Process Safety Beacon: Hydrogen Leak
The CCPS Process Safety Elements
This post continues our series to do with formal incident reports from organizations, including 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.
The Process Safety Beacon Report dated September 2025 is entitled, Several errors lead to a hydrogen leak & fire at https://ccps.aiche.org/resources/process-safety-beacon/archives/2025/september/english. The incident is analyzed using the CCPS process safety elements as shown below. (Those that appear to be most relevant to this incident have been highlighted.) This report is particularly relevant today because hydrogen is seen as a possible source of ‘green energy’. Hence, we need to understand the pertinent safety concerns. While the use of hydrogen may reduce carbon emissions, its unique physical and chemical hazards — small molecule size, low ignition energy, and invisible flames — make it a challenging material to handle safely.
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
Evidently, there was pressure to ‘get the job done’ rather than pause operations to ensure safety. A strong culture empowers employees to stop work and call for assistance when unsure.
2. Compliance with Standards
Repairs to pressurized hydrogen systems must comply with recognized standards such as CGA G-5.5 and NFPA 2. The driver and trainee appeared unaware of these requirements, or did not follow them.
3. Competence
The trainee’s lack of understanding of the control system led to an inadvertent restart of hydrogen flow. Both workers demonstrated inadequate knowledge of the system’s operating logic. Competence includes not just training but demonstrated understanding of hazards and controls.
4. Workforce Involvement
If other workers had been involved, their input and knowledge may have helped prevent this incident.
5. Stakeholder Outreach
If the use of hydrogen does increase in response to the climate crisis, it will be important to provide emergency procedures and training to local responders.
6. Knowledge Management
Knowledge of valve positions and interlocks was evidently incomplete.
7. Hazard Identification and Risk Management
The risk of inadvertent hydrogen flow during maintenance was foreseeable. A job safety analysis or pre-task hazard review could have identified the risk of starting the filling system while piping was open. Hydrogen’s low ignition energy (0.02 mJ) and wide flammability range (4–75%) make these risks critical.
8. Operating Procedures
Written procedures for filling, isolating, and leak response were either unclear or not followed. Procedures should specify the sequence for valve closures, depressurization, and confirmation steps before disconnecting any line. Complex pneumatic systems require explicit steps to avoid human error.
9. Safe Work Practices
Removing piping from a hydrogen system without full isolation violated safe work fundamentals. A formal Lockout-Tagout (LOTO) process should have been applied.
10. Asset Integrity / Reliability
The initial hydrogen leak suggests underlying integrity issues; possibly worn fittings or improper assembly.
11. Contractor Management
Although the driver and trainee were company employees, similar work is often performed by contract operators or drivers. Contractor management programs must ensure that any personnel involved in filling, transfer, or maintenance are trained in hydrogen-specific hazards and approved procedures.
12. Training / Performance Assurance
The incident was directly caused by a training gap. The trainee lacked the necessary skills to distinguish between fill and stop controls.
Hydrogen flames are almost invisible in daylight, producing little radiant heat and no visible smoke. This can delay detection, confuse emergency responders, and lead to unrecognized exposure zones.
13. Management of Change (MOC)
The temporary disassembly of the fill line constituted a change to the process configuration. Even temporary modifications during maintenance require MOC evaluation to identify new hazards introduced by configuration changes.
14. Operational Readiness
Before resuming operations after the repair attempt, there was no readiness check to confirm the system’s configuration or valve lineup.
15. Conduct of Operations
Confusing control labels, inadequate supervision, and ad-hoc decision-making evidently contributed to the incident.
16. Emergency Management
When the hydrogen ignited, relief devices activated and added fuel to the fire. Emergency isolation procedures should account for rapid escalation in hydrogen fires, including invisible flames and rapid re-ignition risk.
Emergency drills and fire response training for hydrogen should describe the hazards to do with invisible flames and rapid re-ignition risk. Because hydrogen flames are nearly invisible, responders may unknowingly walk into active fire zones. Thermal imaging or flame detection systems tuned for hydrogen should be used during response and facility design.
17. Incident Investigation
The fact that the Beacon reported details of this event to a wide process safety community is encouraging.
18. Measurement and Metrics
Recording and analyzing small leaks, training errors, and near-miss events could have revealed the weaknesses that led to this larger release.
19. Auditing
20. Management Review
Senior management should review this event as a warning about the hidden risks of ‘green’ hydrogen operations. Leadership must ensure that as hydrogen adoption increases, process safety systems evolve accordingly.
