Safety performance risk assessment

Regulatory authorities require all pharmaceutical companies to perform rigorous safety and risk assessments on any compounds considered for use in humans. Copious amounts of data from these tests must be submitted before any 59... 

It is necessary at this stage to carry out some form of performance-risk assessment in order to show that specified safety fimctions are su ient to reduce the risk to a level (Rm) well below the Safety Targets - i.e minimum acceptable level (Ra) - as indicated in Figure 6. Ra-Rn in Figue 6 represents that portion of the Safety Target, which can be allocated to (functional) failure - clearly these must be a realistic figures otherwise there is no point in proceeding further. 

The ERDEC Safety Office has since performed risk assessments on various detectors brought to government facilities for testing. Such procedures, when followed, permit the return of contaminated items to manufacturers. In the following, assessments of two detectors, the MiniRae and the M43A1 upgrade, are used as examples of how risks were assessed. Tables 3.16 and 3.17 define hazard severity and probability levels used as the criteria for assessing risk. 

At first glance, it seems that every industry performs safety and risk assessment differently. On closer look, however, the fundamental precepts are the same The methods are systematic and comprehensive. An industry may favor one method over another, but in most cases, this is mostly out of tradition. Now is a good time to review the way different industries apply safety and try to learn from each other. In most cases, you can literally lift the safety method from one industry and apply it directly to another. 

Glyn Garside is a safety consultant for Pilz Automatbn Safety L.P. He performs risk assessments and safety evaluations of clients prcxJucts for manufacturing and other industries. Glyn is a member of UL s Standards Technical Panel for UL 6420, as UL 508, UL 61010, UL 1740 and UL 1998. 

The SAR does not utilize an analysis worksheet since it is a summary document of safety analyses, risk assessments, test results, and safety studies already performed. As a minimum, the following basic information is required from the SAR document ... 

Do you perform safety analyses/risk assessment, e.g. road safety audits, benefit/cost analysis, in preparation of developing project scope and design for 3R projects ... 

Methods for performing hazard analysis and risk assessment include safety review, checkhsts, Dow Fire and Explosion Index, what-if analysis, hazard and operabihty analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis. Other methods are also available, but those given are used most often. 

A failure modes and effects analysis is a systematic analytical technique for identifying potential failures in a design or a process, assessing the probability of occurrence and likely effect, and determining the measures needed to eliminate, contain, or control the effects. Action taken on the basis of an FMEA will improve safety, performance, reliability, maintainability and reduce costs. The outputs are essential to balanced and effective quality plans for both development and production as it will help focus the controls upon those products, processes, and characteristics that are at risk. It is not the intention here to give a full appreciation of the FMEA technique and readers are advised to consult other texts. 

Performance-influencing factors analysis is an important part of the human reliability aspects of risk assessment. It can be applied in two areas. The first of these is the qualitative prediction of possible errors that could have a major impact on plant or personnel safety. The second is the evaluation of the operational conditions under which tasks are performed. These conditions will have a major impact in determining the probability that a particular error will be committed, and hence need to be systematically assessed as part of the quantification process. This application of PIFs will be described in Chapters 4 and 5. 

Where possible, it is preferable to demonstrate safety without the application of advanced risk assessment techniques such as QRA, which can be resource intensive, time consuming, and costly. The decision to proceed with QRA should be based on an estimate of the benefits to be derived from such a study. Management should evaluate the expected cost of improving safety against the cost of conducting a detailed QRA to determine if there is potential benefit to performing QRA. If the expected benefits of perform-... 

Hazard identification can be performed independent of risk assessment. However, the best result is obtained if they are done together. One outcome is that hazards of low probability and minimal consequences are identified and addressed with the result that the process is gold-plated. This means that potentially unnecessary and expensive safety equipment and procedures are implemented. For instance, flying aircraft and tornadoes are hazards to a chemical plant. What are the chances of their occurrence, and what should be done about them For most facilities the probability of these hazards is small No steps are required for prevention. Likewise, hazards with reasonable probability but minimal consequences are sometimes also neglected. 

In 1993, the Center for Chemical Process Safety (CCPS) published Guidelines for Safe Automation of Chemical Processes (referred to henceforth as Safe Automation). Safe Automation provides guidelines for the application of automation systems used to control and shut down chemical and petrochemical processes. The popularity of one of the hazard and risk analysis methods presented in Safe Automation led to the publication of the 2001 Concept Series book from CCPS, Layer of Protection Analysis A Simplified Risk Assessment Approach. This method builds upon traditional process hazards analysis techniques. It uses a semiquantitative approach to define the required performance for each identified protective system. 

Despite numerous safety measures, accidents with hazardous substances still occur even though Safety Indicators (Sis) have been developed as pre-warning signs to focus companies resources on risk areas. Moreover, Sis required by authorities enabled them to assess the safety performance of companies and focus their resources on companies which have problems controlling their risks, Modarres (Modarres et al., 1994). 

Offshore facilities are dramatically different from onshore facilities because instead of being spread out the equipment is segregated essentially into compartments or separated into a complex of platforms. Offshore facilities pose critical questions of personnel evacuation and the possibility of total asset destruction if prudent risk assessments are not performed. A through analysis of both life safety and asset protection measures must be undertaken. These analyses should be commensurate with the level of risk a particular facility represents, either in personnel exposed or financial loss. An unmanned wellhead platform might only require the review of wellhead shut-in, flowline protection and platform ship collisions to be effective, while manned drilling and production platforms may require the most extensive analysis. 

Risk assessment studies can be performed using whatever process information is available (CCPS 1992a). Obviously, the more information and knowledge that is available, the more thorough and valuable the risk study can be. For facilities that must meet regulatory requirements for process hazard analyses, certain process safety information (PSI) is required to be compiled and up to date before starting the analysis. 

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