Solid oxide fuel cells (SOFC) operating at temperatures in excess of 600ºC in air/fossil fuel environments present unusual problems for the engineer designing balance of plant (BOP) components. The major problem is finding an alloy that can withstand the operating temperature in an environment made up of air and a hydrogen derivative for long times. Currently, SOFC's operate at temperatures in excess of 750ºC where very few alloys can survive for long times. However, research continues on the development of fuel cell stacks that can operate at lower temperatures. Lower temperature SOFC operation would greatly facilitate the selection of components for the BOP. This presentation will summarize the major materials challenges for designing and selecting BOP alloys in terms of alloy classes, microstructural stability, strength, and corrosion/oxidation resistance. Available alloys suitable for use in the balance of plant will be surveyed with respect to availability, cost and performance.