Asbestos surveys are essential for identifying asbestos-containing materials (ACMs) within buildings, assessing their condition, and determining the risk they pose to occupants. These surveys are a critical part of managing asbestos safely, especially in older structures where the material was commonly used in construction. The process of conducting an asbestos survey involves several detailed steps, including visual inspections, material sampling, risk assessments, and comprehensive reporting. Each step requires expertise to ensure accuracy and compliance with industry regulations.
In this article, we will break down how asbestos surveys are performed, highlighting the technical aspects involved in identifying and managing asbestos risks.
Pre-Survey Planning and Preparation
Before an asbestos survey begins, a comprehensive planning phase takes place. This phase involves reviewing any existing records or documentation on the building, such as architectural plans, renovation histories, or previous asbestos surveys. Having a thorough understanding of the building’s structure and previous work helps the surveyor identify areas that are more likely to contain asbestos.
The surveyor also needs to assess the type of survey required based on the building’s current or future use. For example, if the building is in use and no major refurbishment is planned, a management survey may be adequate. However, if demolition or extensive refurbishment is scheduled, a more invasive refurbishment and demolition survey is necessary to inspect hidden or inaccessible areas.
Risk assessments for safety measures are also conducted to protect both surveyors and occupants. This may involve arranging temporary evacuation or isolation of certain building sections, as well as ensuring that personal protective equipment (PPE) and other control measures are in place to prevent accidental asbestos exposure during the survey.
Visual Inspection and Material Sampling
Once planning is complete, the survey itself begins with a thorough visual inspection of the building. The surveyor, typically a qualified asbestos professional, systematically inspects each area of the building, visually identifying potential ACMs. Common materials that may contain asbestos include ceiling tiles, pipe insulation, floor tiles, roofing materials, and cement sheets. The surveyor pays special attention to any damaged or deteriorating materials, as these are more likely to release asbestos fibers into the air.
During the visual inspection, the surveyor marks suspect materials and collects samples for laboratory testing. Sampling is a critical part of the asbestos survey process because visual identification alone is not sufficient to confirm the presence of asbestos. To avoid disturbing asbestos fibers, surveyors follow stringent protocols when collecting samples. Small, carefully controlled sections of the suspect material are cut out and sealed in airtight containers to prevent fiber release. All samples are clearly labeled with details about their location in the building for accurate record-keeping and analysis.
In many cases, surveyors use specialized tools such as borescopes to inspect hidden spaces without causing significant disturbance to the building structure. This allows for the inspection of areas such as wall cavities, floor voids, and above suspended ceilings. In more invasive surveys, demolition techniques may be employed to access hidden ACMs behind walls or under floors.
Laboratory Testing of Samples
The collected samples are then sent to a certified laboratory for analysis, where they undergo testing to confirm the presence of asbestos and determine its type. The three main types of asbestos commonly found in building materials are chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). These types differ in their appearance, fiber structure, and level of health risk.
The laboratory uses techniques such as polarized light microscopy (PLM) and transmission electron microscopy (TEM) to analyze the asbestos fibers at a microscopic level. PLM is commonly used for identifying asbestos fibers in bulk materials, while TEM may be employed for more detailed fiber analysis, particularly when air samples are being evaluated.
Once the laboratory confirms the presence of asbestos, it will classify the material based on its type and condition, helping the surveyor determine the level of risk associated with the ACMs.
Risk Assessment and Condition Evaluation
Following sample analysis, the surveyor performs a detailed risk assessment based on the laboratory results and visual inspection findings. The risk assessment evaluates the condition of the asbestos-containing materials, the likelihood of fiber release, and the potential exposure risk to building occupants.
Key factors in this assessment include:
Material Condition: ACMs in good condition are less likely to release fibers, whereas damaged or deteriorating materials pose a higher risk.
Location and Accessibility: ACMs located in high-traffic areas or near HVAC systems are more likely to be disturbed, increasing the risk of airborne fibers.
Current Use of the Building: In buildings where construction, renovation, or demolition is planned, the risk of disturbing ACMs is greater.
Watch the video above to learn more about how asbestos surveys in London are done!.
