Hydrogen

In the early hours of January 2, 2025, a fire broke out at the Optymo bus depot in Danjoutin, Territoire de Belfort, France. The blaze destroyed seven hydrogen-powered buses, resulting in significant property damage. Fortunately, no injuries or fatalities were reported.

Date
02/01/2025
Location
France
Industry
Public Transportation
Substance
Hydrogen
Cause

Initial investigations suggest that the fire originated from an electrical malfunction in one of the buses, which had been out of service since December 31, 2024. Importantly, the incident was not related to hydrogen leakage or its usage.

Consequence
  • Destruction of seven hydrogen-powered buses, each valued at approximately €700,000, totaling over €4 million in damages.
  • Temporary confinement of nearby residents due to air pollution concerns; however, subsequent air quality tests indicated no immediate danger.
  • No injuries or fatalities reported.
Injuries

None reported.

Fatalities

None reported.

Lessons Learned

Although these lessons haven’t been raised from an official investigation report, the following lessons can be taken on-board from the incident:

  • Electrical System Maintenance: Regular and thorough inspections of electrical systems in vehicles are crucial to prevent potential malfunctions that could lead to fires.
  • Emergency Response Preparedness: Having well-trained emergency response teams and clear protocols can effectively manage incidents, minimizing harm to personnel and property.
  • Public Communication: Timely and transparent communication with the public during incidents helps in managing safety measures and alleviating concerns.
Sources / References
  1. https://www.sustainable-bus.com/news/danjoutin-hydrogen-buses-fire-optymo
  2. https://www.sustainable-bus.com/news/fire-fuel-cell-buses-belfort-yannick-monnier
  3. https://hydrogen-central.com/more-than-4-million-euros-of-damage-a-fleet-of-hydrogen-buses-catches-fire-an-impressive-plume-of-smoke-in-the-middle-of-the-night-france
Fire Destroys Hydrogen Buses at Optymo Depot in Danjoutin – January 2, 2025

The Optymo bus depot in Danjoutin, France, experienced a fire that destroyed seven hydrogen-powered buses on January 2, 2025.

Source: https://www.sustainable-bus.com/news/danjoutin-hydrogen-buses-fire-optymo

Analysis

The fire commenced around 2:20 a.m. on January 2, 2025, at the Optymo bus depot in Danjoutin. The blaze was substantial, with smoke visible from several kilometers away. Firefighters responded promptly, deploying 52 personnel and 21 vehicles to control and extinguish the fire. The hydrogen refueling station adjacent to the depot was not affected. Environmental assessments confirmed no significant impact on air or water quality.

On December 27, 2024, a hydrogen leak occurred at a refueling station in Hoedong-dong, Busan, South Korea. The leak led to a fire, which was extinguished within approximately 50 minutes. Initial reports described the incident as an explosion due to a loud noise and vibrations felt in nearby buildings; however, subsequent investigations clarified that it was a fire that resulted from a hydrogen leak caused by the activation of a safety valve, not an explosion. No casualties were reported.

Date
27/12/2024
Location
South Korea
Industry
Public Transportation
Substance
Hydrogen
Cause

The incident was caused by a hydrogen leak resulting from the activation of a safety valve. The exact cause of ignition remains unknown.

Consequence
  • Fire at the hydrogen refueling station, leading to temporary closure and inspection of the facility.
  • No injuries or fatalities reported.
Injuries

None reported.

Fatalities

None reported.

Lessons Learned

Although these lessons haven’t been raised from an official investigation report, the following lessons can be taken on-board from the incident:

  • Equipment Maintenance: Regular inspection and maintenance of safety valves and other critical components are essential to prevent unintended activations and leaks.
  • Emergency Response Preparedness: Establishing and practicing comprehensive emergency response plans can ensure swift action to mitigate incidents and protect personnel and property.
Sources / References
  1. https://www.hydrogeninsight.com/transport/safety-concerns-grow-after-two-explosions-at-south-korean-hydrogen-filling-stations-in-same-week/2-1-1759496
Busan Hydrogen

Firefighters outside the machine room at the Busan hydrogen refuelling station following the fire on 27 December.Â

Image Source: Busan fire department via Hydrogen Insights.

Analysis

At approximately 11:10 AM on December 27, 2024, a hydrogen leak occurred at a refueling station in Hoedong-dong, Busan. The leak led to a fire, which was extinguished within about 50 minutes. Initial reports described the incident as an explosion due to a loud noise and vibrations felt in nearby buildings; however, subsequent investigations clarified that it was a fire that resulted from a hydrogen leak caused by the activation of a safety valve, not an explosion. No casualties were reported.

