Risk assessment consequence evaluation

Risk assessment - the evaluation of the likelihood and the biological and economic consequences of entry, establishment and spread of a hazard within the territory of an importing country (OIE, 2010a). Thus, risk assessment can be broken down into three parts (i) release assessment (entry into the importing country), (ii) exposure assessment (contact of the hazard with a susceptible population), and, (iii) consequence assessment (establishment of infection and spread, ecological and economic impact) (see Rg. 12.1). 

Process Hazards Analysis. Analysis of processes for unrecogni2ed or inadequately controUed ha2ards (see Hazard analysis and risk assessment) is required by OSHA (36). The principal methods of analysis, in an approximate ascending order of intensity, are what-if checklist failure modes and effects ha2ard and operabiHty (HAZOP) and fault-tree analysis. Other complementary methods include human error prediction and cost/benefit analysis. The HAZOP method is the most popular as of 1995 because it can be used to identify ha2ards, pinpoint their causes and consequences, and disclose the need for protective systems. Fault-tree analysis is the method to be used if a quantitative evaluation of operational safety is needed to justify the implementation of process improvements. 

Several tools can be used to evaluate the environmental consequences of an industrial ventilation project. Some of the most common methods used are covered in this chapter. The life cycle assessment tool is considered in detail, as it is a comprehensive and product-oriented approach that is covered by international standardization. Other tools, such as risk assessment, cost-benefit... 

The objective of consequence analysis is to evaluate the safety (or quality) consequences to the system of any human errors that may occur. Consequence Analysis obviously impacts on the overall risk assessment within which the human reliability analysis is embedded. In order to address this issue, it is necessary to consider the nature of the consequences of human error in more detail. 

Risk evaluation of accidents serves a dual purpose. It estimates tlie probability tliat an accident will occur iuid also assesses tlic severity of the consequences of an accident. Consequences may include dmnage to tlie surrounding environment, financial loss, or injury to life. This cliapter is primarily concerned witli tlie metliods used to identify hazards and tlie causes and consequences of accidents. Issues dealing witli healtli risks have been explored in die previous chapter. Risk assessment of accidents provides an effective way to help ensure eidier diat a mishap does not occur or reduces die likelihood of an accident. The result of the risk assessment allows concerned parties to take precaudons to prevent an accident before it liappens. 

This cliapter serves to introduce tlie general subject of hazard risk assessment and analysis, including cause-consequence risk evaluation. The cause-consequence aspect of this topic is perliaps tlie key to understanding hazard risk. As such, it is treated in a separate section later in diis cliapter. 

It should be noted that consequence screening is performed without regard to the likelihood of an event s occurring. As a result, consequence screening does not determine risk. Furthermore, the consequence evaluation performed may not represent a detailed evaluation of consequences to the process plant. Instead, it is an approximation of expected consequences, given an estimate of potential blast overpressure and anticipated response of representative building types. The user should not mistake this evaluation for a detailed consequence assessment. 

The terminology used varies considerably. Hazard identification and risk assessment are sometimes combined into a general category called hazard evaluation. Risk assessment is sometimes called hazard analysis. A risk assessment procedure that determines probabilities is frequently called probabilistic risk assessment (PRA), whereas a procedure that determines probability and consequences is called quantitative risk analysis (QRA). 

Figure 23-1 shows the hazards identification and risk assessment procedure. The procedure begins with a complete description of the process. This includes detailed PFD and P I diagrams, complete specifications on all equipment, maintenance records, operating procedures, and so forth. A hazard identification procedure is then selected (see Haz-ard Analysis subsection) to identify the hazards and their nature. This is followed by identification of all potential event sequences and potential incidents (scenarios) that can result in loss of control of energy or material. Next is an evaluation of both the consequences and the probability. The consequences are estimated by using source models (to describe the... 

Decision Analysis. An alternative to making assumptions that select single estimates and suppress uncertainties is to use decision analysis methods, which make the uncertainties explicit in risk assessment and risk evaluation. Judgmental probabilities can be used to characterize uncertainties in the dose response relationship, the extent of human exposure, and the economic costs associated with control policies. Decision analysis provides a conceptual framework to separate the questions of information, what will happen as a consequence of control policy choice, from value judgments on how much conservatism is appropriate in decisions involving human health. 

Figure 5-1 shows how the FHA is integrated into an overall risk assessment. A process hazard analysis is required to identify likely fire scenarios that are carried forward to the FHA. An FHA provides the tools to characterize the hazards and evaluate consequences. The results are incorporated into an overall risk assessment. See Chapter 6 for more information on fire risk assessment. 

Consequently, the environmental risk assessment (ERA) of medicinal products has to be evaluated and appropriate legislation and regulatory guidance has been issued in the European Union (EU). Recently, Directive 2001/83/EC [12], as amended by Directive 2004/27/EC [13], requires an evaluation of the potential environmental risks to be performed for every application for each active ingredi-ent/excipients from every medicinal product to be authorized. However, the... 

HAZAN, on the other hand, is a process to assess the probability of occurrence of such accidents and to evaluate quantitatively the consequences of such happenings, together with value judgments, in order to decide the level of acceptable risk. HAZAN is also sometimes referred to as Probabilistic Risk Assessment (PRA) and its study uses the well-established techniques of Fault Tree Analysis and/or Event Tree Analysis ... 

Improvement will not come from policies based on the precautionary principle or any similar principle, which ignores the specifics of different risks and the benefits that accompany the substance or process that is being examined. Good policy cannot be derived by skipping over the fact that we live in a world of trade-offs and that actions have consequences. A regulatory and policy system that produces greater value for society must have a foundation of credibility. Far better to emphasize science in the risk assessment process and to examine the process and evaluate how well it works than to chase after lofty aspirations embodied in a principle without definition. 

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