Phase hazard identification

During the concept phase, hazard identification is initiated and documented by preparing a preliminary hazard list (PHL). 

As indicaled above, the PHA may ser c as a precursor lo further hazard analyses. It is included in lliis chapter because it can pro ide a cost effective, early-on plant method for hazard identification. As its title indicates, the PHA is really intended for use only in the preliminary phase of plant development for cases where past e.spcriencc provides little or no insight into any potential safety problems, e g., a new plant with a new process. 

In general, hazard identification criterion represents the deviation of one or more measured variables from specified values. This is the basis upon which a significant percentage of risk analyses are done. For a chemical process, a number of measurable variables, physical properties, and states or positions of various parts of the overall equipment, e.g., pumps, valves, and motors, can be specified for every time or phase of the process. Certain deviations from the "standard" recipe or settings can then be defined in advance as hazardous, and thus can be used for initiation of an alarm at the early stage of a runaway or upset condition. 

During the process hazards identification and definition phase of a project design, a basic process control system (BPCS) strategy is normally developed in conjunction with heat and material balances for the process. 

Fig. 1. Applicability of various hazards identification and analysis methodologies during various phases of the design process.

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

Three assessment phases are recognised widely. The first is hazard identification this is described as a Phase la investigation. In this, a conceptual model is developed for the site that identifies potential receptors, contaminant sources and pathways, by which contamination can reach receptors. The second phase (Phase lb) tests the conceptual model, by collecting and analysing quantitative information to support model validation. The final phase is risk assessment (Phase 2) in which the conceptual model is used to estimate and evaluate the actual or potential risks to receptors. 

While aU of these Elements of Safety Management Systems are significant in avoiding accidents resulting in severe consequences, the section titled Hazard Identification and Evaluation is principally relevant here. It requires hazard identification and avoidance or mitigation, both on an anticipatory basis in the design process and during all phases of operations. That encompasses both routine and unusual operations. This is how the directive reads ... 

B-l] Mannan S (ed) (2005) Lees loss prevention in the process industries, hazard identification, assessment and control, 3rd edn. Elsevier, Amsterdam [B-2] Louvar JF, Louvar BD (1998) Health and environmental risk analysis fundamentals with applications, vol 2. Prentice Hall, Upper Saddle River [B-3] PHASE Version 6.51 (2006)... 

This section describes the hazard identification and evaluation process performed for the SNL HOF and for the HOF associated radioactive material storage areas. The purpose of this information is to present a comprehensive evaluation of potential process-related, natural phenomena and external hazards that could possibly affect the public, workers, collocated workers, and the environment due to single or multiple failures or incidents. Consideration is given to all phases of isotope production operation of the HCF, including the activities, materials, facilities, and equipment of the production process. 

Similarly, if the system definition or hazard identification phases are performed too narrowly, there is an immediate risk for not including relevant factors in the assessment. Establishing guidelines which allow for inclusion of all relevant factors is therefore important. 

The team responsible to build the matrix should include, besides experienced DCU operators, automation specialists and process engineers involved in the DCU design and operation. Ideally, the experts responsible for the matrix development should integrate the H AZOF team, which is performed in a foUowing step inside the DCU basic design phase. During the hazard identification carried out with HAZOP methodology. 

Hazard identification includes determining what parts of the project constitute a hazard and determining the location of these hazards. Hazard identification continues throughout the life cycle but is concentrated in the concept and design phases and when changes are made or accidents occur (Fig. 7-2). 

The job safety analysis (JSA) [also referred to as the job hazard analysis (JHA)], which is a more simplified form of task analysis, has been a longstanding tool for task and function analysis. JSA has been available and utilized in general industry for many years by the industrial safety community. However, many practitioners do not understand or are simply unfamiliar with the connection between the JSA and the system safety tasks of hazard identification and analysis. It has even been suggested by some in the profession that the JSA itself is a type of oversimplified system safety analysis and, if performed earlier in the job development phase, could be used as the basis of a preliminary hazard analysis for a specific task or set of tasks. However, because JSA is often (if improperly) used to analyze a function only after it has been implemented, much of the data is not factored into the system safety process. The primary purpose of the JSA is to uncover inherent or potential hazards that may be encountered in the work environment. This basic definition is not unlike that previously discussed regarding the various system safety analyses. The primary difference between the two is subtle but important and is found in the end-use purpose of the JSA. Once the job or task is completed, the JSA is usually used as an effective tool for training and orienting the new employee into the work environment. The JSA presents a verbal picture of a specific job. 

Hazard identification refers to the potential health effects that may occur from different types of pesticide exposure. It is strongly related to the extent and the type of a pesticide s toxic properties. This phase, usually involves the gathering of data on whether exposure to a pesticide causes an adverse effect. 

The safety core-process itself starts with the Preliminary Hazard Identification (PHI) and the Preliminary Hazard Assessment (PHA). During diat phase a preliminary hazard list with severities is created via brainstorming and the use of historical data and checklists. Outputs are the preliminary hazard list, including severities and hazard target rates, and initial development process integrity level allocations as detailed in various standards, e.g. Safety Integrity Level (SIL) in lEC 61508 or CENELEC EN 50128. 

Preliminary hazard analysis (PHA) Purpose—To get a quick survey of all phases of an operation. In low hazard situations, the PHA may be the flnal hazard identification tool... 

Pre-design Phases 1 —5 9 End-user Hazard identification, specify requirements, setting up target SIL... 

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