A process hazard analysis (PHA) describes a rigorous and step-by-step review of the operating procedures in a manufacturing plant. A PHA has one main goal — to prevent and mitigate the risks and consequences of hazardous chemical releases.
It tries to achieve this goal through three specific aims:
- Identifying the potential causes of hazardous chemical releases
- Evaluating the consequences of these releases
- Developing effective controls and mitigation measures to reduce the risks
A PHA works by identifying various risks that might lead to a chemical release. These risks are multifactored and they may include:
- Equipment failure
- Process failure
- Human error
- External factors
Identifying these risks on time can help in securing workplace and worker safety, preventing lost work hours due to accidents, as well protecting the environment adjacent to your manufacturing plant.
OSHA standards mandate a PHA for any industrial process that involves hazardous chemicals that Hazardous chemical releases pose a significant risk to the environment and human communities close to manufacturing plants. In addition, such releases will have major implications for the offending company. This means hefty fines and other legal liabilities.
Many employers and businesses may have the technical know-how and expertise to conduct a PHA. However, you can save time and cost by delegating this task to HSE experts with the experience and ability.
This is what we offer here at CDMS. Read on to learn more about how to conduct a process hazard analysis, the different types of hazard analysis, and how CDMS can help you conduct one.
The Different Process Hazard Analysis Methods
A PHA can be conducted through a variety of methods. Some of them are more complicated than others. The one you choose will depend on a variety of factors. This includes the type of industry you are in, the size of your company, and the resources available to you, among others.
There are nine PHA methods. They include:
What-If Analysis
A “What If” PHA is a risk assessment technique to identify potential hazards in a process or operation by using hypothetical “what if” scenarios. This method relies heavily on team brainstorming to determine any possible deviations from normal operations and their consequences.
By considering alternative scenarios, such as equipment failure, human error, or environmental factors, the team evaluates potential risks and their severity. In addition to this, the analysis helps develop preventive measures or contingency plans by taking into consideration all what-if scenarios.
This technique is commonly used in industries like chemical processing, manufacturing, and engineering to improve safety and operational stability and reliability.
This method relies heavily on team thinking. Therefore, it would be best to have a team that is experienced and with a wide-ranging background— this makes it more likely that they can predict a wider spectrum of alternative scenarios.
Hazard and Operability Study
A hazard and operability study (HAZOP) is a PHA method that is systematic in identifying potential hazards in a process. To conduct a HAZOP, you need a team of experts who will rigorously examine each step in a process to identify and evaluate issues that may pose as risks to personnel safety, equipment integrity, or smooth operations.
A HAZOP relies on qualitative techniques that make use of guide-words and is executed by a multi-disciplinary team of professionals. A HAZOP tries to achieve the following:
- Identify when a system or process deviates from the standard functioning process
- Decide whether the issues identified require action
- Ensure that actions decided are followed up
- Inform employers and operators of identified hazards and operability issues
It is best to implement a HAZOP as early as possible in the design phase as this will help eliminate the need for major restructuring after the facility has been built. However, a HAZOP can also be conducted on an existing facility to identify changes required to reduce risk and operability issues.
Failure Modes and Effects Analysis
Failure Modes and Effects Analysis (FMEA) is a PHA method that represents a systematic and step-by-step approach to identifying potential failure modes before assessing their effects. In carrying out a FEMA, the target can be a process, product, or system.
Failure mode is simply a term used to describe how a component or a process can fail. The analysis makes three evaluations:
- It assesses how a component or process can fail
- It evaluates the effects of these failures on overall operations or safety
- It determines the causes of these failures
Each failure mode is ranked in terms of its severity, frequency, and how easy it is to detect. FMEA is used to prioritize corrective actions to prevent failures or mitigate their impact, and it is frequently used in the manufacturing, aerospace, automotive, and healthcare industries.
Checklist-Based Hazard Analysis
Checklist-Based Hazard Analysis is a systematic PHA approach. It relies on predefined checklists to identify potential hazards in processes, equipment, or systems.
