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Contract No. DE-AC36-08GO28308

Hydrogen Technologies Safety 

Guide

C. Rivkin, R. Burgess, and W. Buttner

National Renewable Energy Laboratory

Technical Report

NREL/TP-5400-60948

January 2015
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Hydrogen Technologies Safety 

Guide

C. Rivkin, R. Burgess, and W. Buttner

National Renewable Energy Laboratory

Prepared under Task No. HT12.7310

Technical Report

NREL/TP-5400-60948

January 2015
NOTICE

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trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors 

expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

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List of Acronyms

AHJ authority having jurisdiction

ANSI American National Standards Institute

ASM American Society of Materials

ASME American Society of Mechanical Engineers

ASTM American Society of Testing Materials

BPV boiler and pressure vessel

CFC California Fire Code

CFR Code of Federal Regulations

CGA Compressed Gas Association

CSA Canadian Standards Association

DOT U.S. Department of Transportation

EPA U.S. Environmental Protection Agency

H2 hydrogen

HGV hydrogen gas vehicle

IBC International Building Code

IFC International Fire Code

IFGC International Fuel Gas Code 

IMC International Mechanical Code

NFPA National Fire Protection Association

NIST National Institute of Standards and Technology

NREL National Renewable Energy Laboratory

OSHA Occupational Safety and Health Administration

PEM proton exchange membrane

PHA process hazard analysis

SAE Society of Automotive Engineers

UL Underwriters Laboratories
iv

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Table of Contents

List of Figures ............................................................................................................................................. v

List of Tables ............................................................................................................................................... v

Introduction ................................................................................................................................................. 1

General Safety Issues and Physical Properties of Hydrogen ................................................................ 3

History of Hydrogen Technologies ........................................................................................................... 8

Discovery of Hydrogen .......................................................................................................................... 8

Hydrogen Use and Applications............................................................................................................. 8

Glass Manufacturing........................................................................................................................ 8

Industrial Heat Transfer Fluid.......................................................................................................... 9

Semiconductor Manufacturing......................................................................................................... 9

Ammonia Production via the Haber-Bosch Process........................................................................ 9

Hydrogen in the Petrochemical Industry ......................................................................................... 9

Hydrogen as a Fuel for Fuel Cells ................................................................................................. 10

Hydrogen Safety Incidents................................................................................................................... 10

Regulations, Codes, and Standards ....................................................................................................... 12

Material Selection for Hydrogen Technologies...................................................................................... 27

Component Selection for Hydrogen Technologies ............................................................................... 29

The Permitting Process............................................................................................................................ 31

The Permit Applicant ........................................................................................................................... 33

Permit Template and Example Permit.................................................................................................. 34

Template—Hydrogen Dispenser Added to Existing Fueling Station............................................ 34

Example Permit.............................................................................................................................. 57

References................................................................................................................................................. 61

Informational Websites............................................................................................................................. 62

Appendix A. NREL Process Hazard Analysis on a Representative Hydrogen Fueling Station........ 63
v

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List of Figures

Figure 1. Timeline of codes and standards development and the codes and standards hierarchy 13

Figure 2. Schematic of a typical hydrogen dispensing station with single dispenser with gaseous 

and liquid hydrogen storage ............................................................................................................. 60

Figure A-1. Schematic of a representative hydrogen station............................................................... 63

Figure A-2. NREL risk matrix ................................................................................................................... 65

List of Tables

Table 1. Comparison of Total Vehicles and Fuel Consumed by Alternative Fuel Type....................... 2

Table 2. Hydrogen Properties .................................................................................................................... 4

Table 3. DOT Hazard Classification Scheme............................................................................................ 5

Table 4. Overview of Regulations, Codes, and Standards Related to Hydrogen Infrastructure 

Safety................................................................................................................................................... 14

Table 5. Hydrogen Dispensing Station Permitting/Potential Permits Required................................. 32

Table 6. Hydrogen Dispensing Station Approvals ................................................................................ 32

Table A-1. Risk Value Frequencies ......................................................................................................... 64

Table A-2. NREL Event Probability Classification Table....................................................................... 66

Table A-3. Total Risk at Node .................................................................................................................. 67
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Introduction

The purpose of this guide is to provide basic background information on hydrogen technologies.

It is not intended to be a comprehensive collection of hydrogen technologies safety information.

It is intended to provide project developers, code officials, and other interested parties the 

background information to be able to put hydrogen safety in context. For example, code officials 

reviewing permit applications for hydrogen projects will get an understanding of the industrial 

history of hydrogen, basic safety concerns, and safety requirements.

What are hydrogen technologies? For the purposes of this report they are processes that use or 

produce hydrogen. Hydrogen can be used as fuel to power internal combustion engines or fuel 

cells, or as an energy carrier. Hydrogen has been used as an industrial chemical for more than a 

century. The Haber process for producing ammonia was developed in 1909 (Austin 1984), and 

the production of ammonia accounts for approximately half of the hydrogen produced worldwide

(Ramachandran and Menon 1998). Approximately 40% of hydrogen produced is used to 

hydrogenate petroleum products. Hydrogen is also used in several industrial processes including

the following:

• Glass production

• Electronics manufacturing

• Coolant applications (low viscosity and high heat transfer) (Austin 1984).

Safety requirements for industrial uses of hydrogen are relatively well established. The National 

Fire Protection Association (NFPA) and the Compressed Gas Association (CGA) have published 

safety standards that address the storage, use, and handling of hydrogen in industrial applications 

that date back to the first edition of NFPA 567 (later renumbered as NFPA 50A) (National Fire 

Protection Association 1963) circa 1960.

In the last 20 years there has been a developing interest in using hydrogen as a fuel for fuel cells, 

primarily proton exchange membrane (PEM) fuel cells. PEM fuel cells are the preferred fuel cell 

technology for vehicles and other new applications because of their fast start-up time and low 

operating temperature. These fuel cells are used for stationary power, primarily in backup power 

units, and to produce electricity for electric vehicles. Hydrogen fuel cell vehicles require fueling 

at intervals comparable to a gasoline powered vehicle. This fueling activity will likely require 

vehicle owners and operators to operate fueling equipment, although in some states all fueling is 

conducted by fueling station personnel. Fueling a hydrogen fuel cell vehicle requires 

approximately five minutes. This exposure of the general public to hydrogen represents a 

significant change in the hydrogen risk spectrum from that of trained workers in a controlled 

environment handling hydrogen.

Placing hydrogen at public fueling stations and using it in vehicles has created a need for new 

safety requirements. These requirements reside in several documents and are addressed in the 

Regulations, Codes, and Standards section of this document.

This document is organized into the following seven sections:

• Introduction
2

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• Physical properties of hydrogen

• History of hydrogen technologies

• Overview of regulations, codes, and standards for hydrogen technologies

• Material selection for hydrogen technologies

• Component selection for hydrogen technologies

• Overview of permitting hydrogen technologies.

Table 1 (U.S. Census Bureau 2012) shows that approximately 174,000 gasoline equivalent 

gallons of hydrogen were consumed in 2011. This is well under 1% of the total alternative fuels 

consumed in that year. However, this number should increase as zero-emission-vehicle mandates 

drive increased usage of fuel cell vehicles. This table shows that hydrogen fuel cell vehicles are 

in the developmental phase. Each year has shown an increase in the number of vehicles and the 

amount of fuel consumed, but the totals are very small relative to other alternative fuels.

