Polarized light microscopy (PLM) analysis is the most commonly accepted technique for analysing bulk samples for asbestos. Bulk material samples are typically collected during an asbestos survey by an EPA accredited inspector.The PLM analysis is based on optical mineralogy and uses a phase contrast microscope equipped with polarizing filters. Identification of asbestos is based on the determination of optical properties displayed when the sample is treated with various dispersion staining liquids. Identification is further substantiated by fibre morphology and the effect of polarized light on the fibres. PLM analysis is specific to fibrous materials and allows for the determination of:
- • Presence and amount of asbestos in the sample, and
- • Type of asbestos (Chrysotile, Amosite, Crocidolite, other).
The PLM analysis is adequate for most asbestos analytical needs. Where necessary, alternative laboratory services are available. This would include transmission electron microscopy (TEM).