The checklist includes a series of questions or items that guide the analysis team in examining specific areas of concern — namely, safety procedures, equipment integrity, or operational practices. The advantage of this method lies in the fact that all critical elements are considered in this approach.
This method is also simple and efficient. It is commonly used in the manufacturing, chemical processing, and construction industries to improve safety and compliance.
Layer of Protection Analysis
Layer of Protection Analysis (LOPA) is a semi-quantitative risk assessment method used in process hazard analysis (PHA) to evaluate and manage risks associated with industrial processes.
It determines the likelihood and severity of hazardous events by identifying multiple layers of protection that are meant to prevent such events. These layers of protection include:
- Safety systems
- Alarms
- Operator actions
Each layer is analyzed to ascertain its ability to reduce risk. Then, the overall risk is compared against the standard safety criteria. LOPA helps determine whether additional safeguards are needed, ensuring a balanced, cost-effective approach to managing hazards. It is commonly used in the oil, gas, and chemical industries.
Fault Tree Analysis
Fault Tree Analysis (FTA) is a deductive, top-down risk assessment method used in Process Hazard Analysis (PHA) to identify the root causes of potential system failures.
The first step in FTA is to define an undesirable event (otherwise known as the “top event”), such as a system failure or accident. Then, you should systematically trace it backward to uncover all possible causes or failure modes using a logic diagram.
The diagram uses “AND” and “OR” gates to represent relationships between failures and contributing factors. FTA helps to shed light on how different failures combine to cause an event and is widely used in industries like aerospace, nuclear, and chemical processing to improve system reliability and safety.
Event Tree Analysis
Event Tree Analysis (ETA) is a PHA method that is inductive and forward-looking and is used to evaluate the outcomes of an initiating event. It begins by looking at a specific event. This could be equipment failure or process breakdown.
An ETA determines the potential sequences of events that will follow from this event by using a branching tree structure. Each branch represents different possible safety systems, operator actions, or safeguards that may succeed or fail.
The analysis tries to put a number on the likelihood and consequences of each scenario. In this way, it helps to identify risks and evaluate the effectiveness of protective measures.
ETA is commonly used in the nuclear power, aerospace, and chemical processing industries to determine system reliability and accident progression.
Bow Tie Analysis
Bow-Tie Analysis is a risk assessment method used in PHA that takes elements of both Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) and combines them visually. HSE experts use it to identify the causes of a hazardous event, its consequences, and the control measures in place.
The diagram that results from this approach resembles a bow tie, with the “hazard” placed in the center. The left side outlines the potential causes using a Fault Tree structure, and the right maps out possible consequences using an Event Tree.
Bow-Tie Analysis focuses on the barriers or safeguards put in place to prevent or mitigate risks, ensuring a balanced risk management approach.
Hazard Identification
Hazard Identification (HAZID) analysis is also another systematic PHA method. It is used to recognize and document potential hazards that could cause harm to people, property, or the environment in industrial or operational contexts.
It is an early step in risk management and focuses on identifying sources of danger, unsafe conditions, or hazardous situations before they turn into accidents. The analysis process may involve several strategies, including:
- Brainstorming
- Checklists
- Using historical data,
- Expert judgment
These strategies are employed to uncover a wide range of hazards, including chemical, mechanical, electrical, and human factors. HAZID is commonly used in industries like oil and gas, chemical processing, and construction to improve safety planning and mitigation efforts.
6 Steps to Conduct a Process Hazard Analysis
To conduct a hazard analysis, several steps need to be taken. You first begin with defining your objectives. After establishing your objectives, you need to ensure that you have a qualified team of experts to conduct a PHA effectively.
These experts will then identify and assess risks before developing and implementing controls. However, it does not end there. PHAs are a continuous process that should always be reviewed and updated for continual improvement.
Below, we discuss in depth the various steps in conducting a PHA.
1. Define the Scope and Objectives
Defining the scope and objectives of the analysis is the first step of a PHA. This means you should identify the following. Setting out the scope means that you determine how ambitious the PHA will be in terms of goals.
