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Three Keys to Conducting a Quality Process Hazard Analysis


Hargrove Controls & Automation’s seasoned and highly-trained Process Safety Team helps clients operate safe facilities and comply with OSHA process safety regulations. Having completed dozens of process hazard analyses (PHAs), the Team has identified three keys vital to conducting a quality PHA. In this article, Hargrove Controls & Automation TUV Certified Functional Safety Engineer and expert PHA facilitator John Binion, PE, shares the Team’s insights gained from the company’s combined decades of experience conducting PHAs.

Overview of a Process Hazard Analysis (PHA)

A process hazard analysis, also called a risk analysis for hazardous processes, is a systematic examination of a chemical or manufacturing facility to document the hazards inherent in the specific processes used there.  “We systematically analyze the different ways a process can deviate from what it’s supposed to do,” said John Binion, PE, Safety Engineer at Hargrove Controls & Automation. “And because of that deviation, we examine what safety, environmental, or business risks can come as a result.”  A PHA can take from a few days up to several months depending on the complexity of the process being inspected.

PHAs are required by OSHA to protect workers and the environment for any industrial process that uses hazardous chemicals, such as those in the petrochemical, specialty chemical or refining process industries.  During the design of a new facility, multiple PHAs are required to ensure the process risks can be properly mitigated.  “When designing a facility, PHAs are completed during several of the design phases to make sure the design is safe,” said Binion. “It is much more costly to implement safeguards late in the design phase rather than earlier on in the conceptual, basic, and detailed engineering phases.”

Quality PHA Key #1: The Right Team

Putting the right team together is an essential element for a successful PHA.  The size of the team and key roles to be filled for a PHA will vary depending on the site and complexity of the process. “There has to be a facilitator, someone to steer the discussion.”  The facilitator’s role is to plan, facilitate and manage the PHA, and is often required to be from outside the plant’s organization.  “Some companies require an outside facilitator because it’s easy for an employee that’s embedded on-site within the company to either get complacent or have a stake in it,” said Binion. “An outside facilitator has less skin in the game, so they’re able to look at the process with fresh eyes and not have some of those biases that can crop up when you see the same thing all day every day.”

In addition to the facilitator, the scribe position is also required.  The scribe plays the vital role of accurately and completely recording the significant discussions and results of the PHA.  “There may or may not be a separate scribe on a PHA,” said Binion. “The facilitator can also act as scribe, which is what I often do.”

“I don’t think the size of the team is as important as the people on it,” said Binion. “I’ve had very good PHAs that only have the facilitator and two experts with other people available to comment as necessary. I’ve also had great PHAs with 10 or 15 people with varied experience, so it doesn’t necessarily matter how many people; you just have to have the right people. Many of these roles aren’t strictly exclusive – you don’t have to have a different person for each if someone has multiple applicable skillsets.”

The right team starts with a good knowledge base. “You need to involve someone familiar with operations and secure their buy-in. If it’s a running plant or a new design, you may bring in an operator from a similar facility that has this process running, but having an operations representative is key.”

Knowledge Base and Roles for the PHA Team

  • Facilitator
  • Scribe
  • Process
  • Operations
  • Controls
  • Relevant mechanical knowledge
  • Operator experience
  • Rules of the PHA

“Another important item to address, especially for facilities that have been running for several years (not in design-phase PHAs), is discrepancies between the facility’s design and how it operates in practice. We like to have operators in on the PHA to discuss the actuality of operations, which will likely help uncover process safety risks that weren’t considered in the design. Several times, I’ve been in a PHA talking about a certain process, and then the operator will chime in and say, ‘That’s not how we do this. We can’t do it this way because it will shut the plant down.’ Then we must go back and understand whether that presents a risk or if it mitigates another risk.”

A process lead is another critical PHA role – someone who’s very familiar with the chemistry of what’s happening.  “Additional roles needed are controls and mechanical specialists. We might need to know design parameters for certain equipment, pump information, or details about rotating machinery.”

