Introduction to Hydrogen Safety for First Responders
Welcome to the U.S. Department of Energy's
Introduction to Hydrogen Safety
for First Responders
The information presented here is intended for fire, law enforcement, emergency medical personnel,
or individuals involved with fleet operations who may witness or discover a hydrogen release and
must initiate an emergency response sequence.
This course was developed to help first responders •
Understand the properties of hydrogen, how it compares to other fuels, and the safety
mechanisms of hydrogen systems
•
Recognize and identify hydrogen vehicles, stationary power generators, storage containers,
and refueling equipment
•
Identify typical ignition sources and other potential hazards
•
Execute initial "awareness-level" response actions
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Introduction to Hydrogen Safety for First Responders
Disclaimer
All published versions of this Introduction to Hydrogen Safety for First Responders, including both printed and electronic
(see www.hydrogen.energy.gov) formats thereof and all associated videos, supplementing documents, and related
electronic links, are provided as a public service by the United States Department of Energy, an agency of the United
States government.
Neither the United States government nor any agency thereof, nor any of their employees, nor any of their contractors,
subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility
for the accuracy, completeness, or any third party's use of any information, apparatus, product, procedure, or process
disclosed, or represents that its use would not infringe privately owned rights.
Reference to any specific commercial product, process, or services by trade name, trademark, manufacturer, or otherwise,
does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government,
any agency thereof, its contractors, or subcontractors.
Any electronic website link in this document is provided for user convenience and its publication does not constitute or
imply its endorsement, recommendation, or favoring by the United States government, any agency thereof, its contractors,
or subcontractors. Neither the United States government nor any agency thereof, nor any of their employees, nor any of
their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal
liability or responsibility for the accuracy, completeness, or any third party's use of any linked website, or represents that
such use would not infringe privately owned rights.
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Copyright Status
The published versions of this document, both printed and electronic, were prepared by Pacific Northwest National
Laboratory, a contractor of the United States government under contract DE-AC06-76RL01830, and by Volpentest
Hazardous Materials Management and Emergency Response Training and Education Center, a subcontractor to Pacific
Northwest National Laboratory, under contract ICP33538. To the extent the specified contractor or subcontractor may
assert copyright in the document, the United States government would retain at least a nonexclusive, royalty-free license to
publish or reproduce these documents or to allow others to do so for United States government purposes. Accordingly,
these documents may be freely copied and distributed for governmental purposes.
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Introduction to Hydrogen Safety for First Responders
Course Contents
INTRODUCTION TO HYDROGEN SAFETY FOR FIRST RESPONDERS ..................................................................................1
DISCLAIMER...........................................................................................................................................................................................2
COURSE CONTENTS ...........................................................................................................................................................................3
HYDROGEN BASICS ............................................................................................................................................................................4
TRANSPORT AND STORAGE ..........................................................................................................................................................16
HYDROGEN VEHICLES .....................................................................................................................................................................19
HYDROGEN DISPENSING.................................................................................................................................................................33
STATIONARY FACILITIES.................................................................................................................................................................36
CODES AND STANDARDS ...............................................................................................................................................................44
EMERGENCY RESPONSE.................................................................................................................................................................49
SUMMARY.............................................................................................................................................................................................65
QUIZ........................................................................................................................................................................................................66
SUPPORTING DOCUMENTS ............................................................................................................................................................69
RELATED LINKS .................................................................................................................................................................................70
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Introduction to Hydrogen Safety for First Responders
Hydrogen Basics
Hydrogen Basics
This section covers the basic properties and behaviors of hydrogen and how it compares to other fuels. You'll also learn where
potential hazards with hydrogen may differ from those of other fuels and what controls are commonly used to assure the safe
use of hydrogen.
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Introduction to Hydrogen Safety for First Responders
Hydrogen Basics
Hydrogen Uses
The use of hydrogen is not new—industry has used it safely for many
decades. The U.S. produces over 9 million tons of hydrogen every year.
•
•
•
•
•
•
•
•
•
•
•
Petroleum refining
Glass purification
Aerospace applications
Fertilizers
Annealing and heat treating metals
Pharmaceutical products
Petrochemical manufacturing
Semiconductor industry
Hydrogenation of unsaturated fatty acids in vegetable oil
Welding
Coolant in power generators
It's important to note that the use of hydrogen is not new. U.S. industry produces more than 9 million tons of hydrogen each
year. It has been used safely for decades in petroleum refining and for a variety of purposes, as shown here. Hydrogen has
become part of our nation's long-term energy strategy because in addition to its traditional uses in industry, it can also be used
as a transportation fuel and to provide electricity and heat to homes.
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Hydrogen Basics
Hydrogen Production
Hydrogen is abundant in nature, but not in its pure form. It must be produced from
compounds that contain it. Hydrogen can be produced from fossil, nuclear and
renewable energy resources using a variety of process technologies.
Many different technologies are under research, but two currently-used hydrogen
production technologies include:
•
•
Natural Gas Reforming: uses high-temperature steam to produce hydrogen
from methane in natural gas
Electrolysis: uses electrical current to split water into hydrogen and oxygen
Photos: NREL
Hydrogen is abundant in nature but rarely found "by itself." Instead, it must be produced from compounds that contain it, such as
natural gas, coal, water, and biomass resources including biofuels and other agricultural products. Two currently used methods
include natural gas reforming and electrolysis.
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Introduction to Hydrogen Safety for First Responders
Hydrogen Basics
Hydrogen Properties and Behaviors
•
•
•
•
•
•
Colorless, odorless, tasteless, nontoxic, non-corrosive and nonpoisonous
Lightest and smallest element
A gas at ambient conditions
Fourteen times lighter than air, it
rises and disperses rapidly
Exists as a liquid at -423°F (-253°C)
Volume ratio of liquid to gas is 1:848
Molecular Hydrogen
Like gasoline or natural gas, hydrogen is a fuel that must be handled properly; it can be used as safely as other common fuels
when simple guidelines are observed.
Hydrogen is colorless, odorless, and tasteless. It's non-toxic and non-poisonous; it's non-corrosive, but can embrittle some
materials. Hydrogen is the lightest and smallest element—and a gas under ambient conditions. It's 14 times lighter than air,
which means that when it's released, it rises and diffuses quickly.
The volume ratio of liquid to gas is 1:848. So, if you picture a gallon of liquid hydrogen, that same amount of hydrogen, existing
as a gas, would, theoretically, occupy 848 gallon containers (without compression).
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Hydrogen Basics
Hydrogen Properties and Behaviors
Video: Sandia National Laboratory
Hydrogen is flammable. It burns with a pale blue flame that is nearly invisible in daylight, and hydrogen flames do not produce
smoke unless impurities such as carbon are present. A pure hydrogen flame has low radiant heat—much less than the amount
of heat radiated from the burning of conventional fuels. The flame itself, however, is just as hot as a hydrocarbon flame.
Please note that this video was filmed in a controlled laboratory setting. Although hydrogen flames have low radiant heat, you
should not approach a hydrogen flame as demonstrated in the video.
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Hydrogen Basics
Fuel Comparison
Fuels
Odorant Added
Toxic
Hydrogen
NO
NO
Compressed Natural Gas
(CNG)
YES
NO
Liquefied Natural Gas
(LNG)
NO
NO
Propane
YES
NO
Gasoline
NOT NEEDED NATURALLY STRONG
ODOR
YES
As we prepare for using hydrogen to power vehicles and stationary equipment in a consumer environment, it's helpful to
compare it with other familiar fuels such as natural gas, propane, and gasoline.
Hydrogen has no odor. Natural gas and propane are also odorless, but industry adds a sulfur-containing odorant so people can
detect them. Currently, however, odorants cannot be used with hydrogen. As noted earlier, hydrogen is extremely light and
disperses quickly in air. There is no known odorant light enough to "travel with" hydrogen, and at the same dispersion rate.
Current odorants also contaminate fuel cells, which, as we'll cover later, are an important application for hydrogen. We should
also note that hydrogen is not toxic.
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Hydrogen Basics
Fuel Comparison
Hydrogen is 14X lighter than
air and 57X lighter than
gasoline vapor.
Hydrogen and natural gas
have similar auto-ignition
temperatures, almost 2.5X
higher than the auto-ignition
temperature of gasoline vapor.
