Process hazard analysis reviews

A reactive chemicals/process hazard analysis (PHA) to be completed every three years (see Reference 11). Special consideration may be given to facilities that have lower levels of process risk and which have demonstrated superior safety performance to extend this frequency up to five years. Facilities that pose higher process risk or who have lower safety performance may be recommended to have reactive chemicals/PHA reviews more frequent than every three years. In certain countries, government regulation will determine the frequency and other requirements for Process Hazard Analysis reviews. Dow will follow the government requirements where they are more stringent. 

A detailed review process and protocol has been developed for the review of existing chemical processes. This review is primarily a reactive chemicals review but also includes process risk and loss prevention questions. The protocol and questionnaire is referred to as the RC/PHA /Reactive Chemicals/Process Hazard Analysis) review. 

As can be seen from the Global Reactive Chemicals Standard, all existing chemical processes will have a Reactive Chemicals/Process Hazard Analysis review on a predefined periodic basis. In addition, every new plant Production Leader should review their process with the Reactive Chemicals Committee within 90 days of assuming responsibility for a pilot or production plant. Prior to the review, the Leader should acquire training on the chemistry and processes that they are working with. This should include an evaluation of raw materials, processes, products and waste to understand any potential reactive chemical hazards. They should review and be prepared to answer questions from the completed and updated RC/PHA protocol questionnaire as well as other relevant materials in their plant Process Safety Folder, such as F EI, CEI, etc. The review should cover all auxiliary operations to the process such as raw material and product storage drum, tank car and truck loading. 

The reader is reminded that a HAZOP or What-If report is a living document for a facility. As changes are made to a facility or its procedures the HAZOP or What-If review(s) will be updated to represent the current facility. Process hazard analysis reviews are also required to be updated and revalidated every five years as a minimum by U.S. regulations (OSHA and EPA). 

The Project Manager (or project, process, drilling, facility engineer) is the individual responsible for the accomplishment of the process hazard analysis. The process hazard analysis review should be considered part of a project just as an ordinary design review is. He is essentially the manager of the review and all other participants support his requests. 

The project manager is responsible that a process hazard analysis review has been performed for a project. In this respect the other team members provide support and assistance. The manager or engineer, directs and controls the other members as he would for any other aspect of the project or facility management. 

The ultimate responsibility for the safety of a process facility lies with the senior management. A company s senior and local management should therefor ensure the appropriate process hazard analysis reviews are undertaken. (Appendix A provides an example of a typical statement from a company s CEO). 

A worksheet (data base spreadsheet) form is used to collect and collate the process hazard analysis review data. A computer software generated spreadsheet is typically used. For a complete description of commercially available HAZOP or What-If software, the user should refer to the manufacturer s HAZOP or What- If software User Instructions. Although pre-printed forms may be used, they are highly inefficient and should be maintained only as a backup in case of computer hardware or software failures. 

How long will it take and how much will it cost to use a consultant to lead and a scribe to conduct a process hazard analysis review on a finished design for a new two train, crude production separation facility ... 

Diversity is recognized as a useful approach to reduce the number of defects. The team that conducts the process hazards analysis does not implement the safety interlocks but provides the specifications for the safety interlocks to another organization for implementation. This organization reviews the specifications for each safety interlock, seeking clarifications as necessary from the process hazards analysis team and bringing any perceived deficiencies to the attention of the process hazards analysis team. 

Chemical Exposure Index (CEI) Chemical Exposure Index, 1994). The CEI provides a method of rating the relative potential of acute health hazard to people from possible chemical release incidents. It may be used for conducting the initial process hazard analysis and it establishes the degree of mrther analysis needed. The CEI also may be used as part of the site review process. 

Perform process hazards analysis Perform management of change review... 

While material safety data sheets (MSDS) provide important information they may not provide information on all hazards that may be encountered during processing. A review of the MSDS is not a substitute for conducting a process hazards analysis. Additional information to consider should include ... 

The effort and time that is required for a process hazard analysis for these examples should not be an issue. A thorough management of change system will call for the change coordinator to make a decision as to what type of review is appropriate for the change. 

Process Hazard Analysis (PHA) An organized effort to identify and evaluate hazards associated with chemical processes and operations to enable their control. This review normally involves the use of qualitative techniques to identify and assess the significance of hazards. Conclusions and appropriate rec-... 

The safety status of the process should be periodically reviewed against the guiding principles for the original design. Monitoring of add-ons can detect potentially dangerous modifications. Process hazards analysis or process safety audits are useful tools for this review. Documentation of inherently safer principles is critical to ensure that future changes don t nullify the positive features of the initial installation. 

Designs should be based on knowledge of what the human body (and human nature) will do. Include educated operators in design reviews. The HAZOP methodology for process hazard analysis offers an excellent opportunity to identify design and procedural opportunities for inherently safer systems. After all, the OP in HAZOP stands for operability (COPS, 1992). For example, a safe start-up procedure that requires the operator to walk up and down the stairs three times to manipulate valves in the correct sequence can be made inherently safer by locating the valves so that operator has to walk up the stairs only once during the start-up. 

