A new method for the design of safety devices for distillation columns based on dynamic simulation is presented. A simulation model for the description of the column behavior after an operational failure was developed and successfully validated. The model includes the description of weeping, entrainment, and pressure relief (one-phase or two-phase flow). Based on the simulation results, a more efficient design of safety measures is possible. (C) 2010 American Institute of Chemical Engineers AIChE J, 57: 458-472, 2011