Event
- Event ID
- 433
- Quality
- Description
- After cooldown of a LH2 system, the operator noticed cold gas issuing from a small hole in a flexible section of the vent line. Subsequent examination revealed that a deflagration had taken place in the vent line and there was a small hole in the flexible section. The vent cap showed signs of fire and was stuck in the open position.
[Ordin, NASA (1974)] - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- -
- Main component involved?
- Venting System (Line)
- How was it involved?
- Internal Explosion (H2-Air Mixture)
- Initiating cause
- Inadequate Or No Purge
- Root causes
- Unknown (No additional details provided)
- Root CAUSE analysis
- The INITIATING CAUSE was the formation of hydrogen-air mixture in the vent.
The mixture may have formed when the line warmed and sucked air back into the line around the seal of the vent cap or the cap may have stuck open and air diffused into the line. No source of ignition was determined. The ROOT CAUSE is unknown.
Facility
- Application
- Non-Road Vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- Hydrogen Transfer (No additional details provided)
- All components affected
- vent
- Location type
- Unknown
- Location description
- Industrial Area
- Operational condition
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Environmental damage
- 0
- Property loss (onsite)
- 0
- Property loss (offsite)
- 0
Event Nature
- Release type
- liquid
- Involved substances (% vol)
- H2 100%
- Release duration
- unknown
- Presumed ignition source
- Not reported
- Ignition delay
- N
References
- Reference & weblink
Mishap no 74 in <br />
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565<br />
https://ntrs.nasa.gov/citations/19740020344Lowesmith 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
Hankinson and Lowesmith, Qualitative Risk Assessment of Hydrogen Liquefaction, Storage and Transportation, FCH JU project IDEALHY, Deliverable 3.10 (2013)<br />
confidential<br />
(accessed October 2025)
JRC assessment
- Sources categories
- ORDIN