Hydrogen is about 57 times lighter than gasoline vapor and 14 times lighter than air. This means that if it is released, it will rise
quickly (and in open environments will rapidly disperse) rather than pool on the ground near the point of release.
In a comparison of auto-ignition temperature, hydrogen and natural gas are very similar—both have auto-ignition temperatures
almost two and a half times higher than the auto-ignition temperature of gasoline vapor.
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Hydrogen Basics
Fuel Comparison
Hydrogen's flammability range
is very wide. It is most easily
ignited at a 29% hydrogen-toair volume ratio.
In optimal combustion
conditions, hydrogen can be
ignited with minimal energy
(such as a small spark).
Hydrogen's flammability range is very wide compared to other fuels. Under optimal combustion conditions (at a 29% hydrogento-air volume ratio), the energy required to initiate hydrogen combustion is much lower than that required for other common
fuels. But at low concentrations of hydrogen in air, the energy required to initiate combustion is similar to that of other fuels.
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Hydrogen Basics
Designing Safe Systems - Gaseous Hydrogen
Characteristic
Potential Hazard
Control
•
Colorless, odorless,
tasteless
•
Impossible for
human senses to
detect
•
Detection sensors
•
•
Low viscosity
Very small atom (can
be absorbed into
materials)
•
•
Leaks
Embrittles certain
materials; can result
in structural failure
•
Leak detection
systems
Ventilation
Material selection
Low volumetric
energy density
•
•
Stored at high
pressures
•
•
•
•
Storage container
design
Pressure relief
devices
Here we'll examine the ways in which industry designs systems with the unique properties—and potential hazards—of hydrogen
in mind.
Hydrogen is a very small atom with low viscosity—and therefore prone to leakage. Hydrogen atoms are also known to absorb
into certain materials, which can lead to embrittlement and structural failure. So, in addition to designing systems with leak
detection and sufficient ventilation, industry is careful to select materials that will not suffer hydrogen embrittlement.
Hydrogen has a high energy content by weight—but not by volume. This is a particular challenge for storage. In order to store
sufficient quantities of hydrogen gas, it's compressed and stored at high pressures. For safety, hydrogen tanks for vehicles are
also equipped with pressure relief devices that will prevent the pressure in the tank from becoming too high.
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Hydrogen Basics
Designing Safe Systems - Gaseous Hydrogen
Characteristic
Potential Hazard
Control
•
Not breathable
(not oxygen)
•
Potential for
accumulation in
confined spaces (any
gas that is not
oxygen is an
asphyxiant in
sufficient
concentrations)
•
•
Ventilation
Leak detection
systems
•
Wide flammability
range, from 4% to
75% (hydrogen-to-air
volume ratio
•
Can ignite over a
wide range of
concentrations; leaks
of all sizes are a
concern
•
•
Ventilation
Leak detection
systems
Hydrogen is highly buoyant and diffuses quickly into nonflammable concentrations in open air—a safety advantage in an outside
environment.
In confined spaces, though, hydrogen can accumulate and could reach a flammable concentration. Additionally, any gas other
than oxygen is an asphyxiant in sufficient concentrations. Proper ventilation and the use of detection sensors can mitigate this
hazard. This control is particularly important in a closed environment, as leaks of any size—large or small —are a concern, given
that hydrogen is impossible for human senses to detect and can ignite over a wide range of concentrations.
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Hydrogen Basics
Designing Safe Systems - Gaseous Hydrogen
Characteristic
Potential Hazard
Control
•
Low ignition energy
•
Minimal energy
(small spark) can
ignite
•
•
•
Ventilation
Grounding
System
design/removal of
possible ignition
sources
•
Burns with a pale
blue flame that is
nearly invisible in
daylight and does
not produce smoke
Low heat emission
•
Potential for
undetected flames
•
•
Flame detectors
Leak detection
systems
•
As noted earlier, hydrogen has a low ignition energy in ideal combustible concentrations. So, in addition to ensuring sufficient
ventilation, like today's gasoline systems, hydrogen systems are designed with grounding mechanisms to prevent ignition by
static charge. And because hydrogen is lighter than air and will quickly rise if released, electrical equipment is not placed directly
above a potential source of hydrogen.
Because hydrogen burns with low radiant heat and a nearly invisible pale blue flame, it can be difficult to detect by human
senses. Detection sensors are built into hydrogen systems to quickly identify any leak and eliminate the potential for undetected
flames.
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Hydrogen Basics
Designing Safe Systems - Liquid Hydrogen
Characteristic
•
•
Low liquefying
temperature
(-423 °F/-253 °C)
Potential Hazard
•
Cryogenic burns
and/or lung damage
Control
•
•
•
•
Rapid phase change
from liquid to gas
•
Pressure explosions
•
•
•
System design
Leak detection
systems
Personal protective
equipment
System design
Pressure relief
devices
Ventilation
As a liquid, hydrogen has different characteristics and different potential hazards—and therefore different control measures are
used to ensure safety. Hydrogen is stored as a liquid at -423°F, a temperature that can cause cryogenic burns or lung damage,
so detection sensors and personal protective equipment are critical when handling liquid hydrogen. Hydrogen also undergoes a
rapid phase change from liquid to gas—so ventilation and pressure relief devices are built into hydrogen systems to ensure
safety.
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Introduction to Hydrogen Safety for First Responders
Transport and Storage
Transport and Storage
Photo: Praxair, Inc.
In this module, we'll cover bulk transport of hydrogen—hydrogen stored on board passenger vehicles will be covered in the
Hydrogen Vehicles section, and hydrogen stored at fueling stations or for stationary power generation will be covered in
Stationary Facilities.
Hydrogen has been delivered safely for decades, mostly by pipeline or over the road. The current U.S. hydrogen pipeline
infrastructure is small—about 700 miles, compared to more than a million miles of natural gas pipeline—so hydrogen is often
delivered by trucks carrying gaseous or liquid hydrogen in cylinders or tanks.
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Transport and Storage
Hydrogen Transport
Hydrogen is transported in commerce in a variety of containers and piplelines
under U.S. DOT regulations (U.S. DOT 49 CFR).
Photo: Air Products and Chemicals, Inc.
Photo: Fuel Cells Today
To view U.S. DOT 49 CFR: www.gpoaccess.gov/cfr/index.html
The U.S. DOT, Title 49, Code of Federal Regulations includes requirements for the transport and storage of hydrogen, along
with other hazardous materials regulated in commerce. Approved shipping containers, including pipelines, have testing,
maintenance, and inspection requirements for safety.
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Transport and Storage
Hydrogen Storage for Transport
Photo: Praxair, Inc
Tube Trailers
Photo: Air Products and Chemicals, Inc.
Liquid Cargo Tanks
Image: Airgas, Inc.
Canisters
Tube trailers transport bulk quantities of hydrogen gas, while cargo tanks carry bulk liquid hydrogen. Placards and/or other
markings are required on bulk shipments to help first responders recognize the material and respond appropriately in the event
of an emergency. Information about those markings is included in the Emergency Response section of this course.
Aluminum or steel cylinders are a common approved packaging for compressed gases, including hydrogen.
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Introduction to Hydrogen Safety for First Responders
Hydrogen Vehicles
Hydrogen Vehicles
Video: CaFCP
All of the major auto manufacturers are developing vehicles powered by hydrogen. Although it will be some time before they're
widely available to consumers, you may have already seen hydrogen cars or buses in your area as part of ongoing
demonstration and evaluation programs. Through DOE's National Hydrogen Learning Demonstration, for example, auto and
energy company teams are installing hydrogen fueling stations and placing hydrogen vehicles on the road to validate their
performance in real world conditions..
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Hydrogen Vehicles
A Review of Vehicle Types — Alternative Fuel Vehicles
•
•
•
•
Dedicated AFVs: Use a single
fuel.
Bi-fuel AFVs: Have two
separate fuel systems and can
switch from one to the other
(e.g., gasoline and compressed
natural gas).
Dual-fuel AFVs: Have two fuel
tanks and operate on a mixture
of two fuels.
Flex-fuel AFVs: Have a single
fuel tank but can use either
gasoline or an alcohol mixture
like E-85 (85% ethanol and
15% gasoline), or a mixture of
the two.
