos management plan that sets out how you will monitor, maintain, and manage identified ACMs
- Ensure all relevant staff and contractors are made aware of the register and the location of ACMs before they begin any work
- Arrange regular air monitoring in areas where ACMs are present or where work is being carried out
- Provide appropriate training for all workers who may encounter asbestos
- Review your plan annually and update it whenever the condition of ACMs changes or work is carried out
This is not an exhaustive list, but it covers the core obligations that the HSE will look for if they inspect your premises.
Frequently Asked Questions
What are the current asbestos exposure limits in the UK?
The UK sets two legal asbestos exposure limits under the Control of Asbestos Regulations. The long-term control limit is 0.1 fibres per cubic centimetre of air (f/cm³), averaged over four hours. The short-term limit for non-licensed work is 0.6 f/cm³, averaged over any 10-minute period. These are maximum thresholds — employers must reduce exposure to as low as reasonably practicable below these levels.
Is there a safe level of asbestos exposure?
No. The HSE is clear that there is no known safe level of asbestos exposure. The control limits define the maximum legally permissible concentration of fibres in workplace air — they are not targets to work towards. The goal must always be to reduce exposure as far as possible, using appropriate controls and working methods.
Who is responsible for managing asbestos exposure in a workplace?
Under the Control of Asbestos Regulations, the duty to manage asbestos falls on the ‘duty holder’ — typically the owner of the premises or the person or organisation responsible for maintaining and repairing it. In practice, this often means the employer, landlord, or facilities manager. Where responsibilities are shared between parties, they must cooperate to ensure the duty is met.
How often should asbestos air monitoring be carried out?
There is no single fixed frequency — it depends on the nature of the work and the condition of ACMs in the building. Air monitoring must be carried out whenever asbestos work is being undertaken. Ongoing background monitoring is also recommended in buildings where ACMs are present and in poor condition. Your asbestos management plan should specify the monitoring schedule appropriate for your premises.
What should I do if I suspect asbestos has been disturbed in my building?
Stop all work in the affected area immediately and prevent access. Do not attempt to clean up any debris yourself. Contact a licensed asbestos contractor or accredited asbestos surveyor to assess the situation. Air monitoring should be carried out to determine whether fibres have been released. If exposure above the control limit is confirmed, workers must be informed and health records updated accordingly.
Get Expert Help Managing Asbestos Exposure
Managing asbestos exposure limits correctly requires expertise, the right equipment, and a thorough understanding of UK regulations. At Supernova Asbestos Surveys, we have completed over 50,000 surveys nationwide, helping duty holders across the UK stay compliant and keep their workers safe.
Whether you need a management survey, a refurbishment and demolition survey, or ongoing air monitoring support, our accredited team is ready to help. Call us on 020 4586 0680 or visit asbestos-surveys.org.uk to find out more or book a survey.