CHECK OUT OUR MOST RELEVANT INCIDENT LISTINGS! 

Disclaimer: The Lessons Learned Database includes the incidents that were voluntarily submitted. The database is not a comprehensive source for all incidents that have occurred.

An investigative communication notes that "mechanical integrity programs at refineries repeatedly emphasize inspection strategies rather then the use of inherently safer design to control the damage mechanisms that ultimately cause major…

Carbon steel Nelson curve methodology cannot be depended on to prevent HTHA equipment failures and cannot be reliably used to predict the occurrence of HTHA equipment damage. Revisions to recommended practices should be considered regarding the…

Because the bottle was located outside at the time of the event, and the hydrogen did not find a source of ignition while venting through the relief valve, nothing serious happened. The failed regulator was replaced and operations continued.…

The following actions were proposed as a result of this incident: The company in charge of valve calibration and maintenance will be subject to approval of the plant service inspection team. Plant operating procedures will be improved. The…

In addition to the probable causes listed above, the lack of a standard operating procedure for hydrogen leak detection was one of the probable causes of this incident. Additional contributing factors included the following:
- Severe pipe…

Based on the results of the company investigation and analysis of an amateur video, the company determined that the incident could have been caused by the failure of one of the following plant components:
· pipes leading to the reactor…

1.  Combustible gas detectors calibrated for hydrogen can falsely report hydrogen alarms due the presence of other gases the detector may pick up, such as carbon monoxide from engine exhaust or other sources. Since this event occurred, two…

Active GH2 sensors should be installed and continuously monitored in all enclosed buildings near GH2 sources. All buildings near areas where hydrogen is used should be designed to preclude GH2 entrapment (e.g., sloping roof with ventilation at…

Recommendations:

The using organization should define necessary activities in order to place hydrogen systems in long-term periods of inactivity. The defined activities should address requirements for rendering inert, isolation (i.e.,…

To prevent a similar flashback, the following measures have been taken:

The valve is opened slowly to avoid a major leading shock into the venting line.
A special nozzle (Laval or similar) is mounted directly after the opening…

It is important to understand the requirements and standards associated with safe equipment design (especially electrical equipment containing an internal ignition source with flammable gas) in potentially explosive atmosphere environments.…

1. Management must ensure that operating decisions are not based primarily on cost and production. Performance goals and operating risks must be effectively communicated to all employees. Facility management must set safe, achievable operating…

The SS 24-inch pipe that failed was replaced with 1-1/4 Cr 1/2 Mo alloy pipe that is corrosion-resistant to SCC. A revised HTS bypass piping layout was installed to prevent the hazardous conditions that lead to the failure. A detailed hazard…

The following corrective actions have been taken:

The non-return valve was dismantled, cleaned, and tested. Following positive testing, the system was restarted and pressurized without any further malfunctioning.
The hydrogen…

Inadequate Safeguards - The system was designed with low-point drains to facilitate water removal, however, these were found to be inadequate in both location and size. The fact that the mixed feed pre-heat coil was not self-draining was unknown…

Train personnel on delivery procedures and emphasize the safety aspects of hydrogen connections and disconnections, and verification of clearance for trailer movement prior to departure.
Provide site-specific delivery procedures and…

Safe work procedures will be prepared and followed. Hydrogen will be vented out of the system to create an inert atmosphere before working on system tubing and joints. The importance of purging hydrogen piping and equipment is discussed in the…

Provide additional retraining of operators. Curriculum should emphasize the proper response to high oxygen in the hydrogen gas.
Evaluate current knowledge of operators. Operators should know proper response, such as contacting engineering…

Replace the existing copper and carbon steel hydrogen pipeline with ¾-inch schedule 40 stainless steel.
Reroute the new hydrogen line in the preferred location.
Locate new hydrogen shut-off valves in a more convenient location.…

For the use of mechanical fittings in hydrogen service, administrative controls should be in place, as in this case, to ensure that leak testing is conducted on a regular basis. It should never be assumed that every fitting is tight. Additional…

Key:

  • = No Ignition
  • = Explosion
  • = Fire
Hydrogen Incident Summaries by Equipment and Primary Cause/Issue
Equipment / Cause Equipment Design or Selection Component Failure Operational Error Installation or Maintenance Inadequate Gas or Flame Detection Emergency Shutdown Response Other or Unknown
Hydrogen Gas Metal Cylinder or Regulator   3/31/2012
4/30/1995
2/6/2013
4/26/2010 12/31/1969     3/17/1999
11/1/2001
12/23/2003
Piping/Valves 4/4/2002
2/2/2008
5/11/1999
4/20/1987
11/4/1997
12/31/1969
8/19/1986
7/27/1991
12/19/2004
2/6/2008
10/3/2008
4/5/2006
5/1/2007
9/19/2007
10/31/1980
2/7/2009 1/24/1999
2/24/2006
6/8/1998
12/31/1969
2/7/2009

9/1/1992
10/31/1980

10/3/2008  
Tubing/Fittings/Hose   9/23/1999
8/2/2004
8/6/2008
9/19/2007
1/1/1982 9/30/2004
10/7/2005
  10/7/2005  
Compressor   10/5/2009
6/10/2007
8/21/2008
1/15/2019
    10/5/2009 8/21/2008  
Liquid Hydrogen Tank or Delivery Truck 4/27/1989 12/19/2004
1/19/2009
8/6/2004 12/31/1969   1/1/1974 12/17/2004
Pressure Relief Device 7/25/2013
5/4/2012
1/15/2002
1/08/2007
12/31/1969        
Instrument 1/15/2019 3/17/1999
12/31/1969
2/6/2013
    11/13/73    
Hydrogen Generation Equipment 7/27/1999     10/23/2001      
Vehicle or Lift Truck   7/21/2011         2/8/2011
12/9/2010
Fuel Dispenser   8/2/2004
5/1/2007
6/11/2007
9/19/2007
  2/24/2006
1/22/2009
     
Fuel Cell Stack            

5/3/2004
12/9/2010
2/8/2011

Hydrogen Cooled Generator       12/31/1969
2/7/2009
     
Other (floor drain, lab
anaerobic chamber,
heated glassware,
test chamber,
gaseous hydrogen
composite cylinder,
delivery truck)
  11/14/1994
7/21/2011
7/27/1999
6/28/2010
8/21/2008
12/31/1969
3/22/2018
    6/10/2019
  • = No Ignition
  • = Explosion
  • = Fire