Every day, plant managers and engineers need to make decisions to balance productivity and process safety. Some of these decisions involve process safety exceptions. A process safety exception is a deviation from a standard or a management decision that does not align with the major objective of process safety management (i.e., to prevent unwanted releases of hazardous chemicals especially into locations that could expose employees and others to serious hazards). For example, plant management might decide to continue operating a facility with a minor gas pipeline or flange leak, diluting the leak with steam and providing gas detectors to trigger alarms in case the leak increases, until the next planned shutdown. Another example of a process safety exception is continuing to operate a piece of equipment that has, based on routine inspection, been recommended by inspection to be repaired or replaced. The risk levels associated with such decisions could vary from low risk to high risk, depending on the type of gas, operating parameters, and asset integrity history.
An organization cannot depend on the varying risk tolerance levels of the individuals making these decisions. In the chemical process industries, decisions that require distinguishing between acceptable and unacceptable process safety risk must be guided by an organizational risk management framework established at the highest levels of corporate management (e.g., the board of directors), and through which such decisions are made and communicated appropriately to the top management.
This article discusses several types of process safety exceptions, and offers guidance on developing and implementing a system for managing these exceptions.