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Flame retardants in electronics: Are halogen-free alternatives the future? Stephanie Dalquist 14 May 2002 Introduction of flame retardants • Consumer use since 1930’s • 300,000 tons of brominated FR in 1998 – 6,000 tons alone in European household electronics • Most contain bromine or phosphorus • Newer organic alternatives – Less effective and more expensive – More environmentally friendly? – Fewer health risks? Why flame retardants? • Significant fire damage worldwide – 12.9 billion in the US annually (1% GDP) – 425,000 fire incidents – 4,000 deaths and 26,000 injuries • Delayed or suppressed ignition – Reduce damage, prevent spread – Slow evolution of toxic gases, factor in 80% of deaths • Save 290 lives in the US annually Driving forces of change • Legislative – European Union eliminates PBDE and PBB by 2004, all brominated retardants by 2008 – Japan considers legislation • Environmental and worker concerns – Sweden’s TCO – Large buyer guidelines • Public Perception – Dioxins and furans in human blood, breast milk – Increased value seen in green products Types of flame retardants • Reactive – Chemically bound to polymer • Cannot evaporate, migrate through polymer • Alter polymer properties, increasing cost • TBBA • Additive – Small molecules in PVC, PS, polyester • More effective • More evaporation, can penetrate tissue Toxicity of flame retardants • PBDE decompose to PBDD, PBDF – Public fear of dioxins and furans • TBBA fairly safe – Low acute toxicity – Dioxins and furans in rare circumstances • Increasing MSW from 8% to 27%, no changes • At low temperatures, yields up to 10% • Halogen-free compounds decompose to relatively benign aromatics Performance of halogen-free retardants • Available for all key electronics applications • Laminates for PWBs – Pass peel strength, pressure cooker tests – Few compare in surface insulation resistance • Additive loading up to 30% to meet V0 – – – – – Brominated loading around 6-10% Alter polymer curing kinetics Reduce peel strength Increase moisture adsorption Reduce electrical properties Performance of halogen-free retardants • Substitution occurs regardless – Voluntary or as a result of legislation – Unable to meet V0 standards – Requires costly changes to manufacturing processes – Challenges established product reliability Conclusions • European Union has made the right move by phasing out PBDE • Push to eliminate all halogenated FRs is extreme, based on available data • Halogen-free technology not comparable for fire safety • Substitution with safer FRs like TBBA until new FRs fully developed