The U.S. Environmental Protection Agency (EPA) formed a partnership to investigate the use of Flame Retardants in Printed Circuit Boards (PCBs). The partnership includes members of the electronics industry, flame retardants industry, environmental groups, academia, and others. The goals of the project were to advance understanding of the human health and environmental impacts of conventional and new flame-retardants that can provide fire safety for PCBs. The resulting report provides objective information to help members of the electronics industry more efficiently factor human health and environmental considerations into decision-making when selecting flame retardants for PCB applications. It can also serve as a step toward developing a more comprehensive understanding of the human health and environmental implications of flame-retardants by noting gaps in the literature. The objective is not to recommend a single best flame retardant for PCB applications or to rank the evaluated flame retardants but to present information on environmental and human health impacts, life-cycle impacts and exposure considerations, to be used together with performance and cost in arriving at decisions. PCBs are found in electronic products, including computers and cell phones. The majority of the PCBs produced worldwide meet UL 94 V0 fire safety requirements; they are known as FR-4 boards. Typically this fire performance is achieved by using brominated epoxy resins with tetrabromobisphenol A (TBBPA) as part of the polymeric backbone of the resin. Alternative flame retardants are used in only a small percentage of FR-4 boards, but the use of alternatives has been increasing in recent years, and more materials are under development. The level of available human health and environmental information varies widely by additive. While little information exists on some alternative flame retardants, established chemicals, including TBBPA and silicon dioxide, are more fully characterized. EPA used its tools and expertise to estimate the potential impacts of flame retardants when no experimental data were available. The partnership evaluated 8 commercially available (and viable) flame retardants (found via market research and recommendation from industry): TBBPA, DOPO, Fyrol PMP, aluminum hydroxide, Exolit OP 930, Melapur 200, silicon dioxide and magnesium hydroxide. TBBPA, a reactive flame retardant, is used in > 90% of FR-4 boards; alternative materials are used in only 3-5% of current boards. The reaction products of epoxy resin with TBBPA, DOPO, and Fyrol PMP were also evaluated, because they are reactive flame retardants that undergo chemical reactions during manufacturing; therefore trace quantities of reaction products may remain in the polymer matrix. A key table shows relative hazard levels for nine human health effects, two aquatic toxicity effects, and two environmental fate endpoints for the flame retardants and their byproducts. The selected flame retardants are characterized as to whether they have a reactive or additive nature. Results in the table are shown in terms of high, moderate and low hazard. Evaluations of flame retardants in the report are hazard assessments with considerations for exposure, and not risk assessments. Whereas hazard measures a material’s inherent dangers, risk takes into account both hazard and the amount of material to which workers, the community, or the environment may come into contact (probability of exposure). In addition to evaluating chemical hazards, life-cycle considerations were also used, since human health and environmental impacts can occur throughout a life cycle, from raw material extraction and chemical manufacturing, through manufacturing and product use, to end of life disposal. In summary, multiple factors must be considered when selecting an appropriate flame retardant. In addition to fire properties and health and environmental considerations, the fla
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