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.

An accident occurred during setup for a popular hydrogen-oxygen balloon science demonstration at a local public school. The demonstrator suffered painful second-degree burns to his right forearm and was taken to the hospital. The paramedics feared that grave respiratory damage (due to flame inhalation) might have occurred.

The demonstrator had transported 15 helium-quality balloons, pre-filled with a hydrogen-oxygen mixture, in a large, black, polyethylene garbage bag. During the setup, he opened the bag to remove a single balloon for stringing and floating. Without warning, the entire bag of balloons detonated violently. Fortunately, the incident occurred an hour prior to the program and no one else was near. It was also fortunate that only a small box caught fire and none of view more

During the early morning hours on a Tuesday, a university support staff member was preparing for an off-campus community outreach program for high-school-age students in the community. One of the program demonstrations was to show students the reaction energy and properties of the hydrogen + oxygen = water chemical reaction. It was a demonstration that the professor and the staff member overseeing the program had done for over 15 years with no incidents ever occurring.

To prepare for the demonstration, eight balloons were filled, four with pure hydrogen and four with the proper combination of hydrogen and oxygen. The balloons were placed into a larger plastic garbage bag and carried outside to a university-owned SUV located next to the building's loading dock. The bag of view more

In the fall of 2007, the operations team began a procedure (a written procedure was being followed) to sample the liquid hydrogen (LH2) storage vessels ("tanks"), and associated transfer system. This procedure was being performed to determine the conditions within the system, and if necessary, to purge the system of any excess gaseous hydrogen (GH2) in preparation for reactivation of the system. The system had not been used since 2003.

The LH2 storage system contains two (2) spherical pressure vessels of 225,000 gallons in volume, with a maximum working pressure (MAWP) of 50 psig. Eight-inch transfer piping connects them to the usage point. Operations began with activation of the burnstack for the LH2 storage area. Pneumatic gaseous nitrogen (GN2) systems in the view more

A hydrogen explosion occurred in a university biochemistry laboratory. Four persons were taken to the hospital for injuries. Three of these were treated and released shortly thereafter; the fourth was kept overnight and released the following evening. All of the exterior windows in the laboratory were blown out and there was significant damage within the laboratory. One sprinkler was activated that controlled a fire associated with a compressed hydrogen gas cylinder.

First responders from the local community and the university campus were quickly on the scene. Once the injured were attended to and the site secured, response efforts focused first on assessing potential hazards (electrical, fire, hazardous materials, etc). Campus personnel worked into the night to board up windows view more

Severe vibrations caused by broken low-pressure turbine blades damaged the main turbine generator at a nuclear power plant. These vibrations also caused multiple hydrogen leaks at equipment connections to the generator, resulting in hydrogen flames outside of the generator casing that caused minimal damage to the facility. Hydrogen is used to internally cool the plant's electric generators. Water from the fire suppression system and oil released from the turbine lube oil system during the event were contained within the plant, resulting in no impact to the environment. The plant's nuclear systems were unaffected by the event.

A laboratory had an incident with an ammonia tank. When the valve was opened, the packing in the valve apparently "moved," and a faint ammonia smell was noticed. The tank was returned to the supplier.

An employee of an incubator company that was working in a university-owned laboratory facility was checking the hydrogen pressure through the main valve on a hydrogen cylinder. The regulator on this cylinder had not been properly closed. Hydrogen escaped through the regulator and was ignited. The fire was contained in the laboratory and extinguished by the building's fire sprinkler system before fire crews arrived. There were no injuries, and damage estimates were not available.

A facility uses small crucibles to heat precious metals within a fume hood, with natural gas as the fuel source for the Bunsen burner. Hydrogen is fed into the crucible at low pressure (<20 psi) to control the atmosphere within the vessel in order to prevent oxidation. The hydrogen is routed through a manifold with flexible tubing, which is connected to a ceramic tip and fitted into the crucible through a small opening in the crucible's lid. The hydrogen is consumed in the process. The facility believes that the hydrogen tubing developed a leak which eventually ignited. The plastic interior of the fume hood ignited and started to spread. The person working in the area shut off the natural gas and hydrogen (they had valves at the hood) and used a halon extinguisher in the view more

A liquid hydrogen tank’s rupture disc failed prematurely, which caused the tank to vent its entire gas contents through the tank’s vent stack. Venting was very loud and formed a condensed moisture cloud visible from the top of the stack. Liquid air was also visible coming off the stack. Venting ceased after approximately 5 minutes. On-site staff called the fire department, which arrived promptly and evacuated the area. Normal operations resumed after the Fire Department was able to determine there were no unsafe conditions.

A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.