Table 1. Comparison of Total Vehicles and Fuel Consumed by Alternative Fuel Type

Fuel Type 2003 2004 2005 2006 2007 2008 2009 2010 2011

Compressed Natural Gas

Total Vehicles 114,406 118,532 117,699 116,131 114,391 113,973 114,270 115,863 118,214

Total Fuel 

Consumeda 133,222 158,903 166,878 172,011 178,565 189,358 199,513 210,007 220,247

Electricity

Total Vehicles 47,485 49,536 51,398 53,526 55,730 56,901 57,185 57,462 67,295

Total Fuel 

Consumeda 5,141 5,269 5,219 5,104 5,037 5,050 4,956 4,847 7,635

Ethanol, 85 percent

Total Vehicles 176,799 211,800 246,363 297,099 364,384 450,327 504,297 618,506 862,837

Total Fuel 

Consumeda 26,071 31,581 38,074 44,041 54,091 62,464 71,213 90,323 137,165

Hydrogen

Total Vehicles 9 43 119 159 223 313 357 421 527

Total Fuel 

Consumeda 2 8 25 41 66 117 140 152 174

Liquefied Natural Gas

Total Vehicles 2,640 2,717 2,748 2,798 2,781 3,101 3,176 3,354 3,436

Total Fuel 

Consumeda 13,503 20,888 22,409 23,474 24,594 25,554 25,652 26,072 26,242

Liquefied Petroleum Gas

Total Vehicles 190,369 182,864 173,795 164,846 158,254 151,049 147,030 143,037 139,477

Total Fuel 

Consumeda 224,697 211,883 188,171 173,130 152,360 147,784 129,631 126,354 124,457

Other Fuels

Total Vehicles 0 0 3 3 3 3 3 0 0

Total Fuel 

Consumeda 0 0 2 2 2 2 2 0 0

a Fuel consumption unit: thousand gasoline equivalent gallons.
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General Safety Issues and Physical Properties of 

Hydrogen

Hydrogen is a flammable gas with a wide flammability range (4%–75% by volume) and 

relatively low ignition energy (0.02 millijoules) (McCarty et al. 1981). It has a very low density 

and therefore must be stored at high pressures (10,000–15,000 psi range) to achieve enough mass 

for practical use. The ease of ignition and high storage pressure of hydrogen create a large 

portion of the risk associated with hydrogen usage.

Hydrogen also has the ability to attack—and damage to the point of leakage—certain materials 

that are used for the construction of storage containers, piping, valves, and other appurtenances.

This destructive capability is sometimes referred to as hydrogen embrittlement (Cramer and 

Covino 2003). The mechanisms of hydrogen embrittlement can be complex and vary with 

several physical parameters including temperature and pressure. Hydrogen’s ability to escape 

through materials based on its destructive abilities and small molecule size also contributes to the 

risk associated with hydrogen usage.

Hydrogen is the lightest element with an atomic number of 1. It is a colorless, odorless, 

flammable gas. Table 2 (McCarty et al. 1981) shows several key properties including the 

following:

• Hydrogen has a specific gravity of 0.0696, which explains its powerful buoyancy.

• Hydrogen has a boiling point of −423°F, which means that it takes a lot of energy to 

liquefy hydrogen and that liquid hydrogen presents hazards as a cryogenic fluid.

• It is not on the U.S. Environmental Protection Agency (EPA) List of Lists,

1 which means 

that it is not generally considered a pollutant.

• It has a liquid density of 4.23 lb/ft3, which means that it is a light liquid—there is more 

mass of hydrogen in a gallon of water than in a gallon of liquid hydrogen.

• Because of the very low boiling point, a liquid release of hydrogen will rapidly vaporize 

and very likely not reach the ground in liquid form.

 1 The EPA List of Lists is the list of all materials regulated by the EPA, 

http://www.epa.gov/emergencies/tools.htm#lol.
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Table 2. Hydrogen Properties

U.S. Units SI Units

Chemical formula H2 H2

Molecular weight 2.016 2.016

NFPA rating Health=0

Flammability=4

Instability=0

DOT classification 2.1

EPA list of lists No

Vapor pressure at −423°F (−252.8°C) 14.69 psia 101.283 kPa

Density of the gas at boiling point and 1 atm 0.083 lb/ft3 1.331 kg/m3

Specific gravity of the gas at 32°F and

1 atm (air=1) 0.0696 0.0696

Specific volume of the gas at 70°F (21.1°C)

and 1 atm 192.0 ft3

/lb 11.99 m3/kg

Specific gravity of the liquid at boiling point and 1 

atm 0.0710 0.0710

Density of the liquid at boiling point and 1 atm 4.23 lb/ft3 67.76 kg/m3

Boiling point at 14.69 psia (101.283 kPa) −423.0°F −252.8°C

Melting point at 14.69 psia (101.283 kPa) −434.5°F −259.2°C

Critical temperature −399.8°F −239.9°C

Critical pressure 188 psia 1296.212 kPa, abs

Critical density 1.88 lb/ft3 30.12 kg/m3

Triple point −434.8°F at 1.021 psia −259.3°C at 7.042 kPa, abs

Latent heat of fusion at triple point 24.97 Btu/lb 58.09 kJ/kg

Latent heat of vaporization at boiling point 191.7 Btu/lb 446.0 kJ/kg

Specific heat of the gas at 70°F (21.1°C) and 

1 atm

Cp 3.425 Btu/(lb)(°F) 14.34 kJ/(kg)(°C)

Cv 2.418 Btu/(lb)(°F) 10.12 kJ/(kg)(°C)

Ratio of specific heats 1.42 1.42

Solubility in water vol/vol at 60°F (15.6°C) 0.019 0.019

Flammable limits in air 4% to 75%

Air required for combustion -

Autoignition temperature 752°F 400°C
5

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The following paragraphs describe each table parameter in more detail.

1. Molecular weight. The molecular weight of a material is used in many calculations. For 

example, a basic equation used in industrial hygiene—calculating the required flow rate 

to dilute material—requires the use of the molecular weight. The specific gravity (and 

density) of a gas is proportional to the molecular weight. This means that as the 

molecular weight of a material increases, the gas density increases. This relationship does 

not hold true for liquids where the specific gravity of a liquid does not necessarily 

increase with the molecular weight of the material.

2. Chemical formula. The chemical formula shows the atoms that make up a chemical 

molecule and their approximate configuration. This information is important for several 

reasons. First, it tells what atoms make up the material. Second, the molecular 

configuration often indicates properties of the material. For example, materials that 

contain OH (oxygen–hydrogen) groups will likely have specific chemical properties.

3. NFPA rating. The NFPA rating system gives information on health hazards, flammability 

hazards, instability hazards, and other special hazards such as whether a material is an 

oxidizer. For health, flammability, and instability hazards, a scale of 0 to 4 is used with 

hazard level increasing with increasing numeric magnitude. The criteria that define the 

hazard levels are set forth in NFPA 704 Identification of the Hazards of Materials for 

Emergency Response 2001 edition.

DOT classification. The U.S. Department of Transportation (DOT) has a list of hazardous 

materials in 49 CFR 172.101. This hazard class identifies what the primary hazard of the 

material is and what packaging requirements, weight restrictions, and other shipping 

safety requirements would apply. The hazard classification scheme is listed in Table 3.

Table 3. DOT Hazard Classification Scheme

Label code Label name

1 Explosive

1.1 1 Explosive 1.11

1.2 1 Explosive 1.21

1.3 1 Explosive 1.31

1.4 1 Explosive 1.41

1.5 1 Explosive 1.51

1.6 1 Explosive 1.61

2.1 Flammable Gas

2.2 Non-Flammable Gas

2.3 Poison Gas

3 Flammable Liquid

4.1 Flammable Solid

4.2 Spontaneously Combustible
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4.3 Dangerous When Wet

5.1 Oxidizer

5.2 Organic Peroxide

6.1 (inhalation hazard, 

Zone A or B)

Poison Inhalation Hazard

6.1 (other than 

inhalation hazard, Zone 

A or B)

Poison

7 Radioactive

8 Corrosive

9 Class 9

4. EPA listed hazardous substance. These are substances listed in 40 CFR Table 302.4.

These are materials that are considered hazardous wastes if released into the 

environment. The column will either be marked as Yes, meaning the material is listed, or 

No, meaning the material is not listed. If the material is listed the reportable quantity will 

be shown in pounds. Note that there may be materials not listed that must be reported 

because they meet the definition of an unlisted waste under 40 CFR 261.2. However, this 

definition addresses solid materials and would likely not apply to most of the materials 

covered in this chapter. Also, most of these materials would be regulated as air pollutants 

and would be subject to air pollution control requirements under 40 CFR.

5. Boiling point. The NFPA 30 Flammable and Combustible Liquids Code defines the 

boiling point as follows:

The temperature at which the vapor pressure of a liquid equals the 

surrounding atmospheric pressure.

For purposes of defining the boiling point, atmospheric pressure shall be 

considered to be 14.7 psia (760 mm Hg). For mixtures that do not have a 

constant boiling point, the 20 percent evaporated point of a distillation 

performed in accordance with ASTM D 86, Standard Method of Test for 

Distillation of Petroleum Products, shall be considered to be the boiling 

point.

The boiling point is the temperature at which a material will make the 

phase transition from liquid to gas. This piece of information is critical in 

understanding what is happening to a material as the storage temperature 

changes. Many materials are stored under conditions such that the ambient 

temperature and eventually the material temperature can drop below the 

boiling point and the material will make a phase transition from a gas to a 

liquid.

