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.

A facility manager was notified that an authorization basis requirement, associated with roofing contractor work, had not been met. The requirement was that an unused hydrogen gas cylinder adjacent to the building and not connected to a manifold be removed prior to the use of propane tanks for the hot tar portion of the work.

The project manager failed to remove the extra gas bottle as required because he did not recognize from the bottle color and lack of stencil that the bottle contained hydrogen.

An explicit checklist containing all the administrative controls and requiring careful inspection was not available at the time of the inspection. The checklist preparation also would have made obvious the fact that administrative controls had been established. The project view more

A facility experienced a major fire in its Resid Hydrotreater Unit (RHU) that caused millions of dollars in property damage. One employee sustained a minor injury during the emergency unit shutdown and there were no fatalities.

The RHU incident investigation determined that an 8-inch diameter carbon steel elbow inadvertently installed in a high-pressure, high-temperature hydrogen line ruptured after operating for only 3 months. The escaping hydrogen gas from the ruptured elbow quickly ignited.

This incident occurred after a maintenance contractor accidentally replaced an alloy steel elbow with a carbon steel elbow during a scheduled heat exchanger overhaul. The alloy steel elbow was resistant to high-temperature hydrogen attack (HTHA), but the carbon steel elbow was not. view more

DESCRIPTION: On a Friday afternoon in 2007 a traffic accident occurred at the corner of two urban streets. Two vehicles were involved. Each vehicle contained a single driver (no passengers). Vehicle 1 was a Fuel Cell Vehicle. Vehicle 2 was a conventional Toyota Camry. Vehicle 1 was traveling west, approaching an intersection with a green light, and proceeded into the intersection. Vehicle 2 was traveling north on a cross street. The driver of Vehicle 2 incorrectly perceived a green light and proceeded into the intersection. The vehicles collided in the intersection.

RESPONSE: The police were coincidentally in the area and able to respond quickly to the site. The vehicles were moved out of the intersection. Vehicle 1 (fuel cell vehicle) shut down upon impact and was pushed out of view more

Incident Synopsis
A H2 delivery truck accident occurred on a highway. The truck was pulling a trailer containing gaseous H2. Upon entering a sharp curve, the truck and trailer started to weave and pushed to the side of the road. The truck and trailer rolled about 40 feet downhill; the trailer rolled over 1 1/2 times and the tractor once, ending in the upright position with the driver still in his seat. The truck was completely totaled, but little damage was incurred by the trailer. The trailer shell was satisfactory with normal venting through the stack. The rear cabinet doors were warped shut.

Cause

The accident occurred on a bad road, which was steep with many sharp curves. The driver was going too fast for the road conditions and the type of trailer being view more

Incident Synopsis
During pressure testing of a H2 tank for investigation of quick-release manhole cover, the tank burst at a pressure between 60-67 psig. Flow regulators indicated peak pressure of 67 psig.

Cause
The tank was over pressurized. A mistake was made in interpreting the blueprint, believing the tank was designed to withstand 150 psig, yet the actual design limit was 50.7 psig.

A fatal accident took place at an onshore processing facility for slop water from the offshore petroleum industry.

Drilling fluids, or mud, are typically oil-water emulsions consisting of base oil (continuous phase), water (dispersed phase), and emulsifying agents. Used drilling mud, or slop, is mud enriched with water and rock cuttings from drilling --- typically 60-80% water, 10-20% emulated base oil, and 10-20% rock cuttings. The used drilling fluids are collected in slop tanks on oil platforms and later shipped to onshore facilities for further processing.

On the day of the accident, two operators were trying to remove the lid from a manhole on top of a 1600-cubic meter storage tank. However, they were not able to unscrew the rusted bolts holding the lid in place, and view more

A fueler drove away without disconnecting the fueling hose from the vehicle. The breakaway did not open and the receptacle fitting sheared off the vehicle. Subsequent testing of the breakaway showed that the breakaway operated at 210 lbs, which was above the design value of 133 lbs. The hydrogen contained in the hose between the dispenser shutoff valve and the vehicle check valve was released.

A gas mixture cylinder was connected to a Fourier Transform Infrared (FTIR) Spectrometer to purge residual carbon dioxide and water vapor. A staff member was preparing to use the FTIR instrument. Prior to use of the instrument, it must be purged with dry nitrogen to remove residual carbon dioxide and water vapor. When the gas mixture reached the instrument's globar (resistively heated ceramic) heat source, a localized explosion occurred. No injuries resulted from the explosion but the spectrometer housing was heavily damaged. The internal components, including the optics and computer hardware, appeared to be in good shape.

A mixture of hydrogen and nitrogen was inadvertently connected for the purging rather than dry nitrogen. The staff member, even though an expert in the view more

An explosion occurred in a 90-ton-per-day incinerator at a municipal refuse incineration facility. Three workers were seriously burned by high-temperature gas that spouted from the inspection door, and one of them died 10 days later. The accident happened during inspection and repair of the furnace ash chute damper. The workers injected water to remove some blockage, and the water reacted with incinerated aluminum ash to form hydrogen, which caused the explosion.

Workers noticed that the post-combustion zone was full of ash and the ash pusher was not working properly, so they tried to remove the ash from the inspection door with a shovel. They discovered a solid layer of "clinker", which is formed by solidification of molten material such as aluminum. The explosion view more

A researcher was using numerous compressed gases in his lab. To facilitate reconfiguring his experimental apparatus, he installed "quick-disconnect" fittings on flexible tubing connected to his compressed gas cylinders/regulators. He also fitted all of the equipment that needed gas with complementary "quick-disconnect" fittings.

The day of the incident, he needed to purge his IR spectrometer with nitrogen as the element heated up. He mistakenly attached the "quick-disconnect" fitting from a cylinder of 10% nitrogen and 90% hydrogen to the "quick-disconnect" fitting on his spectrometer. As soon as the gas started flowing and he switched on the element, the instrument exploded, completely destroying a $6,000 piece of equipment. Only minor view more