Addressing the real challenges of fire safety tomorrow and ensuring environment and health safety, including in recycling, showed as priorities in the panel discussion, organised by pinfa at the AMI (online) Fire Resistance in Plastics Conference, 23-25 February 2021. Panellists were from industry (pinfa, Clariant, ICL), science (French National School for Chemistry ENSCL at Lille, Masaryk University) and civil society organisations (ECOS).
Opportunities and challenges
Lein Tange, ICL Europe, underlined the global priority of climate change. For flame retardants, the greenhouse gas emissions related to production are negligible compared to the product use phase, for example energy savings from insulation materials, lightweight materials or e-mobility. Such applications pose new fire safety challenges which must be addressed, whilst ensuring sustainable end-of-life solutions for flame retardant containing materials. He noted that new substances continue to be added to the SVHC (Substances of Very High Concern) list, for example discussion is ongoing on titanium dioxide (a pigment, not an FR) which is widely present in many plastics, meaning that a material which is recyclable today may not be tomorrow.
Sophie Duquesne, ENSCL Lille, France, suggested that key questions for the future of flame retardants are end-of-life and recycling, the demand for fire safety in the global energy transition (especially building energy savings, e-mobility) and the need to develop efficient fire testing which is representative of reality (scaling up of laboratory test results)
Samy Porteron, ECOS (European Environmental Citizens Organisation on Standardisation), emphasised the importance of the Circular Economy, posing a challenge and opportunities for industry. Flame retardants in plastics are difficult to separate from the polymer and so flame retardants included in a material can, through recycling, find their way into other products, not intended to contain them, in the future. Flame retardants now banned can thus still be found in consumer products (“legacy” substances). Fire safety is a real issue requiring solutions, but we need to find solutions which do not create future problems, for health, the environment and the economy. Flame retardants can leach out of products and contribute to cocktails of chemicals with health risks which we do not today understand.
Fire testing standards should be robust and as close to reality as possible. Fire safety solutions which are sustainable for health and the environment are essential and should include basic fire safety principles and safety-by-design.
Franck Poutch, Crepim, France, also emphasised the demand for flame retardant solutions to ensure fire safety in building insulation and e-mobility. The development of bio-based polymers and use of renewable materials (timber, fibres) means more flammable organic materials in buildings and in their contents, requiring flame retardants. The development of flame retardant solutions integrated into the polymer matrix can improve environment and health safety, but can be an obstacle to recycling.
Sebastian Hörold, Clariant, underlined that in addition to fire safety, environment and end-of-life requirements, flame retardants must not deteriorate the mechanical or electrical performance, or the durability, of materials. E-mobility brings new technical demands for flame retardants, in applications such as high-voltage connectors, batteries, vehicle chargers, with demanding requirements such as smoke opacity. Developing state-of-the-art, environmentally safe flame retardants has a cost.
FRs, plastics additives and recycling
The panel discussed how to enable recycling despite the wide range of different additives (of which flame retardants are just one type) in plastics and textiles:
Adrian Beard, for pinfa, indicated the potential interest of chemical markers to enable identification of materials. Further research is needed to address e.g. mixing of markers in recycling. Identification of additives poses questions of formulation confidentiality, but this can be addressed by a non-quantitative list of ingredients (not detailed “recipes”). pinfa is working to develop R&D proposals and dialogue with downstream industry (FR users, compounders, polymers industry …) on possible solutions, but this needs to be taken forward across industry because FRs are only one of many technical additives concerned.
Lisa Melymuk, Masaryk University, Czech Republic, suggested that information on chemicals in product parts can be provided by bar codes and an online data base to enable inclusion on small parts.
Sophie Duquesne, ENSCL, notes that some contaminants in recycled materials may impact the performance of flame retardants and other additives
Lein Tange, ICL Europe, suggested that new recycling technologies can bring solutions, because “legacy” contaminants are eliminated. Full-scale demonstration sites should be developed, like the PolyStyreneLoop industrial pilot. The challenges of logistics and of achieving economically viable quantities must be addressed.
ECOS has questions about the life cycle analysis of chemical recycling: more information is needed on the energy balance and so climate emissions, and on the level of sorting needed for the input waste streams.
Adrian Beard, pinfa, notes that 40% of WEE plastics are “small volume” speciality polymers. Work engaged by pinfa with Fraunhofer LBF (see pinfa Newsletter n°105) show that the principal obstacle to material recycling, after logistics (separation, collection), is deterioration of the polymer in re-extrusion, not the flame retardant. New formulations and corrective additives are needed to address this.
Environmental safety of flame retardants
Lisa Melymuk, Masaryk University, Czech Republic, notes that currently three families of chemicals stick out looking at toxicology indicators: PFAS (perfluorinated chemicals), phthalates and the older brominated flame retardants such as PBDEs, HBCD. Phosphorus-based and other non-halogenated flame retardants have received less attention so far. The toxicological and environmental science is behind today’s market and is still working on the brominated flame retardants used in the past because they are very persistent in the environment whereas there is a need for more environmental research into new flame retardants.
Samy Porteron, ECOS considers that, today, information on chemicals present in products (articles) is inadequate and does not allow traceability along the value chain, resulting in problems for recycling. This will be partly addressed by the ECHA SCIP database (Chemicals of Concern in Products, see pinfa Newsletter n°119), where companies must declare all products containing >0.1% w/w of any chemical on the REACH Candidate List of SVHCs, as required by the revised Waste Framework Directive.
Adrian Beard, pinfa, recognises that it is a challenge to release confidential toxicity data held by companies concerning their products because the data was generated at high cost and so companies are reluctant to share e.g. with competitors.