Asbestos Survey
Asbestos containing material (ACM) that crumbles under hand pressure is called friable. Friable ACM has the potential to become airborne, where it may be inhaled. If airborne ACM is inhaled, asbestos fibres can enter the body and cause serious long-term health problems.
Undisturbed ACM can lie for decades in residential or commercial structures without impacting the health of anyone in the building. It is only when ACM becomes airborne that it becomes hazardous. When a building is demolished or undergoes renovation, friable ACM may become airborne. Professional asbestos surveys identify ACM hazards and protect the health of workers and building occupants.
There are two types of asbestos surveys. Management asbestos surveys involve a walk through with a visual inspection and sampling of specific materials. Management asbestos surveys evaluate the condition of the suspected ACM, and samples are only taken if the suspected material is friable.
Demolition or refurbishment asbestos surveys use a much more thorough sampling program than the management asbestos surveys. Inspectors identify all ACM through sampling without regard to condition, and the test results are used to calculate the total volume of ACM present in the structure.
There are also two types of asbestos sampling. Air testing identifies airborne fibres. In this test, a known quantity of air is pulled through a specific type of filter, which is then examined under a microscope with a special polarizing light, and the fibres in a certain area are counted. That figure is extrapolated to estimate the number of fibres present on the entire filter. The number of fibres present on the filter can be used to estimate the number of fibres in a given volume of air, since a known volume was sampled.
Bulk sample testing involves the analysis of pieces of suspected ACM. Samples are mechanically pulverized in a laboratory and the pulverized dust is examined under a microscope. If fibres are present, they are extracted and examined under polarized light. Based on their appearance under polarized light, the laboratory can confirm or rule out the presence of asbestos in the material.
The information obtained from asbestos surveys may be used to create an asbestos register. Unlike a survey, which documents asbestos present at a given time, the register is a working document that changes as the status of ACM present in the structure changes. If ACM is subsequently removed or mitigated, the asbestos register is updated to reflect these changes.
About Types of Asbestos Surveys
There are 3 types of asbestos survey available to you. The asbestos survey company will be able to advise you as to which one is appropriate for your property. An outline of what you can expect from each type of survey is given below:
Asbestos Survey Type 1 – This is a visual inspection of the building and is the cheapest and quickest way of putting your mind at ease while still complying with asbestos regulations. As it is a visual inspection only and no samples are taken, any suspicious material is assumed to be, or assumed to contain, asbestos. Although this can save money if no likely material is found, it could mean that the cost is greater over the long term as suspect material will need to be dealt with on the assumption that it is asbestos. It also has a disadvantage as any material not obviously visible may be omitted from the survey.
Asbestos Survey Type 2 – This is an extension of the survey above, in which a visual survey is carried out and any material suspected of containing asbestos is sampled and taken for analysis. The laboratory tests will then prove or disprove the presence of asbestos, and the report will indicate the best way of dealing with any that is confirmed. This type of survey is the most common type undertaken and is the most cost effective way of complying with asbestos legislation. As it confirms both the presence and absence of asbestos as appropriate, removal costs are kept to a minimum and the process can be focused only on those areas and materials where asbestos has been confirmed. No time or money is wasted on the ‘just in case’ approach associated with a type 1 survey.
Asbestos Survey Type 3 – This type of survey is also known as a ‘fully intrusive’ survey, and it is normally used when a building is to be demolished or fully refurbished and there is a high chance of asbestos containing materials being disturbed. Samples are taken in a more intrusion or destructive fashion than for a type 2 survey, e.g. panels, bricks and coverings may be removed, and many more samples are taken so that the location and amount of all asbestos present can be calculated.
Whichever survey type you choose, you will receive an asbestos survey report after it is completed. This will detail the results and the recommendations of the surveyor, allowing you to plan or arrange the asbestos removal or simply to serve as a record that you have complied with legislation.