Asbestos Fibre Counting refers to airborne fibre sampling that assesses exposure and the effectiveness of control measures. Air monitoring includes exposure, control, and clearance monitoring. When carrying out air monitoring, air pumps draw a known quantity of air over a known period over a membrane filter.
The filter traps asbestos fibres, which can then be counted under a phase-contrast microscope. The number of fibres on the filter, when combined with a known volume of air, allows a concentration of asbestos fibres in the air to be calculated. This asbestos concentration is an indication of whether the air in the tested area is satisfactory or not when compared to World Health Organisation guidelines.
Focus Analytics offers an IANZ accredited Fibre counting service under the following method. NOHSC: 3003(2005) Guidance Note on the Membrane Filter Method for Estimating Airborne Asbestos Fibres. Air monitoring is required for air monitoring during Class A asbestos removal work.
Air monitoring can also be undertaken for background or reassurance purposes in areas of high risk or difficult class B operations.