Process Hazard Analysis Emphasizing Ammonia Refrigeration Systems

Upcoming dates (3)

Sep. 25-27, 2024

Madison, WI

Course Overview

A PHA is required for facilities covered under OSHA’s Process Safety Management standard and EPA’s Risk Management Plan (RMP) rule. To be effective, the PHA team must be able to identify hazards, evaluate their significance, and develop recommendations to control or eliminate the hazards in and around ammonia refrigeration systems. In this course, you will have the opportunity to put the principles of PHA to work as you develop a mock PHA for a refrigerated facility.

Who Should Attend?

  • PSM coordinators
  • Refrigeration operators
  • Refrigeration design engineers
  • Safety and environmental professionals with PSM and/or RMP responsibilities
  • Others responsible for developing and implementing process safety management programs 

Additional Information

This course is part of the Process Safety Management Professional Certificate. Increase your knowledge and effectiveness at managing PSM/RMP programs for your ammonia refrigerated facility, while earning a recognized credential. Course can be taken individually as well.

Attendees participating in this course will be able to earn a digital badge as evidence of the knowledge they obtained during the course. Digital badges are micro-credentials that can be earned by successfully passing a final quiz administered online after completing the course. Click here for information on digital badges.

Course Outline

Day 1


Introduction to Process Hazard Analysis

  • Hazards – what they are and how to identify them
  • PHA regulatory requirements
  • When and why should you conduct hazard evaluations or analyses?
  • OSHA interpretations on PHAs

Preparing for a PHA

  • How to define PHA objectives and scope
  • Staffing
  • Information requirements
  • Strategies to effectively engage all PHA participants

Critical Factors to Include in PHAs

  • Human factors
  • Facility siting
  • Failure of engineering and administrative controls (safeguards)
  • How to account for all operating scenarios

Workshop (Human Factors-Related)

P&IDs -Their Role in the PHA Process

  • Purpose of P&IDs
  • Characteristics of effective P&IDs
  • Role of P&IDs in the PHA process

Management of Change (MOC)

  • How changes impact the process hazard analysis
  • “Change” vs. “replacement in-kind”
  • Types of changes that should trigger a PHA
  • OSHA interpretations on MOCs that lead to PHAs

Day 2

Overview of PHA Methodologies

  • What-if/Checklist
  • Hazard and Operability Study/Analysis (HAZOP)
  • Failure Mode and Effects Analysis (FMEA)
  • Fault tree analysis
  • Advantages, disadvantages, and limitations of each methodology
  • Importance of matching the PHA methodology to the complexity of the process

How to Conduct a PHA Using the What-if/Checklist Methodology

  • Identify PHA objectives, scope, and subsystems
  • Gather required information as input to the process
  • Develop and modify the What-if/Checklist
  • Rank risks and how risk impacts requirements for recommendations
  • Document the PHA process and findings
  • Pitfalls
  • Preview of What-if/Checklist workshop

What-if/Checklist Workshop

Given appropriate preliminary documentation (P&IDs, photos, etc.), you will work in groups to define PHA objectives and subsystems for analysis, review given information, modify the What-if/Checklist, and complete a first-cut of a hazard evaluation list. Representatives from each group will present their PHA objective(s) and What-if/Checklist modifications.

Site Visit-Engine Room Walk-thru

Day 3

What-if/Checklist Workshop – (Continues)
Each group conducts a mock PHA using their What-if/Checklist.

What-if/Checklist Workshop Closeout

Roundtable discussion of site visit and PHA using the What-if/Checklist methodology

PHA Revalidation

  • Revalidation requirements
  • Planning for revalidation
  • Redo, update, revise and revalidate-what’s the difference?
  • How to conduct and document the PHA revalidation

Action Required Following a PHA

  • Determine actionable recommendations
  • Resolution of PHA action items
  • Prioritization
  • Management response
  • Communication of findings

PHA Process Quality Improvement

  • Post-mortem evaluation of a PHA session
  • Strategies to achieve PHA process improvement


"Your courses are well thought out and planned to provide everything I expected. All speakers were very helpful and professional. Thank you."

"I came in clueless and I feel comfortable with the knowledge gained."

"Good class. I learned all I expected to."

"Great enlightening experience on PHAs, HAZOP, etc. Very informative material and an excellent, resourceful staff. Thanks."

"Excellent program!"


Douglas Reindl

Douglas Reindl, PhD, PE is a professor at the Department of Mechanical Engineering and a Program Director at the Office of Interdisciplinary Professional Programs at the University of Wisconsin-Madison. He has extensive experience in mechanical systems – including industrial ammonia refrigeration systems. As the founding director of the Industrial Refrigeration Consortium, he works extensively to improve the safety, efficiency, reliability, and productivity of ammonia refrigeration infrastructure. Dr. Reindl received his BS in mechanical engineering technology from the Milwaukee School of Engineering, MS in mechanical engineering from UW–Madison, and PhD in mechanical engineering from UW–Madison. He is a registered professional engineer in the State of Wisconsin.

Marc Claas

Marc Claas is an Associate Researcher with the Industrial Refrigeration Consortium and has been involved in industrial refrigeration since 2009. His interests include refrigeration system maintenance requirements, criteria for safe system operation, troubleshooting systems for safe and efficient operation, regulatory compliance in refrigeration systems, and emerging cooling technologies. His teaching experience includes online operator training programs, and his field experience includes PSM related activities such as PSM audits and PHAs. He also has experience investigating energy efficiency and other operational opportunities. Claas holds a Bachelor’s degree in Mechanical Engineering from UW-Platteville and Master’s of Mechanical Engineering in Thermal Science from UW-Madison. He is an active member of the International Institute of Ammonia Refrigeration.

Todd Jekel

Todd Jekel, PhD, PE is the assistant director of the Industrial Refrigeration Consortium at the University of Wisconsin–Madison. Jekel has been actively conducting research on refrigeration systems including vessel design practices, oil separators, and analysis of dehumidification alternatives for cold storage warehouses. He holds degrees from Calvin College and the University of Wisconsin–Madison.

Upcoming dates (3)

Program Director

Douglas Reindl

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