Risk evaluation quantitative

Significance of the predicted impacts should be assessed in the process of impact evaluation or interpretation. At this stage the health risk estimates (quantitative and qualitative) are analyzed in terms of their acceptability against relevant regulatory and/or technical criteria environmental quality standards or exposure limits. 

Risk evaluation methods should use data that is relevant to the facility under examination. Where other data is used an explanation should be provided to substantiate it s use, otherwise inaccurate assumptions will prevail in the analysis. Where highly accurate data is available, the findings of a quantitative risk evaluation will generally only be within an order of magnitude of 10 of the actual risk levels since some uncertainty of the data to the actual application will always exist. 

This means the obligation to carry out an extensive, quantitative risk evaluation and socio-economic analysis of the alternatives being considered by the authorities with, at the same time, a legally and systematically founded lack of information. 

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 ... 

With the focus on the actual quantities of wastes identified in the site inventory, appropriate field sampling and analysis must be undertaken to verify that the identified hazards actually exist. If a hazard has been identified and the potential for causing adverse effects confirmed, after considering both the qualitative and quantitative dimensions of the situation, the process requires proceeding to the next step - Risk Evaluation. 

Risk characterization is the most important and final part of a risk assessment. It summarizes and interprets the information from hazard identification, dose-response, and exposure steps, identifies the limitations and uncertainties in risk estimates, and communicates the actual likelihood of risk to exposed populations. The uncertainties identified in each step in the risk assessment process are analyzed and the overall impact on the risk estimate(s) is evaluated quantitatively and/or qualitatively. 

In conclusion, early risk evaluation is an absolutely essential feature or element in the development of new products. The range and sequence of tests to be done at this stage are subject to discussion and various approaches can be chosen. A first attempt to establish a structured risk evaluation scheme was made by Gisi and Staehle-Czech (.13). This is an interesting and valuable approach towards a more quantitative risk estimation. 

Gomparison of the baseline human health risk assessment and the risk evaluation of alternatives. Baseline Human Health Risk Assessment (quantitative) ... 

Using the consequence and likelihood categories, risk matrix, and risk evaluation criteria, the team reviewed three release scenarios (small, medium, and large) for the segments identified for each of the chemical movements. The result of the semi-quantitative risk estimation for this facility s hazardous material transportation operation is detailed in Table 4.12. From this results table, the following are determined ... 

As these parameters are monitored and changes in risk identified, critical issues can be escalated for more detailed review. Once several risk reduction strategies are identified, the same types of risk evaluation criteria (e.g., risk index, risk matrix, or other quantitative measures) described earlier in this book can be used to assess the relative benefits of each proposed risk mitigation option. Risk reduction can thus be defined as the process of evaluating and identifying options available to reduce risk, that achieve the desired level of risk reduction, and can be justified on a cost-benefit basis. 

Once a set of recommendations has been developed, the options must be analyzed to determine the benefits, or essentially the level of risk reduction. The risk analysis method utilized to assess the baseline operational risks should be the same method used to analyze each of the potential risk mitigation options. Therefore, if a semi-quantitative technique was used to assess the baseline risk, then the same assumptions, techniques, and risk evaluation criteria (risk matrix, risk index, etc.) should be used to evaluate the effectiveness of the risk reduction options. 

Risk Evaluation Criteria A quahtative or quantitative expression of the level of risk that an individual or organization is wilhng to assume in return for the benefits obtained from the associated activity. 

Field studies are highly recommended to provide ecological (generic) data on potentially exposed wildlife species for refined risk assessments. As can be seen from the case study, the required input data (generic and/or compound specific) on relevant species and crop scenarios can be generated by tailor-made field studies. These quantitative data are very suitable for ETE-calculations. Therefore, specific data obtained from field studies may contribute to more scientific and realistic risk evaluations. 