On December 23, 2024, at approximately 11:10 AM, a hydrogen-powered city bus exploded at a refueling station in Mokhaeng-dong, Chungju-si, Chungcheongbuk-do, South Korea. The explosion occurred shortly after the bus had completed refueling and the driver attempted to start the engine. The blast resulted in significant damage to the rear of the bus and caused injuries to three individuals present at the scene.

Date
23/12/2024
Location
South Korea
Industry
Public Transportation
Substance
Hydrogen
Cause

The exact cause of the explosion remains under investigation. Initial reports suggest that the hydrogen fuel cell “stack,” located at the lower rear of the bus and responsible for converting hydrogen into electric energy, may have malfunctioned, leading to the incident.

Consequence
  • Severe damage to the hydrogen-powered bus, particularly the rear section.
  • Injuries to three individuals: a charging station employee, the bus driver, and another person present at the scene. All three were hospitalized with non-life-threatening injuries.
  • Temporary suspension of all 18 hydrogen-powered buses operating in Chungju for safety inspections.
Injuries

3

Fatalities

None reported.

Lessons Learned

Although these lessons haven’t been raised from an official investigation report, the following lessons can be taken on-board from the incident:

  • Comprehensive Vehicle Maintenance: Regular and thorough inspections of hydrogen fuel cell components are essential to identify and address potential malfunctions before they lead to hazardous situations.
  • Enhanced Safety Protocols at Refueling Stations: Implement stringent safety measures and emergency response plans at hydrogen refueling stations to mitigate risks associated with hydrogen fueling operations.
Sources / References

1. https://www.hydrogeninsight.com/transport/man-seriously-injured-after-faulty-hyundai-hydrogen-bus-explodes-at-refuelling-station-in-south-korea/2-1-1757947

2. https://www.mobilityplaza.org/news/39892

3. https://www.koreatimes.co.kr/www/nation/2025/02/113_389147.html

Hydrogen-Powered Bus Explosion at Chungju Refueling Station – December 23, 2024

Picture showing the aftermath of a hydrogen-powered bus explosion at a refueling station in Chungju, South Korea, highlighting the importance of stringent safety measures in hydrogen fuel applications.

Image source: Korea Times

Analysis

The incident occurred at approximately 11:10 AM on December 23, 2024, when a hydrogen-powered city bus, having just completed refueling at a station in Mokhaeng-dong, Chungju-si, exploded as the driver attempted to start the engine. The explosion originated from the rear section of the bus, causing substantial damage to the vehicle and injuring three individuals: a charging station employee, the bus driver, and another person nearby. All three were transported to a local hospital with injuries deemed non-life-threatening. In response to the incident, Chungju city authorities suspended the operation of all 18 hydrogen-powered buses in the region to conduct comprehensive safety inspections. Investigations by relevant authorities, including the Korea Gas Safety Corporation, are ongoing to determine the precise cause of the explosion.

On the morning of August 26, 2024, a hydrogen tanker truck exploded at the Linde facility within the Leuna Chemical Park in Saxony-Anhalt, Germany. The explosion resulted in a significant fire, producing dark smoke visible from a distance. The facility’s fire brigade responded promptly, extinguishing the fire by midday. Fortunately, no injuries or fatalities were reported.

Date
26/08/2024
Location
Germany
Industry
Hydrogen Transportation
Substance
Hydrogen
Cause

The exact cause of the explosion remains under investigation. Initial reports indicate a deflagration reaction involving a hydrogen leak from a truck trailer. The precise ignition source has not been identified.

Consequence
  • Explosion and subsequent fire at the Linde facility.
  • Temporary suspension of operations at the affected site.
  • No reported injuries or fatalities.
  • Significant impact on Germany’s hydrogen supply chain, leading to shortages at hydrogen filling stations nationwide. It is reported that 23 of the country’s 83 H2 fuelling stops were significantly affected for several weeks after the incident.
Injuries

None reported.

Fatalities

None reported.

Lessons Learned

Although these lessons haven’t been raised from an official investigation report, the following lessons can be taken on-board from the incident:

  • Enhanced Safety Protocols: Implement rigorous safety checks for hydrogen transportation vehicles to detect and address potential leaks before they lead to hazardous situations.
  • Emergency Response Preparedness: Ensure that on-site emergency response teams are adequately trained and equipped to handle hydrogen-related incidents promptly.
  • Supply Chain Resilience: Develop contingency plans to mitigate the impact of supply disruptions resulting from unforeseen incidents, ensuring the stability of hydrogen distribution networks.
Sources / References
  1. https://www.hydrogeninsight.com/transport/linde-explosion-a-quarter-of-germanys-hydrogen-filling-stations-out-of-action-as-supply-problem-enters-eighth-week/2-1-1731102
  2. https://www.h2-view.com/feature/how-a-tube-trailer-fire-exposed-germanys-fragile-hydrogen-refuelling-supply-chain/2117721.article
  3. https://h2-international.com/2024/10/06/h2-deflagration-in-leuna
No featured image found

Analysis

On August 26, 2024, at approximately 8:00 AM, an explosion occurred involving a hydrogen tanker truck at Linde’s facility within the Leuna Chemical Park. The blast resulted in a fire that produced substantial black smoke, visible over a wide area. The facility’s internal fire brigade responded swiftly, containing and extinguishing the fire by midday. No injuries were reported, and the immediate area was secured to prevent further hazards. The incident prompted a nationwide hydrogen supply shortage, affecting numerous hydrogen filling stations across Germany.

An experimental facility to generate green hydrogen through the use of an electrolyser from solar energy was setup in Gangneung, South Korea. On 23rd May 2019 the Hydrogen Storage tank exploded resulting in multiple fatalities and injuries.

Date
23/05/2019
Location
South Korea
Industry
Hydrogen
Substance
Hydrogen
Cause

Multiple causes were identified:
– A malfunctioning separation membrane in the electrolyser allowed oxygen to diffuse into the Hydrogen stream contaminating it with upto 6% Oxygen.
– Membrane malfunction was exacerbated by the Electrolyser operating below its minimum power levels due to variable output of the solar panels.
– A static spark combined with the presence of oxygen in the Hydrogen stream resulted in the explosion.

Additional factors that also played a part included:
– Design Deficiencies: System lacked oxygen removal and static spark prevention mechanism in the storage tank. Potentially due to cost.
– Operator Error: Operators ignored the oxygen detectors indicating Oxygen levels had risen above 3%.
– Management Failures: Failure to adhere to the requirement of daily testing of the hydrogen stream quality.

Consequence

– Destroyed the centre’s 5,100m2 building.
– Damaged the windows and structures of neighbouring buildings within 100m.
– Two people died.
– Six others were injured.
– Explosion was heard in the city 7km away from the site.

Injuries

6

Fatalities

2

Lessons Learned

The following lessons were learnt on the aftermath of the incident:
– Important to ensure design is properly reviewed and scrutinised for safety and cost cutting measures not implemented in lieu of safety.
– Operator training on alarm response is critical.
– Ensuring that operational requirements for testing is regularly monitored and audited to ensure adherence to procedures.

Sources / References
  1. European Hydrogen Incidents and Accidents database HIAD 2.1, European Commission, Joint Research Centre, Petten, the Netherlands
No featured image found

Analysis

The experimental facility consisted of:
– Three buffer tanks, each with a capacity of 40 m3.
– One Tank Pressurised at 12bar, other two at 7 bar.
– 200kW alkaline electrolyser with a production capacity of 40 m3/hr of Hydrogen at 12bar.

On February 11, 2018, at approximately 1:15 p.m. PST, a release of compressed hydrogen occurred from a tube trailer module operated by Air Products and Chemicals, Inc. The incident took place on Golden Springs Drive in Diamond Bar, California. The tube trailer module, mounted on a 2015 Cheetah Chassis Corporation chassis and towed by a 2014 Mack CXU613 truck tractor, contained 25 fully wrapped carbon fiber-reinforced aluminum-lined cylinders, with 24 of them fully loaded with approximately 240 kilograms of compressed hydrogen. The release led to a subsequent fire, activating pressure relief devices on 12 cylinders, releasing about 120 kilograms of hydrogen, which was likely consumed in the fire. The Los Angeles County Fire Department evacuated an estimated 1,400 to 2,000 people from the adjacent business district and nearby residential area. Equipment damages were estimated at $175,000.

Date
11/02/2018
Location
United States of America
Industry
Hydrogen Transportation
Substance
Hydrogen
Cause

The probable cause was the installation of an incorrectly rated pressure relief device in cylinder No. 14 by a requalification technician, which actuated during normal transportation and released high-pressure hydrogen.


Contributing factors included:


• The tube trailer module assembly contractor’s failure to sufficiently tighten compression fittings on the pressure relief device vent lines. These disassembled under the pressure of escaping gas, allowing a fire to develop inside the module and impinge on adjacent cylinders.


• Lack of a requirement for requalification inspectors to verify the pressure relief device pressure rating and to inspect for vent line assembly securement.

Consequence
  • Activation of PRDs on 12 cylinders, releasing approximately 120 kilograms of hydrogen.
  • Subsequent fire consuming the released hydrogen.
  • Evacuation of approximately 1,400 to 2,000 individuals from nearby areas.
  • Equipment damages estimated at $175,000.
  • No reported injuries or fatalities.
Injuries

None reported.

Fatalities

None reported.

Lessons Learned
  1. Emergency responder awareness is critical; training is needed for incidents involving hydrogen tube trailer modules.
  2. Requalification and inspection requirements must be improved to prevent similar incidents. This includes verifying PRD compatibility and vent line securement.
  3. Hydrogen tube trailer component design criteria need to be enhanced, particularly for PRD vent systems.
  4. The importance of verifying that PRDs of the correct pressure rating are used.
  5. The importance of ensuring that PRD venting equipment is inspected and tested.
Sources / References
  1. National Transportation Safety Board. 2019. Air Products and Chemicals, Inc. Tube Trailer Module Hydrogen Release and Subsequent Fire, Diamond Bar, California, February 11, 2018. Hazardous Materials Incident Report NTSB/HZM-19/02.
No featured image found

Analysis

The incident in Diamond Bar, California, on February 11, 2018, was initiated by the installation of an incorrectly rated pressure relief device (PRD) in cylinder No. 14. This PRD, designed to activate at 5,833 psi, was mistakenly installed instead of the required 10,000 psi PRD during a requalification inspection. During normal transportation, the incorrect PRD actuated, releasing high-pressure hydrogen. The force of the escaping gas caused the pressure relief device vent tubing to eject from its fitting because the compression fittings were not sufficiently tightened. This directed the hydrogen into the interior of the module, leading to a fire that damaged 21 of the cylinders.

The fire’s intensity caused six additional pressure relief device vent tubes to eject from improperly secured compression fittings, further escalating the situation

The Los Angeles County Fire Department (LACoFD) responders lacked familiarity with hydrogen tube trailer modules, which added to the initial confusion and challenges in managing the incident. The generic guidance in the Emergency Response Guidebook (ERG) Guide 115 did not adequately address the unique hazards associated with compressed hydrogen, further complicating the emergency response.

As a result of the incident, several safety recommendations were made to prevent similar occurrences in the future:
• The Pipeline and Hazardous Materials Safety Administration (PHMSA) was urged to revise the Emergency Response Guidebook (ERG) to include specific information about hazards and protective actions for hydrogen, as well as guidance for managing incidents involving fuel cell electric vehicles (FCEVs) and hydrogen fuelling infrastructure. 


• PHMSA was also recommended to revise hazardous materials special permits for transporting gases in manifolded horizontal cylinders. The revision would require that requalification inspections include verifying that PRDs of the correct pressure rating are used and that PRD venting equipment is inspected to ensure it can withstand forces generated by PRD actuation. 


• Additionally, PHMSA was advised to revise Title 49 Code of Federal Regulations Part 180, subpart C, “Requirements for Requalification of Specification Cylinders,” to ensure that inspectors verify PRD pressure ratings and inspect venting equipment. 


• PHMSA was encouraged to collaborate with the Compressed Gas Association (CGA) to develop design guidelines for tube trailer PRD vent systems. 


• The US Department of Energy, Pacific Northwest National Laboratory, was recommended to revise its hydrogen emergency responder training programs to include specific information and guidance on hazard recognition and firefighting related to tube trailers and FCEV fuelling infrastructure. 


• The Compressed Gas Association (CGA) was also advised to work with PHMSA to develop design guidelines for tube trailer PRD vent systems. 


These recommendations emphasise the need for improved training, stricter inspection protocols, and better design standards to enhance the safety of hydrogen transportation.

On November 29, 1981, an explosion occurred at a refinery hydrotreater plant in Jordan. The incident involved a furnace and hydrogen, with the source of ignition identified as the furnace. The explosion was attributed to faulty operation.

Date
29/11/1981
Location
Jordan
Industry
Energy (Oil Refining)
Substance
Hydrogen
Cause

The exact cause is unknown, however it was an operator error that led to hydrogen being released which was ignited by the furnace leading to the explosion.

Consequence

The explosion resulted in damage to the hydrotreater plant. Specific details regarding the extent of the damage were not provided.

Injuries

None reported.

Fatalities

None reported.

Lessons Learned

While specific lessons were not detailed in the available information, such incidents typically underscore the importance of adhering to operational protocols, regular maintenance, and comprehensive training to prevent equipment failures and ensure safety.

Sources / References
  1. IChemE Accident Database
No featured image found

Analysis

The explosion at the Jordanian refinery’s hydrotreater plant on November 29, 1981, highlights the potential hazards associated with oil refining operations, particularly when handling flammable substances like hydrogen. Although specific details about the incident are limited, the involvement of a furnace suggests that high-temperature operations may have played a role. This incident emphasizes the need for strict adherence to safety protocols, regular equipment inspections, and thorough training programs to mitigate risks in refinery operations.