Acceptable risk achievement

Process Design from the Assessed Hazards and Achieving an Acceptable Risk... 

Requirements to achieve an acceptable risk level in the design process can usually be met without great cost if the decision-making takes place sufficiently upstream. When that does not occur, and retrofitting to eliminate or control hazards is proposed, the cost may be so great as to be prohibitive. 

For workplace design, management and operations, and task performance aspects of safety, application of hazard analysis and risk assessment methods are vital to achieving an acceptable risk level. 

A few safety practitioners object to the idea that they make risk acceptability decisions. They create an atmosphere of being above that sort of thing, of super-righteousness. Perhaps they believe that if all that they propose is favorably acted upon, a risk-free enviromnent will be achieved. Safety professionals know that is not possible. If they want to be a part of the management team, they must share in risk acceptance decisions. Chapter 14, Acceptable Risk, is devoted to this subject. 

When required by the results of the risk assessment, alternate proposals for the design and operational changes necessary to achieve an acceptable risk level would be recommended. In their order of effectiveness, the action listing shown in The Safety Decision Hierarchy mentioned in Chapter 15, Acceptable Risk, would be the base upon which remedial proposals are made. For each proposal, remediation cost would be determined and an estimate of its effectiveness in achieving risk reduction would be given. 

At a recent safety corrference, a speaker reviewed the hazard analysis and risk assessment methods used in his company and said the outcome to be achieved through the use of those methods was acceptable risk. During the question period, some questioners implied by the nature and tone of their questions that no risk is acceptable. They asked What do you mean by acceptable risk Are you suggesting that some risk is acceptable Acceptable to whom ... 

Presents a methodology to achieve an acceptable risk level. 

The purpose of a risk management matrix is to (a) provide a logical framework for hazard analysis and risk assessment and (b) assist risk decision makers in arriving at their risk reduction and risk acceptance or declination conclusions. The implicit goal is to achieve acceptable risk levels. Several standards and guidelines now include the concepts of residual risk and acceptable or tolerable risk (e.g., ANSl/Bll TR3, ISO/IEC Guide 51, SEMI SIO—see references for full titles). 

Achieving understanding of the terms used in risk assessment matrices is vital for their use in a particular organization. For example, in actual practice, a variety of definitions are used of the terms establishing probability and severity levels, as in Table 15.1. Terms applicable to a discussion of acceptable risk are presented in the following definitions. 

USING RISK DECISION MATRICES TO ACHIEVE ACCEPTABLE RISK LEVELS... 

Earlier in this chapter, reference was made to a speaker who reviewed the hazard analysis and risk assessment methods used in his company, which relied on typical risk assessment and decision-making matrices, to achieve acceptable risk levels. Use of such matrices is a method some organizations apply to arrive at acceptable risk levels. Table 15.1 is an example of such a risk assessment matrix. Using the results from Table 15.1, levels of remedial action or risk acceptance for individual risk categories can be established, as in Table 15.2. 

Many authors have written on the benefits of designing to exceed the requirements of published standards. Achieving an acceptable risk level very often requires doing so. Complying with industry or government standards (e.g., OSHA, ANSI, European Community) will meet the consensus arrived at by the industry or government group that wrote the... 

Standard. However, complying with such standards will not necessarily achieve an acceptable risk level. 

In the six years since the second edition of On the Practice of Safety was published, several developments have taken place that require or propose that hazards be recognized and analyzed in the design process and that risk assessments be made toward achieving an acceptable risk level. Safety practitioners—pay attention. Comments on some of those developments follow. 

To be in a position to anticipate hazards, one must be involved in the design process. To effectively participate in the design process, the safety professional must be skilled in hazard analysis and risk assessment techniques. Influencing the design process and using hazard analysis and risk assessment techniques to achieve acceptable risk levels are the bases upon which system safety is built. 

Thus for waste management, and landfill disposal, the objectives are clear and apparently achievable, and in this way. Agenda 21 represents a step towards the attainment of common standards across the world, (in those aspects of landfill management that are specifically referred to), and which helps to ensure progress towards sustainable waste management. Whether or not landfill is truly sustainable is a moot point, and one which will be considered throughout this book. The concept of acceptable risk and the "nature and assimilative ctqracity of the receiving environment" are important factors in this discussion and are considered later. 

Considering the NORSOK Standard Z-013 model for risk estimation, analysis and evaluation this proposed framework can be used as a framework to deal further risk reducing measures after achieving the acceptable risk levels and there still safety improvements that can be implemented. And also held decisions about which risk reduction measures should be implemented, the priority of each action, the risk involved in different parts of the process. 

The proposed framework will be illustrated by a case study using realistic data in a situation where all the acceptable risk limits has been achieved but there stiU some safety improvements that could be done, and the decision problem is to implement or not these... 

Let us comment on the case where a safety specification is not available. Generally speaking, the lawgiver demands that the hazards and risks of the system are acceptable for all stakeholders. He requires that new systems should use state-of-practice technologies for achieving acceptable risks. Based on these principles often safety requirements are specified in standards. If standards are not available, necessary risk reduction measures can be derived from system analysis and quantitative or quahtative hazard and risk analysis (see e.g. lEC 61508). The hazard and risk analysis should consider all potential hazards, for instance, all stakeholders brainstorm on the basis of sufficient system knowledge. 

Almost every activity will include risk, and even though striving to reduce it, it will be impossible to achieve a complete elimination of risk. Hence we will always face the problem of what is acceptable risk (Fischhoff et al. 1981 Vatn 1998). 

What factors are weighed when deciding what level of risk is acceptable Let s consider the concepts of risk-benefit and cost-benefit as they relate to laboratory research. Risk-benefit means that we consider how much risk we are willing to accept to achieve a certain benefit. What are we willing to risk to successfully accomplish something Cost-benefit refers to the cost in effort and money to achieve a certain benefit, such as reducing a risk. 

The role of the safety professional is to anticipate, identify, and evaluate hazards give advice on the avoidance, elimination, or control of hazards and attain a state for which the risks are judged to be acceptable. To achieve this, they adopt a system-safety concept that includes ... 

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