7 - Process technology safety and hazard analysis

In 2020, a fire and explosion accident occurred in Taiwan because of the reverse flow of high‐pressure recycle gas. This accident resulted in three minor injuries and caused the Taiwanese government to instruct the top three chemical groups in Taiwan to conduct procedural hazard and operability (HAZOP) studies in addition to normal HAZOP studies. The cause analysis based on the accident timeline and cause factor chart indicated that improper control of the protection logic bypass and the lack of four process safety management (PSM) elements, namely mechanical integrity, process safety information (PSI), operating procedures, and process hazard analysis (PHA), were the root causes of the aforementioned accident. The deficiencies leading to accidents are related to planning problems in PSM promotion but unrelated to the implementation of PSM programs. Maintenance processes should be evaluated and developed according to PHA results or equipment structure to guarantee equipment integrity. The incompatibility of process chemicals with pipeline materials should be considered; then, the construction materials mentioned in PSI should be extended to those of pipelines, not just equipment. In addition to the hazards of normal operations, those of non‐routine operations should be identified to ensure the completeness of the PSM program. Protection logic bypass should be appropriately controlled, and a complete safety evaluation must be conducted before resetting the initiated protection logic. A majority of the deficiencies identified in this study exist in most Taiwanese chemical companies, including the leading ones performing PSM. The lessons learned from the aforementioned accident provide advance information that can be used to develop an improved PSM system.

In 2006/2009, PETRONAS Carigali embarked on its Process Safety Programme; driven primarily by concerns over an increasing trend in process-related incident occurring throughout the Company. The programme, aimed at institutionalizing process safety and creating a process safety culture throughout the Company, focused on defining explicit process safety expectations, thereafter putting in place the required processes to intensify the implementation and mandatory compliance. To ensure comprehensive programme, eight (8) key process safety areas, spanning the entire value chain of technical and operational integrity, were identified; these are: ■Design Integrity;■Mechanical Integrity;■Management of Change;■Process Safety Information;■Process Hazard Analysis;■Pre-Activity Safety Review;■Operating Procedures; and■Proprietary and Licensed Technology Assessment. For each of the identified 8 process safety areas, explicit expectations were defined; and in ensuring sustained implementation, these expectations were integrated in an existing HSE Management System. Additionally, detail implementation processes were also defined in procedures and guidelines associated with the HSE Management System. Detail aspect of the programme and its implementation will be covered in the full paper. Some 3-4 years into the programme, tangible improvement can be felt across the organization, particularly in areas of compliance culture to process safety, and the ensuing improved process safety performance. The critical success factors for the effective implementation of the Process Safety Programme can be summarized as follows: ■Unequivocal demonstration of process safety leadership at all levels, including dedicated teams charged with process safety responsibilities;■Explicit process safety expectations integrated as part of the overall technical and operational integrity;■Clearly defined processes; i.e. apart from stipulation on WHO need to do WHAT, WHEN and WHY, guidelines on HOW these are to be done were also formalised;■Regular process safety audits, and effective tracking to closure, including oversight by senior management; and■Effectiveness of implementation and compliance regularly reviewed by facility management, business unit management and senior management; and effective in-house tracking mechanism developed for standardization of reporting.

Industrial processes contain inherent risks and to assess such risks the use of Process Hazard Analysis (PHA) are commonly applied. The benefits of first principles qualitative and quantitative models and empirical knowledge support for PHA are explored. The use of qualitative hazard analysis based on functional modelling to guide hazard analysis is emphasized. The study proposes a framework for investigating potential hazard scenarios based on functional modeling, e.g. Multilevel Flow Modeling of process system. Subsequently quantitative hazard analysis is used to prioritize the hazard scenarios with highest potential. MFM represents the process on several levels of abstraction and supports logical inference. The potential hazard scenarios are ranked by likelihood and severity. Judgment about likelihood, severity and the tolerability of the resulting risk is made on a subjective basis using the empirical knowledge of the PHA team members. The potential hazard scenario generation procedure can be computer-aided. The proposed framework is applied for a water injection system to increase oil recovery from existing reservoir with better safety performance. Qualitative functional models are efficient for detailed description of possible accident scenarios. Domino effects can be visualized in an MFM model. The possible major accident scenarios are selected by likelihood and severity of their effects. The major accident scenarios can be examined in detail through further quantitative analysis. The hazard analysis of a water injection system demonstrates the feasibility and applicability of the proposed framework. In industrial practice, formulation of the major accident scenario is usually based on historical incidents and the outcome of HAZOP/HAZID type hazard identification studies. Such studies are dependent on the team and their collective knowledge rather than being systematic and objective in nature. The proposed framework performs systematic and comprehensive plant failure and consequence path generation by a computer-aided tool.

