To ensure ACM removal was objectively prioritised based on risk, the VAEA developed a fit for purpose risk assessment model in consultation with Victorian OHS regulators, occupational hygienists, licensed asbestos removalists, trade unions and employers.
The VAEA risk assessment model incorporates the risk factors: ACM friability, ACM condition, ACM disturbance potential and building rating (see Figure 1).
Attributing a consistent percentage weighting for each risk factor develops an overall risk score, providing a more objective approach to assessing ACM risk.
Download overview of the VAEA risk model:
ACM friability and ACM condition are based on information from the survey assessment of each ACM, and together contribute 50% of the final risk assessment score. The most significant factor in the risk model, ACM friability, is weighted at 35%, as friability increases the risk of fibre release. ACM friability is attributed from a friability scale based on the ACM product type. The condition of ACMs contributes up to 15%.
Disturbance potential and building rating risk factors contribute 50% of the weighting for the final risk assessment score. These account for the built environment where the ACM is located. Disturbance potential is categorised into four levels and contributes up to 25% of the overall risk score (refer Figure 2). The building rating is based on the building use, public access, nature and frequency of access, building type and operation of mobile plant equipment, and contributes the remaining 25% of the overall risk score.
There is no known safe level of exposure to asbestos, so each risk factor has a value that contributes to the overall risk score – no risk factors have a zero score. A precautionary approach was used to give a higher risk weighting to assumed ACMs, where condition, disturbance potential or friability are listed as ‘unknown.’
The calculation of the four risk factors and their weighting results in a minimum possible risk score of 19 and a maximum possible risk score of 100.
The risk assessment is automatically applied by the AIRSystem to ACMs, and determines the priority for removal of that ACM.Figure 2: VAEA Risk Overview detail
Download VAEA Risk Overiew detail:
Reviewed 21 March 2023