6. Melting point. The melting point is the temperature at which a material makes the 

transition from the solid phase to the liquid phase. This information is important in 

determining the physical state of a material. There may be storage conditions that bring a 

material into the solid phase.
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7. Vapor pressure. The pressure of a vapor exerted by a pure liquid in equilibrium at a given 

temperature is referred to as the vapor pressure. The pressure exerted by the vapor is 

independent as long as there is liquid present. When all of the liquid in a system is 

vaporized, a further increase in volume will decrease the system pressure in accordance 

with the ideal gas law.

8. Gas density. The gas density is important data because it is the mass per unit volume at a 

given temperature and pressure. This is used to determine the pressure required to load a 

given mass of material into a gas storage container.

9. Gas specific density. This is the density relative to the density of air and will be a strong 

indicator of whether the gas will rise or sink after a release.

10. Liquid density. This is the mass per unit volume. Unlike gases, the density of liquids is 

not correlated to molecular weight.

11. Flammable limits in air. The flammable limits are the lower volume limit concentration 

of a chemical in air that will continue to propagate a flame once initiated. The flame

would propagate at any concentration from the lower limit until it reaches an upper limit 

where the fuel to air ratio is too rich and the flame is quenched. The upper limit may be 

of concern in a situation where a container with a saturated atmosphere is being vented. 

During the ventilation process the concentration will move from saturation through the 

upper flammable limit and into the concentration range where sustained combustion will 

occur.

12. Net heat of combustion. The heat of combustion is a measure of the amount of energy 

released during the combustion of a specific chemical. This information is a strong 

indicator of the impact that a chemical would have if it were involved in a fire.

13. Specific heat. The specific heat of a substance is the amount of heat it absorbs per degree 

of increased temperature. It is expressed as the thermal energy required to raise a unit 

mass of the chemical one temperature degree. The constant pressure and constant volume 

specific heats are given where data are available.

14. Air required for combustion. The air required for combustion is the volume of air 

required to achieve a stoichiometric mixture that will propagate a flame once initiated.

15. Ignition temperature. The temperature at which a chemical ignites.
8

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History of Hydrogen Technologies

Hydrogen has been used in industrial applications for more than 100 years (Austin 1984). As a 

result, the physical properties of hydrogen are well understood for many applications. The effect 

of hydrogen on a range of materials has been studied and there is extensive literature available on 

the properties of hydrogen and its effects on materials.

With the emergence of hydrogen fuel cell applications, the following areas are new:

• Storage of high pressure hydrogen in composite materials

• The potential exposure of the general public to high-pressure hydrogen fueling operations

• The location of high-pressure storage containers on vehicles where they are subject to the 

stresses of vehicle operation

• The widespread use of high-pressure hydrogen storage systems where they could be 

modified or damaged by individuals unqualified to work on these systems.

Discovery of Hydrogen

In 1761, Robert Boyle was able to produce hydrogen from reacting iron filings and dilute acids

(Lewis 2001). In 1776, Henry Cavendish identified hydrogen as a unique substance. In 1783, 

Antoine Lavoisier produced hydrogen (from iron) and named the material hydrogen (Lewis 

2001). In 1839 a British scientist, Sir William Robert Grove, developed the first hydrogenpowered fuel cell (Lewis 2001). He was able to produce an electric current flow by constructing 

a cathode, anode, ceramic membrane, and mixed acid conductive medium. This discovery 

eventually led to the current hydrogen-powered fuel cell.

Hydrogen has been a known material for more than 200 years. As a result of this relatively early 

discovery compared to other elements and the widespread industrial use, hydrogen properties are 

relatively well known. Hydrogen is arguably the most studied element (Rigden 2003). It has the 

simplest atomic structure, and as a result of that simple structure it has been used to verify 

fundamental atomic properties.

Hydrogen Use and Applications

Hydrogen has many industrial applications, the two most important (based on usage) being 

ammonia production and hydrogenation of petroleum products to improve combustion 

characteristics (Ramachandran and Menon 1998). Hydrogen is used in smaller quantities in a 

variety of industries and applications. Some of these applications are described below.

Glass Manufacturing

Larger panes of glass are manufactured using a tin bath upon which molten glass is deposited. 

The bath creates a flat smooth surface. To prevent oxidation, the tin bath is provided with a 

positive pressure protective atmosphere consisting of a mixture of nitrogen and hydrogen (Austin 

1984).
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Industrial Heat Transfer Fluid

Hydrogen is used as coolant in electric generating equipment. Its relatively low viscosity and 

high heat capacity make it an effective cooling material.

Hydrogen has a constant pressure heat capacity of 3.41 Btu/(lb R) and a gaseous viscosity of 

88.05 micropoise. It has a thermal conductivity of 0.17064 Watts/(m K) (McCarty et al. 1981).

Hydrogen can be used in approximately 100% concentration, which means that there is no 

oxygen present to support combustion.

The absence of oxygen in its cooling gas also means the generator’s high-voltage insulation 

system will not be damaged by any corona activity in the generator’s stator windings. The 

localized electric field near a conductor can be sufficiently concentrated to ionize air close to the 

conductors. This ionized air can create an electrical discharge that has the potential to damage 

equipment or ignite materials in their flammable concentration range. This is a significant factor 

in the machine's reliability.

Semiconductor Manufacturing

Hydrogen is used in semiconductor manufacturing primarily because of its reducing or oxygen 

scavenging properties (Wolff 2008). It is also an extremely effective heat transfer fluid, which is 

an advantageous property in some operations. Hydrogen is used in the following semiconductor 

manufacturing operations:

• Semiconductor manufacturing

• Semiconductor sintering

• Semiconductor packaging

• Wafer annealing.

Ammonia Production via the Haber-Bosch Process

The Haber-Bosch process can produce large amounts of ammonia. Fritz Haber discovered a

chemical reaction to produce ammonia and Carl Bosch developed the technology for 

commercial-scale production of ammonia (Austin 1984). This process is significant because it 

allows ammonia production on a scale to support large crop production. Ammonia and 

associated compounds are critical for providing nitrogen to crops.

The Haber process for production of ammonia is shown in the following chemical reaction:

1/2N2 (g) + 3/2H2 (g) ↔ NH3 (g).

The yield for this reaction is increased by using an iron catalyst and increasing the reaction 

pressure. Hydrogen is a raw feedstock for this reaction. Because of the demand for ammonia, 

hydrogen is an industrial gas that is produced in large quantities.

Hydrogen in the Petrochemical Industry

Hydrogen is used to reduce double bonds to single bonds in hydrocarbons. This reduction

process produces hydrocarbon fuels that have better combustion characteristics in internal 

combustion engines. Hydrogenation of petrochemicals is one of the largest uses of hydrogen.
10

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Hydrogen as a Fuel for Fuel Cells

As mentioned earlier, hydrogen can be converted into electricity using a fuel cell. These fuel 

cells can be placed in vehicles to provide electricity for vehicles powered by electric motors or 

they can be used as stationary sources of electricity. They offer advantages including no 

combustion emissions and, in the case of stationary fuel cells, reliable power that can be used in 

emergency situations such as storms or grid outages.

The basic reaction in a hydrogen-powered fuel cell is as follows:

H2 + 1/2O2 → H2O + e- (Larminie and Dicks 2003)

This reaction typically takes place in the presence of a platinum catalyst. The cost of the catalyst 

is one of the major factors that determine the overall cost of the fuel cell or cells. A single fuel 

cell does not provide sufficient power for most applications, so the fuel cells are stacked to 

increase power; hence the term fuel cell stack is used to describe the fuel cells used in both 

stationary and vehicular applications.

Hydrogen Safety Incidents

Pacific Northwest National Laboratory, a DOE national laboratory, administers a database of 

hydrogen incidents called H2LL, or Hydrogen Lessons Learned.

2 This database contains 

information about incidents that have been voluntarily reported although identifying information 

has been removed. These lessons learned provide information on safety issues and concerns with 

hydrogen technologies, but because they are not part of a systematic program of monitoring and 

reporting on defined processes, frequency information cannot be derived from this database. This 

database contains approximately 200 entries and is organized using the following classifications:

• Settings

• Equipment

• Damages and injuries

• Probable causes

• Contributing factors.

Many of these entries describe events involving the industrial use of hydrogen or hydrogen usage 

for applications other than fuel cell electric vehicles or the infrastructure required to support 

these vehicles. There are very few entries involving the retail use of hydrogen or hydrogen 

applications that involve exposure to the general public.

