Safety order of precedence

Design for Minimum Risk The system safety order of precedence dictates that, from the first stages of product or system design, the system should be designed for the elimination of hazards, if possible. Unfortunately, in the real world, this is not always practical or feasible. If an identified hazard cannot be eliminated, then the risk associated with it should be reduced to an acceptable level of hazard probability through design selection. 

To clearly understand the relative importance of this element in the system safety order of precedence, consider the following example. An entrepreneur wishes to establish a small manufacturing facility that will be involved in the production of school desks. Part of the finishing process will require the application of several coats of lacquer to each desk surface. An enamel-based paint will also be used on the understructure of each desk. The facility will have only one small open-faced paint booth. Ventilation will be provided, and the operator will be supplied with respiratory protection in the form of disposable respirators. However, during the design phase, a system safety evaluation of the painting process required the identification... 

Through proper and detailed consideration of the system safety order of precedence, the potential risk of the paint operation will be reduced to its lowest perceivable level and the risk acceptance, the next and last step, wiU be much easier to justify. 

To clearly understand the relative importance of this element in the system safety order of precedence, consider the following example. 

In the above example, the management of this manufacturing plant has determined that many other comparable paints/lacquers available on the market also contain isocyanates or other equally hazardous commodities. The installation of automated technologies will be too cost prohibitive to operate a competitive enterprise. Therefore, the system safety order of precedence dictates that suitable safety devices should be installed to control the hazard risk posed by the toxic lacquer. This would mean that the management team must decide whether... 

See Mishap Risk Index (MRI) and Safety Order of Precedence (SOOP) for additional related information. 

When providing the ICA, it is worthwhile reflecting on the following system safety design order of precedence (tailored from M1L-STD-882E para 4.3.4), which is listed in order of decreasing effectiveness ... 

The order of precedence for satisfying system safety requirements and resolving identified hazards is not unlike that which apphes to general industrial safety considerations. There are five basic steps, as follows (MIL-STD-882) ... 

Use of a variety of system safety concepts and tools, such as the order of precedence for hazard reduction, the hazard severity and probability tables, and... 

This section gives the steps in the risk reduction order of precedence. It relates to the Hierarchy of Controls outlined in ZIO and is discussed here in Chapter 12, Hierarchy of Controls The Safety Decision Hierarchy. ... 

Section 4, General Requirements, in 882E delineates the minimum mandatory requirements for an acceptable system safety program. Section 4.1.4, as follows, gives the steps to be taken in reducing risk, in an order of precedence. ... 

Use of a variety of system safety concepts and tools, such as the order of precedence for hazard reduction, the hazard severity and probability tables, and the hazard risk matrix, will assist the analyst in determining the appropriate risk assessment code to assign to a particular hazard risk. The RAC will prioritize for management the specific level of risk associated with a specific, identified hazard concern. 

Last, but not least, safety is considered in terms of the analysis of the risks associated with potential hazards identified by detailed consideration of the proposed process flowsheet. Safety is the number one concern for chemical engineers and the reader should not confuse the fact that it is the focus of the final chapter in this book with its order of importance. However, in order to carry out a hazard study and risk assessment, one must understand the concepts on which a process flowsheet is developed, and these are covered in the preceding chapters. The procedure describe in Chapter 10 is recognised as best practice in the process industry sector. 

Determining exposures a company faces is a formidable task, but it must be undertaken. Companies may choose to bring in an outside consultant or depend on the advice of a representative such as a loss control expert from their insurance company. This person will review activities, procedures, and processes to determine where exposures occur. Once exposures are identified, the company selects the critical exposures and prioritizes them in order of importance. Even large corporations have limited resources and must make decisions as to where to commit their resources. While controlling losses may seem to the safety manager like the most important way to utilize resources, the marketing director may feel that a new product introduction should take precedence. The safety function competes with... 

To say that safety is a priority means that it will change based on the needs or urgencies of the moment, and therefore will not always be the top priority Refer to Figure 2-1. The dictionary defines a priority as a precedence established by order of importance or urgency [10]. Think about how often your priorities change either at work or at home. 

It is necessary to be aware that some corrective measures are better able to produce the desired results than others, and that some are very ineffective indeed as controls. The safety precedence sequence shows the order of effectiveness of measures ... 

These are not separate objectives and must be considered together. The order in which they are listed is not meant to imply the precedence of any objective over another, other than that of putting safety first. Product quality, production rate and the cost of production will be dependent on sales requirements. For example, it may be a better strategy to produce a better-quality product at a higher cost. 

In the previous Chapter it was shown that most accidents are preceded by deviations in the operational process, e.g. Heinrich (Heinrich, 1959), Turner (Turner, 1978), Leplat (Leplat, 1987), Reason (Reason, 1997), etc. Additionally, it was shown that a specific class of deviations is present which is not covered by current pro-active safety indicators. These deviations are characterised by a high likelihood and low perceived safety related consequences and were defined as precursors and re-occur in the operational process of the organization prior to an accident. In order to find these deviations in a real life operation and to eventually find their underlying causes, the concepts of re-occurring deviation and operational process have to be explained in more detail. The various definitions and concepts derived in this Chapter are necessary to understand the next Chapters, which shows how they are applied in practice. 

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