Included in OSH As JHA Booklet, 3071, is a good description of a process hazard analysis (PHA) [1]. This is being used in the Process Safety Management (PSM) program (29 CER 1910.119) to understand how hazards exist. There are some good methods listed in the manual that can be used to conduct a JHA. As you review each method you can determine which one may be useful for your operation. The typical method chosen is the checklist. 

You can quickly identify these plant sections by reviewing process flow diagrams and valving arrangements. Isolation points are defined by control valves or powered block valves that can be remotely activated. Process hazard analysis techniques help you identify the maximum credible accident scenarios. (Note that manual valves should not be considered reliable isolation points unless they are located to be accessible following a major accident. However, remotely-activated valves can only be considered reliable isolation points if there are adequate reliability engineering and maintenance programs in place.)... 

One of the most important elements of the PSM Rule is the process hazard analysis (PrHA). It requires the systematic identification of hazards and related accident scenarios. The PSM Rule allows the use of different analysis methods, but the selected method must be based on the process being analyzed. The PSM Rule specifies that PrHAs must be completed as soon as possible within a 5-year period. However, one-fourth of the PrHAs must have been completed by May 26, 1994, with an additional one-fourth completed each succeeding year. The highest risk processes were to be done first. A schedule for PrHAs must be established at the outset of a process safety management (PSM) program to give priority to the highest risk processes. PrHAs must be reviewed and updated at least every 5 years. 

The essence of the ASTM E 2012 approach is to determine incompatibility scenarios that could foreseeably occur by examining all possible binary combinations. It may be necessary to review a process by using a systematic method such as a process hazard analysis (PHA) to identify all incompatibility scenarios that have a significant likelihood of occurrence and severity of consequences. The same review can then be used to evaluate whether adequate safeguards exist or whether further risk reduction is warranted. 

Chemical Exposure Index (CEI) (Chemical Exposure Index, 1994 Mannan, 2005, pp. 8/22-8/26.) The CEI provides a method of rating the relative potential of acute health hazard to people from possible chemical release incidents. It may be used for prioritizing initial process hazard analysis and establishing the degree of further analysis needed. The CEI also may be used as part of the site review process. The system provides a method of ranking one risk relative to another. It is not intended to define a particular containment system as safe or unsafe, but provides a way of comparing toxic hazards. It deals with acute, not chronic, releases. Flammability and explosion hazards are not included in this index. To develop a CEI, information needs include... 

The facility is subjected to a process hazard analysis commensurate to the level of hazard the facility represents (i.e., Checklist, PHA, HAZOP, What-If review, Event Tree, FMEA, etc.). The results of these analyses are fully understood and acknowledged by facility management. Where high risk events are identified, quantifiable risk estimation and effects of mitigation measures should be evaluated and applied if productive. 

Suggested control and instrumentation for the management of process components are shown in API RP I4C which is still relatively the standard within the industry. All process control systems are usually reviewed by a Process Hazard Analysis, which will deem if the provided mechanism area is adequate to prevent a catastrophic incident. 

Process hazard reviews, in pilot plant safety, 18 733 Process hazards analysis of, 21 861 control of, 21 861-863 preventing, 21 832-846 Process industries, weighing in, 26 248 Processing... 

This checklist may be used to stimulate the thinking of inherent safety review and process hazard analysis teams, and any other individuals or groups working on process improvements. It is intended to promote "blue-sky" or "out-of the-box" thinking, and to generate ideas that might be usable in an existing facility or a "plant of the future" concept. 

Several qualitative approaches can be used to identify hazardous reaction scenarios, including process hazard analysis, checklists, chemical interaction matrices, and an experience-based review. CCPS (1995a p. 176) describes nine hazard evaluation procedures that can be used to identify hazardous reaction scenarios-checklists, Dow fire and explosion indices, preliminary hazard analysis, what-if analysis, failure modes and effects analysis (FMEA), HAZOP study, fault tree analysis, human error analysis, and quantitative risk analysis. 

Design reviews are conducted to refine requirements. Hazards are introduced to plant operators following laboratory work, EHS review, capital requirements review, and process hazard analysis. Reactivity is addressed during process hazard analysis and the initial review. 

For example, the hazard review requirements have the following differences from OSHA s process hazard analysis provision ... 

The process hazard analysis can be a starting point for the selection of fire scenarios. The process hazard analysis can be reviewed to develop a list of scenarios that result in fire as a consequence. Generic release sizes for small, medium, and large releases have been proposed as shown in Table 5-1 (Spouge, 1999). This saves time by eliminating the need to develop a detailed scenario. The analyst can use these release sizes to perform fire modeling calculations and determine the impact by moving the release point locations. The release criteria are considered to be representative of scenarios that could reasonably be expected to occur. 

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