Safe and Sustainable by Design, Scoping, and Simplified Assessment of Alternative Flame Retardants for Use in Insulation Foams

The European Green Deal underscores the need for a Safe and Sustainable by Design (SSbD) strategy for chemicals and innovative materials. This initiative, along with the Ecodesign for Sustainable Products Regulation, marks a significant step toward promoting environmentally friendly practices in product design and manufacturing, facilitating the transition to a more sustainable economy in Europe. To implement this strategy effectively, the Joint Research Centre (JRC), the World Business Council for Sustainable Development (WBCSD), and the European Chemical Industry Council have developed guidelines outlining criteria for SSbD and providing data-driven recommendations. However, few cases have successfully implemented SSbD in research and development projects.
The PLANETS project addresses this gap by promoting the development and implementation of straightforward, effective, and cost-efficient SSbD strategies for materials and products through a tiered approach. This begins with scoping and simplified assessments in Tier 1, followed by risk screenings combined with life-cycle assessments (LCA) using existing data in Tier 2, and culminating in experimental methods alongside comprehensive LCA in Tier 3. In this work, we focused on applying Tier 1 assessments to identify alternatives to brominated polymeric flame retardants. Halogenated flame retardants containing bromine or chlorine release free radicals that disrupt combustion but face regulatory scrutiny. Phosphorus-based flame retardants promote char formation while producing non-flammable gases. Nitrogen-based flame retardants release nitrogen gas during decomposition, helping dilute flammable gases, while inorganic flame retardants, such as aluminum hydroxide, release water vapor when heated, providing cooling effects.
We assessed over 30 SSbD alternatives to brominated flame retardants, including polyFR and HBCD, comparing alternatives such as s-triazine phosphonate, ammonium polyphosphate, organic phosphate, DOPO-P-S polymer, and styrene-organophosphorus-sulfur copolymer. The target use is in insulation foams made from polyurethane, polyethylene, and polystyrene. Alternatives were evaluated based on hazard profiles and categorized by performance, compatibility, cost, degradation products, and recyclability. By utilizing the ECOTOX and ECHA databases, along with Safety Data Sheets and the HARMLESS Decision Support System tool, we identified the most suitable alternative flame retardants.