Hazards identification procedure

Most hazard identification procedures have the capabiUty of providing information related to the scenario. This includes the safety review, what-if analysis, hazard and operabiUty studies (HAZOP), failure modes and effects analysis (FMEA), and fault tree analysis. Using these procedures is the best approach to identifying these scenarios. 

The framework to be described later in this chapter can be seen as a complementary procedure to hardware orientated hazard identification procedures. Ideally, the two approaches should be applied in parallel to a plant evaluation, in order to benefit from the synergy of considering both perspectives. 

The words "wlicir and "where appear in numerous hazard identification procedures. List some qucstioiis/coimnenis tliat are concerned with tlicse two terms. 

An important part of the hazard identification procedure shown in Figure 10-1 is the risk acceptance step. Each organization using these procedures must have suitable criteria. 

Checklists should be applied only during the preliminary stages of hazard identification and should not be used as a replacement for a more complete hazard identification procedure. Checklists are most effective in identifying hazards arising from process design, plant layout, storage of chemicals, electrical systems, and so forth. 

The hazards identification procedures presented in chapter 10 include some aspects of risk assessment. The Dow F EI includes a calculation of the maximum probable property damage (MPPD) and the maximum probable days outage (MPDO). This is a form of consequences analysis. However, these numbers are obtained by some rather simple calculations involving published correlations. Hazard and operability (HAZOP) studies provide information on how a particular accident occurs. This is a form of incident identification. No probabilities or numbers are used with the typical HAZOP study, although the experience of the review committee is used to decide on an appropriate course of action. 

Figure 23-1 shows the hazards identification and risk assessment procedure. The procedure begins with a complete description of the process. This includes detailed PFD and P I diagrams, complete specifications on all equipment, maintenance records, operating procedures, and so forth. A hazard identification procedure is then selected (see Haz-ard Analysis subsection) to identify the hazards and their nature. This is followed by identification of all potential event sequences and potential incidents (scenarios) that can result in loss of control of energy or material. Next is an evaluation of both the consequences and the probability. The consequences are estimated by using source models (to describe the... 

The design and operation of a process plant form an integral part of safety and systematic procedures and should be employed to identify hazards and operability and, where necessary, should be quantified. During the design of a new plant, the hazard identification procedure is repeated at intervals. This is first performed on the pilot plant before the full-scale version as the design progresses. Potential hazards whose significance can be assessed with the help of experiments are often revealed by this study. 

Information flow during the execution of the hazards identification procedure is shown in Fig. 9. It is composed of two phases ... 

The basis of safety, as outlined above, results from partly organizational, partly technical measiues dedicated to preventing identified hazard potentials from taking effect. The systematic hazard identification procedures are discussed in Chapter 6 in more detail. Each element of this basis of safety is of a certain quality which is given by its type of action, the degree of efficiency and its availability. A first simplistic classification for some elements is given in Table 1-1 ... 

When designing a new plant the hazard identification procedure should be repeated at intervals, first on the pilot plant and then on the full-scale version, as the design becomes more closely defined. This may reveal new potential hazards whose significance can only be assessed with the help of new experimental data thus there will probably be some overlap with the assessment of chemical reaction hazards. 

Per Occupational Safety and Health Administration (OSHA) regulation 29 CFR 1910.1450, Occupational Exposures to Hazardous Chemicals in Laboratories, is a written plan that includes specific work practices, standard operating procedures, equipment, engineering controls, and policies to ensure that employees are protected from hazardous exposure levels to all potentially hazardous chemicals in use in their work areas. The OSHA standard provides for training, employee access to information, medical consultations, examinations, hazard identification procedures, respirator use, and record-keeping practices. 

Finally, it should be noted that the validity of the system model can be confirmed by testing it with known scenarios. In other words, the equipment states and process conditions of every component at different stage of the batch operation should be simulated and compared with the expected system behavior before actual implementation of the proposed hazard identification procedure. 

Consider how a safety case regime would have prevented this accident. The standard hazard identification procedure in the industry is a HAZOP (hazard and operability study). Two other gas plants at the Longford site had been HAZOPed but a planned HAZOP of the plant where the... 

It is clear, therefore, that both styles of major hazard regulation would have averted the accident, had they been in place. A safety case regime would have mandated a systematic hazard identification procedure which would have identified and controlled the hazard of cold temperature embrittlement. An incident report system which required the reporting and investigation of abnormal temperature events and leaks would also have resulted the discovery and control of the danger of embrittlement. 

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