What Is Asbestos Air Testing?
Asbestos air testing — also called airborne fibre monitoring or fibre counting — measures the concentration of asbestos fibres suspended in the air of a building or work area. Air samples are collected using calibrated pumps drawing air through a membrane filter, which is then analysed in a UKAS-accredited laboratory using phase contrast microscopy (PCM) or transmission electron microscopy (TEM).
Types of Asbestos Air Test
| Type | Purpose | When Required |
|---|---|---|
| Clearance air test | Confirm asbestos removal is safe | After all licensed removal work |
| Background test | Establish baseline fibre levels before work | Before licensed removal |
| Personal air sampling | Monitor worker exposure | During licensed removal works |
| Reassurance test | Give confidence after disturbance concerns | On request — not legally required |
The Four-Stage Clearance Procedure
After licensed asbestos removal work, a four-stage clearance procedure must be completed before the area can be reoccupied:
- Visual inspection to confirm the area is clean and free of visible debris
- Background air test taken before the enclosure is broken down
- Air test inside the enclosure once the contractor confirms removal is complete
- Final clearance certificate issued if results are below the clearance criterion (0.01 fibres/ml)
Who Can Carry Out Air Testing?
Clearance air testing after licensed removal must only be carried out by a UKAS-accredited body independent of the removal contractor. The analyst must hold a relevant BOHS qualification (typically P403 or P404). You cannot use the same company that did the removal work to sign off on the clearance test.
Cost of Asbestos Air Testing
| Test Type | Typical Cost |
|---|---|
| Clearance air test (small area) | £150 – £300 |
| Clearance air test (large area) | £300 – £800+ |
| Background air test | £100 – £200 |
| Reassurance air test | £150 – £350 |