Membrane filter method required for Class A air monitoring

A membrane filter method is required for air monitoring during Class A asbestos removal work.

What is a membrane filter method?

The ‘membrane filter method’ is the common method used to determine airborne asbestos fibre concentrations in the work environment. It refers to one of a number of published methodologies which set out specifications for sampling, processing and analysing equipment and procedures, supported by protocols for classifying, counting and reporting results. 

The commonly used methodologies are:

  • (Australia)  NOHSC: 3003(2005) Guidance Note on the Membrane Filter Method for Estimating Airborne Asbestos Fibres (2nd Ed)
  • (UK) HSG 248 Asbestos: The analysts' guide for sampling, analysis and clearance procedures 2005
  • (International - ISO) ISO 8672-2014 Air quality. Determination of the number concentration of airborne inorganic fibres by phase contrast optical microscopy. Membrane filter method
  • (International - WHO) Determination of airborne fibre concentrations. A recommended method, by phase-contrast optical microscopy (membrane filter method), WHO Geneva 1997 (ISBN 92 4 154496 1)
  • (US) ASTM STP834 Membrane Filter Method for Estimating Asbestos Fiber Exposure. 

Class A air monitoring carried out by licensed asbestos assessor

Class A air monitoring should be conducted by an independent licensed asbestos assessor. Until 4 April 2018, a competent person may carry out Class A air monitoring.

The competent person or licensed assessor who undertakes air monitoring for Class A removal work must use a membrane filter method for the air monitoring.

The PCBU who commissions the removal work needs to make sure that the air monitoring results will provide correct information. A good way to do this is to confirm that the sample will be tested by a laboratory which is accredited for the particular membrane filter method which is used.

For information on laboratories that are accredited to use a membrane filter method search the list of IANZ-accredited laboratories(external link), and type membrane filter method in the Search by keyword field, then click Go.

For information on assessor licensing and a definition of a ‘competent person’, see the Overview.