The following page shows a screenshot of the database home page.

 2 H2LL: Hydrogen Lessons Learned from Incidents and Near-Misses, http://h2tools.org/lessons/. 
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Regulations, Codes, and Standards

Hydrogen technologies are controlled through codes and standards in a manner similar to other 

fuels. Figure 1 illustrates the codes and standards hierarchy. The top level of the pyramid 

consists of building and fire codes that are directly adopted by jurisdictions and are therefore the 

law in the jurisdiction in which they are adopted. Any code or standard referenced in the body of 

a building or fire code adopted by a jurisdiction becomes a legally enforceable document in that 

jurisdiction. These reference documents must be written in an enforceable format to be 

referenced in building or fire codes. In the topical area of hydrogen technologies these 

documents comprise the second level of the pyramid. Key documents at this second level include

the NFPA 2 Hydrogen Technologies Code and the NFPA 853 Standard for Fuel Cell Energy 

Systems.

These documents contain references to component standards, which comprise the bottom or third 

rung of the pyramid. These component standards must also be written in legally enforceable text 

to be referenced by these second-level codes and standards. Examples of these documents 

include the CGA S series of documents for pressure relief devices and the American Society of 

Mechanical Engineers (ASME) B31.12 standard for piping.

Viewed as a package, these documents address all key aspects of system design, construction, 

operation, and maintenance. Compliance with these requirements should reduce the system risk 

to a safe level.

The timeline in Figure 1 reflects the development of hydrogen codes and standards over the last 

eight years.
13

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Figure 1. Timeline of codes and standards development and the codes and standards hierarchy

Fire and 

building codes

Hydrogen-specific codes

Example: NFPA 2

Component standards and equipment 

design codes

Example: CGA G-5.5 or ASME B31.12

2014 2013 2012 2011 2010 2009 2008 2007 2006 2005

California

references 

NFPA 2 in CFC

IFC 

references

NFPA 2

IFC Chapter 

22 Hydrogen 

Fueling

Draft 2nd ed. 

NFPA 2 

developed

NFPA 55 

published with 

clarified 

setback tables

NFPA 52 

authority 

added to 

NFPA 2

NFPA 2 

1st ed.

NFPA 2 

draft

Task 

Group 

Bulk 

Hydrogen

Task 

Group 

Bulk 

Hydrogen

NFPA 2 

first

committee 

meeting

NFPA 52 

2006 ed. 

w/ hydrogen 

fueling

SAE J2601 

revision 

complete

SAE J2579 

reissue

CGA H-10 

issued

SAE 

J2719 

issued

CSA H 

series of 

drafts 

issued

ASME 

B31.12 

issued

CSA 

HGV 4

UL2267
14

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At the federal level there are regulations, such as 29 CFR 1910 Subpart H Hazardous Materials,

that specifically address the storage, use, and handling of hydrogen. Table 4 gives an overview of 

the regulations, codes, and standards that address hydrogen technologies safety.

Table 4. Overview of Regulations, Codes, and Standards Related to Hydrogen Infrastructure 

Safety

Federal Regulations

OSHA Regulations 29 CFR 1910 

Subpart H

Safe storage, use, and handling of hydrogen in the workplace

DOT Regulations 49 CFR 171-179 Safe transport of hydrogen in commerce

U.S. National Codes

International Building Code (IBC) General construction requirements for building based on 

occupancy class

International Fire Code (IFC)/NFPA 1 

Uniform Fire Code

Requirements for hydrogen fueling stations, flammable gas, and 

cryogenic fluid storage

International Mechanical Code (IMC) Requirements for ventilation for hydrogen usage in indoor 

locations

International Fuel Gas Code (IFGC) Requirements for flammable gas piping

Hydrogen Technologies Specific Fire Codes and Standards

NFPA 2 Hydrogen Technologies 

Code

Comprehensive code for hydrogen technologies constructed of 

extract material from documents such as NFPA 55 and 853 and 

original material

NFPA 55 Compressed Gas and 

Cryogenic Fluids Code

Comprehensive gas safety code that addresses flammable gases 

as a class of hazardous materials and also contains hydrogenspecific requirements

NFPA 853 Standard for the 

Installation of Stationary Fuel Cell 

Power Systems

Covers installation of all commercial fuel cells including hydrogen 

PEM fuel cells

Hydrogen Technologies Component, Performance, and Installation Standards

ASME B31.3 and B31.12 Piping and 

Pipelines

Piping design and installation codes that also cover material 

selection

ASME Boiler and Pressure Vessel 

(BPV) Code

Addresses design of steel alloy and composite pressure vessels

CGA S series Addresses requirements for pressure relief devices for containers

CGA H Series Components and systems

UL 2075 Sensors

CSA H series of hydrogen 

component standards

CSA FC1 Stationary fuel cells

SAE J2601/SAE J2600 Dispensing and dispenser nozzles

The following sections from the OSHA regulations (found in 29 CFR §1910 Subpart H) address 

the storage, use, and handling of gaseous and liquefied hydrogen. Although these regulations are 

based on older NFPA documents they are federal regulations. Many jurisdictions will accept 

compliance with current codes and standards as meeting the OSHA regulations.
15

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§ 1910.103 Hydrogen.

(a) General—(1) Definitions. As used in this section (i) Gaseous hydrogen system 

is one in which the hydrogen is delivered, stored and discharged in the gaseous

form to consumer’s piping. The system includes stationary or movable containers, 

pressure regulators, safety relief devices, manifolds, interconnecting piping and 

controls. The system terminates at the point where hydrogen at service pressure 

first enters the consumer’s distribution piping.

(ii) Approved—Means, unless otherwise indicated, listed or approved by a 

nationally recognized testing laboratory. Refer to § 1910.7 for definition of 

nationally recognized testing laboratory.

(iii) Listed—See “approved”.

(iv) ASME—American Society of Mechanical Engineers.

(v) DOT Specifications—Regulations of the Department of Transportation 

published in 49 CFR Chapter I. (vi) DOT regulations—See § 1910.103 (a)(1)(v).

(2) Scope—(i) Gaseous hydrogen systems. (a) Paragraph (b) of this section 

applies to the installation of gaseous hydrogen systems on consumer premises 

where the hydrogen supply to the consumer premises originates outside the 

consumer premises and is delivered by mobile equipment.

(b) Paragraph (b) of this section does not apply to gaseous hydrogen systems 

having a total hydrogen content of less than 400 cubic feet, nor to hydrogen 

manufacturing plants or other establishments operated by the hydrogen supplier or 

his agent for the purpose of storing hydrogen and refilling portable containers, 

trailers, mobile supply trucks, or tank cars.

(ii) Liquefied hydrogen systems. (a) Paragraph (c) of this section applies to the 

installation of liquefied hydrogen systems on consumer premises.

(b) Paragraph (c) of this section does not apply to liquefied hydrogen portable 

containers of less than 150 liters (39.63 gallons) capacity; nor to liquefied 

hydrogen manufacturing plants or other establishments operated by the hydrogen 

supplier or his agent for the sole purpose of storing liquefied hydrogen and 

refilling portable containers, trailers, mobile supply trucks, or tank cars.

(b) Gaseous hydrogen systems—(1) Design—(i) Containers. (a) Hydrogen 

containers shall comply with one of the following:

(1) Designed, constructed, and tested in accordance with appropriate requirements 

of ASME Boiler and Pressure Vessel Code, section VIII—Unfired Pressure 

Vessels—1968, which is incorporated by reference as specified in § 1910.6.

(2) Designed, constructed, tested and maintained in accordance with U.S. 

Department of Transportation Specifications and Regulations.

(b) Permanently installed containers shall be provided with substantial 

noncombustible supports on firm noncombustible foundations.
16

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(c) Each portable container shall be legibly marked with the name “Hydrogen” in 

accordance with the marking requirements set forth in § 1910.253(b)(1)(ii). Each 

manifolded hydrogen supply unit shall be legibly marked with the name 

“Hydrogen” or a legend such as “This unit contains hydrogen.”

(ii) Safety relief devices. (a) Hydrogen containers shall be equipped with safety 

relief devices as required by the ASME Boiler and Pressure Vessel Code, section

VIII Unfired Pressure Vessels, 1968 or the DOT Specifications and Regulations 

under which the container is fabricated.

(b) Safety relief devices shall be arranged to discharge upward and unobstructed 

to the open air in such a manner as to prevent any impingement of escaping gas 

upon the container, adjacent structure or personnel. This requirement does not 

apply to DOT Specification containers having an internal volume of 2 cubic feet 

or less.