For example, will you be considering only hazards from a specific chemical being handled or will you be more systematic? Then you move on to decide the following:
- The process to be analyzed
- The team members involved in the analysis
- The specific objectives of the analysis.
After implementing this step, you move on to deciding what experts would be responsible for implementing the analysis.
2. Decide the PHA Team
The next step is to assemble a team of PHA experts to carry out the analysis. Some companies may decide to hire experts in-house. However, some small companies may not have experts to carry out this process. Also, even when companies do have this expertise, it would benefit them to outsource part of the process to make things more efficient.
Whatever the choice, the team you end up with should be made up of individuals who are competent, experienced, and equipped with the proper expertise. Ideally, there should be some balance between general expertise in risk management and specific expertise in PHA methodologies.
3. Identify the Hazards
The team will then go on to find and identify all the potential hazards associated with the process being analyzed. This includes the following:
- Equipment failures
- Human error
- External factors
- Any other sources of potential risk
They can do so through a variety of methods, including observation of plant layout and operations, observing work processes and procedures, interviews with employees and management, and so on.
4. Assess the Risks
After identifying the various hazards, the team should assess the risks associated with each hazard. This would mean determining the chances of each hazard occurring, as well as the extent and depth of the consequences resulting from them.
In addition to this, they also evaluate how effective the existing controls and mitigation measures are. In short, they look at what measures you have in place to prevent process-based hazards, as well as the contingency plans you have in place in case of a hazardous event.
5. Develop and Implement Controls
The risk assessment will serve as the basis for corrective action after the review. Based on its results, the team will develop and implement new or repaired controls to reduce the associated risks of each hazard. These controls may include engineering controls or administrative controls.
In engineering controls, measures to mitigate risk focus on modifying the workplace, and they include:
- Using protective barriers
- Ventilation
- Modifying equipment to make them safer
- Installing guardrails
The list is much longer than that. However, the aim of engineering controls is to reduce exposure by shielding workers from contact with hazards. Administrative controls, on the other hand, focus on changes to work practices or behaviors designed to reduce hazard impact.
6. Review and Update the PHA
Finally, the team reviews and updates the PHA regularly. This ensures the PHA remains up-to-date. Between the last PHA and the review, maybe too much time has elapsed. Maybe there has been a change in the laws of the state regarding HSE requirements.
Whatever it is, regularly reviewing and updating the PHA means that you stay on top of things.
The Importance of Process Hazard Analysis
Process hazard analysis is important for the obvious reason that it promotes the safety of your workers and the environment. However, it also plays a major role in protecting valuable assets and enhancing your business reputation and consequently your bottomline.
Let’s take a look at the advantages of PHAs.
1. Risk Management
A PHA improves risk management by identifying potential hazards and risks, determining the chances of and severity of accidents, and developing appropriate controls and measures of mitigation. In addition to that, it ensures regulatory compliance.
2. Promoting a culture of safety
PHAs can help promote a culture of safety in the workplace. They do so by improving process reliability and safety. Also, PHAs create a work environment that is safe for workers. Implementing the controls advised by a PHA will create a culture that puts safety first or that doesn’t separate safety from smooth operations and profit.
3. Improve your company’s bottomline
PHAs have the potential to attract potential clients or business partners by enhancing your organization’s reputation. This reputation is gained from keeping a clean HSE record. This will eventually send the signal that yours would be an ideal organization to do business with.
Conclusion
A process hazard analysis (PHA) is a systematic and step-by-step review of the operating procedures in a business. It aims to prevent and mitigate the risks and consequences associated with the release of hazardous materials.
A PHA should be carried out by those with the proper expertise. It also has the major advantage of promoting a culture of safety in your workplace, which protects company assets, your employees, your reputation, and eventually your bottomline.
Considering the importance of a PHA, we recommend that you rely on the appropriate expertise. This is where we come in at CDMS. We offer the expertise and experience required to ensure that your company carries out PHA of the highest standard considering the unique factors of your establishment.
Get in touch with us today to see how we can help.
