Response information is for reference. We recommend attending an emergency response workshop to better understand the properties of hydrogen and fuel cell electric vehicles.

1. Why hydrogen?
•
•
•
•
•
•
Excellent energy carrier
Nonpolluting
Economically competitive
As safe as gasoline
Used safely for over 50 years
Produced from a variety of sources
10/24/2013

2. How fast does it rise?
• “Hydrogen rises 2
times faster than
helium and 6 times
faster than natural
gas, at a speed of
almost 45 mph
(20m/s).”
Buoyancy relative to air
Air
--National Hydrogen Association;
Hydrogen Safety Fact Sheet
Hydrogen
Natural Gas
Gasoline
Courtesy of Ballard
Propane

3. How quickly does it disperse?
Courtesy of Ballard

4. Comparison of properties
Hydrogen
Color
Toxicity
Odor
Buoyancy
Relative to Air
Energy by
Weight
Energy by
Volume
Natural Gas
Gasoline
No
No
Yes
None
Some
High
Odorless
Mercaptan
Yes
14X Lighter
2X Lighter
3.75X
Heavier
2.8X >
Gasoline
4X <
Gasoline
~1.2X >
Gasoline
1.5X <
Gasoline
43 MJ/kg
120
MJ/Gallon

5. Comparison of flammability
Hydrogen
0
4
Natural Gas
1
0
4
Gasoline
0
1
3
0
Flammability in air
(LFL – UFL)
4.1% - 74%
5.3% - 15%
1.4% - 7.6%
Explosive limits in
air (LEL – UEL)
18.3% - 59%
5.7% - 14%
1.4% - 3.3%
Most easily ignited
mixture in air
29%
9%
2%
Flame temperature
( C)
2045
1957
1977

6. Gas properties & characteristics
• Displaces O2
(Asphyxiant)
• Burns with a pale blue
flame
– near invisible in daylight
(can see what it burns)
– much less radiant heat of
gasoline fire
Photos: HAMMER

7. How explosive is it?
45
44
40
35
More Explosive Energy
30
25
gTNT/M 3
20
20
15
10
7
5
2
0
Hydrogen
Natural Gas
Gasoline
Propane
Courtesy of Ballard

8. Where do we get hydrogen?
Renewable sources
Traditional sources
Solar, wind, geothermal,
hydro, biomass, algae
Natural gas, gasoline,
nuclear, coal

9. Hydrogen distribution
• DOT approved…
• Cryogenic liquid
transport
• Pressurized gas trailers
• Truck, rail, barge and
pipeline
Photo: Air Products and Chemicals, Inc.
Photo: Praxair, Inc.
Photo: Ovonics