Photos: NREL PIX (police car and flex-fuel pickup truck)
Photo: AFDC (red pickup truck)
Before we talk about hydrogen vehicles, let's quickly review the other kinds of alternative vehicles that are out on the road today.
An alternative fuel vehicle, or AFV, is any vehicle designed to operate on at least one alternative fuel such as biodiesel,
electricity, ethanol, hydrogen, natural gas, or propane.
Dedicated AFVs use a single fuel, such as compressed natural gas. Bi-fuel AFVs have two separate fuel systems. Dual-fuel
vehicles have two fuel tanks and operate on a mixture of two fuels, such as natural gas and diesel. Flexible-fuel, or flex-fuel,
vehicles have a single fuel tank and run on either gasoline or an alcohol fuel mixture such as E85 (or a mixture of E85 and
gasoline).
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Hydrogen Vehicles
A Review of Vehicle Types — Hybrid Vehicles
As seen on the road today,
these are primarily gasoline
hybrid-electric vehicles that
use both an internal
combustion engine and
electric motor.
Photos: AFDC
Generally speaking, a hybrid vehicle system consists of two energy storage elements (such as a liquid fuel and a battery) and
two energy conversion elements (such as an engine and an electric motor). Nearly all of today's hybrid vehicles are gasolineelectric—they have both an internal combustion engine and an electric motor, but refuel with gasoline. Electricity is provided by
a battery, regenerative braking system, and in some vehicles, an on-board electric generator. There are also some diesel-hybrid
electric vehicles, primarily buses.
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Hydrogen Vehicles
Hydrogen Vehicles
Hydrogen can provide power to a vehicle using
a fuel cell or an ICE.
Internal Combustion Engine
(ICE): Converts the energy
released when a fuel is burned
into mechanical energy; most
vehicles today have ICEs.
Fuel Cell: Directly converts the
chemical energy of hydrogen
and oxygen (from the air) to
electricity that can power a
motor; the only byproducts
are water and heat.
Photo: BMW Group
Photo: U.S. DOE
Photo: Toyota Motor Corp.
As noted at the start of this section, all of the major auto manufacturers are developing hydrogen vehicles—most of these are
fuel cell vehicles, although some use an internal combustion engine, or ICE.
In a fuel cell, hydrogen electrochemically combines with oxygen from the air to create electricity that powers a motor, which
propels the vehicle. Although they're currently more expensive than traditional power systems, fuel cells have many advantages.
For example, they can be more than twice as efficient as conventional internal combustion gasoline engines, and the only
byproducts of the process are water and heat, there are no other emissions from the vehicle tailpipe.
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Hydrogen Vehicles
Fuel Cell Animation
The graphic here shows a polymer electrolyte membrane (or PEM) fuel cell and the movement of hydrogen and oxygen
producing electricity with the byproduct water and heat. A single fuel cell cannot generate enough power to propel a vehicle; so
many individual fuel cells are combined in series to form a fuel cell stack. The stack sends electricity to the motor that powers
the vehicle. Although the fuel cell generates electricity it does not store it; electricity can be stored on-board the vehicle in a
battery, or batteries, or ultra-capacitor.
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Hydrogen Vehicles
Hydrogen Fuel Cell Vehicle *Sample* Cutaway View
Photo: DaimlerChrysler
Although different auto manufacturers are developing their own prototype and demonstration vehicles, hydrogen fuel cell
vehicles usually have several basic components in common: an energy storage device, such as a battery or ultra-capacitor; an
on-board hydrogen storage system or fuel tank; fuel cell stack; and an electric motor.
Here we see a cutaway view of a sample fuel cell vehicle. It is important to note that this is only an example—vehicles made by
different manufacturers may be configured differently, and as hydrogen fuel cell technologies continue to evolve, vehicle
configurations will evolve as well.
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Hydrogen Vehicles
Storing Hydrogen On-Board a Vehicle
•
•
Hydrogen can be
stored as gas or liquid
 Compressed
hydrogen gas —
Up to 10,000 psi
 Liquid hydrogen —
Up to 100 psi at 423 °F
How much can today's
Photo: Quantum Technologies
vehicles store?
 Passenger cars — typically up to 5 kg
 Buses — with multiple tanks, can store ~50 kg
Research is under way to develop new methods and materials for on-board hydrogen storage. Most of today's demonstration
hydrogen vehicles use tanks that store hydrogen as a gas—on-board liquid hydrogen storage is less common.
Today's light-duty (passenger) hydrogen vehicles typically store up to 5 kg of hydrogen on-board. As hydrogen storage
technologies develop, vehicles may store more hydrogen—up to 13 kg—to allow for a 300-mile minimum driving range between
fills. Hydrogen buses, which are heavier and get much less mileage per gallon, use multiple storage tanks and store on the order
of 50 kg of hydrogen on board.
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Hydrogen Vehicles
Compressed Hydrogen Gas Storage System
Image: Quantum Technologies
Most vehicles can store compressed hydrogen gas on board in composite tanks at pressures up to 10,000 psi.
As shown, tanks are equipped with pressure relief devices for safety.
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Hydrogen Vehicles
Liquefied Hydrogen Storage System
Image: Linde Gas, LLC
Liquefied hydrogen is denser and has a higher energy content on a volume basis than gaseous hydrogen. But, as shown in this
graphic, keeping liquid hydrogen from evaporating requires a specially-designed, super-insulated tank.
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Hydrogen Vehicles
Vehicle Tank Validation Testing
Photos: Quantum Technologies
As with on-board storage tanks used in natural gas vehicles for decades, hydrogen storage systems must meet strict
manufacturer guidelines and undergo third-party testing for safety and structural integrity. As shown here, tanks are subjected to
extreme testing applications before they are certified for use.
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Hydrogen Vehicles
On-board Hydrogen Storage Tanks
Video: Hydrogen 2000, Hydrogen, The Safe and Clean Fuel
The video clip shows the carbon-fiber over-wrap being applied to a fuel tank, as well as various views of vehicles and tanks
undergoing crash tests and a tank containing in-tank valves that automatically shut off the hydrogen flow.
Video Transcript
"These ultra-light tanks have an aluminum liner with a carbon-fiber over-wrap.
They're tested under rather extreme conditions to ensure that they can withstand rugged use without compromising safety.
In one test that went beyond requirements, cars with these tanks installed were dropped from up to ninety feet without rupturing
the tanks.
The equivalent of a fifty-two mile-per-hour collision, directly onto a tank, caused nothing more than cosmetic damage.
The newly-developed tanks contain in-tank valves that automatically shut off the hydrogen flow, in the event of an emergency."
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Hydrogen Vehicles
Today's Hydrogen Vehicles
Hydrogen vehicles are equipped
with multiple safety features •
•
•
•
Leak detection
Collision sensors
Pressure relief devices
Tank valves (solenoid)
Photo: Quantum Technologies
Today's hydrogen fuel cell vehicles have redundant safety systems including on-board leak detection and collision sensors,
pressure relief devices, and tank valves—and are designed to fail safe.
Although today's hydrogen fuel cell vehicles are equipped with these different safety features, vehicle safety systems can be
configured differently, depending on the vehicle manufacturer—this means, for example, that not all pressure relief devices are
located in the same place on different vehicle models.
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Hydrogen Vehicles
Today's Hydrogen Vehicles
•
•
•
•
When collision sensors activate/when air bags deploy, the vehicle safely shuts
down
 tank solenoid valves close so that high-pressure hydrogen remains locked
in the tank
 high-voltage relays open so that the high-voltage battery/capacitors are
isolated from the system
Tank solenoid valves also close when the vehicle is turned off or power is cut
When a leak is detected, tank solenoid valves close, shutting off the flow of
hydrogen—the vehicle safely shuts down
Thermally-activated pressure relief devices prevent the pressure inside the
tank from becoming too high
When a leak is detected, tank solenoid valves close, shutting off the flow of hydrogen and allowing the vehicle to safely shut
down.
Similarly, when collision sensors activate, the vehicle safely shuts down—tank solenoid valves close so that high-pressure
hydrogen remains locked in the tank, and high-voltage relays open so the high-voltage battery/capacitors are isolated from the
system.
