This work presents two applications of Safeness Index-based model predictive control to improve process operational safety in safety critical chemical processes. In the first case study, a high-pressure flash drum separator together with pressure relief valve as safety system is used to analyze the benefits of integrating Safeness Index-based considerations in model predictive control (MPC). In the second case study, four units in an ammonia process are simulated to demonstrate the application of Safeness Index-based MPC to handle significant disturbances. (C) 2019 Elsevier Ltd. All rights reserved.