This article presents a brief analysis of the Occupational Safety and Health Administration (OSHA) Petroleum Refinery Process Safety Management National Emphasis Program (NEP) citation results as of early 2009. It includes trends distilled from the OSHA inspections performed to date. Recommendations for preparing for PSM NEP level inspections are provided.A proven approach to designing and implementing an upgrade project for OSHA process safety management systems and EPA risk management program is described. The model presented can be targeted to a facility's NEP specific citations or used for a general PSM system effectiveness upgrade.This article includes recommendations for improving PSM as a result of an NEP inspection. The recommendations are for the PSM elements that routinely have major OSHA citations; that is: Operating Procedures, Mechanical Integrity, Process Hazards Analysis, Process Safety Information, Management of Change, and Incident Investigations. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009

With the popularization and application of chemical process safety management (PSM) systems in the chemical industry, the use of such systems in China has become the focus of a large volume of research. In this article, 12 elements included in the current Chinese PSM system are divided into four stages from a structural point of view. This division will be helpful in the follow‐up analysis. After a careful analysis of the evaluation results for one PSM pilot study in Nanjing, some correlations have been found between the results of the elemental evaluation. Small‐ and medium‐sized chemical plants make up a large proportion of Chinese chemical plants and many chemical accidents take place in these plants, so a simplified PSM system in practical operation need to be found. Based on a previous PSM structural analysis, the secondary elements of the PSM system can be removed. This allows researchers to avoid the traditional method of analyzing PSM elements individually. In the concrete analysis process, a theoretical analysis of the correlation degree between elements can be combined with the results of accident investigations. The simplified Chinese PSM system consists of four core elements: Process safety information, process hazard analysis, training, and emergency management. Based on the current applications of these four core elements in China, a consideration of correlations between these elements is used to make several suggestions for improving China's PSM systems. © 2017 American Institute of Chemical Engineers Process Saf Prog 36: 378–381, 2017

Companies use metrics to monitor their process safety performance. Process safety metrics may relate to any aspect of a process safety program but many metrics are developed for individual process safety elements, such as process hazard analysis (PHA). Traditional metrics for PHA mostly address aspects of managing PHA studies, such as the timely completion of corrective actions. However, there are other types of metrics that are of interest, specifically those that characterize the level of safety achieved for a process and the level of quality achieved in a study. This article describes the use of such metrics in PHA and provides examples of their use.

Chapter 3 - Objective and Description of PHA, What-If, and HAZOP Reviews

While developing responses to help a client respond to occupational safety and health administration (OSHA) citations, we discovered that little or nothing has changed in 14 years at many facilities. OSHA is still finding the same gaps today. Chemical plants generally know how to complete a process hazard analysis (PHA), management of change (MOC), an incident investigation, etc. What is incomplete are the work processes to ensure continuity and completion.It is imperative that you have a functional process safety management (PSM) program. For example, OSHA states that the best defense against a National Emphasis Program (NEP) inspection is a strong PSM program. Failures can result in citations and incidents, which can lead to repeat or egregious citations, financial losses, public disgrace, and fatalities. Once your company has been cited for minor offenses, it becomes a target for repeat inspections.The teachings of this article will reduce failures by designing, implementing, and using complete work processes for PSM‐related activities. Many failures can be addressed by (1) improving the documentation of what you already do, (2) promptly resolving PSM‐related recommendations of all types, and (3) dealing with the challenge of keeping track of the ever‐changing recognized and generally accepted good engineering practices (RAGAGEP) that apply to many aspects of your PSM program. In addition, management support/involvement and systems that follow‐up to ensure all work activities are complete and adequately documented are essential. Instituting complete work processes will improve your PSM program, improve your efficiency, and reduce the chance of citations. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011

This paper looks at how safety evaluations used at commercial and Department of Energy (DOE) nuclear facilities can be used in the Occupational Safety and Health Administration’s (OSHA) management of change process. The paper can be viewed from either the regulator’s or facility owner’s perspective. Preventing and minimizing consequences relating to highly hazardous materials does not stop with the collection of process safety information and the preparation of a process hazard analysis. Process changes evaluated against process safety information may lead to increases in the probability or consequences of catastrophic releases contained in the process hazard analysis. A comparison is presented of the management of change process used at process facilities versus those used at nuclear facilities. The results of the comparison show that the safety evaluation offers process facilities an alternative approach in performing a final check on a process change that could confirm that no unreviewed hazards exist.

