A representative sample of the material, suspected to be asbestos containing, is collected and submitted immediately to the laboratory for testing. In the analytical laboratory, this suspect material is analysed by a detailed examination by stereo microscopy. One or more representative sub samples are prepared mechanically and or chemically for further examination. Fibres observed in the course of the examination are categorised tentatively on the basis of morphology and certain physical properties.

Each fibre type recognised is sampled by selecting a few fibres or bundles and these are mounted in a refractive index liquid to match the most likely asbestos type. The fibres are then positively identified as one of the six regulated types on the basis of their detailed optical properties using polarised light microscopy.