Air Monitoring

Air sampling and analysis is extremely important in determining such factors as the potential risk of exposure to any asbestos containing materials. It is therefore essential that such measurements are carried out competently, using the appropriate sampling procedures and equipment.

Asbestos Consultants to the Environment, part of the AcePSI Group, are committed to providing reliable asbestos site sampling and testing services and for ensuring that sampling and testing is carried out correctly and reliably. Fundamental to this commitment is ensuring such levels that include our technicians being adequately trained to perform sampling and testing, that we provide suitable laboratory accommodation, and that the equipment we use is suitable for the specific test activity.

An air sampling strategy will be devised prior to asbestos remedial works to ensure that all aspects of the work are covered. This strategy typically includes background sampling, leak testing, site clearance certification for re-occupation, reassurance sampling, personal sampling, and sampling certification and reporting.

 

Background Sampling

Technicians employed by Asbestos Consultants to the Environment, part of the AcePSI Group, to carry out asbestos air sampling and analysis will use a number of sampling applications depending on the client's specification and scope of works. One such method is Background Sampling. Prior to the commencement of any activity that may lead to asbestos fibres becoming airborne, and as a consequence becoming hazardous, ‘background sampling’ must be conducted in order to establish ambient levels of asbestos.

 

Leak (Enclosure Check) Testing

Sampling outside an enclosure and in adjacent areas during the removal process to ensure that effective fibre containment is being maintained.

 

Site assessment for Re-occupation

Following asbestos removal, the premises must be assessed to determine whether they are thoroughly clean and fit for reoccupation (or, as appropriate, demolition).

The clearance certification process is a vital component in asbestos removal work. The issue of a certificate of reoccupation by an impartial and competent organisation provides the crucial reassurance and security to the subsequent building users. The multi-stage certification process is designed to allow the inspection and assessment to be performed in a structured, systematic and consistent manner.

It is the responsibility of the licensed contractor undertaking the asbestos removal work to thoroughly and diligently clean up the work area. When the contractor is satisfied that the area is clean and ready for future use, the area is assessed by an analyst of an independent organisation which is accredited by UKAS as complying with ISO 17025. The analyst's role is to provide independent verification that the area is clean and suitable for subsequent use.

There are four stages to the site certification for reoccupation assessment procedure carried out by the analyst:

• 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.

Stage 3 air sampling takes place once a thorough visual inspection has been carried out and the analyst is satisfied that all the asbestos in the POW has been removed, and there is no visible debris or layers of settled dust. All air measurements completed by the analyst comply with the ISO 17025 standard. The value calculated from each sample taken during site clearance testing is compared with the clearance indicator value 0.010 fibres per cubic centimetre. Only when this assessment of the workplace is passed as satisfactory is a certificate of reoccupation issued. The certificate is issued to the contractor and, as appropriate, to the customer where the latter has engaged the analyst.

Asbestos remaining in enclosures (by design) should be labelled that it is asbestos and that it is to remain. These asbestos items to remain can then be checked by the analyst against the work plan and recorded on the certificate of reoccupation. The building owner should ensure the presence of the asbestos is included in their asbestos management plan.

 

Reassurance Sampling

This type of monitoring may be required in certain circumstances, such as when an enclosure has been dismantled on completion of asbestos removal, to confirm that the residual asbestos airborne fibre concentrations are less than 0.01 fibres per cubic centimetre of air sampled.

 

Personal Sampling

Personal Sampling is to be carried out when it is necessary to assess the exposure level of an individual carrying out his/her work. In this instance sampling is carried out on asbestos removal personnel working in enclosures, checking that adequate respiratory protective equipment is worn (referred to as an RPE test). Furthermore, sampling to check compliance with the Control Limit under the Control of Asbestos Regulations 2006 is another example of where personal sampling is applied.