Types of Hazards Analysis

Hazards analysis techniques fall in two broad categories. Some techniques focus on hazards control by assuring that the design is in compliance with a pre-existing standard practice. These techniques result from prior hazards analysis, industry standards and recommended practices, results of incident and accident evaluations or similar facilities. Other techniques are predictive in that they can be applied to new situations where such pre-existing standard practices do not exist. 

The most common hazards control technique is a checklist. The checklist is prepared by experienced personnel who are familiar with the design, construction and operation of similar facilities. Checklists are relatively easy to use and provide a guide to the evaluator of items to be considered in evaluating hazards. API RP 14J has examples of two checklists which can be used to evaluate facilities of different complexity. Because production facilities are very similar and have been the subject of many hazard analyses, a checklist analysis to assure compliance with standard practice is recommended for most production facilities. The actual procedure by which the checklist is considered and the manner in which the evaluation is documented to assure compliance varies from case-to-case. 

The most common predictive technique which is used to analyze facilities which contain new equipment or processes, or where there is an unusually high risk to personnel or the environment is the Hazard and Operability technique or HAZOP. A HAZOP study requires a team of five to ten multi-discipline personnel consisting of representatives from engineering, operations, and health, safety, and environmental staff. The 

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As part of a site s overall ISMS, hazard analyses are conducted at the site, facility, activity, and task levels utilizing a variety of resources. The need for an integrated approach is illustrated by reviewing DOE directives, and OSHA and EPA standards and regulations, many of which call for some type of hazard analysis. At the nuclear facility level, DOE-STD-3009-94, the preparation guide for SARs, requires hazard analysis in Chapter 3, Hazard and Accident Analyses, and Chapter 8, Section 11, Occupational Chemical Exposures. At the activity or worker level, DOE O 440.1A and its related guides (DOE G 440.1-1 and DOE G 440.1-3) requires the identification of workplace hazards and evaluation of risk, and calls out OSHA standards (i.e., 29 CFR 1910 and 29 CFR 1926). 

OSHA stresses the importance of a team-based approach to all types of hazards analysis, but such an approach is fundamental for those techniques that fall into the first category, i.e., those that are primarily creative or imaginative. (Other techniques such as fault tree analysis are less suitable for team participation. However, even in such cases, a team is needed to identify the base events, and to discuss the cause and effect relationships that exist within the system being analyzed.)... 

This type of hazards analysis can be either deductive or inductive. A deductive (top-down) analysis is one that first defines an undesirable event, and then considers what events and chains of circumstances are needed to occur before the overall undesirable event occurs. A deductive approach is used by detectives to solve crimes. A widely used type of deductive analysis in process risk analysis is the fault tree method, described in the next chapter. 

An FMEA is a bottom-up approach to hazards analysis. When linked with a top-down method (such as FTA) a powerful synergy can ensue. The top-down method will highlight those areas which pose the greatest risk the FMEA can then be used to investigate those areas in greater detail. Like other types of hazards analysis, an FMEA should be carried out by a team. In most cases, however, only two or three team members—who are specialists in the required fields— are involved. 

A PSR is not a last-minute hazards analysis. The review team must check that the right types of hazards analysis were carried out at the right times, and that the quality of those analyses is satisfactory. The team must also check that all the findings were implemented or closed out in a professional manner. But the team does not actually analyze the new system for hazards. 

These same positive trees are very useful feeder documents for many types of hazard analysis. For example, the item layout for failure mode and effects analysis worksheets can be taken directly from the positive tree for the project. Positive trees can easily be converted into negative trees for troubleshooting or accident analysis. 

At what point in the life cycle are FTAs generally done For what types of hazard analysis are FTAs most appropriate ... 

Part 1910.119 presents the objectives of hazard analysis and some of the considerations that determine the choice of techniques. The material presented below in Section 16.4.2.4 is consistent with this discussion. The type of hazard analysis chosen should be appropriate to the complexity of the process studies, and there should be a system to ensure prompt action on the findings of the study. 

Do not make the mistake of limiting your employees participation to what they can tell the professionals. Make sure that employees participate in the various types of hazard analysis. It makes good sense to involve employees in change analysis of new equipment and/or processes because of their valuable insights into how things really work. As indicated in Chapter 15 on job hazard analysis, many companies regularly include employees in this activity. Employees can play a similar role in... 

The tools and approaches used in the various types of hazard analysis tend to overlap. This overlap helps ensure total coverage and a more comprehensive inventory on which to base your prevention program. 

Hazards Analysis It is assumed that the drilling crew did not carry out any type of hazards analysis even though the well proved to be difltoult to control. 

Prestartup review Critical safety equipment (the sonar) was not working properly. If a presaiTaway review had been properly carried out, this deficiency weuld have been recorded and corrected. At the very least some type of hazards analysis would have helped determine if the ship was safe to sail. Also, the identification of such a deficiency would have led to the issuance of temporary operating precedures, pessibly the selection of a safer route, and training for those Invelved. 

Many books and papers, including Process Risk and Reliability Management, explain the various types of hazards analysis techniques that are used. A very brief overview of some of the techniques that are used offshore is provided in this section. 

As stated earlier, each type of hazard analysis is suitable for a range of use. Table V/1.0-1 further illustrates this point ... 

Table 5.9 shows a typical O SHA worksheet. Of course, the worksheet can be in a tabular form as with the first two types of hazard analysis, but many engineers like to put each operational hazard on one worksheet. The figure shows such a format. 

The different types of hazards analysis that have been carried out, and the recommendations and actions from each. The analyses can cover issues such as dropped objects from cranes or release of gas from a high pressure system. 

Phase hazard analysis is a useful tool for construction and other industries that involve a rapidly changing work environment, different contractors, and widely different operations. A phase is defined as an operation involving a type of work that presents hazards not experienced in previous operations, or an operation where a new subcontractor or work crew is to perform work. In this type of hazard analysis, before beginning each major phase of work, the contractor or site manager should assess the hazards in the new phase. Appropriate supplies and support are coordinated as well... 

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