(c) Safety relief devices or vent piping shall be designed or located so that 

moisture cannot collect and freeze in a manner which would interfere with proper 

operation of the device.

(iii) Piping, tubing, and fittings. (a) Piping, tubing, and fittings shall be suitable 

for hydrogen service and for the pressures and temperatures involved. Cast iron 

pipe and fittings shall not be used.

(b) Piping and tubing shall conform to section 2—“Industrial Gas and Air

Piping”—Code for Pressure Piping, ANSI B31.1–1967 with addenda B31.1–

1969, which is incorporated by reference as specified in § 1910.6.

(c) Joints in piping and tubing may be made by welding or brazing or by use of 

flanged, threaded, socket, or compression fittings. Gaskets and thread sealants 

shall be suitable for hydrogen service.

(iv) Equipment assembly. (a) Valves, gauges, regulators, and other accessories 

shall be suitable for hydrogen service.

(b) Installation of hydrogen systems shall be supervised by personnel familiar 

with proper practices with reference to their construction and use.

(c) Storage containers, piping, valves, regulating equipment, and other accessories

shall be readily accessible, and shall be protected against physical damage and 

against tampering.

(d) Cabinets or housings containing hydrogen control or operating equipment 

shall be adequately ventilated.

(e) Each mobile hydrogen supply unit used as part of a hydrogen system shall be 

adequately secured to prevent movement.

(f) Mobile hydrogen supply units shall be electrically bonded to the system before 

discharging hydrogen.

(v) Marking. The hydrogen storage location shall be permanently placarded as 

follows: “HYDROGEN—FLAMMABLE GAS—NO SMOKING—NO OPEN 

FLAMES,” or equivalent.
17

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(vi) Testing. After installations, all piping, tubing, and fittings shall be tested and 

proved hydrogen gas tight at maximum operating pressure.

(2) Location—(i) General. (a) The system shall be located so that it is readily

accessible to delivery equipment and to authorized personnel.

(b) Systems shall be located aboveground.

(c) Systems shall not be located beneath electric power lines.

(d) Systems shall not be located close to flammable liquid piping or piping of 

other flammable gases.

(e) Systems near aboveground flammable liquid storage shall be located on 

ground higher than the flammable liquid storage except when dikes, diversion 

curbs, grading, or separating solid walls are used to prevent accumulation of 

flammable liquids under the system.

(ii) Specific requirements. (a) The location of a system, as determined by the 

maximum total contained volume of hydrogen, shall be in the order of preference 

as indicated by Roman numerals in Table H–1.

TABLE H–1

Nature of location

Size of hydrogen system

Less than 

3,000 CF

3,000 CF 

to 15,000 

CF

In excess 

of 15,000 

CF

Outdoors I IDI

In a separate building II II II

In a special room III III Not 

permitted

Inside buildings not in 

a special room and 

exposed to other 

occupancies

IV Not 

permitted

Not 

permitted

(b) The minimum distance in feet from a hydrogen system of indicated capacity 

located outdoors, in separate buildings or in special rooms to any specified 

outdoor exposure shall be in accordance with Table H–2.

(c) The distances in Table H–2 Items 1 and 3 to 10 inclusive do not apply where 

protective structures such as adequate fire walls are located between the system 

and the exposure.
18

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TABLE H–2

Type of outdoor exposure

Size of hydrogen system

Less than 

3,000 CF

3,000 CF 

to 15,000 

CF

In excess 

of 15,000 

CF

1. Building or structure Wood frame construction 1

Heavy timber, noncombustible or 

ordinary construction 1

Fire-resistive construction 1

10

0

0

25

10

0

50

2 25

0

2. Wall openings Not above any part of a system

Above any part of a system

10

25

10

25

10

25

3. Flammable liquids above ground 0 to 1,000 gallons

In excess of 1,000 gallons

10

25

25

50

25

50

4. Flammable liquids below ground—0 to 

1,000 gallons

Tank

Vent or fill opening of tank

10

25

10

25

10

25

5. Flammable liquids below ground—in 

excess of 1,000 gallons

Tank

Vent or fill opening of tank

20

25

20

25

20

25

6. Flammable gas storage, either high 

pressure or low pressure

0 to 15,000 CF capacity

In excess of 15,000 CF capacity

10

25

25

50

25

50

7. Oxygen storage 12,000 CF or less 4

More than 12,000 CF 5 ----

--

--

--

--

8. Fast burning solids such as ordinary lumber, excelsior or paper 50 50 50

9. Slow burning solids such as heavy timber or coal 25 25 25

10. Open flames and other sources of ignition 25 25 25

11. Air compressor intakes or inlets to ventilating or air-conditioning equipment 50 50 50

12. Concentration of people 3 25 50 50

1 Refer to NFPA No. 220 Standard Types of Building Construction for definitions of various types of construction. 

(1969 Ed.)

2 But not less than one-half the height of adjacent side wall of the structure. 3 In congested areas such as offices, lunchrooms, locker rooms, time-clock areas. 4 Refer to NFPA No 51, gas systems for welding and cutting (1969). 5 Refer to NFPA No 566, bulk oxygen systems at consumer sites (1969).

(d) Hydrogen systems of less than 3,000 CF when located inside buildings and 

exposed to other occupancies shall be situated in the building so that the system 

will be as follows:

(1) In an adequately ventilated area as in paragraph (b)(3)(ii)(b) of this section.

(2) Twenty feet from stored flammable materials or oxidizing gases.

(3) Twenty-five feet from open flames, ordinary electrical equipment or other 

sources of ignition.

(4) Twenty-five feet from concentrations of people.

(5) Fifty feet from intakes of ventilation or air-conditioning equipment and air 

compressors.

(6) Fifty feet from other flammable gas storage.

(7) Protected against damage or injury due to falling objects or working activity in 

the area.
19

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(8) More than one system of 3,000 CF or less may be installed in the same room, 

provided the systems are separated by at least 50 feet. Each such system shall 

meet all of the requirements of this paragraph.

(3) Design consideration at specific locations—(i) Outdoor locations. (a) Where

protective walls or roofs are provided, they shall be constructed of 

noncombustible materials.

(b) Where the enclosing sides adjoin each other, the area shall be properly

ventilated.

(c) Electrical equipment within 15 feet shall be in accordance with subpart S of 

this part.

(ii) Separate buildings. (a) Separate buildings shall be built of at least 

noncombustible construction. Windows and doors shall be located so as to be

readily accessible in case of emergency. Windows shall be of glass or plastic in 

metal frames.

(b) Adequate ventilation to the outdoors shall be provided. Inlet openings shall be 

located near the floor in exterior walls only. Outlet openings shall be located at 

the high point of the room in exterior walls or roof. Inlet and outlet openings shall 

each have minimum total area of one (1) square foot per 1,000 cubic feet of room 

volume. Discharge from outlet openings shall be directed or conducted to a safe

location.

(c) Explosion venting shall be provided in exterior walls or roof only. The venting 

area shall be equal to not less than 1 square foot per 30 cubic feet of room volume 

and may consist of any one or any combination of the following: Walls of light, 

noncombustible material, preferably single thickness, single strength glass; lightly 

fastened hatch covers; lightly fastened swinging doors in exterior walls opening 

outward; lightly fastened walls or roof designed to relieve at a maximum pressure

of 25 pounds per square foot.

(d) There shall be no sources of ignition from open flames, electrical equipment,

or heating equipment.

(e) Electrical equipment shall be in accordance with subpart S of this part for 

Class I, Division 2 locations.

(f) Heating, if provided, shall be by steam, hot water, or other indirect means.

(iii) Special rooms. (a) Floor, walls, and ceiling shall have a fire-resistance rating 

of at least 2 hours. Walls or partitions shall be continuous from floor to ceiling 

and shall be securely anchored. At least one wall shall be an exterior wall. 

Openings to other parts of the building shall not be permitted. Windows and doors 

shall be in exterior walls and shall be located so as to be readily accessible in case 

of emergency. Windows shall be of glass or plastic in metal frames.

(b) Ventilation shall be as provided in paragraph (b)(3)(ii)(b) of this section.

(c) Explosion venting shall be as provided in paragraph (b)(3)(ii)(c) of this

section.
20

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(d) There shall be no sources of ignition from open flames, electrical equipment,

or heating equipment.

(e) Electric equipment shall be in accordance with the requirements of subpart S 

of this part for Class I, Division 2 locations.

