Event
- Event ID
- 427
- Quality
- Description
While welding cable suspended over stainless steel H2 instrument line, two holes were burned through tubing. A hissing sound was heard and operator closed a valve. In feeling for gas leak which had been ignited, the operator's hand was burned.
- Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- -
- Component involved
- pipe (generic)
- Failure mode
- leak & ignition
- Initiating cause
- wrong operation
- Root CAUSE analysis
The INITIATING CAUSE was a short circuit during welding caused the pinholes in the tubing containing the compressed hydrogen.
The ROOT CAUSE was probably a lack of effective operative instructions / procedures aiming at avoiding hazardous actions in the neighbourhood of a system containing flammable materials.
- Root causes
- Date entry in HIAD
- 01/11/2025
Facility
- Application
- Non-road vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- Unknown
- All components affected
instrumentation (hydrogen) line
- Location type
- Unknown
- Location
- countryside or desert
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 1
Lesson Learnt
- Lesson Learnt
H2TOOLS provided this general lesson:
“Because of the near invisibility of a hydrogen flame in daylight and hydrogen's extremely low ignition coefficient, if a known leak is present (e.g., an audible hissing), ignition should always be presumed.“
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
- Explosion type
References
- Sources categories
- ORDIN
- Reference & weblink
Mishap no 65 in
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565
https://ntrs.nasa.gov/citations/19740020344Hankinson and Lowesmith, Qualitative Risk Assessment of Hydrogen Liquefaction, Storage and Transportation, FCH JU project IDEALHY, Deliverable 3.10 (2013)
confidential
(accessed October 2025)Lowesmith et al., Safety issues of the liquefaction, storage and transportation of liquid hydrogen: An analysis of incidents and HAZIDS, Int. J. Hydrogen energy (2014) https://doi.org/10.1016/j.ijhydene.2014.08.002
Also uptaken in US database H2TOOLS
https://h2tools.org/lessons/invisible-hydrogen-fire-injures-technician
(accessed Decembr 2025)
