In Situ Identification of Asbestos-Containing Materials in Buildings by Using Handheld Raman Spectrometer

Asbestos-containing materials (ACMs) are among the most common types of hazardous building materials. Usually, ACMs are identified by laboratory methods, which can slow down and complicate the processes of demolition and refurbishment of old buildings. The hypothesis applied in this study is that ACMs, both in friable and non-friable forms, can be reliably identified in situ using a handheld Raman spectrometer (HHRS). A HHRS equipped with two temperature-controlled diode lasers (785 nm and 852 nm) was used. Two groups of ACMs were examined: one, consisting of ACMs with a known type of asbestos, previously determined by standardised tests used for the HHRS method’s validation, and the second, consisting of presumed ACMs, where HHRS was used for the identification of asbestos. Additional testing according to ISO 22262-1 was applied. The impact of several factors on the asbestos identification was evaluated. The results confirm that the identification by HHRS of all main types of asbestos minerals is possible with a certain level of probability, regardless of whether the fibres are in an unbound form (fabrics, ropes, wools) or bound within cementitious or polymer composites. Some processing (scaling, smoothing) of the reference spectra should be applied to increase the percentage of asbestos minerals’ identification. In conclusion, it has been proven that the majority of ACM in buildings may be identified in situ by HHRS in a rapid manner, thus accelerating the pre-demolition/pre-renovation audit (PDA/PRA), avoiding risks to demolition/refurbishment workers’ health due to asbestos unawareness, as well as preventing the contamination of other CDW and environmental pollution.