In conducting a PHA for an existing process, it is good practice for the PHA team to conduct a field tour of the process being reviewed. However, the PHA team leader may encounter resistance from team members, especially for a PHA being conducted for an older process for which previous PHAs have been conducted. Team leaders need to be prepared to deal with such resistance and be able to provide guidance to the team on what to look for during a field tour.

          It has become apparent that some equipment damage mechanisms may be overlooked in the performance of PHA studies. Table 1 provides examples of process safety incidents that resulted from such causes. The Division of Occupational Safety and Health within the California Department of Industrial Relations has amended its process safety management (PSM) regulations for petroleum refineries in California to include requirements for conducting damage mechanism reviews (DMRs) to be addressed in PHA studies. Also, API Recommended Practice (RP) 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, addresses the subject.

NFPA 652-2016, Standard on the Fundamentals of Combustible Dust, provides the basic principles of and requirements for identifying and managing the fire and explosion hazards of combustible dusts and particulate solids. The standard is intended to provide the minimum general requirements necessary to manage the fire, flash fire, and explosion hazards posed by combustible dusts and directs the user to other NFPA standards for industry-specific and commodity-specific requirements.

The standard contains requirements for dust hazards analysis (DHA) which is a systematic review to identify and evaluate the potential fire, flash fire, or explosion hazards associated with the presence of combustible particulate solids in a process or facility. DHA is part of a prescriptive approach to combustible dust safety but a performance-based approach can be used which relies of a dust risk assessment (DRA). 

When completing any task, having the right tool makes all the difference. You have probably heard this expression used many times and it holds true even for conducting Process Hazard Analysis (PHA) studies. Yes, you can use paper and pencil or a spreadsheet program, but, long-term, you would end up spending more time and money, and study quality and consistency would be lost. 

So why use PHA Software?  

Process safety programs require many decisions on their design and implementation. These decisions directly impact the risks posed by processes. Unfortunately, decisions can be unreliable when they are influenced by cognitive biases, which are influences on human judgment and decision making that can cause reasoning errors and produce irrational decisions. Many different cognitive biases have been identified and they occur commonly. They are difficult to detect and override because they are used unconsciously and automatically.

The identification of hazard scenarios in process hazard analysis (PHA) is subject to the effects of cognitive bias by PHA team members, which may lead to the omission of scenarios from PHA studies.

Current educational technology, such as computer-based instruction, has been found to be disappointing. Recent research has suggested that the design of current learning technologies relies on erroneous assumptions about how the human mind learns. The human mind has evolved to assimilate and store information through social interaction. For virtually the entire period of human existence, learning has occurred in social environments by listening to others and engaging with them. As a result of this conditioning over millennia, the human mind depends on social cues to facilitate learning. Most current educational technologies are devoid of such cues. Even videos of human speakers do not provide real social interaction where the verbal and non-verbal cues of one party are responsive to those of the other party.

Simultaneous operations (SIMOPs) are situations where two or more operations or activities occur at the same time and place in a facility. They may interfere or clash with each other and may involve risks that are not identified when each activity is considered by itself. Thus, they can increase the risks of the activities or create new risks. A number of major process industry accidents have involved simultaneous operations.

The draft standard, ISA-62443-3-2, requires that a cybersecurity risk assessment be performed for industrial automation and control systems to determine target security levels. The standard provides a basis for specifying security countermeasures by aligning risk-ranked vulnerabilities with security capabilities in ISA-62443-3-3.

Critical thinking and creative thinking are both needed in process safety management. Creative thinking was addressed in the previous blog post. This blog post addresses critical thinking.

Conventional thinking can be flawed in various ways resulting in beliefs, opinions, or judgments that are false. Important considerations may be overlooked and conflicting viewpoints ignored. People may be persuaded by emotion or the personal attributes of others such as their position or reputation, rather than logic. The discipline of critical thinking has evolved to address such flaws in human decision making.

Creative thinking is needed in various areas of process safety, for example:

• Identifying hazard scenarios in PHA
• Performing MOC reviews
• Identifying ways in which processes may be mis-operated
• Investigating the causes of incidents
• Planning for emergencies

Unfortunately, formal education usually discourages creative thinking and most people don’t need to be creative for much of what they do in daily life. Consequently, the ability to think creatively is not common. However, creative thinking is a skill that can be learnt. Guidance is available on ways in which creative thinking can be approached by anyone when the need arises.