Air sampling is used to detect and measure the level of asbestos fibres present. For some types of asbestos removal work, air sampling is mandatory but it can also be used to assess personal exposure, background levels and to provide reassurance following minor works. Whether a single background air sample or large complex areas such as boiler houses within a hospital, we have the experience, skills and knowledge to provide a competent service.
Air monitoring will be carried out in compliance with the HSE’s Guidance Note HSG248 Asbestos: The analysts’ guide as we are a UKAS accredited Testing Laboratory No. 4234 ensuring conformity to ISO/IEC17025:2005.
Air Monitoring can be offered on an emergency basis, available 24 hours a day 365 days a year. Read below for details of different types of test that can be provided or contact us for a consultation, where we will recommend a suitable strategy.
The type of air sampling will vary during repair or removal projects and a hierarchy of tests will be needed. We work closely with our clients to ensure that asbestos projects are effectively planned to provide quantitative evidence and reassurance to both occupants and visitors alike.
Free Download from HSE:HSG248: Asbestos: The analysts’ guide for sampling, analysis and clearance procedures
Air sampling involves drawing a measured volume of air, through a filter using a small pump. The filter is mounted onto a microscope slide for examination. The fibres are counted using phase contrast optical microscopy (PCM) and the concentration of fibres is calculated using the World Health Organisation (WHO) method.
Background sampling is completed to establish fibre concentrations usually before work starts. This type of test is often referred to as a datum test and is used to collect information on the background levels of fibres.
Personal Air Monitoring
Personal sampling is used principally to check the effectiveness of control measures used during the work and to assess if the appropriate respiratory protection is being used. The information can be used for future risk assessments and also medical surveillance of the operator.
Reassurance sampling is completed to monitor fibre concentrations usually during or after removal work to ensure levels are satisfactory before returning to the client.
Asbestos Removal Work
The removal of asbestos by its very nature will cause disturbance and spread of asbestos fibres, therefore most asbestos work can only be carried out by companies who have obtained a licence from the HSE. These contractors are independent organisations from the analytical laboratories. When asbestos removal work is taking place additional control measures will be used to contain any fibres released. In addition to the standard tests detailed above, the following types of test are all associated with licensed asbestos removal projects.
Leak sampling is completed in any location around the work area to establish if any fibres are “leaking” from the work area and being released into the adjacent areas. Multiple locations will be utilised and set to run alongside the entire project so that the cause of any fibre levels above background, can be investigated throughout the project.
Following asbestos removal, the work area must be assessed to determine whether it is thoroughly clean and suitable for reoccupation. This is completed by undertaking a 4 stage clearance and issuing a Certificate of Reoccupation. The four stages to the procedure:
- Preliminary check of site condition and job completeness
- A thorough visual inspection inside the enclosure/work area
- Air monitoring
- Final assessment post-enclosure/work area dismantling
The clearance air test will take place only when the enclosure is dry and a visual inspection confirms that it is free from debris and dust. This test is used to confirm the airborne asbestos fibre concentrations are within acceptable levels and used to certify that the controls may be removed.