Tank solenoid valves will also close when the vehicle is turned off or the power is cut, and thermally-activated pressure relief
devices will prevent the pressure inside the tank from becoming too high.
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Hydrogen Vehicles
Hydrogen Fueled Vehicles Have Multiple Safety Systems
Animation: NREL
Audio: Hydrogen 2000
Animation Transcript
"Hydrogen-fueled vehicles have multiple safety systems that detect and prevent the accidental release of hydrogen. There are
sensors that detect leaks, a computer that monitors fuel flow, and an excess flow shut-off valve. Hydrogen tanks also have a
pressure relief device, much like those on natural gas water heaters in our home.
If a leak is detected, the flow of fuel is shut off so the amount that leaks would be small and most likely vent harmlessly into the
air."
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Hydrogen Dispensing
Hydrogen Dispensing
Photo: CaFCP
Photo: DaimlerChrysler
In most demonstration programs, hydrogen vehicles are refueled by trained personnel. This will become less common as the
number of demonstrations increases and hydrogen vehicles become available to consumers.
Refueling a hydrogen vehicle is similar to refueling any other vehicle, and the same general safety rules apply—drivers should
not smoke or use cell phones while refueling.
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Hydrogen Dispensing
Hydrogen Dispensing
Video: Hydrogen 2000, Hydrogen, The Safe and Clean Fuel
The video clip shows a vehicle being refueled as well as views of the dispenser and the flame detector at the station.
Video Transcript
A. Paul: Steve, will you show us how to refuel this car?
S. Mathison: Sure! It's actually quite simple. This is the refueling nozzle. And you just connect this to the receptacle on the
vehicle and then lock it in place.
A. Paul: That is easy!
S. Mathison: Yeah, it's not much different than refueling your regular car. Hydrogen stations are designed with a number of
sensors and safety systems that protect against potential hazards. We have hydrogen sensors that sense for any hydrogen
leaks, we have a computer system that monitors all systems to ensure that there's no problems, and we have a flame detector
that watches the refueling station at all times.
hydrogen.energy.gov/firstresponders
February 2007
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Introduction to Hydrogen Safety for First Responders
Hydrogen Dispensing
Dispensers for Hydrogen are Similar to
Compressed Natural Gas (CNG)
Refueling a hydrogen
fuel cell vehicle
Refueling a compressed natural gas vehicle
Photos: Honda Motor Co.
Refueling a hydrogen vehicle is similar to refueling a compressed natural gas vehicle, which now occurs on a daily basis across
the country. Like CNG refueling systems, hydrogen vehicle refueling is a closed-loop system. The dispensing nozzle "locks on"
to the vehicle receptacle before any hydrogen will flow. And like natural gas systems, hydrogen dispensers are equipped with
safety devices including breakaway hoses, leak detection, and grounding mechanisms. These controls help ensure safety in the
case of human error, such as a driver trying to drive away while the nozzle is still connected to the vehicle.
Hydrogen dispensing nozzles used are also unique to particular operating pressures, so nozzles specific to one pressure cannot
physically connect to vehicles with on-board storage at a different pressure.
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February 2007
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Stationary Facilities
Photo: Chevron Technology Ventures, LLC
Photo: Plug Power, Inc.
Photo: Air Products and Chemicals,
In this module we'll cover stationary facilities—defined in this course as stationary bulk storage, stationary fuel cells, and
hydrogen fueling stations.
Although much attention is paid to vehicles, hydrogen and fuel cell technologies will reach the commercial market in stationary
and portable applications first. In fact, portable and stationary fuel cells are already available and use across the country is
growing.
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Bulk Storage
•
•
•
Includes both liquid and gaseous
hydrogen storage in cylinders, tubes,
and tanks
Typically located at  Refineries or other hydrogen
production sites
 Refueling facilities
 Some stationary fuel cell
installations
 Research and development,
testing, and manufacturing
facilities
Can be above ground (including
on the canopy at a refueling
station) and below ground
Photo: NREL
Liquid hydrogen is stored at Santa Clara Valley
Transit Authority (CA), which operates fuel cell
buses
As noted earlier, hydrogen has been used for decades for industrial purposes and can be stored as a liquid or compressed gas
in approved cylinders, tubes, or tanks. Liquid hydrogen tanks are the most common way to store larger quantities of hydrogen
because they provide a higher volumetric density than gaseous storage. Larger tanks are usually spherical and can hold
between 400 and 6,650 kg of hydrogen.
Bulk storage may be located at refineries or other hydrogen production sites, fueling stations, and research and development or
manufacturing facilities, as well as with some stationary fuel cell installations. Approved storage containers can be either above
or below ground. Some fueling stations are being designed with storage high above ground, on the canopy.
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Stationary Fuel Cells
•
•
•
Generate electricity (and heat)
 Uninterruptible power supply
 Backup power
 Power for remote locations
Some direct-hydrogen units use
on-site hydrogen storage
Others (primarily larger units,
>10kW) use natural gas or other
fuel and an internal reformer
Fuel cell (left)
and hydrogen
storage
(right) near
Albany
International
Airport
Photo: Plug Power, Inc.
Fuel cells at a
municipal
wastewater
treatment
plant in New
York City, NY
Photo: NYSERDA
Stationary fuel cells generate electricity and heat (for more on how fuel cells work, see Hydrogen Vehicles, slide 5). Stationary
fuel cells are beginning to enter the commercial market in many places across the country and around the world. Examples
include fuel cells for back-up power at regional emergency shelters, uninterruptible power at hospitals, and power in remote
locations for telecommunications. There are several different types of fuel cells. Some direct-hydrogen fuel cells use on-site
hydrogen storage, while others use fuels like natural gas and produce hydrogen with an internal reformer that is part of the fuel
cell system.
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February 2007
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Stationary Fuel Cells
Video: Hydrogen 2000, Hydrogen, The Safe and Clean Fuel
The video clip shows how hydrogen fuel cells provide power to buildings like the New York City Police Department in Central
Park.
Video Transcript
"Already we're seeing fuel cells provide clean, reliable power in buildings like this office building in Tokyo, these apartments in
Osaka and Hamburg, and this building in Times Square in New York. In the U.S., power companies are also testing fuel cells to
provide electricity and heat for homes. Even the Police Station in Central Park gets its power from the fuel cell. Putting the power
close to the customer is called 'distributed generation.' In New York's Central Park, the benefits of distributed generation are all
on display. The Police Station was short of power, but the city didn't want to install ugly power lines, and burying the lines was
expensive. The fuel cell installed at Central Park Precinct brought high-quality power where it was needed most, with no power
lines and almost no pollution. There's even power left over to charge the Department's electric vehicles."
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Hydrogen Fueling Stations
•
•
•
Typically combine bulk storage with
refueling dispenser(s)
May be designed to fuel cars,
buses/large trucks, or forklifts with
gaseous hydrogen, liquid hydrogen, or
both
Can be on private or industrial
property, or in consumer retail
settings, such as multi-fuel stations
that provide gasoline and other fuels
Photo: NREL
This station owned by the Alameda-Contra
Costa Transit District (CA) serves cars and
buses
Photo: Shell Hydrogen
Washington, DC Shell fueling station
(gasoline, diesel, hydrogen)
It will be quite a while before hydrogen is available at most corner fueling stations. The number of hydrogen stations is growing,
however, as demonstration programs ramp up—particularly in certain parts of the country. Through DOE's National Hydrogen
Learning Demonstration, energy and auto company teams are installing hydrogen fueling stations and placing hydrogen vehicles
on the road to validate their performance in real world conditions.
As with any fueling station, hydrogen stations typically combine bulk storage and dispensing. They may provide gaseous
hydrogen, liquid hydrogen, or both to cars, buses, or other vehicles such as forklifts. And, like other fuels, hydrogen stations can
be on private property or industrial grounds, as well as part of retail fueling stations that also provide gasoline, diesel, or other
fuels.