Unforfunafely, fhere currenfly is no generally accepted formal approach as to how to assess fhe benefif-risk balance in a quantitative manner. Medical judgment has been the method of choice by regulatory bodies in the past. More recently, the need to switch from implicit to more explicit decisions has been demanded by Eichler et al. (2009) in Europe. This, however, calls for more quanfifafive approaches to risk assessment. Major initiatives were found to systematically evaluate fhese approaches, for example, fhe IMI-Protect project Chapter 15 discusses benefif-risk assessment in depth. Noteworthy, the FDA continues to not support these approaches for the time being (U.S. Food and Drug Administration 2013). There is consensus, though, on the value of fhe use of a formal framework for benefit-risk evaluation. 

McCutcheon, P., Norager, O., Karcher, W. and Devillers, J. (1990) Sources of data for risk evaluation and QSAR studies, in Practical Applications of Quantitative Structure-Activity Relationships (QSAR) in Environmental Chemistry and Toxicology (eds W. Karcher and J. Devillers), Kluwer, Dordrecht. 

Several methods relating to hazards analysis and risk assessment exist. They are generally divided into qualitative and quantitative (lEC 61508 lEC 61511). The choice of specific method depends on accident scenario being considered and available data. When a risk evaluated for scenario considered is high, it is necessary to reduce it to an acceptable level using protection layers, each of specified reliability, expressed often as the probability of failure on demand (PFD) (LOPA 2001). 

The approaches developed for quantitative risk evaluation are focused on mortality and thus enable to estimate expected number of deaths in the exposed population. The most easily accessible and precise number provides the 50 % probability of death (the further from the optimal value of the centre, the hi er is the value of deviation) therefore it could be preferred instead of other percentage probabilities estimations. Nevertheless, the 50% human loss is unacceptable and so limits referring to 1% mortality or first observed the dead are preferred. It is obvious, that in the case of apphcation of these two approaches, substantially different values will be obtained, therefore a separation is needed. 

According to the ISO/IEC Guide 51 1999, risk evaluation is defined as a wide process of estimation and analysis. In its terminology risk analysis is defined as the systematic use of information to identify hazards and estimate risk, and the risk estimation is defined as a procedure to determine if the risks are tolerable or not. In this manner ISO/IEC Guide 51 1999 presents a iterative process model to evaluate and reduce risks that can be applied to qualitative and quantitative risk evaluations, as shown in Fig. 1. 

In the risk evaluation we need to see beyond the computed risk picture in the form of the summarising probabilities and expected values. Traditional QRAs often fail in this respect. This observation was the starting point for the development of the semi-quantitative... 

Quantitative risk evaluation for the tunnel and acceptability evaluation... 

Risk evaluation The appraisal of the significance or consequences of a given quantitative measure of risk (SSDC). 

A simplified fire safety evaluation of a building (see Table F.2). It consists of analyzing and scoring hazard and other related risk parameters to produce a rapid and simple estimate of relative fire risk. A detailed fire risk evaluation may not include attributes such as human behavior and attitudes. The structure of a risk index system facilitates quantification and inclusion of such factors. Where a quantitative fire safety evaluation is desirable, detailed fire risk assessment may not be cost-effective or appropriate. Fire risk indexing may provide a cost-effective means of fire safety... 

If a full quantitative evaluation is conducted, a risk evaluation should be presented for each hazard)... 

It is becoming increasingly important that individuals involved in design and evaluation of nuclear systems be knowledgeable in the area of quantitative risk evaluation. 

Risk evaluation The comparison of the estimated risk to given risk miteuia using a quantitative or qualitative scale to determine the significance of the risk. 

Risk evaluation will make risk prioritising possible. The use of a (semi-) quantitative scale can make risk evaluation more sophisticated. The determination of a risk criterion for risk acceptance is another addition. See Sect. 21.4.2. 

A quantitative method of risk evaluation - which takes into account the risk magnitude equation discussed above - considers the frequency (number... 

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