Risk assessment consequence analysis/appropriate

Professor Martel s book addresses specifically some of the more technical eispects of the risk assessment process, mainly in the areas of hazard identification, and of the consequence/effect analysis elements, of the overall analysis whilst where appropriate setting these aspects in the wider context. The book brings together a substantial corpus of information, drawn from a number of sources, about the toxic, flammable and explosive properties and effect (ie harm) characteristics of a wide range of chemical substances likely to be found in industry eind in the laboratory, and also addresses a spectrum of dangerous reactions of, or between, such substances which may be encountered. This approach follows the classical methodology and procedures of hazard identification, analysing material properties eind... 

The hazards identification procedures presented in chapter 10 include some aspects of risk assessment. The Dow F EI includes a calculation of the maximum probable property damage (MPPD) and the maximum probable days outage (MPDO). This is a form of consequences analysis. However, these numbers are obtained by some rather simple calculations involving published correlations. Hazard and operability (HAZOP) studies provide information on how a particular accident occurs. This is a form of incident identification. No probabilities or numbers are used with the typical HAZOP study, although the experience of the review committee is used to decide on an appropriate course of action. 

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. 

In the case of degradation products and metabolites, the situation is different. Generally, these compounds were not analysed because in most cases they are not regulated and no effective analytical methods exist for their determination. This means that a correct diagnosis of the environmental situation cannot be made and, as a consequence, no appropriate action can be taken. Therefore, in order to improve the risk assessment of a hazardous waste site for example, as many compounds as possible should be analysed at the beginning of the investigations (non-target analysis). 

The analysis of the media articles show that terrorism has changed liom rational political violence to a description of terrorists as an irrational, catastrophic societal risk that would, if they had the opportunity, use weapons of mass destruction. This is a risk that is unacceptable for the society. Consequently the implications of the terrorism-discourse raise pubhc fear and powerlessness. The public must thenrely on the authorities ability to give correct assessments and implement appropriate measures. 

Although this guidance focuses on the LOPA technique, other techniques such as fault tree analysis or detailed quantitative risk assessment, used separately, may be a more appropriate alternative under some circumstances. Quantified methods can also be used in support of data used in a LOPA study. It is common practice with many dutyholders to use detailed quantified risk assessment where multiple outcomes need to be evaluated to characterise the risk sufficiently, where there may be serious off-site consequences, where the Societal Risk of the site is to be evaluated, or where high levels of risk reduction are required. 

II-3. Possible abnormal conditions and their causes, such as failures of protection systems or human errors, need to be identified in safety assessments for incorrect operation. The likelihood, significance and consequences of such abnormal conditions are then assessed by means of an appropriate methodology for risk analysis some examples are given below. Probabilistic safety analysis (PSA) is an established technique in risk evaluation for nuclear power plants [II-l], and much of the experience gained from it is adaptable in simplified form to complex applications involving radiation sources. As noted in para. 3.8, the inability of analyses to account adequately for human factors imposes some limitation on the value of these assessments. 

---