Asbestos Air Monitoring
Air monitoring measures airborne fibre concentrations and helps assess the effectiveness of asbestos control measures. Our BOHS P403/P404 qualified analysts provide personal monitoring, leak testing, background sampling, and reassurance monitoring throughout your project.
What Is Asbestos Air Monitoring?
Asbestos air monitoring involves collecting air samples and analysing them for airborne asbestos fibres using phase contrast microscopy (PCM), the standard method for fibre counting in the UK. Monitoring measures the concentration of airborne fibres. During asbestos removal projects, the results help assess whether enclosures and other controls are working effectively and help assess worker exposure, which must be kept as low as reasonably practicable and below the control limit (0.1 fibres per cubic centimetre of air averaged over 4 hours). Air monitoring provides ongoing information during works, complementing the formal 4 stage clearance process conducted at project completion.
When Is Air Monitoring Required?
- During licensed asbestos removal works (statutory requirement)
- Before, during, and after enclosure work
- For four-stage clearance certification
- As reassurance monitoring during building occupation
- Following suspected asbestos disturbance incidents
- To establish background fibre levels before works commence
- For leak testing of removal enclosures
Who Needs Air Monitoring?
- Licensed asbestos removal contractors
- Clients overseeing asbestos removal projects
- Building managers requiring reassurance testing
- Employers investigating suspected exposure incidents
- Demolition contractors during strip-out works
- Healthcare and education premises during refurbishment
What You Receive
- Personal and static air monitoring throughout works
- Background, leak, and reassurance test results
- Rapid turnaround results for informed decision-making
- Analyst site attendance notes and observations
- Fibre counting by phase contrast microscopy (PCM)
- Comprehensive monitoring summary report
- Documentation for health and safety records
Types of Air Monitoring
Background Monitoring
Samples collected before works commence to establish baseline fibre levels. Essential for comparison during and after removal operations.
Leak Testing
Monitoring outside enclosures during removal to detect any fibre leakage. Immediate results enable rapid response if issues are identified.
Personal Monitoring
Samplers worn by workers to assess individual exposure levels. Required for compliance with workplace exposure limits.
Reassurance Monitoring
Post-works or periodic sampling to verify ongoing fibre levels remain safe. Provides documented assurance for building occupants.
Frequently Asked Questions
What qualifications do your analysts hold?
All our analysts hold BOHS P403 (Asbestos Fibre Counting) and P404 (Air Sampling and Clearance Testing) qualifications. Clearscan is a BOHS (British Occupational Hygiene Society) Affiliate Member.
How quickly can you attend site?
Attendance within 24–48 hours, subject to availability. For ongoing removal projects, we provide dedicated analyst attendance aligned with your project programme.
What is the clearance level for reoccupation?
The clearance indicator is an airborne fibre concentration below 0.010 fibres per millilitre (f/ml), measured by phase contrast microscopy (PCM) while surfaces inside the enclosure are deliberately disturbed. Passing this air test is Stage 3 of the four-stage clearance only and does not by itself mean the area can be reoccupied. Once Stage 3 is passed the enclosure can be dismantled, and a Certificate for Reoccupation is issued only after the Stage 4 final visual assessment has also been passed.
Do you provide monitoring for non-licensed works?
Yes. While not always a statutory requirement, we recommend reassurance monitoring for non-licensed removal works to demonstrate due diligence and protect building occupants.
Can you provide continuous site attendance?
Yes. For larger removal projects, we provide dedicated analysts for continuous or programmed attendance throughout the project duration.
What happens if clearance testing fails?
If clearance requirements are not met, a Certificate for Reoccupation cannot be issued. The analyst records the problem and the removal contractor carries out the necessary remedial work, including further cleaning where needed. After a formal Stage 2 failure, the process restarts at Stage 1 once the contractor’s supervisor has reinspected the enclosure and issued a new handover document. Problems at other stages are addressed using the relevant HSG248 procedure. All four stages must be satisfactorily completed before reoccupation.
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