(156b) Bridging Hazard Recognition Knowledge and Competency for Process and Occupational Safety

Understanding hazards and risk is essential for the success of process safety as well as occupational safety.  Process safety involves managing energy transfers throughout a process life cycle in order to minimize the risk of releasing highly hazardous chemicals that can result in large-scale harm.  The goal of the process industry is to manage safe and efficient transfers of energy that result in the safe manufacture of products.  Occupational safety involves managing energy as workers perform jobs involving routine operations, maintenance, or repair in order to prevent personal injuries and illnesses, damage to facilities, and environmental harm.  A consistent and systematic approach to hazard recognition can improve the efficiency and effectiveness of process safety and occupational safety.   Establishing an effective safety culture requires solid hazard recognition and evaluation principles coupled with effective communication of process and occupational hazards.  Successful process safety management requires that workers understand the technical documentation about a process (formally known as the process knowledge) and be able to conduct effective hazard identification and risk analysis.

          The process knowledge is the resource that allows operators, maintenance workers, engineers, and other personnel to understand the various forms of energy involved so that the process can be monitored and controls adjusted to maintain the operation within design specifications.  Hazard identification and risk analysis requires these personnel to recognize conditions, circumstances, and events that have the potential to cause harm.  Process parameters occurring outside of operating limits, upset conditions, and emergency situations must be understood in terms of the states of energy within the process.  It is necessary to understand how energy in a process is intended to behave, what catastrophic consequences can result from unintended conditions or interactions, and what interventions are required to prevent an incident. 

          An incident cannot take place without an energy transfer.  Understanding all of the energy associated with a process or job and managing potentially harmful energy are necessary to ensure that incidents are prevented.  A hazard can be defined as the potential for an uncontrolled release of, or an unwanted contact with, energy that can cause harm to people, the environment, and/or equipment and facilities.  In some circumstances, a loss or lack of energy can initiate events that result in harm.  Process and occupational risk both stem from the potential for energy transfer in an undesirable manner that can result in harm.  The potential magnitude of harm is the general characteristic that differentiates process hazards from occupational hazards. 

          Process hazards are potential catastrophic events such as loss of containment (uncontrolled release) of highly hazardous chemicals resulting in spills, toxic vapor clouds, fires, explosions, and other large-scale events.  These events can harm many people, the process unit, the processing facility, local communities, public areas, and the environment well beyond the facility boundaries.  Process safety incidents often involve the shut-down of part or all of a process. 

          Occupational hazards usually include only one worker or just a few workers and can cause localized damage to the environment, equipment, or parts of the facility.  The process often continues during and immediately after the incident.  Energy contained within a process can present occupational hazards to operators, maintenance personnel, and others who are required to work with the process in order to perform adjustments, sampling, testing, repair, maintenance, and related process service work.  When performing these tasks the workers have occupational risk stemming from their own physical actions, tools, equipment, and temporary use of external energy sources unassociated with the process such as motion, pressure, chemicals, or electricity that are used to accomplish the tasks. 

          The Management Oversight and Risk Tree (MORT) is a logic diagram that maps incident structure and includes energy as a prominent factor in all incidents.  In MORT there are four conditions that are necessary for an incident to take place.  An incident is not possible if any one of the four conditions is missing.  Three of these conditions are: (1) the presence of potentially harmful energy, (2) the lack of adequate barriers and controls to manage the potentially harmful energy, and (3) the presence of vulnerable people or objects that can be exposed to the potentially harmful energy.  The fourth condition is a sequence of events that leads to an uncontrolled release of energy, unwanted contact with energy, or incompatible interactions among the energies present.  An incident occurs when people or objects are harmed because of this sequence of events.

          There are five energy-based questions derived from MORT that can help workers recognize, evaluate, and manage hazards for a safe job outcome.  These five energy-based questions are:

1.  What is the job?

2.  What energy is involved?

3.  Where is the energy going?

4.  How will we manage the energy for a safe job?

5.  What are the stop-the-job triggers?  

These questions are the key to accurately identifying hazards, determining the level of risk posed by the hazards, and formulating risk reduction options.  All process operations and occupational tasks use energy that can be placed in one of the following categories— motion, chemical, pressure, heat and cold, gravity, biological agents, electrical, and radiation.  These energy categories can be used as a guide for addressing the five energy-based questions.  Answers to the questions will help determine what can go wrong, how bad it can be, and how often it might occur. 

          The first question (“What is the job?”) focuses on identifying the goal and nature of the job and the steps required to complete the job.  Important information for this question includes who will be involved, where and when will the job take place, what are the surrounding environmental conditions, and whether or not there are simultaneous operations.  In addition, the answers to this question will determine whether or not special process procedures, permits (e.g., hot work, confined space entry), or additional resources are required.  The second question (“What energy is involved?”) focuses on the energy associated with the process or job.  This question is intended to help workers understand all of the energy that is associated with the process or job.  The third question (“Where is the energy going?”) helps determine how the energy can be released or contacted and how interactions among different energy sources can occur.  The third question also addresses several issues that are related to the potential transfer of energy and the resulting type and scale of harm that can occur.  These issues include the state, magnitude, release direction, release duration, points of contact, interactions with other energy, and target resilience.  The answers to this question help workers determine the hazards associated with the process, job, and environment where the job will be performed.

          After the hazards have been identified, risk reduction efforts can focus on managing the energy that is identified as a hazard.  The fourth question (“How will we manage the energy for a safe job?”) addresses energy management techniques that will be used to manage all of the energy associated with the process or job.  The fifth question (“What are the stop-the-job triggers?”) helps predict unsafe situations that might arise during the running of a process or as a job is being done.  These are situations that involve the possibility of an uncontrolled release, unwanted contact, or incompatible interactions among different types of energy.   These situations can be called stop-the-job triggers and they require workers to stop the job or process or ensure that the potentially harmful energy involved is properly managed if the risk of shutting down the process is greater than continuing the operation.

          Perceptions of risk vary depending upon a worker’s knowledge of energy and whether the worker is focused on process or occupational hazards.  This creates a need for common terminology about hazards so that the risk associated with a process or job can be effectively communicated, especially when process and occupational hazards are present simultaneously.  Knowledge of the energy involved in a job or process is paramount to determining possible harmful outcomes.  This knowledge also serves as the basis for managing energy for a safe job outcome.  It must include an understanding of the type and magnitude of energies involved, release properties of the energies, interactions among energies, means of detecting energies, and other relevant characteristics of the energies.  Effectively answering risk-based process safety questions in order to understand risk (“What can go wrong?”, “How bad could it be?”, and “How often might it occur?”) is rooted in identifying and evaluating all of the energy involved.  Teaching workers how to use an effective energy-based hazard recognition tool for both process and occupational safety provides an efficient and effective way to improve process and job knowledge.  This will result in improved hazard identification competency, risk reduction plans, and communication among work groups with respect to hazards, risk evaluations, and subsequent risk reduction actions.