Risk acceptance defined

Risk-Based Inspection. Inspection programs developed using risk analysis methods are becoming increasingly popular (15,16) (see Hazard ANALYSIS AND RISK ASSESSMENT). In this approach, the frequency and type of in-service inspection (IS I) is determined by the probabiUstic risk assessment (PRA) of the inspection results. Here, the results might be a false acceptance of a part that will fail as well as the false rejection of a part that will not fail. Whether a plant or a consumer product, false acceptance of a defective part could lead to catastrophic failure and considerable cost. Also, the false rejection of parts may lead to unjustified, and sometimes exorbitant, costs of operation (2). Risk is defined as follows ... 

Bnrmaster DE, Thompson KM. 1995. Backcalculating cleanup targets in probabilistic risk assessments when the acceptability of cancer risk is defined under different risk management policies. Hnman Ecol Risk Assess 1 101-120. 

The accepted risk is a risk inferior to a level defined in advance either by law, technical, economical, or ethical considerations. The risk analysis, as it will be described in the following sections, has essentially a technical orientation. The minimal requirement is that the process fulfils requirements by the local laws and that the risk analysis is carried out by an experienced team using recognized methods and risk-reducing measures that conform to the state of the art It is obvious that non-technical aspects may also be involved in the risk acceptation criteria. These aspects should also cover societal aspects, that is, a risk-benefit analysis should be performed... 

To classify risks, a system or framework for classification must be agreed upon. In a perfect world, a societal consensus on levels of "risk acceptability" would be at hand and be straightforward in how it would be applied in each situation being evaluated. However, in the real world there is no consensus, and we can only evaluate and then define the ranges of risks posed in actual situations and then judge them for their acceptability to society. 

Risk characterization includes a comparison between toxicity values and/or exposure criteria and exposure (dose or media concentration) to determine whether the exposure is acceptable. US EPA developed a formalized system that is commonly used to determine whether chemicals are likely to present an unacceptable risk based on current and likely future use of the property. The estimated dose is used to calculate an additional lifetime cancer risk for each chemical regulated as a carcinogen. Typically, a total site risk (sum of the risk associated with all carcinogens identified at the site) is presented. Acceptable risk is defined by the agency, in the appropriate laws, or by regulations that govern the site. Acceptable risk is a function of policy or law but is supposed to be rooted in science. 

Acceptable defined as 10 risk (upper bound). Based on mouse and rat bioassay (10 risk). 

On this basis the concept of so far as is reasonably practicable (SFAIRP) was bom and subsequently enshrined in the 1974 UK Health and Safety at Work Act. SFAIRP, whilst a significant step forward, fails however to precisely acknowledge the notion of risk and its relationship to practicability. As such the slightly modified term as low as reasonably practicable (ALARP) has been widely adopted in the UK and some other countries as the basis for risk acceptability. The ALARP principle can be defined as that level of risk which can be further lowered only by an increment in resource expeuditure that is disproportionate in relation to the resulting decrement of risk [2],... 

Risk acceptance criteria can be defined relative to the risk matrix. The as-low-as-reasonably practicable (ALARP) approach may be chosen, defining three risk levels [4] ... 

Tolerable risk is defined as that risk which is accepted in a given context based on the current values of society (3.7). 

Although the concept of acceptable risk is becoming more commonly adopted throughout the world, definitions of the term acceptable risk can only be generally written. While it can be said that safety is that state for which the risks are judged to be acceptable, and that tolerable risk is defined as that risk which is accepted in a given context based on the current values of society, applications of those premises in individual situations result in great variations. 

A survey has been made of the regulatory and industry requirements in the Oil and Gas industry for defining Risk Acceptance Criteria (RAC). The focus has been on Norwegian and UK offshore oil industry. RAC may be quahtative or quantitative, and are known variously in the Oil and Gas industry as, e.g., risk criteria , decision criteria , screening criteria , tolerability criteria . 

