Severity
Incident
Leak
Yes
Ignition
Yes
Ignition Source
(Spontaneous combustion)

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 to spent AB resulted in hydrolysis of the boron and hydrogen production. This is an exothermic reaction. The high temperature then caused the small amount of unreacted AB to produce pyrophoric gases such as diborane that ignited in the presence of air. The lead scientist pulled the fire alarm, effectively evacuating the building, retrieved a fire extinguisher, and immediately put out the fire. The fire department arrived and confirmed the fire was out, releasing the building for re-entry.

From previous experimental results, it had been concluded that spent AB does not produce diborane with either heat or water addition. However, spontaneous combustion may occur under those conditions with partially spent material. Subsequent causal analysis concluded that the event occurred when water was added to solidified AB material that had been broken up during removal from a flask.

While ammonia borane does not react with water, partially and fully thermally reacted AB does react to produce hydrogen. Use of a small amount of water (50 mL) with a large quantity of hydrogen storage material (>100 g) can result in very high reaction temperatures. With some unreacted AB, the high temperatures can release pyrophoric by-products that would then initiate a flame.

Incident Date
Feb 07, 2014
Setting
Equipment
  • Ventilation System
  • Glove Box/Fume Hood
  • Laboratory Equipment
  • Glassware
  • Safety Systems
  • Fire-Extinguishing Equipment
  • Heating Equipment
  • Laboratory-scale oil bath
Damage and Injuries
When Incident Discovered
Lessons Learned

The procedure for disposal of spent or partially spent AB has been modified so that it does not include the use of water. Instead, the AB is removed from containers and transferred for disposal by rinsing with mineral oil, silicone oil or other similar inert materials. It is then disposed of as a slurry.

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