(f) Heating, if provided, shall be by steam, hot water, or indirect means.

(4) Operating instructions. For installations which require any operation of

equipment by the user, legible instructions shall be maintained at operating

locations.

(5) Maintenance. The equipment and functioning of each charged gaseous

hydrogen system shall be maintained in a safe operating condition in accordance

with the requirements of this section. The area within 15 feet of any hydrogen

container shall be kept free of dry vegetation and combustible material.

(c) Liquefied hydrogen systems—(1) Design—(i) Containers. (a) Hydrogen 

containers shall comply with the following: Storage containers shall be designed,

constructed, and tested in accordance with appropriate requirements of the ASME 

Boiler and Pressure Vessel Code, section VIII—Unfired Pressure Vessels (1968) 

or applicable provisions of API Standard 620, Recommended Rules for Design 

and Construction of Large, Welded, Low-Pressure Storage Tanks, Second Edition

(June 1963) and appendix R (April 1965), which is incorporated by reference as

specified in § 1910.6.

(b) Portable containers shall be designed, constructed and tested in accordance

with DOT Specifications and Regulations.

(ii) Supports. Permanently installed containers shall be provided with substantial

noncombustible supports securely anchored on firm noncombustible foundations. 

Steel supports in excess of 18 inches in height shall be protected with a protective 

coating having a 2-hour fire-resistance rating.

(iii) Marking. Each container shall be legibly marked to indicate “LIQUEFIED

HYDROGEN—FLAMMABLE GAS.”

(iv) Safety relief devices. (a)(1) Stationary liquefied hydrogen containers shall be 

equipped with safety relief devices sized in accordance with CGA Pamphlet S–1, 

part 3, Safety Relief Device Standards for Compressed Gas Storage Containers, 

which is incorporated by reference as specified in § 1910.6.

(2) Portable liquefied hydrogen containers complying with the U.S. Department

of Transportation Regulations shall be equipped with safety relief devices as 

required in the U.S. Department of Transportation Specifications and Regulations. 

Safety relief devices shall be sized in accordance with the requirements of CGA 

Pamphlet S–1, Safety Relief Device Standards, part 1, Compressed Gas Cylinders 

and part 2, Cargo and Portable Tank Containers.

(b) Safety relief devices shall be arranged to discharge unobstructed to the 

outdoors and in such a manner as to prevent impingement of escaping liquid or 

gas upon the container, adjacent structures or personnel. See paragraph (c)(2)(i)(f) 

of this section for venting of safety relief devices in special locations.
21

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(c) Safety relief devices or vent piping shall be designed or located so that

moisture cannot collect and freeze in a manner which would interfere with proper 

operation of the device.

(d) Safety relief devices shall be provided in piping wherever liquefied hydrogen

could be trapped between closures.

(v) Piping, tubing, and fittings. (a) Piping, tubing, and fittings and gasket and

thread sealants shall be suitable for hydrogen service at the pressures and

temperatures involved. Consideration shall be given to the thermal expansion and 

contraction of piping systems when exposed to temperature fluctuations of 

ambient to liquefied hydrogen temperatures.

(b) Gaseous hydrogen piping and tubing (above –20 °F.) shall conform to the 

applicable sections of Pressure Piping section 2—Industrial Gas and Air Piping, 

ANSI B31.1–1967 with addenda B31.1–1969. Design of liquefied hydrogen or 

cold (–20 °F. or below) gas piping shall use Petroleum Refinery Piping ANSI 

B31.3–1966 or Refrigeration Piping ANSI B31.5–1966 with addenda B31.5a–

1968 as a guide, which are incorporated by reference as specified in § 1910.6.

(c) Joints in piping and tubing shall preferably be made by welding or brazing;

flanged, threaded, socket, or suitable compression fittings may be used.

(d) Means shall be provided to minimize exposure of personnel to piping

operating at low temperatures and to prevent air condensate from contacting

piping, structural members, and surfaces not suitable for cryogenic temperatures.

Only those insulating materials which are rated nonburning in accordance with 

ASTM Procedures D1692–68, which is incorporated by reference as specified in 

§ 1910.6, may be used. Other protective means may be used to protect personnel. 

The insulation shall be designed to have a vapor-tight seal in the outer covering to 

prevent the condensation of air and subsequent oxygen enrichment within the 

insulation. The insulation material and outside shield shall also be of adequate 

design to prevent attrition of the insulation due to normal operating conditions.

(e) Uninsulated piping and equipment which operate at liquefied-hydrogen

temperature shall not be installed above asphalt surfaces or other combustible

materials in order to prevent contact of liquid air with such materials. Drip pans 

may be installed under uninsulated piping and equipment to retain and vaporize 

condensed liquid air.

(vi) Equipment assembly. (a) Valves, gauges, regulators, and other accessories 

shall be suitable for liquefied hydrogen service and for the pressures and 

temperatures involved.

(b) Installation of liquefied hydrogen systems shall be supervised by personnel 

familiar with proper practices and with reference to their construction and use.

(c) Storage containers, piping, valves, regulating equipment, and other accessories 

shall be readily accessible and shall be protected against physical damage and 

against tampering. A shutoff valve shall be located in liquid product withdrawal 

lines as close to the container as practical. On containers of over 2,000 gallons 

capacity, this shutoff valve shall be of the remote control type with no 
22

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connections, flanges, or other appurtenances (other than a welded manual shutoff 

valve) allowed in the piping between the shutoff valve and its connection to the 

inner container.

(d) Cabinets or housings containing hydrogen control equipment shall be 

ventilated to prevent any accumulation of hydrogen gas.

(vii) Testing. (a) After installation, all field-erected piping shall be tested and 

proved hydrogen gas-tight at operating pressure and temperature.

(b) Containers if out of service in excess of 1 year shall be inspected and tested as 

outlined in (a) of this subdivision. The safety relief devices shall be checked to

determine if they are operable and properly set.

(viii) Liquefied hydrogen vaporizers. (a) The vaporizer shall be anchored and its 

connecting piping shall be sufficiently flexible to provide for the effect of 

expansion and contraction due to temperature changes.

(b) The vaporizer and its piping shall be adequately protected on the hydrogen 

and heating media sections with safety relief devices.

(c) Heat used in a liquefied hydrogen vaporizer shall be indirectly supplied 

utilizing media such as air, steam, water, or water solutions.

(d) A low temperature shutoff switch shall be provided in the vaporizer discharge 

piping to prevent flow of liquefied hydrogen in the event of the loss of the heat 

source.

(ix) Electrical systems. (a) Electrical wiring and equipment located within 3feet 

of a point where connections are regularly made and disconnected, shall be in 

accordance with subpart S of this part, for Class I, Group B, Division 1 locations.

(b) Except as provided in (a) of this subdivision, electrical wiring, and equipment 

located within 25 feet of a point where connections are regularly made and 

disconnected or within 25 feet of a liquid hydrogen storage container, shall be in 

accordance with subpart S of this part, for Class I, Group B, Division 2 locations. 

When equipment approved for class I, group B atmospheres is not commercially 

available, the equipment may be—

(1) Purged or ventilated in accordance with NFPA No. 496–1967, Standard for 

Purged Enclosures for Electrical Equipment in Hazardous Locations,

(2) Intrinsically safe, or

(3) Approved for Class I, Group C atmospheres. This requirement does not apply 

to electrical equipment which is installed on mobile supply trucks or tank cars 

from which the storage container is filled.

(x) Bonding and grounding. The liquefied hydrogen container and associated 

piping shall be electrically bonded and grounded.

(2) Location of liquefied hydrogen storage—(i) General requirements. (a) The 

storage containers shall be located so that they are readily accessible to mobile 

supply equipment at ground level and to authorized personnel.
23

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(b) The containers shall not be exposed by electric power lines, flammable liquid 

lines, flammable gas lines, or lines carrying oxidizing materials.

(c) When locating liquefied hydrogen storage containers near above-ground 

flammable liquid storage or liquid oxygen storage, it is advisable to locate the 

liquefied hydrogen container on ground higher than flammable liquid storage or 

liquid oxygen storage.

(d) Where it is necessary to locate the liquefied hydrogen container on ground that 

is level with or lower than adjacent flammable liquid storage or liquid oxygen 

storage, suitable protective means shall be taken (such as by diking, diversion 

curbs, grading), with respect to the adjacent flammable liquid storage or liquid 

oxygen storage, to prevent accumulation of liquids within 50 feet of the liquefied 

hydrogen container.