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Hydrogen Fueling Stations
Hydrogen fueling stations have multiple
configurations; fuel can be delivered to the
station or generated on-site
•
•
Delivered hydrogen can be:
 Liquid; dispensed to vehicles as liquid
or compressed gas
 Gaseous; delivered via truck or
pipeline and compressed on-site for
Photo: CaFCP
dispensing
Liquid hydrogen is delivered to the
California Fuel Cell Partnership in
On-site generation can be:
Sacramento, CA
 Via natural gas reforming using
existing infrastructure
 Via electrolysis of water (using
electricity from the grid or an on-site source)
Hydrogen can be delivered to the station as either a gas or liquid, but unlike most other fuels, it also can be generated on-site at
the station. On-site generation from natural gas, for example, can take advantage of existing infrastructure. Hydrogen can also
be produced at the station via electrolysis of water, using electricity from the grid or an on-site renewable source such as solar
photovoltaic panels.
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Common Stationary Facility Safety Systems
•
•
•
•
Pressure relief devices - rupture disks, pressure relief valves, and safety vents
Leak detection, flame detection
Design elements
 Siting to established codes
 Engineering safety margins and analysis
 Use of hydrogen-compatible materials
Monitoring, controlled access, and emergency stops
In general, stationary facilities are equipped with pressure relief devices including rupture disks, pressure relief valves, and
safety vents. Vent stacks are standard for liquid hydrogen storage systems. Excess gaseous hydrogen (created from boil-off of
liquid to gas) is routinely vented, a practice commonly known as "burping."
Monitoring, controlled access, and emergency stops and shut-offs also can provide an additional level of safety. Stationary
facilities are designed with the specific properties of hydrogen in mind. For more on safety controls and system designs, please
see Hydrogen Basics, pages 13-16.
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Introduction to Hydrogen Safety for First Responders
Stationary Facilities
Stationary Facility Safety Systems
In addition to pressure relief systems, leak detection, and other safety design
elements, hydrogen fueling
stations are equipped with
safety systems including •
•
•
•
•
Fueling line leak check on
nozzle connects
Break-away devices on
hoses
Impact sensors at
dispensers
Excess flow control
Infrared cameras
Photo: SunLine Transit Agency
Photo: DOE
In addition to pressure relief systems, leak detection, and general design elements, hydrogen fueling stations have fueling line
leak checks on nozzle connects and break-away devices on hoses to prevent accidental releases. They also have impact
sensors at dispensers and excess flow control, as well as infrared cameras to help identify a hydrogen flame if needed. For
more on the refueling process, see Hydrogen Dispensing.
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Introduction to Hydrogen Safety for First Responders
Codes and Standards
Codes and Standards
In this module, we'll quickly review codes and standards—what they are and why they're important.
Detailed information and specific references to hydrogen and fuel cell codes and standards are not included here, although links
to more information and other codes-and-standards-related resources are provided.
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Introduction to Hydrogen Safety for First Responders
Codes and Standards
Codes and Standards
•
Provide information needed to safely build, maintain, and operate
equipment, systems, and facilities
• Help ensure uniformity of safety requirements
• Give local inspectors and safety officials the information needed to
certify systems and installations
Codes...
• Are guidelines for design of the built environment
• Are adopted by local jurisdictions
• Refer to or invoke standards for equipment used within a built environment
Standards...
•
•
•
Rules, guidelines, conditions, or characteristics for products or related
processes
Generally apply to equipment or components
Can have regulation-like status when referenced in codes or other government
regulations
Codes and standards provide the information needed to safely build, maintain, and operate equipment, systems, and facilities.
They help ensure uniformity of safety requirements and give local inspectors and safety officials the information they need to
certify systems and installations.
Codes are guidelines for the built environment—buildings and facilities. They are generally adopted by local jurisdictions,
thereby achieving the force of law. Codes often refer to or invoke standards for the equipment used within the given built
environment.
Standards are rules, guidelines, conditions, or characteristics for products or related processes, and generally apply to
equipment or components. Although they're not regulations, standards achieve a regulation-like status when they are referred to
in codes or through other government regulations.
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Introduction to Hydrogen Safety for First Responders
Codes and Standards
Codes and Standards are being Adopted, Revised, or
Developed for:
•
•
•
•
Vehicles
 Fuel cell vehicle systems
 Fuel delivery systems
 Containers
 Reformers
 Emissions
 Recycling
 Service/repair
Fuel Delivery and Storage
 Composite containers
 Pipelines
 Equipment
 Fuel transfer
Fueling, Service, and Parking Facilities
 Storage tanks
 Piping
 Dispensers
 On-site hydrogen production
 Facilities housing hydrogen equipment
Vehicle Fueling Interfaces
 Fuel specifications
 Weights and measures
 Fueling/defueling
 Sensors/detectors
 Connectors
 Communications
Although hydrogen has been used in industry for decades, its use as a fuel for vehicles or stationary power generation in
consumer environments is relatively new. As such, hydrogen and fuel cell codes and standards are in various stages of
development.
Industry, manufacturers, the government, and other safety experts are working with code development organizations and
standards development organizations to prepare, review, and promulgate technically-sound codes and standards for hydrogen
and fuel cell technologies and systems.
Codes and standards are being adopted, revised, or developed for vehicles; fuel delivery and storage; fueling, service, and
parking facilities; and vehicle fueling interfaces.
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Introduction to Hydrogen Safety for First Responders
Codes and Standards
Codes and Standards are being Adopted, Revised, or
Developed for:
•
•
•
•
Stationary Fuel Cells
 Systems
 Installation
 Performance test procedures
Interfaces
 Installation piping
 Storage
 Compressors
 Sensors/detectors
 Fuel specifications
 Weights/measures
 Dispensers
 Codes for built environment
 Interconnection
Portable Fuel Cells
 Handheld systems
 Portable systems
 Handheld fuel containers
 Portable fuel containers
 Hydrogen fuel specifications
 Performance test procedures
Hydrogen Generators
 Electrolyzers
 Reformers
 Performance test procedures
 Chemical hydrides
Codes and standards are also being adopted, revised, or developed for stationary and portable fuel cells and interfaces, as well
as hydrogen generators.
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Introduction to Hydrogen Safety for First Responders
Codes and Standards
For More Information
www.hydrogenandfuelcellsafety.info
The Hydrogen and Fuel Cell Safety Report
www.FuelCellStandards.com
Matrix of known codes and standards for hydrogen and fuel cells
www.pnl.gov/fuelcells/permit_guide.stm
Regulators' guides for permitting hydrogen installations (stationary fuel cells and
fueling stations)
http://hcsp.ansi.org
American National Standards Institute (ANSI) portal to information about codes,
standards, and regulations
www.hydrogen.gov/regulations
U.S. statutes and regulations pertaining to hydrogen
The U.S. Department of Energy and its partners have developed a number of resources for information about hydrogen and fuel
cell codes and standards and related issues.
The Hydrogen and Fuel Cell Safety Report, at www.hydrogenandfuelcellsafety.info, includes technical resources and supports
the activities of the National Hydrogen and Fuel Cell Codes and Standards Coordinating Committee.
FuelCellStandards.com provides a matrix of all known codes and standards for hydrogen and fuel cells, information about the
status of hydrogen and fuel cell codes and standards, a Q&A bulletin board, and quick reference guide.
DOE and its partners developed a guide to permitting hydrogen installations for regulators, which includes information for
stationary fuel cell installations as well as hydrogen fueling facilities, available at www.pnl.gov/fuelcells/permit_guide.stm. And
information is also available through the American National Standards Institute (ANSI) portal, at http://hcsp.ansi.org/.
Information about Federal regulations and statutes pertaining to hydrogen, including an interactive map highlighting agency
regulatory authorities, is available at www.hydrogen.gov/regulations.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Emergency Response
Photos: HAMMER
This section includes information to help you identify hydrogen equipment, vehicles, and related storage equipment; detect a
hydrogen release; identify potential hazards; and take initial protective actions if you witness or need to approach an incident.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Identifying Hydrogen Vehicles
•
Blue Diamond
 Society of Automotive
Engineers recommended
practice for hydrogenfueled vehicles
Photo: CaFCP
There are several different placards and signage that may identify a hydrogen vehicle, storage container, or stationary system.
Many of today's demonstration hydrogen vehicles are easily recognizable with colorful logos and labels. That won't always be
the case, though. The Society of Automotive Engineers recommends a blue diamond to identify hydrogen vehicles. It's not
required, but most, if not all, of the auto manufacturers use them. The decal is relatively small and typically found on the back of
the vehicle.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Identifying Hydrogen in Commercial Transport
•
Gaseous Hydrogen
DOT Placards
 For commercial transport
of hydrogen
Liquid Hydrogen
U.S. Department of Transportation placards and orange identification panels for commercial transport of hydrogen are similar to
placards for any other hazardous material.
