Expert review notes progress in FR durability over time, but research is needed on outdoor durability and recycling. Fire protection expert Jürgen Troitzsch analysed over fifty publications on ageing of flame retardant treated materials and on mechanical recycling. He notes that FRs play an important role in ensuring safety for lives and property. Studies analysed are based on artificial ageing, including exposure to heat, moisture, UV light, salt. Evidence is also provided from use in practice, documented by e.g. standards or guidelines for fire protection durability in buildings and in industrial installations, or by value certification of second-hand E&E equipment. This real-life experience shows lifetimes of FR materials of several decades or more. Dr. Troitzsch summarises conclusions for different families of FRs, noting that brominated FRs are themselves generally very durable but may cause deterioration over time of polymers and stabilisers, some PIN FRs may hydrolyse and/or leach out of materials so deteriorating fire performance, that certain PIN FRs (e.g. phosphinates) are highly stable ensuring long-term durability and that some PIN FRs can even show improvements in fire performance with ageing (e.g. ATH). Mechanical recycling has also been demonstrated for FR materials, but more research is needed on recycling of mixed end-of-life polymers containing FRs.
“Fire Performance Durability of Flame Retardants in Polymers and Coatings”, J. Troitzsch, Advanced Industrial and Engineering Polymer