Barrier walls have been proposed as a means for reducing the exposure to accidental jet flames from commercial hydrogen refueling systems. While reducing the jet extent, the walls may introduce other hazards if not properly configured. A combined experimental and modeling program is being carried out by Sandia National Laboratories to investigate barriers using a quantitative risk assessment approach.  The goal of this work is to provide guidance on configuration and placement of these walls to minimize overall hazards.  Results from the modeling and experimental studies performed are presented and discussed in the paper.