Check that asbestos air monitoring meets the 480 L minimum volume required by WorkSafe NZ for clearance certification.
Min 480 L total = 240 min at 2 L/min
Enter pump flow rate and sampling duration to verify minimum volume.
WorkSafe NZ requires ≥480 L for clearance monitoring. Clearance limit: 0.01 f/mL (10 f/L) by PCM. All asbestos air monitoring must be conducted by a licenced assessor.
WorkSafe NZ requires a minimum of 480 litres of air to be collected for clearance air monitoring after asbestos removal. At a standard pump flow rate of 2 L/min, this requires 240 minutes (4 hours) of sampling. The clearance limit is 0.01 fibres per millilitre (10 fibres per litre) by phase contrast microscopy (PCM).
In NZ, clearance air monitoring must be conducted by an Independent Licensed Asbestos Assessor (ILAA) — not the asbestos removal contractor. The ILAA must hold a WorkSafe NZ Class B or higher licence. The assessor must operate independently from the removal contractor to ensure impartial clearance certification.
If fibre concentration exceeds 0.01 f/mL, the area cannot be cleared for re-occupation. The removal contractor must identify the source of remaining fibres, conduct additional cleaning, and the assessor must repeat the monitoring sampling. The area remains a controlled zone until clearance is achieved and a written clearance certificate is issued.