Emergency response information for both gaseous hydrogen (UN1049) and liquid hydrogen (UN1966) can be found in Guide
115 of the Emergency Response Guidebook.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Identifying Stationary Facilities
•
NFPA 704 Hazard Placards
 Stationary facilities
Liquid Hydrogen
Gaseous Hydrogen
The National Fire Protection Association also has a standard for hazard placards to identify hydrogen used at stationary
facilities. The NFPA 704 hazard placards used for gaseous and liquid hydrogen are shown here—the "4" shown in both the
gaseous and liquid hydrogen placards indicates flammability, and the "3" on the liquid placard denotes the health issue related
to a cryogenic substance.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Detecting Hydrogen
•
•
•
•
Colorless, odorless, and tasteless so
human senses cannot detect gaseous
hydrogen
Listen for high-pressure gas leak (loud
hissing sound)
Use portable hydrogen detectors
Gas and flame detectors may be installed
in storage facilities and fueling stations;
listen and watch for audible or visual
alarms
Photo: HAMMER
We've noted that hydrogen gas is colorless and odorless so human senses can't detect it. As you would with all flammable
gases or fuels, use extreme caution when approaching an incident where there is potential for a hydrogen leak. Listen for the
sound of high-pressure gas escaping.
Use portable hydrogen detectors if you have them (typically, regular combustible gas detectors are not configured to detect
hydrogen). Gas and flame detectors may be permanently installed in storage facilities and fueling stations—where leaks may
occur. Listen and watch for alarms.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Detecting a Liquid Hydrogen Release
•
•
•
A liquid spill will create a white
cloud of condensed water
vapor due to the humidity in
the air
Look for frost or ice crystals on
the outside of a liquid
hydrogen container
Low-temperature vapors have
higher density and may move
horizontally or even downward
until they heat up
Photo: Scott Stookey
A liquid hydrogen release will look similar to the liquid
nitrogen release (shown above)
Liquid hydrogen leaks should be easy to detect without additional equipment.
A leaking liquid hydrogen container may have frost or ice crystals on the outside.
The photo you see here shows a liquid nitrogen release, but a liquid hydrogen release will look very similar. Even in dry
climates, a liquid hydrogen spill will create a white cloud of condensed water vapor. The cloud won't be the hydrogen—but rather
a signature, created by the liquid hydrogen's cryogenic temperature affecting the moisture and humidity in the surrounding air.
The low-temperature water vapor is heavier than air, so the cloud will remain localized and may appear to move horizontally or
even downward. As the hydrogen warms, it will dissipate and quickly rise.
As noted in the Stationary Facilities section, vent stacks are standard for liquid hydrogen storage systems and excess gaseous
hydrogen created from boil-off of liquid to gas is routinely vented (this practice is commonly known as "burping").
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Detecting a Hydrogen Flame
•
•
•
A hydrogen flame is nearly invisible in
daylight
Hydrogen has low flame emissivity (no
carbon to burn results in lower radiant
heat, may be difficult to feel until close)
Use a portable flame detector such as a
thermal imaging camera
Photo: HAMMER
We also noted earlier that hydrogen burns with a pale blue flame that is nearly invisible in daylight. The flame may appear yellow
if there are impurities in the air like dust, sodium from the ocean spray, etc. A pure hydrogen flame will not produce smoke.
Hydrogen flames have low radiant heat—unlike a hydrocarbon fire, you may not feel heat until you are very close to the flame.
Because of these properties, use a portable flame detector, such as a thermal imaging camera, when possible. If flame
detecting equipment is not available, listen for venting hydrogen and watch for thermal waves.
It is also important to note that vent stacks are standard in storage facilities, and the ignition of venting gaseous hydrogen is
common. Systems are designed to do this safely.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Watch for Potential Ignition Sources
•
•
•
Electrical
 Static electricity
 Electric charge from equipment operation
Mechanical
 Impact
 Friction (rubbing surfaces)
 Metal fracture
Thermal
 Open flame
 High-velocity jet heating
 Hot surfaces (e.g., an exhaust manifold)
 Vehicle exhaust
At any incident involving hydrogen, whether it involves stationary equipment or a hydrogen vehicle, keep in mind the properties
of hydrogen and watch for potential ignition sources that can ignite a hydrogen leak. These can be electrical, such as static
electricity or electric charge from operating equipment; mechanical, including impact, friction, or metal fracture; or thermal, such
as open flame, high-velocity jet heating, hot surfaces, or vehicle exhaust.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Potential Hazard Sources
•
•
•
•
Hydrogen storage
 High-pressure gas
 Liquid hydrogen (-423°F/-253°C)
High- and low-pressure fuel lines
Pressure relief device/vent stack, no standard location
Vehicles—high-voltage delivery system and devices (batteries, capacitors, fuel
cell stack)
When approaching any incident that may involve hydrogen, follow standard operating procedure but keep in mind the unique
properties of hydrogen and components of typical hydrogen systems.
As we have noted, hydrogen can be stored in stationary facilities or vehicles as either a compressed gas or cryogenic liquid.
Hydrogen systems include high- and low- pressure fuel lines. They are equipped with pressure relief devices for safety but the
location of the pressure relief device depends on the type of system; there is no standard location.
Hydrogen fuel cell vehicles also have high-voltage delivery systems and high-voltage devices such as batteries, capacitors, and
a fuel cell stack.
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February 2007
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Initial Protective Actions
•
•
•
•
•
•
Keep unauthorized personnel away
Stay upwind
Listen for venting gas, watch for thermal waves that would signal hydrogen
flames
Eliminate ignition sources
Do not touch or walk through product
Allow hydrogen-fed fire to burn, if safe to do so; protect adjacent exposures—
do not spray water into the pressure vent
When approaching an incident, keep unauthorized personnel away and stay upwind. Listen for venting gas and watch for
thermal waves that could signal hydrogen flames. Use portable flame detectors, if possible.
Eliminate all potential ignition sources, and do not touch or walk through the product. If you do detect a hydrogen-fed fire, allow it
to burn if safe to do so, and protect adjacent exposures. Extinguishing a hydrogen fire, prior to stopping the leak, could allow a
build-up of gas that could ignite. Do not spray water into the pressure vent, as this could prevent it from working properly.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Securing a Fuel Cell Vehicle
•
•
•
Approach the vehicle from a 45° angle
Listen for venting hydrogen, watch for thermal waves
If safe to do so, isolate the high-pressure and high-voltage systems by turning
off the key or cutting the negative cable of the battery
 It may take a few minutes for the electrical system to completely discharge.
Note: This is true for electric and hybrid vehicles as well.
 Be aware of other safety features such as air bags, seat belt pretensioners,
curtains, etc.
When approaching a hydrogen vehicle that has been involved in an incident, follow standard operating procedures, as you
would do for any vehicle incident.
When approaching a hydrogen vehicle, however, when possible, do so at a 45° angle to help avoid direct exposure to a
pressure relief device release. Again, as noted earlier, listen for venting hydrogen and watch for thermal waves that could signal
a hydrogen flame. If safe to do so, isolate the high-pressure and high-voltage-systems by turning off the key or cutting the
negative cable of the battery. It may take a couple of minutes for the electrical systems other than the battery to completely
discharge (this is true for hybrid-electric vehicles as well). As you would with any conventional vehicle, be aware of other safety
features such as air bags and seat belt pretensioners.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Securing a Fuel Cell Vehicle
•
•
•
Never cut into hydrogen lines
 No standard markings, most are
silver (stainless steel)
Do not cut high-voltage cables
(typically orange)
 200 - 500 volts
 200-300 amps
Avoid cutting through the floorline
Photo: Honda Motor Co.
Once the vehicle is turned off, the high-pressure systems are isolated. Simply turning off the key closes the high-pressure gas
tank.
Never cut into hydrogen lines. Although there are no standard markings, most are stainless steel and silver in color. Do not cut
the orange electrical cables. Cutting the hydrogen lines or the electrical cables can be a direct hazard to you and anything or
anyone around you.
