When carrying out air monitoring as part of a 4-stage clearance, our experienced analysts all work to the same high standards for inspecting and signing off each stage of the project. Our analysts pay particular attention to detail in carrying out the thorough visual inspection which determines an area is free from dust and debris prior to carrying out air sampling. When an area has passed a 4-stage clearance conducted by an analyst from G&L you can be confident that the area is completely safe to reoccupy.
G&L has specialised mobile laboratories where the microscope can be set up on site. Fibre counting can then be carried out immediately following the air sampling to give you an instant result. All site reports are electronically produced and printed on site so the removal contractor and the client can be issued with the report before the analyst leaves site.
The method of filter analysis normally carried out by G&L is Phase Contrast Microscopy (PCM), which is suitable in almost every circumstance. On very rare occasions other methods such as Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) might be required, which following consultation with the client can be organised by G&L.
The different types of Air Monitoring provided by G&L Consultancy are as follows:
- Background Monitoring – prior to asbestos removal work taking place
- Leak Monitoring – outside the enclosure during asbestos removal
- Reassurance Monitoring – to ensure the air is free from asbestos fibres
- 4-Stage Clearance Monitoring – for Certificate of Reoccupation
- Personal Monitoring – to determine the exposure levels of the operatives
Background Monitoring is very useful to establish whether a problem exists before any removal work begins, especially in relation to any future Leak Monitoring and any problems that might occur with the Clearance Monitoring.
Leak Monitoring can help ensure that the Control Measures used during the removal work are adequate. A high result from Leak Monitoring will give an early warning that asbestos fibres are spreading away from the area of the asbestos removal works. A high leak test result is particularly significant if previous Background Monitoring has demonstrated that the area had no ambient fibre level before the asbestos removal work began.
Reassurance Monitoring is carried out to give reassurance that the area is safe for occupation following certain events:
- If non-licensable asbestos has been removed, Reassurance Monitoring is run to ensure no asbestos fibres remain in the former work area.
- Following a breach in an asbestos enclosure and the subsequent clean up, Reassurance Monitoring is required to demonstrate that the area is safe to re-enter.
- Following the discovery of damaged asbestos in an area and the subsequent remedial actions, Reassurance Monitoring is required to demonstrate that the remedial actions are sufficient until the damage can be fully dealt with by licensed contractors.
4-Stage Clearance Monitoring for Certificate for Reoccupation
Clearance Monitoring must be conducted by a UKAS accredited analytical company following licensable removal work. The Clearance Monitoring involves four distinct stages:
- Stage 1: Preliminary check of site condition and job completeness;
- Stage 2: A thorough visual inspection inside the enclosure / work area;
- Stage 3: Air Monitoring;
- Stage 4: Final assessment post-enclosure / work area dismantling
Only after successful Clearance Monitoring can an area be classed as safe to re-enter.
Personal Monitoring is used to ensure that the person wearing the sampling pump is adequately protected from whatever levels of airborne asbestos fibres are present and to ensure that the control measures in use are suitable and sufficient.