Are melamine flame retardants in sofas beneficial from a life cycle perspective?

Abstract

Flame retardants (FRs) are added to sofas to save lives by improving fire safety. However, increasing concerns about the toxicity of FRs make it relevant to evaluate their net impacts. This study presents a methodological approach for comparing products with and without FRs based on life cycle assessment (LCA) and incorporating quantitative health risk assessment. Sofas with and without melamine FRs are compared, considering environmental and health impacts from cradle to grave. The assessment considered 19 midpoint categories and human health as an endpoint category (measured in disability-adjusted life years). For the midpoint-level LCA results, the main contributing processes are the production of the wooden sofa frame, followed by the polyurethane foam, and then the sofa's waste treatment. The contribution of the melamine FR to the overall impact is small, mainly due to the low quantity used (approximately 4.4% of the sofa's weight) and the relatively low toxicity of melamine. The avoided relative health impact from fire-related fatalities is larger than the health impact from melamine FR emissions. As a result, the net human health impact is lower for the sofa with melamine FRs. This approach provides a clearer understanding of the trade-offs involved in using FRs in furniture.