Fire of released coke gas

Event

Event ID: 226
Quality: 3
Description: Release of gas from a coking plant on a gas holder which ignited causing a fire. The accident took place during repair works. The gas was made of 65 % of hydrogen , 25 % of methane , 4.1 % of carbon monoxide and carbon dioxide . About 100 firemen fought the fire with water nozzles. Fire was extinguished within 45 min. A safety area was set up. Because of the toxicity of the gas, about 40 people were evacuated. No consequence to the environment nor people. However, loss of production was significant.
Event Initiating system: Hydrogen System Initiating Event
Classification of the physical effects: Hydrogen Release and Ignition
Nature of the consequences: Fire (No additional details provided)
Macro-region: Europe
Date: 02/07/1996
Main component involved?: Cgh2 Storage Vessel
How was it involved?: Leak & Formation Of A Flammable H2-Ch4-Mixture
Initiating cause: Unknown
Root causes: Unknown (No additional details provided)

Application: Steel And Metals Industry
Sub-application: Steel manufacturing
Hydrogen supply chain stage: Hydrogen As Process Gas
All components affected: gasholder
Location type: Open
Location description: Industrial Area
Operational condition: Repair
Pre-event occurrences: Accident occurred during repair works
Description of the facility/unit/process/substances: DESCRIPTION OF THE PROCESS
The gas holder had a volume of on 20000 m3
Gas composition:
65 % of hydrogen (C.A.S. No: 1333-74-0), 25 % of methane (C.A.S. No: 74-82-8), 4.1 % of carbon monoxide (C.A.S. No: 630-08-0) and carbon dioxide (C.A.S. No: 124-38-9).

Corrective Measures: The report mentions only that strengthened operations measures will be taken.