Depending on the process, the PHA team could be two or three people, or more than a dozen. “We just need to make sure that the team is composed of the people that have applicable knowledge to the process and that can cover a lot of topics, such as the specific rules of the PHA.  Involving too many people can sometimes hinder the effectiveness of meetings.”

Quality PHA Key #2: A Clear and Consistent Set of Rules

“To maintain consistency throughout not only a single PHA, but across a facility, a clear and consistent rule set is required,” said Binion.  “Clear and consistent rules help you avoid problems such as applying rules unequally to different sections of a plant or applying the same rule in different ways to a certain unit.  Inconsistency can lead to gaps in the PHA which could be a safety risk.”

Typically, the PHA rules are given to the team at the start of the project and are based on international standards and recognized engineering practices.  “Although we can help steer the PHA rules discussion, at the end of the day, the company that’s running the process is the one that’s taking on the risk and has the final decision on what is included.”

“Everyone has a different level of acceptable risk, so you must adjust the facilitation according to that. Additionally, some facilities will take credit for certain types of installed safeguards – check valves, for example – and other places will not take credit for these devices.  A clear and consistent set of rules will create uniformity among the different locations.”

A clear set of rules is also helpful when the PHA team has members rotating in and out.  “In a lengthy PHA, not everyone may be able to stay on the team for an entire month at a time, making it necessary to swap out team members.  If we’re applying the rules the same way throughout, we’ll have a consistent product throughout the entire site.”

Quality PHA Key #3: Good Documentation

The final key to a successful PHA is creating good documentation, keeping in mind that the document must be robust enough to answer questions for future PHA teams as well as those implementing current recommendations. “Whoever is documenting the PHA must remember that the current PHA team is not the only group to ever read that PHA,” said Binion. “Other teams will also be using the PHA to design safeguards to mitigate the identified areas of concern throughout the facility and determine independent protection layers (IPLs).”

Binion continued, “Many people will use the outputs of this PHA for their work who may not be familiar with the context of the PHA, so it must be able to stand alone.  That means clearly documenting assumptions and ensuring that the consequence descriptions are correct.”

This is especially important because the document will be used five years later for revalidation. “The consequence needs to be fully described so you can adequately determine the safeguards and then everyone is aware of the risks.  Once the risks are determined, we can give a very clear and precise description of the recommendations,” Binion said.

“The goal is to be able to have someone look at the PHA documentation after the team has disbanded and understand exactly what was discussed.”


Hargrove has conducted dozens of PHAs and has an engineering staff with a deep bench.  When potential customers reach out to discuss a project, one of their most common questions is about Hargrove’s technical knowledge. Hargrove’s Team has a combined 85+ years of process safety experience.  John Binion has been with Hargrove since 2016 and is a credentialed functional safety engineer and professional engineer, also having completed the HazOp Studies and Other PHA Techniques for Process Safety and Risk Management and Advanced Concepts for Process Hazard Analysis courses from the American Institute of Chemical Engineers (AIChE).  Larry Drapela has worked in industrial safety for more than four decades and has been a process safety consultant for nearly ten years. Glenn Raney has worked in the petrochemical industry for more than 40 years and is a Certified Process Hazards Analysis Team Leader and TUV Certified Functional Safety Expert/Trainer.  He has facilitated hundreds of studies of continuous and batch operations in petrochemical, specialty chemical, refining, gas processing as well as offshore and pipeline facilities.

“Clients are looking for a deep level of experience in facilitating the PHA process,” said Chet Barton, PE, Process Safety Leader at Hargrove Controls & Automation. “They don’t want just anyone coming to facilitate the PHA because of its importance in the plant’s safety.  Our engineering staff has conducted PHAs and revalidations for a wide range of processes and knows how to efficiently and successfully facilitate these projects.”

For more information on Hargrove Controls & Automation’s process hazard analysis services, click here.
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