A new "on-site screening method" enables polystyrene foam containing specific flame retardants to be identified and hence sorted accordingly for recycling. This rapid test method was developed by the Fraunhofer Institute for Process Engineering and Packaging IVV in collaboration with BASF.
Expanded and extruded polystyrene foams (EPS and XPS) for building and construction purposes have contained the brominated flame retardant HBCDD (hexabromocyclododecane) for more than 50 years. Back in 2008 the European Commission classified HBCDD as a substance of very high concern due to its persistent, bioaccumulative, and toxic properties and in 2011 it was added to Annex XIV of the REACH Regulation. At a global level the substance was classified as a persistent organic pollutant (POP) and on 9 May 2013 HBCDD was added to Annex A (Elimination) of the POP list.
In response to these new statutory boundary conditions, a new polymeric brominated flame retardant was developed to replace HBCDD in building and construction applications of EPS and XPS.
For recycling future EPS and XPS waste it is hence necessary to know whether waste contains HBCDD and requires special treatment, or whether it is HBCDD-free. The new screening method can be carried out on-site. The HBCDD is selectively dissolved out of polystyrene foam via a simple on-site extraction procedure. The concentration can also be measured on-site using a hand-held XRF (x-ray fluorescence) analyzer. Older materials containing HBCDD can thus be readily distinguished and sorted from newer materials containing polymeric brominated flame retardants. The test method is simple, favorable in cost, and effective.
A detailed description of the screening method is available for download here: