What is Lessons Learned?

What is H2LL?

This database is supported by the U.S. Department of Energy. The safety event records have been contributed by a variety of global sources, including industrial, government and academic facilities.

H2LL is a database-driven website intended to facilitate the sharing of lessons learned and other relevant information gained from actual experiences using and working with hydrogen. The database also serves as a voluntary reporting tool for capturing records of events involving either hydrogen or hydrogen-related technologies.

The focus of the database is on characterization of hydrogen-related incidents and near-misses, and ensuing lessons learned from those events. All identifying information, including names of companies or organizations, locations, and the like, is removed to ensure confidentiality and to encourage the unconstrained future reporting of events as they occur.

The intended audience for this website is anyone who is involved in any aspect of hydrogen use. The existing safety event records are mainly focused on laboratory settings that offer valuable insights into the safe use of hydrogen in energy applications and R&D. It is hoped that users will come to this website both to learn valuable lessons from the experiences of others as well as to share information from their own experiences. Improved safety awareness benefits all.

Development of the database has been primarily supported by the U.S. Department of Energy. While every effort is made to verify the accuracy of information contained herein, no guarantee is expressed or implied with respect to the completeness, causal attribution, or suggested remedial measures for avoiding future events of a similar nature. The contents of this database are presented for informational purposes only. Design of any energy system should always be developed in close consultation with safety experts familiar with the particulars of the specific application.

We encourage you to browse through the safety event records on the website and send us your comments and suggestions. We will continue to add new records as they become available.

How does H2LL work?

If you have an incident you would like to include in the H2LL database, please click the "Submit an Incident" button at the top of the page. You will be asked for a wide range of information on your incident. Please enter as much of the information as possible. In order to protect your and your employer's identities, information that may distinguish an incident (your contact information, your company's name, the location of the incident, etc.) will not be displayed in the incident reports on H2LL.

Lessons Learned Corner

Visit the Lessons Learned Corner Archives.

Key themes from the H2Incidents database will be presented in the Lessons Learned Corner. Safety event records will be highlighted to illustrate the relevant lessons learned. Please let us know what you think and what themes you would like to see highlighted in this safety knowledge corner. You can find all the previous topics in the archives.

The sensing diaphragm of a pressure transducer (PT), as supplied on an outdoor hydrogen compressor, unexpectedly ruptured and released approximately 0.1 kilograms hydrogen to atmosphere from the compressor discharge line. At time of incident, personnel nearby were alerted by a loud 'pop' and dust disturbance. Simultaneously, the facility monitoring system detected loss of the PT signal and initiated equipment shutdown. Facility personnel then closed isolation hand valves to stop the leak, locked and tagged out the equipment, and restricted the area. The failed component, a cigar type PT rated to 20,000 psi, originally supplied and installed by the manufacturer as part of the compressor package, was removed and inspected. Inspection revealed severed wires, a separated wire housing, view more

A hydrogen leak originating from a tank within a high-pressure storage unit serving a hydrogen vehicle fueling station resulted in fire and explosion. Emergency responders were on scene within 7 minutes and contained the fire within 3 hours. No damage was reported to the separate forecourt H2 dispenser or to other major station components within the station backcourt compound. No personnel injuries resulted directly from the fire and explosion -a nearby vehicle airbag triggered due to the explosion pressure, with minor injuries to the vehicle occupants. Immediately, until root cause was determined, all potentially affected H2 stations were idled.

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A hydrogen leak originating from a tank within a high-pressure storage unit serving a hydrogen vehicle fueling station resulted in fire and explosion. Emergency responders were on scene within 7 minutes and contained the fire within 3 hours. No damage was reported to the separate forecourt H2 dispenser or to other major station components within the station backcourt compound. No personnel injuries resulted directly from the fire and explosion -a nearby vehicle airbag triggered due to the explosion pressure, with minor injuries to the vehicle occupants. Immediately, until root cause was determined, all potentially affected H2 stations were idled.

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A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured. Significant damage to the indoor facility also occurred.

An independent investigation found that drain view more

A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured. Significant damage to the indoor facility also occurred.

An independent investigation found that drain view more

The sensing diaphragm of a pressure transducer (PT), as supplied on an outdoor hydrogen compressor, unexpectedly ruptured and released approximately 0.1 kilograms hydrogen to atmosphere from the compressor discharge line. At time of incident, personnel nearby were alerted by a loud 'pop' and dust disturbance. Simultaneously, the facility monitoring system detected loss of the PT signal and initiated equipment shutdown. Facility personnel then closed isolation hand valves to stop the leak, locked and tagged out the equipment, and view more

As part of preparing for material disposal, a small fire occurred within a fume hood as a researcher was combining several spent ammonia borane (AB) samples that had previously been stored uncovered in the back of the hood for 6+ months. These AB samples consisted primarily of two 40-gram products of a 50wt% AB in silicone oil that had been thermally dehydrogenated. A small amount of unreacted AB slurry is believed to also have been present.

During project clean-up, partially spent (thermally reacted) ammonia borane (AB) residue from a previous experiment was mixed with a small amount of water to rinse the residue from its container. The water reacted with the spent AB resulting initially in a large heat release followed immediately by a fire. It appears that the water addition view more

While performing hydrogen gas release experimentation by thermally reacting a slurry of ammonia borane powder in silicone oil in a plug flow reactor, a discharge port on the test reactor became loose. A foaming white product was leaking from the fitting and discharging in the direction of the heat tape and insulation (back over the reactor). As a result, hot, reacting slurry flowed out of the port and was exposed to air. In the presence of oxygen, the slurry ignited, producing a green flame. A small green flame was noticed at the leak site and flaming product dripped onto the hood deck surface. The flame at the end of the reactor was ~10-12 inches tall at the highest point. The flame on the deck was ~4-6 inches in height.

The incident occurred behind the lowered sashes in the view more

A distillate dewaxing unit at an oil refinery was undergoing hot hydrogen regeneration of the catalyst when an explosion occurred. Catalyst regeneration is a periodically performed procedure, in which the normal liquid hydrocarbon feed is stopped and a hydrogen-rich gas mixture is fed through the catalyst bed for which the normal operating temperature is raised from 700F to 800F. During the catalyst regeneration process the reactor pressure is increased from normal operating levels just below 600 psig to about 640 psig. A pipe failure occurred as a sudden and complete rupture of the 10-inch diameter line at the exit of one of the two reactors. Security video revealed that the release rapidly exapnded and the hot gas mixture ignited shortly after rupture. A shock wave from the resulting view more

A petroleum refinery experienced a catastrophic rupture at one bank of three heat exchangers in a catalytic reformer/naphtha hydrotreater unit because of high temperature hydrogen attack (HTHA). Hydrogen and naphtha at more than 500F were released from the ruptured heat exchanger and ignited, causing an explosion and an intense fire burned for more than three hours.

The rupture fatally injured seven employees working in the immediate vicinity of heat exchanger at the time of the incident. The workers were in the final stages of a start-up activity to put a parallel bank of three heat exchangers back in service following cleaning. Such start-up activities had resulted in frequent leaks and occasional fires in the past and should have been considered as hazardous and nonroutine. view more