Process Safety Beacon: Cooling Tower Explosion
The CCPS Process Safety Elements
This post is part of our series to do with formal incident reports from organizations such as the BSEE (Bureau of Safety and Environmental Enforcement), the CCPS (Center for Chemical Process Safety), and the CSB (Chemical Safety Board). In each case, we attempt to identify the process safety elements that failed in this particular incident.
In this post, we examine a Process Safety Beacon Report dated, October 2025: Refinery Cooling Tower Explosion and Fire at https://www.aiche.org/resources/publications/cep/2025/october/process-safety-beacon-refinery-cooling-tower-explosion-and-fire using the following CCPS process safety elements. (This list covers all the elements of process safety management. Those that appear to be most relevant to this incident have been highlighted.)
Process Safety Culture
Compliance
Competence
Workforce Involvement
Stakeholder Outreach
Knowledge Management
Hazard Identification and Risk Management
Operating Procedures
Safe Work Practices
Asset Integrity / Reliability
Contractor Management
Training / Performance
Management of Change
Operational Readiness
Conduct of Operations
Emergency Management
Incident Investigation
Measurement and Metrics
Auditing
Management Review
1. Process Safety Culture
A strong safety culture emphasizes questioning assumptions, such as assuming cooling water systems contain only water. The incident suggests a weak culture of hazard awareness during commissioning, with inadequate challenge to the assumption that water systems are non-hazardous.
2. Compliance with Standards
The report does not suggest that regulations or standards were not followed. However, the fact that did not follow its own commissioning procedures was an important factor.
3. Competence
Personnel may not have fully understood the risk of trapped hydrocarbons in the cooling water system. Competence gaps could exist among operations, maintenance, and engineering staff who failed to identify or purge the line before opening it.
4. Workforce Involvement
The Beacon notes that many of the injured were contractors. Workforce involvement appears limited. Contractors may not have had the opportunity to share observations about unusual conditions or trapped hydrocarbons prior to startup.
5. Stakeholder Outreach
This was not a factor in the incident. However, the fact that the CCPS chose to share this story (and the fact that I am writing this post) shows that there has been outreach.
6. Knowledge Management
System knowledge, such as the potential for hydrocarbon leaks into cooling water lines, was either unavailable or not effectively communicated.
7. Hazard Identification and Risk Management
The possibility of hydrocarbons accumulating in high points of cooling water piping was not identified in a pre-startup hazard analysis.
8. Operating Procedures
Procedures for commissioning a new cooling tower should include:
Verification that all lines are clean, drained, and purged.
Specific steps for opening isolation valves.
Controls for ignition sources nearby.
The report does not provide information regarding operating procedures; however, experience suggests that the operating procedures were deficient.
9. Safe Work Practices
Startup is a non-routine activity requiring strict adherence to safe work practices such as lockout/tagout, line breaking permits, and gas testing. These appear to have been insufficient or bypassed.
10. Asset Integrity / Reliability
The fact that the heat exchanger had internal leaks reflects inadequate mechanical integrity, and inspection procedures. This highlights the need for rigorous exchanger inspection programs, including tube-side leak detection, corrosion monitoring, and verification of barrier integrity between process and utility systems.
11. Contractor Management
Many injured workers were contractors unfamiliar with the plant’s systems and hazards. Contractor orientation and supervision should ensure understanding of startup risks, communication protocols, and stop-work authority.
12. Training / Performance Assurance
This does not seem to be a factor in this incident, except as training and operating procedures are two sides of the same coin.
13. Management of Change (MOC)
Commissioning a new cooling cell represents a system modification. The MOC process should have triggered hazard reviews, drawing updates, and communication to all affected personnel. It appears as if there was an absence of such a process. We are not told if the MOC process was followed.
14. Operational Readiness
This element is directly implicated. Before startup, verification steps (equipment readiness, purging, hazard checks, personnel clearance) were not properly executed. The release occurred as soon as the valve was opened — clear evidence of inadequate pre-startup safety review (PSSR).
15. Conduct of Operations
Good operational discipline requires controlled, step-by-step valve opening and continuous communication among teams. Deviations from procedure and informal practices (e.g., opening valves without full clearance) point to lapses in conduct of operations.
16. Emergency Management
If a man’s not there, he can’t be killed.
Many incidents are made worse because people who did not need to be present, were present.
The large fire and fatalities suggest deficiencies in emergency response. Workers may not have known safe escape routes or fire suppression systems may have been ineffective. Regular drills and pre-startup contingency planning are essential.
17. Incident Investigation
The Beacon report summarizes that investigators traced the source to a leaking exchanger and trapped hydrocarbons.
18. Measurement and Metrics
Leading indicators such as completion of reviews, and corrosion monitoring should be tracked. Their absence (or unchecked delays) could have warned management of latent weaknesses before the accident. Leading indicators such as overdue exchanger inspections, incomplete prestartup reviews, or open MOC items could have signaled readiness problems before startup.
19. Auditing
Audits should include field verification—not just documentation review.
20. Management Review
Following the incident, leadership must assess the adequacy of process safety management systems, resource allocation, and culture. Management review should ensure that lessons learned are institutionalized and that similar risks are addressed company-wide.
