Plant hazard analysis principles

Guided word plant hazard analysis (PHA) principles. 

However, anyone involved with actual design work soon realizes that there are in fact many choices to be made in arriving at a safe design, and that in reality nothing is 100 per cent safe not even total inactivity, of whose harmful consequences we are all aware The safety implications of plant design choices are, in principle, quantifiable. The techniques for doing this are usually described as hazard analysis (Hazan). 

Risk analysis refers to techniques for identifying, characterizing, and evaluating hazards. The identification of risk, defined in Eq. (12.1), and risk analysis found their way into many applications where they can add value in prioritization and management processes. The application of general risk analysis principles to help prioritize and manage the inspection program for plant equipment, now commonly referred to as risk-based inspection (RBI), is one of the newest applications of risk principles [3]. Some examples of risk criteria and associated units are shown in Table 12.1. 

A pesticide-contaminated Superfund site and a coal-burning electric power plant illustrate the general principles involved in hazard identification, the first step in the risk-assessment process Identify hazardous chemicals to which people might be exposed, the pathways by which exposure might occur, and the populations and subpopulations that are at risk. Once hazards have been identified, the risks they pose can be assessed. Risk is a combination of exposure and toxicity (Figure 1.1). An assessment of risk continues with an analysis of the degrees to which at-risk populations are exposed to chemicals of concern. 

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