Posted on 08/07/2022 in Fire Safety 2022
Industry actions for sustainable fire safety

Christian Battenberg, Clariant, presented the company’s objectives of climate impact reduction, the product portfolio sustainability assessment system and the Clariant “Ecotain” label for best-in-class products (pinfa Newsletter n°79). Clariant has fixed the objective to reduce greenhouse gas emissions by 40% for scope 1+2 and by 14% for scope 3 (link) between 2019 to 2030. Dr. Battenberg presented carbon footprinting of Clariant’s DEPAL (aluminium diethyl phosphinate) and APP (ammonium polyphosphate) PIN flame retardants and the new Terra concept for further reducing the carbon foot printing of DEPAL products. Here Clariant uses the RedCert2 mass balance certification scheme. For DEPAL and APP, the carbon footprint is comparable to that of the polymers in which FRs are used: somewhat higher than PE, PET and PP but lower than polyamides (which have a relatively high carbon footprint). The highest carbon contribution in DEPAL is in production of P4.

Aleksandra Marek, PCC Rokita, presented results of a project co-funded from European Regional Development Fund (“Smart Growth”), looking for alternatives to currently used flame retardants for flexible polyurethane foams. Fire safety performance is especially required for flexible polyurethane foams for applications in transport (e.g. FMVS 302) or furniture (e.g. BS 5852). PCC Rokita has developed a phosphorus flame retardant based on tert-butylated phosphate ester. This PIN FR is not GHS classified, has low viscosity (easy to process) and is non-reactive (enabling drop-in replacement of currently used chlorinated FRs in foam production). The outcomes proved adequacy to requirements, including mechanical properties of foams, flammability results, and processing performance. Tests showed that replacement of TCPP was possible, with c. 50% higher loading of the new FR, offering similar mechanical performance of foam, and achieving automotive fire safety requirements. For UK furniture fire safety requirements, a 1/3 higher loading of melamine together with the same loading of the new PIN FR enabled to keep corresponding fire performance, foam properties and processing.

James Houlder and Callum Doolan, Polymer Compounders Limited (PCL), UK, presented innovative applications of polyphosphonate polymeric PIN flame retardants, developed in partnership with Pinfa member FRX Polymers. The company is a specialist thermoplastics compounder, supplying ABS, ASA, PC/ABS and polycarbonate performance materials to large OEMs for transport, electronics, medical and other applications. The company aims to respond to customer demand to move away from brominated FRs, which are under pressure from regulators, and are banned in certain applications (e.g. certain TV and screen parts under EU Ecodesign requirements) and can pose problems of corrosive bromine compound release. PCL’s latest polyphosphonate co-carbonate compound is halogen-free, non-migratory, has a favourable toxicity profile and is also melt-processable (high flow), and has high impact resistance. UL 94 V0 is achieved for 0.8 mm and GWI (glow wire ignition) of 960°C. Super B has selected the material for lithium-ion battery casings (photo). See also pinfa Newsletter n°137. Initial one-pass mechanical recycling trials (re-melt, re-injection) show that V0 fire performance is maintained and impact performance (INI) is better even after this recycling compared to “virgin” standard FR packages such as RDP and BPA-DP.

Carles Ibanez Brugues, ICL and Daniel De Schryver, Albemarle, both presented tests of mechanical recycling (multiple extrusion, weathering, re-extrusion) of polymers with brominated flame retardants, in both cases concluding where limited deterioration of material properties was found this was due to degradation of the polymer during processing, and was not because of the flame retardants.

Chris Thornton, for pinfa, outlined the important implications for flame retardants of the EU Green Deal and the new Chemicals Strategy for Sustainability “Towards a Toxic Free Environment”. Key changes in chemicals policy announced include possible generic restrictions (families of chemicals), new regulatory definitions (such as Essential Use, Safe and Sustainable by Design), criteria for environmental footprint of chemicals and emphasis on end-of-life and recycling. These developments will open opportunities for non-halogenated flame retardants (PIN FRs). A number of PIN FRs are recognised as environmentally friendly (under schemes such as TCO Certified, Okotex, GreenScreen). Studies show that PIN FRs can be compatible with mechanical recycling (re-processing) and PIN FRs are important to enable safe use of recycled plastics or textiles, as well as for ensuring fire safety of natural materials such as wood or fibres. pinfa underlines that R&D into bio-based FRs should consider durability in use, industrial feasibility and logistics, and chemical safety (toxicity pre-screening and then testing of all proposed new molecules).

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