Environmental assessment of halogen-free printed circuit boards, a design for environment (DfE) project with the high density packaging user group (HDPUG)

Abstract

Restrictions on the use of halogenated flame retardant materials in IT products are being considered due to environmental concerns. Interestingly, little information exists concerning the potential environmental impacts of halogen-free materials which are being developed as alternatives to traditional brominated flame retardants. The primary driver cited for use of halogen-free materials is to eliminate the potential for dioxin/furan formation during incineration at end of life, however the environmental footprint of a material is not solely defined by end of life impacts. Environmental impacts occur throughout the life cycle of a material, from development and manufacture, through product use and finally at end of life. The results of this study include an environmental assessment of seven halogen-free flame retardants and one high-volume halogenated flame retardant, tetrabromobisphenol A. Each flame retardant material was evaluated on the basis of the toxicity of the raw material, potential environmental impacts during use and end of life and incineration and/or degradation by-products. Based on the available literature data, a relative ranking was applied to compare the strengths and weaknesses of each flame retardant evaluated. Additional research is recommended to develop a more comprehensive environmental profile for both halogenated and halogen-free flame retardant materials.