Asbestos air monitoring means sampling of airborne asbestos fibre to assist in the risk assessment and evaluation of control measures associated with the removal regarding human exposure to asbestos fibres by inhalation. The asbestos air monitoring must be undertaken in accordance with with the Guidance Note on the Membrane Filter Method for Estimating Airborne Asbestos Fibres [NOHSC:3003 (2005)].
Asbestos fibre air monitoring is required to be undertaken by a Licensed Asbestos Assessor (eg. competent person or occupational hygienist) for the following situations depending on the purpose of the assessment:
- Background asbestos air monitoring – at any time where it is likely that asbestos fibres are released into the air for an occupied area
- Background asbestos air monitoring – to complement the risk assessment of an asbestos inspection or asbestos survey and determine urgency for removal or treatment option where unstable or deteriorated asbestos containing material is identified
- Background, control and clearance asbestos air monitoring – for the removal of any quantity of friable asbestos and removal of non-friable asbestos if determined as needed by a risk assessment and if the asbestos removal is near a public location
- Exposure air monitoring – undertaken for asbestos workers to estimate and evaluate worker’s exposure.
For asbestos removal at a workplace, under the Work Health and Safety Regulation 2017, the person who commissions the asbestos removal work is responsible for arranging a Licensed Asbestos Assessor (eg. Occupational Hygienist) independent of the asbestos removalist to determine air monitoring requirements. Where the asbestos removal work is being undertaken at domestic premises, the person engaged to do the asbestos removal work is responsible for arranging a competent person independent of the asbestos removalist to determine air monitoring requirements.
Friable asbestos – a person who commissions asbestos removal work that requires a Class A licence (friable asbestos) must ensure that an independent licensed asbestos assessor undertakes asbestos air monitoring of the asbestos removal area at the workplace Non-friable asbestos removal (more than 10 sqm) – an independent licensed asbestos assessor or competent person must be engaged to carry out asbestos air monitoring when it is required Other situations – where asbestos air monitoring is required in any other case (eg. to determine whether the exposure standard has been exceeded following an uncontrolled disturbance or release of asbestos at the workplace), an independent licensed asbestos assessor or competent person may carry it out if the materials disturbed is non-friable. If the release involves friable asbestos, only an independent licensed asbestos assessor can carry out the air monitoring.
Background asbestos air monitoring – the duration of the session may vary. However, a minimum of 400 litres of air volume must be collected per sample. Usually, the duration should not be less than 4 hours Asbestos control air monitoring – must start before the removal work start and stop after the asbestos removal work finishes Clearance asbestos air monitoring – the duration of the session may vary. However, a minimum of 400 litres of air volume must be collected per sample. Usually, the duration is around 2 hours Asbestos exposure air monitoring – must be done within the breathing zone of the worker and for the entire or not less than 60% of the shift duration. A minimum of 400 litres of air volume must be collected per sample.