(e) Storage sites shall be fenced and posted to prevent entrance by unauthorized 

personnel. Sites shall also be placarded as follows: “Liquefied Hydrogen—

Flammable Gas—No Smoking—No Open Flames.”

(f) If liquefied hydrogen is located in (as specified in Table H–3) a separate 

building, in a special room, or inside buildings when not in a special room and 

exposed to other occupancies, containers shall have the safety relief devices 

vented unobstructed to the outdoors at a minimum elevation of 25 feet above 

grade to a safe location as required in paragraph (c)(1)(iv)(b) of this section.

(ii) Specific requirements. (a) The location of liquefied hydrogen storage, as 

determined by the maximum total quantity of liquefied hydrogen, shall be in the 

order of preference as indicated by Roman numerals in the following Table H–3.

TABLE H–3—MAXIMUM TOTAL QUANTITY OF LIQUEFIED HYDROGEN STORAGE PERMITTED

Nature of location

Size of hydrogen storage (capacity in gallons)

39.63 (150 liters) 

to 50 51 to 300 301 to 600 In excess of 600

Outdoors I I I I

In a separate building II II II Not permitted

In a special room III III Not permitted Do.

Inside buildings not in a special room 

and exposed to other occupancies 

IV Not permitted Do. Do.

NOTE: This table does not apply to the storage in dewars of the type generally used in laboratories for 

experimental purposes.

(b) The minimum distance in feet from liquefied hydrogen systems of indicated 

storage capacity located outdoors, in a separate building, or in a special room to 

any specified exposure shall be in accordance with Table H–4.
24

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TABLE H–4—MINIMUM DISTANCE (FEET) FROM LIQUEFIED HYDROGEN SYSTEMS TO 

EXPOSURE 1,2

Type of Exposure

Liquefied hydrogen storage (capacity in 

gallons)

39.63 (150 liters) 

to 3,500

3,501 to 

15,000

15,001 to 

30,000

1. Fire-resistive building and fire walls 3 5 5 5

2. Noncombustible building 3 25 50 75

3. Other buildings 3 50 75 100

4. Wall openings, air-compressor intakes, inlets for air-conditioning 

or ventilating equipment

75 75 75

5. Flammable liquids (above ground and vent or fill openings if 

below ground) (see 513 and 514)

50 75 100

6. Between stationary liquefied hydrogen containers 5 5 5

7. Flammable gas storage 50 75 100

8. Liquid oxygen storage and other oxidizers (see 513 and 514) 100 100 100

9. Combustible solids 50 75 100

10. Open flames, smoking and welding 50 50 50

11. Concentrations of people 75 75 75

1 The distance in Nos. 2, 3, 5, 7, 9, and 12 in Table H-4 may be reduced where protective structures, such as 

firewalls equal to height of top of the container, to safeguard the liquefied hydrogen storage system, are located 

between the liquefied hydrogen storage installation and the exposure. 2 Where protective structures are provided, ventilation and confinement of product should be considered. The 5-foot 

distance in Nos. 1 and 6 facilitates maintenance and enhances ventilation.

3 Refer to Standard Types of Building Construction, NFPA No. 220-1969 for definitions of various types of 

construction. 

In congested areas such as offices, lunchrooms, locker rooms, time-clock areas.

(iii) Handling of liquefied hydrogen inside buildings other than separate buildings 

and special rooms. Portable liquefied hydrogen containers of 50 gallons or less 

capacity as permitted in Table H–3 and in compliance with subdivision (i)(f) of 

this subparagraph when housed inside buildings not located in a special room and 

exposed to other occupancies shall comply with the following minimum

requirements:

(a) Be located 20 feet from flammable liquids and readily combustible materials

such as excelsior or paper.

(b) Be located 25 feet from ordinary electrical equipment and other sources of 

ignition including process or analytical equipment.

(c) Be located 25 feet from concentrations of people.

(d) Be located 50 feet from intakes of ventilation and air-conditioning equipment 

or intakes of compressors.

(e) Be located 50 feet from storage of other flammable-gases or storage of 

oxidizing gases.

(f) Containers shall be protected against damage or injury due to falling objects or 

work activity in the area.

(g) Containers shall be firmly secured and stored in an upright position.
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(h) Welding or cutting operations, and smoking shall be prohibited while

hydrogen is in the room.

(i) The area shall be adequately ventilated. Safety relief devices on the containers 

shall be vented directly outdoors or to a suitable hood. See paragraphs

(c)(1)(iv)(b) and (c)(2)(i)(f) of this section.

(3) Design considerations at specific locations—(i) Outdoor locations. (a) 

Outdoor location shall mean outside of any building or structure, and includes 

locations under a weather shelter or canopy provided such locations are not 

enclosed by more than two walls set at right angles and are provided with ventspace between the walls and vented roof or canopy.

(b) Roadways and yard surfaces located below liquefied hydrogen piping, from 

which liquid air may drip, shall be constructed of noncombustible materials.

(c) If protective walls are provided, they shall be constructed of noncombustible 

materials and in accordance with the provisions of paragraph (c)(3)(i)(a) of this 

section.

(d) Electrical wiring and equipment shall comply with paragraph (c)(1)(ix) (a) 

and (b) of this section.

(e) Adequate lighting shall be provided for nighttime transfer operation.

(ii) Separate buildings. (a) Separate buildings shall be of light noncombustible 

construction on a substantial frame. Walls and roofs shall be lightly fastened and 

designed to relieve at a maximum internal pressure of 25 pounds per square foot. 

Windows shall be of shatterproof glass or plastic in metal frames. Doors shall be 

located in such a manner that they will be readily accessible to personnel in an 

emergency.

(b) Adequate ventilation to the outdoors shall be provided. Inlet openings shall be 

located near the floor level in exterior walls only. Outlet openings shall be located 

at the high point of the room in exterior walls or roof. Both the inlet and outlet 

vent openings shall have a minimum total area of 1 square foot per 1,000 cubic 

feet of room volume. Discharge from outlet openings shall be directed or 

conducted to a safe location.

(c) There shall be no sources of ignition.

(d) Electrical wiring and equipment shall comply with paragraphs (c)(1)(ix) (a) 

and (b) of this section except that the provisions of paragraph (c)(1)(ix)(b) of this 

section shall apply to all electrical wiring and equipment in the separate building.

(e) Heating, if provided, shall be by steam, hot water, or other indirect means.

(iii) Special rooms. (a) Floors, walls, and ceilings shall have a fire resistance 

rating of at least 2 hours. Walls or partitions shall be continuous from floor to 

ceiling and shall be securely anchored. At least one wall shall be an exterior wall. 

Openings to other parts of the building shall not be permitted. Windows and doors 

shall be in exterior walls and doors shall be located in such a manner that they 
26

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will be accessible in an emergency. Windows shall be of shatterproof glass or 

plastic in metal frames.

(b) Ventilation shall be as provided in paragraph (c)(3)(ii)(b) of this section.

(c) Explosion venting shall be provided in exterior walls or roof only. The venting 

area shall be equal to not less than 1 square foot per 30 cubic feet of room volume 

and may consist of any one or any combination of the following: Walls of light 

noncombustible material; lightly fastened hatch covers; lightly fastened swinging 

doors opening outward in exterior walls; lightly fastened walls or roofs designed 

to relieve at a maximum pressure of 25 pounds per square foot.

(d) There shall be no sources of ignition.

(e) Electrical wiring and equipment shall comply with paragraph (c)(1)(ix) (a) and 

(b) of this section except that the provision of paragraph (c)(1)(ix)(b) of this 

section shall apply to all electrical wiring and equipment in the special room.

(f) Heating, if provided, shall be steam, hot water, or by other indirect means.

(4) Operating instructions—(i) Written instructions. For installations which 

require any operation of equipment by the user, legible instructions shall be 

maintained at operating locations.

(ii) Attendant. A qualified person shall be in attendance at all times while the 

mobile hydrogen supply unit is being unloaded.

(iii) Security. Each mobile liquefied hydrogen supply unit used as part of a 

hydrogen system shall be adequately secured to prevent movement.

(iv) Grounding. The mobile liquefied hydrogen supply unit shall be grounded for 

static electricity.

(5) Maintenance. The equipment and functioning of each charged liquefied 

hydrogen system shall be maintained in a safe operating condition in accordance 

with the requirements of this section. Weeds or similar combustibles shall not be 

permitted within 25 feet of any liquefied hydrogen equipment.

