Asbestos testing in Australia is conducted to the Australian Standard AS 4964 Method for the qualitative identification of asbestos in bulk samples. All asbestos testing should be conducted by A NATA accredited laboratory.
Samples of material suspected of containing asbestos are first placed within a dust cabinet and viewed under a stereomicroscope between 10x – 40x magnification to attempt to test fibres of all types. The morphology of the fibres provides a clue as to what type of fibres it may be: chrysotile asbestos, amosite asbestos, crocidolite asbestos, actinolite asbestos, anthophyllite asbestos; or non-asbestos fibre types such as organic fibres or synthetic mineral fibres (SMF).
The suspected asbestos fibres are then extracted by breaking material apart or using needles and tweezers. The fibres to be tested are then mounted on microscope slides with oils of different refractive indexes, depending on the type of asbestos is suspected and then viewed under polarised light.
The suspected asbestos fibres are viewed under polarised light microscopy which provides unequivocal identification through the viewing conditions of:
- Crossed Polars (XP)
- Plane Polarised Light (PPL)
- Dispersion Staining (DS)