Domino effects produce hazard scenarios that involve escalating consequences as a chain of linked events propagates throughout and beyond the process where they originate. Such scenarios have been the subject of accident survey studies and quantitative risk analyses but their identification in process hazard analysis (PHA) has received less attention. This article discusses the nature and types of domino effects and a procedure is provided to address them in PHA. The role of separate domino effects studies is described, insights into domino effects that can assist PHA practitioners are provided, and some pitfalls in addressing domino effects are identified. The identification of domino effects in PHA is illustrated using an actual accident that occurred in a refinery. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 220–227, 2015

Enbridge’s decision to formalize a Process Hazard Analysis (PHA) program has taken the organization through a journey from an informal/ad hoc practice to a rigorous, standardized, best-practice-based process with selected methodologies and tools being applied to all capital and operation projects in the company. This paper begins with a description of past hazard practices in the oil and gas pipeline industry in relation to the application of a hazard analysis. The oil and gas pipeline industry is governed by PHMSA, NEB, TSB, and provincial OHSA regulations, but is not regulated by OSHA or EPA RMP. Using this regulatory framework as a reference, a standard corporate PHA at Enbridge was developed and implemented. The paper describes the process, the methodologies, and the associated templates and tools. The implementation strategy is also discussed, including training deployment and communication plans. Finally, a road map for continuous improvement describes how to make the process sustainable by closing the current process gaps in relation to best practices and achieving a maturity stage of execution.

Chapter 4 - Adaptation to Security Vulnerability Analysis

Dynamic simulation for process hazard analysis: Affordances and limitations in the application to complex process systems

Safety culture has been identified as a critical element in high consequence incidents in the oil and gas industry over the past few decades. Traditionally, safety culture, which is the collection of beliefs, perceptions, attitudes, and behaviors of the stakeholders within an organization regarding safety, has been viewed in terms of occupational safety: i.e., perception of components and norms that affect personal safety. It is clear that lapses in occupational safety can lead to injuries or fatalities to individual workers. However, lapses in process safety can cause injuries or fatalities to groups of workers or the public, or extensive damage to the facility and environment. The visible nature of hazards to individual workers often leads companies to focus more on occupational safety culture as opposed to process safety culture since occupational safety performance is easier to recognize. Process safety hazards are related to the process, conditions which are not necessarily obvious but are hidden within the complex systems comprising the chemical, mechanical, and controls of the process unit. Thus, process safety requires engineering discipline to systematically identify and manage the potential hazards posed by a process system throughout its life. Process safety culture is the collective group of values (i.e., beliefs, perceptions, attitudes) and behaviors that affect the safety management of processes in an organization. In the traditional safety culture assessment approach, the focus is on individual behavior, attitudes, and perception of process safety concerns such as management of change, process hazard analyses, near-miss reporting, etc. has been missing. Due to such gaps, the application of traditional safety culture assessment tools and methods in the process industry does not provide a comprehensive status of the state of process safety culture in such organizations. The objective of this paper is to discuss the differences between the occupational safety culture and process safety culture assessment techniques and present methods and guidelines to develop a process safety culture assessment tool.

The OSHA process safety management (PSM) and EPA risk management program (RMP) standards require that process hazards analyses (PHAs) be performed on processes that contain listed toxic or flammable chemicals. A number of PHA techniques are listed in both standards that can be used to satisfy this requirement. Typical PHA studies use analysis techniques, such as hazard and operability (HAZOP), what‐if, and checklists, to review potential hazards, such as deviations from normal process conditions of flow, temperature, pressure, etc. The influences of control and instrument system failures on process system safety are usually considered indirectly. This paper reviews some of the considerations needed to conduct a PHA that includes control and instrument system failures. Information on (1) how to organize the review analysis team, (2) what type of documentation is needed, and (3) the special considerations needed in a control and instrument system review are included in this paper. The wide use of advanced programmable and electronic systems in the chemical process industry introduces a number of special considerations that must also be included in a review. These considerations are also discussed in this paper.