The utility of X-Ray fluorescence spectrometry as a tool for monitoring compliance with limits on concentrations of halogenated flame retardants in waste polymers: a critical review

This study reviews current knowledge about the presence of brominated and chlorinated organophosphate flame retardants (BFRs and Cl-OPFRs) in plastic consumer articles, with particular reference to the potential as a result of recycling, for such chemicals to unintentionally contaminate articles in which flame retardants are not required. To minimize such unintentional contamination, jurisdictions such as the EU (European Union) have introduced limits on concentrations of some BFRs in waste plastics, with articles exceeding such limits prevented from being recycled. Substantial technical and economic constraints associated with the conventional methods for determining compliance with such limit values exist, leading to less specific, but simpler, more rapid, and less expensive methods such as portable X-ray fluorescence (XRF) spectrometry being identified as possible alternatives. This paper thus examines the evidence that XRF offers a viable method for checking compliance with existing and possible future limits on BFRs and Cl-OPFRs in waste plastics and identifies future research priorities.