Process hazard analysis (PHA) studies provide large databases of information on what can go wrong in processes and the measures that have been taken to prevent incidents. Many companies view PHA studies simply as a means to identify hazard scenarios to comply with regulations and help ensure necessary risk reduction measures have been taken. 

Combustible dust fires and explosions have resulted in many process safety incidents that have caused multiple fatalities and injuries together with considerable property damage. According to the US Chemical Safety Board (CSB), 386 major incidents occurred from 1980 to 2017. They killed 178 people and injured 1021 people. The incidents came from a wide variety of industries. 

Process hazard analysis (PHA) studies identify hazard scenarios in order to determine whether or not existing safeguards need to be enhanced or new safeguards installed. Consequently, recommendations to reduce hazard scenario risks by mitigating the severity of their consequences or reducing their likelihood must be developed.

When outdoor air temperatures drop, it is important for process plants to be prepared for safety challenges posed by cold weather. Low temperatures may affect piping, other equipment, and instrumentation. Cold weather vulnerabilities may result in process safety incidents.

The US Chemical Safety Board’s (CSB’s) Safety Digest, Preparing Equipment and Instrumentation for Cold Weather Operations, addresses this topic.

          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). 

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.