Explosion When Working on a Hydrogen Cylinder
A process operator was working in the collaring/ decollaring area of a mechanical workshop. An electric cross cut saw was used to make two diagonal cuts in the collar of a hydrogen cylinder before removal of the collar with a hammer and chisel. An angle grinder is also occasionally used where a collar is proving difficult to remove. Sparks from the cutting process caused ignition of hydrogen present in container.
Event Date
July 4, 2003
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Immediate cause: Rest hydrogen in cylinder ignited during mechanical workRoot case: lack of risk management throughout the process (gas emptying not controlled).
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Hydrogen cylinder, mechanical workshop
Storage/Process Medium
Location Type
Location description
Unknown
Operational Condition
Pre-event Summary
A process operator was working in the collaring/ decollaring area of a mechanical workshop
Consequences
Number of Injured Persons
1
Number of Fatalities
1
Currency
Lessons Learned
Lessons Learned
The investigation indicated that if the execution of part of the cylinder purging process had been missed, then high concentrations of hydrogen would still be present in the cylinder. In this case, purging is carried out at other locations of this company with subsequently possibilities for confusion on the status of the cylinders. The following measures were taken since the accident:1.All cylinders to be purged at this location and undergo batch control of purging, 2.A physical barrier erected to stop the operator standing in line with the cylinder outlet.
Event Nature
Emergency Action
Not stated
Emergency Evaluation
Purging of the container/cylinder was not performed, resulting in high concentrations of Hydrogen still being present. This would have been ignited by a spark from the cutter.
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event description provided by HSE, original source confidential