Event
- Event ID
- 291
- Quality
- Description
A trailer was transporting 35 tubes of compressed hydrogen (7 m3), when five of them fell, breaking the valves and releasing gas, which ignited on three of them.
The caps designed to prevent the tubes from falling had not been attached before starting the journey.- Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- fire
- Macro-region
- Asia
- Country
- Japan
- Date
- Component involved
- valve (shut-off)
- Failure mode
- rupture & ignition
- Initiating cause
- impact, rollover, crash
- Root CAUSE analysis
The INITIATING CAUSE was the falling of compressed hydrogen tubes from a trailer.
The KHK report attributed the ROOT CAUSE to “mishap”, without however clarifying further if this was a human error (failing to follow the procedures) or a lack of clarity of the procedures.- Root causes
- Date entry in HIAD
- 30/08/2025
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- CGH2 tube trailer
- Hydrogen supply chain stage
- All components affected
valves
- Process temperature range [C]
- ambient temperature (-50°C to +50°C)
- Process pressure range [MPa]
- medium to high pressure (10 to 50 MPa)
- Location type
- Open
- Location
- highway or similar
- Operational condition
- Pre-event occurrences
The trailer was transporting 35 tubes. Assuming that the 7 m3 value provided by the KHK report refers to the total water capacity, a total of 100 kg of transported hydrogen can be calculated, further assuming a pressure of 200 bar.
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Released amount (kg)
- 15
- Release temperature [°C]
- 25
- Probable IGNITION SOURCE
References
- Sources categories
- KHK
- Reference & weblink
High Pressure Gas Accident Cases Database of the KHK (High Pressure Gas Safety Association):
https://www.khk.or.jp/public_information/incident_investigation/hpg_inc…
(accessed May 2025)
