During the last decades concern has been raised about the fate of Waste Electrical and Electronic Equipment (WEEE) urging the European Union to take action in order to regulate their management and avoid negative implications related to their improper treatment. Within this context, the WEEE Directive requires the separation of polymers containing some types of Flame Retardants (FRs) before recycling, due to their toxicity. Thus, the development of efficient identification techniques in order to identify the different polymer types and detect FRs is of significant importance in order to comply with the Directives requirement and increase the quality of recycled plastics. Within the framework of this thesis, experiments were carried out, investigating the performance of Fourier Transform Infrared Spectroscopy (FTIR) in the identification of polymers and FRs found in microwave ovens and personal computers plastic housings using two different identification software types, namely the OPUS/SEARCH and the IDENT. After testing the reliability of the FTIR results by other reference identification methods, it was found that the performance of the FTIR technique strongly depends on the identification software and polymer/FR library used. The results of the OPUS/SEARCH software, which were widely validated by the reference analysis, found presence of FRs in the investigated samples at low level, while the most commonly used and significantly toxic FR type, namely the Brominated Flame Retardants (BFRs), was not found at all. On the contrary, the high level of reliability exhibited by this software was not reached by the IDENT software, suggesting that the FTIR can potentially be used as a very useful tool for the investigation of WEEE plastics, primarily for research purposes, contingent upon the appropriate selection of software and libraries.