Cutting through the bottom of a vehicle below the floorline is not recommended since hydrogen fuel lines, high-voltage electrical
lines, batteries, and fuel cell units are commonly located below the floorline.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Protective Equipment
•
•
•
•
Thermal imager
Structural firefighting personal protective equipment
Insulated hand tools
Positive pressure self-contained breathing apparatus
Photo: HAMMER
Thermal imaging equipment to detect a hydrogen flame is recommended, as are insulated hand tools to avoid igniting any
hydrogen gas. Standard firefighter turn-outs and respiratory protection are necessary when working an incident where a
hydrogen leak or fire may occur. If the incident involves liquid hydrogen, wear thermal protective clothing as well.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
*SAMPLE* Fuel Cell Vehicle Emergency Response Diagrams
All manufacturers are developing fuel cell vehicle ER diagrams that show the locations of potential hazards.
Photos: DaimlerChrysler
For demonstration vehicles on the road today, automakers also provide emergency response information in the form of cut
sheets. As shown in the example, these diagrams illustrate shut-down procedures to isolate both the hydrogen fuel and
electrical systems. In general, cutting through the bottom of a vehicle below the floorline is not recommended since hydrogen
fuel lines, high-voltage electrical lines, batteries, and fuel cell units are commonly located below the floorline. Please remember,
though, that vehicle configurations may change as hydrogen and fuel cell technologies continue to develop and evolve.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Emergency Information Sources
•
•
Material Safety Data Sheets
Vehicle Emergency Response Guide or Owner's Manual
Photo: HAMMER
Image: Honda Motor Co.
You can find additional emergency response information in the vehicle owner's manuals and hydrogen material safety data
sheets. If you are not familiar with material safety data sheets, they're available from a number of different web sites including
http://www.hydrogenandfuelcellsafety.info/resources/mdss.asp.
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Introduction to Hydrogen Safety for First Responders
Emergency Response
Emergency Response Guidebook
•
•
Used by emergency responders
 to quickly identify hazard and
response protocol
 to protect responders and
public during initial phase of
spill or accidental release
Hydrogen is listed under Guide
115 with natural gas, acetylene,
propane, butane, and other
flammable gases and refrigerated
liquids
http://hazmat.dot.gov/pubs/erg/gydebook.htm
Most first responders are familiar with the Emergency Response Guidebook, intended for emergency services personnel who
may be the first to arrive at the scene of a transportation incident involving dangerous goods.
Although developed for use at a dangerous goods incident, the guidebook can be a useful reference for incidents involving
alternative fuels such as hydrogen. For reference, both gaseous and liquid hydrogen are listed under Guide 115, along with
other fuels like natural gas and propane. But you will notice that the Guide highlights key differences in bold, like buoyancy in air,
that will affect how to respond to incidents involving hydrogen.
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Introduction to Hydrogen Safety for First Responders
Summary
Summary
•
•
•
•
Hydrogen has been safely used by industry for many decades; it is no more
dangerous than conventional fuels when handled properly
Leaking gas and burning gas may be difficult to detect
Once vented, hydrogen rises and disperses very quickly
Emergency response: Follow standard response protocol and remember
 Look for recognizable signage, listen for escaping gas, watch for themal
waves
 Let a hydrogen fire burn, if safe to do so.
 Never cut through hydrogen lines or high-voltage electrical lines
 For vehicles, avoid cutting through the floorline, as hydrogen lines and
high-voltage electrical lines and devices are commonly located there
In summary, although using hydrogen as a consumer fuel is a relatively new concept, industry has used it safely for many
decades. It's no more dangerous than conventional fuels when handled properly. Hydrogen is colorless, odorless, and burns
with a nearly invisible flame, so leaking or burning gas may be difficult to detect. It has a low density so it rises and diffuses
quickly.
Hydrogen vehicles can store hydrogen on-board as either a compressed gas or a liquid.
When approaching an incident that you suspect may involve hydrogen, follow standard operating procedures as you would for
any incident. Look for recognizable signage. Listen for escaping gas and watch for thermal waves that could indicate a hydrogen
flame. Let a hydrogen fire burn, if safe to do so. Never cut through hydrogen lines or high-voltage electrical lines.
When the incident involves a hydrogen vehicle, remember to avoid cutting through the floorline, as hydrogen lines, high-voltage
electrical lines, batteries, and fuel cell units are commonly located there.
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Introduction to Hydrogen Safety for First Responders
Quiz
Quiz
1.
Hydrogen flames are nearly invisible in daylight.
True |
False |
2.
Hydrogen is non-toxic and non-poisonous.
True |
False |
3.
Hydrogen flames radiate heat comparable to hydrocarbon flames.
True |
False |
4.
Hydrogen is odorless, and unlike natural gas, cannot be used with odorants, so it is
impossible to smell.
True |
False |
5.
Since hydrogen is lighter than air, it never poses an asphyxiant concern.
True |
False |
6.
When released in an open environment, hydrogen will pool on the ground.
True |
False |
7.
Some composite tanks allow storage of hydrogen gas at pressures up to 10,000 psig.
True |
False |
8.
Liquid hydrogen tanks are the most common way to store larger quantities of
hydrogen; larger bulk storage tanks can hold between 400 and 6,650 kg of hydrogen.
True |
False |
9.
Most hydrogen vehicles can be identified by a blue diamond sticker on the back of the
vehicle.
True |
False |
10. A liquid hydrogen leak will create a white cloud of condensed water vapor due to the
humidity in the air.
True |
False |
11. Fire impinging on a hydrogen fuel tank could cause an overpressure hazard.
True |
False |
12. Under certain circumstances, hydrogen can be ignited by common electrical,
mechanical, and thermal sources such as static electricity, friction between rubbing
surfaces, vehicle exhaust, and hot surfaces (e.g., a vehicle exhaust manifold).
True |
False |
13. Always attempt to extinguish a hydrogen-fed fire.
True |
False |
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Introduction to Hydrogen Safety for First Responders
Quiz
Quiz Answers
How did you do? Check your answers.
1.
Hydrogen flames are nearly invisible in daylight.
 The correct answer is TRUE. Hydrogen burns with a pale blue flame that is nearly invisible in
daylight; if sodium is present in the air, there may be a slight yellow color to the flame.
2.
Hydrogen is non-toxic and non-poisonous.
 The correct answer is TRUE. Hydrogen is non-toxic and non-poisonous.
3.
Hydrogen flames radiate heat comparable to hydrocarbon flames.
 The correct answer is FALSE. Hydrogen flames have low radiant heat, although the flame itself
is just as hot.
4.
Hydrogen is odorless, and unlike natural gas, cannot be used with odorants, so it is impossible to smell.
 The correct answer is TRUE. Because of hydrogen's unique properties, industry currently does
not add odorants to hydrogen. As such, hydrogen systems are designed with leak detection
systems for safety.
5.
Since hydrogen is lighter than air, it never poses an asphyxiant concern.
 The correct answer is FALSE. Hydrogen is highly buoyant and disperses rapidly in air. In
confined spaces, however, hydrogen can quickly accumulate—and any gas that is not oxygen
is an asphyxiant in sufficient concentrations.
6.
When released in an open environment, hydrogen will pool on the ground.
 The correct answer is FALSE. Hydrogen is 14x lighter than air, so if released in an open
environment, it will rise quickly and disperse into a nonflammable concentration.
7.
Some composite tanks allow storage of hydrogen gas at pressures up to 10,000 psig.
 The correct answer is TRUE. Some Composite cylinders—with aluminum or polymer liners
wrapped with carbon fiber or fiberglass—are used to store and transport hydrogen at pressures
of up to 10,000 psig. These cylinders are similar to the air bottles that firefighters use and
provide a very strong but light-weight container.
8.
Liquid hydrogen tanks are the most common way to store larger quantities of hydrogen; larger bulk storage tanks can
hold between 400 and 6,650 kg of hydrogen.
 The correct answer is TRUE. Liquid hydrogen tanks are commonly used for bulk storage.
Larger tanks are usually spherical and can hold between 400 and 6,650 kg of hydrogen
(compared to 5 kg of hydrogen typically stored on board a hydrogen passenger vehicle).
9.
