The Concept of Inherent Safety

The modern design and implementation of chemical process safety programs incorporates risk-based approaches. This chapter introduces five categories of process risk: inherent, spatial, passive, active, and procedural. All five categories can contribute to the overall safety of a process. Inherently safer concepts will enhance overall risk management programs, whether directed toward reducing the frequency or consequences of potential incidents. Approaches to achieving inherently safer processes and plants have been grouped into four major inherent safety strategies: minimize, substitute, moderate, and simplify. Inherently safer considerations may reduce the life cycle cost of the process. The chapter provides a detailed description of inherent safety strategies and discusses layers of protection more thoroughly. If implementing inherently safer approaches alone to meet project risk goals is feasible, other layers of protection – and their associated costs in time, capital, and ongoing expenses – may not be required.