THE ECOLOGICAL FOOTPRINT OF FLAME RETARDANTS OVER THEIR LIFE CYCLE – A CASE STUDY ON THE ENVIRONMENTAL PROFILE OF NEW PHOSPHORUS BASED FLAME RETARDANTS

On the one hand, flame retardants (FRs) save many lives and property because they prevent accidental fires. On the other hand, there are concerns related to chemical release into the environment and poten-tial health effects. Since halogenated flame retardants have been in the focus of public scrutiny, flame retardants based on other chemistries like phosphorus and nitrogen have been promoted. However, halogen free flame retardants need to prove their environmental benefits. Rather than using typical global life cycle assessment parameters like energy consumption or global warming potential, a benchmark approach was used: comparing the performance of new flame retar-dants versus currently employed FR systems and also to the non-flame retarded polymer. The poly-mers studied were polyamide (PA) 6, polyamide 6.6, high temperature nylon (HTN) and polybutylene terephthalate (PBT). Therefore, the release of flame retardant and degradation products over key stages of the life cycle of flame retarded plastics was investigated: processing by extrusion, use phase, accidental fires, incineration and end-of-life disposal. Other end-of-life options like feedstock recy-cling, incineration (energy recovery) or landfilling were studied and current waste streams assessed, in order to gain an estimate of the total material mass flows and balance over the life cycle of the flame retardants. In addition, experiments on mechanical recycling were carried out. The authors believe that the methodology presented can be applied to other flame retardants and plas-tics additives in order to evaluate the environmental profile of these products, especially within the context of upcoming European chemicals regulations (REACH1) and waste regulations for electronic equipment (WEEE2 and RoHS3)