In the other case, the preliminary precaution principle was respected regarding the evaluation of risk acceptability. For that, action values of dosimetric quantities Sr or, if need be, Er defined by the Directive (EUPC. 2004) were used. An rmcertainty related to the existence of athermal effects during the exposure to NIEMF was incorporated using the uncertainty factor UF = 10 and an rmcertainty related to the individual differences in sensitivity was incorporated in the form of the uncertainty factor UFsd = 2. 

The comparison of dosimetric quantities Sav and Eav with corresponding action values served for assessing risk acceptability. If the hazard quotient HQ is defined... 

A risk acceptance criterion is a reference by which risk is assessed to be acceptable or unacceptable. For our situation it is common to define RAC both for individual risk and societal risk (F-N curves). In recent... 

The use of risk acceptance criteria is, despite the critique raised to this approach, one possible approach to ensure that safety is reasonable accounted for. Common practice in Norway is that the enterprises themselves define the RAC even in the case of societal risk. This practice has been questioned, and a broader principal discussion is on the way in Norway. The recent developments in the UK and the Netherlands in relation to land-use planning are believed to also improve the Norwegian thinking. 

Problem definition and setting of boundaries Ship category ship systems and ftmctions, ship operation, external influences of ship, accident categories, risks associated with consequences Defining scope of assessment and system border Describing system IdentiAing relevant stakeholders Defining risk acceptance criteria V.4R, S.4R. tolerance for disturbance... 

As a comprehensive view of the LNG supply chain was intended, a life-cycle view of the system was considered appropriate. To test the methodology, initial smdies were performed on a fictive case, involving only one vessel. The step 0 part of defining system borders, describing relevant stakeholders, and risk acceptance criteria had to be divided into four distinct phases Charter-party, construction, operation and termination. 

Acceptable risk is strongly related with the acceptable probability of failure and the acceptable amount of losses. There is general agreement in the literature and in regulatory circles that risk should at least be judged from two points of view in relation to inundation consequences. The first point of view concerns the risk assessment by society on a national level which relates to the number of casualties due to a certain hazardous event. Risk is defined as the relation between frequency and the number of people suffering from a specified level of harm in a given population from the realisation of specified hazards . If the specified level of harm is limited to loss of life, the societal risk may be modelled by the frequency of exceedance curve of the niunber of deaths, FN-curve. Secondly, the... 

The Dutch major hazards policy deals with the risks to those hving in the vicinity of major industrial hazards, such as chemical plants and LPG-fuelhng stations. The cornerstones of the Dutch major hazards policy are (i) quantitative risk analysis, (ii) individual and societal risk as risk-determining parameters and (iii) quantitative acceptability criteria for evaluating levels of individual and societal risk (Ale 1991, 2002 Bottelberghs 2000). Individual risk is defined as the probability of death of an average, unprotected person that is constantly present at a given location. 

Unfortunately, most RAC matrices use scales that are so subjective and poorly defined as to be virtually meaningless. Granted that accurately placing exact numerical values on either severity or probability scales is difficult, these scales must be quantified to some extent to have any real value. The hurts a little—hurts a lot and maybe—maybe not approach to severity and probability scales, respectively, hardly provides the type of data required to support major risk acceptability decisions. 

Definition of goals and tolerable risks Were risk acceptability criteria clearly defined Were they consistent with safety requirements, yet realistic and obtainable ... 

Ensure that acceptable and unacceptable risks are defined specifically and documented, as a company operating policy, so that decisionmakers are made aware of the risks being assumed when the system operates. 

Documentation of a qualitative method may be a simple description of the issue dealt with, including assessment of associated risks and a conclusion regarding necessary action, if any. Though simple, such a QRM process should also be documented which risks were defined and balanced and who accepted the residual risk. 

Residual risk Risk can never be eliminated entirely, though it can be substantially reduced through application of the hierarchy of controls. Residual risk is defined as the remaining risk after controls have been implemented. It is the organization s responsibility to determine whether the residual risk is acceptable for each task and associated hazard. Where the residual risk is not acceptable, further actions must be taken to reduce risk. 

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