Most hydrogen vehicles can be identified by a blue diamond sticker on the back of the vehicle.
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Introduction to Hydrogen Safety for First Responders
Quiz
 The correct answer is TRUE. Most, if not all, auto manufacturers use a blue diamond sticker to
mark their hydrogen vehicles. The decal is small and typically found on the back of the vehicle.
10. A liquid hydrogen leak will create a white cloud of condensed water vapor due to the humidity in the air.
 The correct answer is TRUE. Even in dry climates, a liquid hydrogen spill will create a white
cloud of condensed water vapor. The cloud is a signature created by the liquid hydrogen's
cryogenic temperature affecting the moisture and humidity in the surrounding air. The low
temperature water vapor is heavier than air, so the cloud will remain localized. As the hydrogen
warms, it will dissipate and quickly rise.
11. Fire impinging on a hydrogen fuel tank could cause an overpressure hazard.
 The correct answer is TRUE. Fire impinging on a hydrogen tank can cause the temperature of
the gas inside the tank to rise, which increases the pressure. Pressure relief devices prevent
the pressure inside the tank from becoming too high, but tanks must be protected from flame
impingement from an adjoining vehicle or other source. Do not, however, spray water into the
pressure relief device or vent.
12. Under certain circumstances, hydrogen can be ignited by common electrical, mechanical, and thermal sources such as
static electricity, friction between rubbing surfaces, vehicle exhaust, and hot surfaces (e.g., a vehicle exhaust manifold).
 The correct answer is TRUE. First responders should watch for potential ignition sources that
can ignite a hydrogen leak. These can be electrical, such as static electricity or electric charge
from operating equipment; mechanical, including impact, friction (rubbing surfaces), or metal
fracture; or thermal, such as an open flame, high-velocity jet heating, hot surfaces (e.g., an
exhaust manifold), or vehicle exhaust.
13. Always attempt to extinguish a hydrogen-fed fire.
 The correct answer is FALSE. Let a hydrogen-fed fire burn, if safe to do so. Extinguishing a
gaseous hydrogen fire, prior to stopping the leak, could allow a build-up of gas that could then
ignite. Do not spray water into the pressure vent.
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Library
Supporting Documents
NFPA 704 Hazard Identification System
http://chemlabs.uoregon.edu/safety/NFPA.html
The NFPA hazard identification placard is a color-coded array of four numbers or letters arranged in a diamond shape.
This Web site explains the color and number coding as they relate to the health, flammability, and reactivity properties
of hazardous materials.
49CFR Transportation Regulations
http://www.access.gpo.gov/nara/cfr/waisidx_03/49cfrv2_03.html
49CFR is the Code of Federal Regulations (CFR) relating to transportation as they may apply to hydrogen transport.
Hydrogen and Fuel Cell Safety
http://www.hydrogenandfuelcellsafety.info
This monthly online publication of the National Hydrogen Association and Fuel Cell Codes & Standards Coordinating
Committee reports on current events relevant to hydrogen codes and standards development.
Regulator's Guide to Permitting Hydrogen Technologies
http://www.pnl.gov/fuelcells/permit_guide.stm
This guide was created to educate regulators on the essentials of hydrogen technology to facilitate the acceptance of
stationary fuel cell technologies for buildings and hydrogen motor fuel dispensing facilities.
2004 Emergency Response Guidebook
http://hazmat.dot.gov/pubs/erg/gydebook.htm
The Emergency Response Guidebook (ERG2004) was developed for use by firefighters, police, and other emergency
services personnel who may be the first to arrive at the scene of a transportation incident involving hazardous material.
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Library
Related Links
National Organizations
U.S. Department of Energy Hydrogen Progam
http://www.hydrogen.energy.gov
The U.S. DOE Hydrogen Program works in partnership with industry, academia, national laboratories, state, federal,
and international agencies to facilitate the widespread adoption of hydrogen technologies.
U.S. Department of Energy H2 Analysis Resource Center
http://hydrogen.pnl.gov/cocoon/morf/hydrogen
The Hydrogen Analysis Resource Center provides well-documented, reliable data to be used for hydrogen-related
analytical activities. These data can serve as the basis for calculations, modeling, and other analytical activities.
U.S. Deparment of Energy—Energy Efficiency and Renewable Energy Information Center
http://www1.eere.energy.gov/informationcenter/
877-EERE-INF(O)
The EERE Information Center can answer basic questions about hydrogen and fuel cell technologies or refer callers to
the most appropriate EERE resources or appropriate expert networks. You can request an abridged version of this
tutorial, Introduction to Hydrogen Safety for First Responders, in print or on CD (as well as DOE Hydrogen Program
technology fact sheets) through the Information Center.
Volpentest HAMMER Training and Education Center
http://www.hammertraining.com
The Volpentest HAMMER (Hazardous Materials Management and Emergency Response) Training and Education
Center has played an integral role in preparing workers and emergency responders for high-risk tasks and the use of
new technologies.
National Hydrogen Association
http://www.hydrogenassociation.org/
The NHA is a 100+ member association formed to foster the development of hydrogen technologies and their utilization
in industrial, commercial, and consumer applications and promote the role of hydrogen in the energy field. This site
includes basic information resources and related links.
U.S. Fuel Cell Council
http://www.usfcc.com
The U.S. Fuel Cell Council is an industry association dedicated to fostering the commercialization of fuel cells in the
United States. Members include the world's leading fuel cell developers, manufacturers, suppliers and customers. This
site includes basic information resources and related links.
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Library
State-related Organizations and Resources
State Fuel Cell and Hydrogen Policy Demonstration Database
http://www.fuelcells.org/info/statedatabase.html
This database catalogues initiatives, policies, and partnerships in the fuel cell and hydrogen arena, including all
stationary fuel cell installations, hydrogen fueling stations, and vehicle demonstrations in the United States.
California Fuel Cell Partnership
http://www. cafcp.org/resource-ctr_ermaterials.htm
The California Fuel Cell Partnership is a unique collaborative of auto manufacturers, energy companies, fuel cell
technology companies, and government agencies committed to promoting fuel cell vehicle commercialization as a
means of moving towards a sustainable energy future, increasing energy efficiency, and reducing or eliminiating air
pollution and greenhouse gas emissions.
NextEnergy
http://www.nextenergy.org
NextEnergy is a non-profit corporation founded to enable the commercialization of energy technologies that
positivelycontribute to economic comptetitiveness, energy security, and the environment.
Florida's Hydrogen Progam: H2 Florida
http://www.floridadep.org/energy/sources/hydrogen/default.htm
H2 Florida partners Florida State with industry, local governments and universities to showcase hydrogen technologies
and educate consumers on the newest hi-tech approach to clean, sustainable energy.
Hydrogen Executive Leadership Panel (HELP)
http://www.nasfmhyrogen.com
The mission of HELP is to bring together emergency responders, government regulators, scientists, consumers and
experts from the automotive and energy industries to facilitate a safe and orderly transition to hydrogen and other
alternative fuel sources.
Safety
H2incidents.org
http://www.h2incidents.org
The Hydrogen Incident Reporting Database is intended to facilitate the sharing of lessons learned and other relevant
informaiton gained from actual experiences using and working with hydrogen. The database contains records of events
involving either hydrogen or hydrogen-related technologies.
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Regulations, Codes and Standards
U.S. Federal Statutes and Regulations
http://www.hydrogen.gov/regulations
The purpose of this Web site is to share and examine the current U.S. federal statutes and regulations that may be
applicable to hydrogen as we move toward the increasingly complex business environment behind a hydrogen
economy.
Fuell Cell/Hydrogen Infrastructure Codes and Standards
http://www.FuelCellStandards.com
This site is dedicated to assist the worldwide community working to develop and interpret fuel cell codes and standards.
Resources include a database of current fuel cell codes and standards activities, a calendar of significant events, an
overview of services related to the hydrogen and fuel cell industries, and a community bulletin board.
American National Standards Institute (ANSI) Hydrogen Codes and Standards Portal
http://hcsp.ansi.org
The ANSI Hydrogen Codes and Standards Portal is designed to allow easy access to codes, standards and regulations
relating to hydrogen used as fuel. Information is organized into two categories: Vehicle Systems and Refueling Facilities
and On-site Hydrogen Generation and Fuel Cells.
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