[39 FR 23502, June 27, 1974, as amended at 43 FR 49746, Oct. 24, 1978; 53 FR 

12121, Apr. 12, 1988; 55 FR 32015, Aug. 6, 1990; 58 FR 35309, June 30, 1993; 

61 FR 9236, 9237, Mar. 7, 1996; 69 FR 31881, June 8, 2004; 72 FR 71069, Dec. 

14, 2007]
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Material Selection for Hydrogen Technologies

Hydrogen can damage storage, piping, and appurtenance materials through processes that are 

partially a function of the relatively small size of the hydrogen molecule. There is an extensive 

literature that covers the destructive capabilities of hydrogen and its effects on materials. Volume 

13a of the American Society of Materials (ASM) handbook series, “Corrosion: Fundamentals, 

Testing, and Protection,” has a chapter devoted to hydrogen (Cramer and Covino 2003).

This guide is primarily focused on assisting with deployment of emerging hydrogen 

technologies, so there will be no literature review. Instead there is a brief discussion of the 

resources available to use when selecting materials for use in hydrogen fueling systems and 

storage systems for stationary fuel cells. Several of these resources are found in codes and 

standards documents. The ASME documents provide key requirements for deploying hydrogen 

technologies.

The ASME B31.12 Hydrogen Pipelines and Piping code specifies materials that can be used for 

hydrogen applications. This material selection information is found in Chapter GR-2 of the code.

The ASME BPV code provides extensive information on material selection and testing for 

hydrogen usage. This material covers the use of both metals and composite materials for 

container construction. This topic is initially covered in Section A, Part UG. The ASME BPV 

Section XIII also contains Code Case 2579-3 Composite Reinforced Pressure Vessels for 

Gaseous H2 Service.

Both of these ASME documents are or will be referenced in building and fire codes and are 

therefore likely enforceable requirements in most jurisdictions in the United States.

The ASME B31.12 documents give procedures for calculating pipe diameters based on operation 

parameters. Chapter GR-2—Materials addresses the following topics:

• Materials and specification

• Temperature limitations

• Impact testing methods and acceptance criteria

• Fluid service requirements for materials

• Deterioration of materials in service

• Joining and auxiliary materials.

The Canadian Standards Association (CSA) document CSA CHMC-1 addresses material testing 

for hydrogen applications. ANSI/CSA CHMC 1—2014 Test Method for Evaluating Material 

Compatibility in Compressed Hydrogen Applications—Phase I—Metals has the following 

scope:

This standard provides uniform test methods for evaluating material compatibility 

with compressed hydrogen applications. The results of these tests are intended to 

provide a basic comparison of materials performance in applications utilizing 

compressed hydrogen. This standard is not intended to replace the targeted testing 
28

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which may be necessary to qualify the design of a component manufactured for 

use in hydrogen applications.

The American Society of Testing Materials (ASTM) has published a book on hydrogen 

embrittlement entitled “Hydrogen Embrittlement: Prevention and Control ASTM STP 692.” This 

book covers the different test methods used to evaluate metals susceptibility to hydrogen attack.

Sandia National Laboratories has published a guide for selecting materials for hydrogen 

technology applications. This document is a compendium of papers detailing the material 

selection criteria for different types of materials that could potentially be used for hydrogen 

applications. It can be found at the following website: http://www.sandia.gov/matlsTechRef/.
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Component Selection for Hydrogen Technologies

Hydrogen component selection and material selection are closely related topics. Components 

must be sized to handle the design loads and materials must be selected that can perform safely 

and reliably over the life of the component. Hydrogen has been used in industrial processes so 

there is information on components that will perform in hydrogen environments that can be used 

in developing hydrogen applications such as hydrogen fuel cell vehicles and stationary 

hydrogen-powered fuel cells. There are several codes and standards that set component design or 

performance requirements. The following are some of the documents that address component 

design:

• ASME B31.12 Hydrogen Pipelines and Piping for pipe sizing procedures

• CGA S-1.1 through 1.3 for pressure relief devices for hydrogen storage containers

• ASME BPV Section XIII for hydrogen containers

• DOT 49 CFR 171-179 for hydrogen cylinders

• CGA H.3 for hydrogen vent systems

• UL 2075 for hydrogen sensors

• NIST Handbook 44 for hydrogen meters

• CSA HGV 4.2 for hydrogen hoses

• CSA HGV 4.2 for hydrogen nozzles.

Hydrogen storage systems typically include the following components:

• Valves

• Pressure relief devices

• Pumps/compressors

• Sensors/detection systems

• Storage containers

• Vent stacks.

Hydrogen dispensing systems typically include the following additional components:

• Meters

• Nozzles

• Dispensing hoses

• Emergency shutoffs or “E stops”

• Sensors for detecting hydrogen leaks.

Component selection consists of sizing and system design. This section cannot address system 

design because that topic is too complex for a guidance document. Generally, hydrogen systems 
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should be designed by engineers with training and experience in system design. Many states 

require that the system be designed by a licensed professional engineer and that all drawings and 

related design documents be sealed.

Design standards for hydrogen system components include the following:

• ASME Boiler and Pressure Vessel Code for tank design

• The CGA S-1.1 through 1.3 for pressure relief device standards

• The CGA H-7 for hydrogen vent systems

• ASME B31.12 for hydrogen piping

• The UL 2075 standard for hydrogen sensors

• The CSA H-7 for hydrogen fueling nozzles

• The CSA H-4 for hydrogen fueling hoses.

The National Renewable Energy Laboratory (NREL) conducted a process hazard analysis (PHA) 

on a representative hydrogen fueling system to better understand the relative risks of the pieces 

of the system. See Appendix A for a full description of the PHA, which gives a picture of the 

components of most concern in a hydrogen fueling system.

The results of this analysis show that the following three nodes present the greatest risk:

1. Compressors

2. Fueling hoses

3. Fueling nozzles.

Only fueling hoses had any failure scenarios that, after safety measures were considered, had 

risks above the low risk level. This result is significant because individuals are directly exposed 

to fueling hoses during fueling operations.

There are a variety of problems with the fueling system components. These problems generally 

fall under the heading of unintended releases brought on by both the high pressure and 

temperature variations that these systems must accommodate. NREL technology validation data 

were used to develop frequency ratings for the incidents associated with system components. The 

relative ranking shown in Table A-3 demonstrates the importance of compressor performance.

The NREL data show a relatively high number of leaks in compressors. These leaks often have a 

significant impact on fueling system performance because they require shutting systems down to 

repair the compressor.

The PHA analysis provided a ranking of hydrogen fueling system component risks. This ranking 

is important for prioritizing safety and performance issues and research required to resolve these 

issues.

The high level of public exposure for hoses and nozzles makes them of particular concern. The 

general public will conduct vehicle fueling and handle the fueling nozzle and hose. A failure of 

either of these components could have severe short- and long-term impacts.
31

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The Permitting Process

The permitting process is actually several processes typically involving multiple permits and 

agencies. The processes are in place to protect public safety, public health, and the environment. 

An example of the permits, agencies, and purposes for these multiple processes is shown in 

Table 5.

The permitting processes can be broken down into the following seven stages that help define the 

overall process and the timeline for completing all of the required components:

1. Preliminary project scoping

2. Station design

3. Approval process

4. Station/dispenser construction

5. Station/dispenser startup

6. Station/dispenser operation

7. Station/dispenser maintenance.

The required permits address all of these phases, but the permitting structure does not correlate 

on a one-to-one basis with the chronological steps required to build and operate a dispensing 

station. Table 5 and Table 6 list elements of the permitting and approval processes. The 

difference between these tables is that there are regulatory agencies that typically issue a permit 

after the applicant has shown compliance with requirements and agencies that approve of an 

applicant’s submission without issuing a permit.
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Table 5. Hydrogen Dispensing Station Permitting/Potential Permits Required

Permit Agency Permit / Permit Scope

Construction Building department Permit to construct general /

Address safety construction issues

Drainage Engineering department Permit to construct drainage /

Modification to sewer drainage

Site grading Engineering department Permit to construct grading /

Modification to site elevation

Electrical Building/electrical department Electrical permit /

Modification to electrical service

Demolition Building department Construction permit /

Demolish structures required for dispenser 

construction

Food services Health department Food sales

Air emission 

impacts

State air pollution control 

agency

Air quality permit or no impact declaration

Fire safety Fire department plans review

office

Fire safety permit /

General fire code compliance

Water quality Water quality management 

agency

Liquid discharges to the environment

Table 6. Hydrogen Dispensing Station Approvals

Approval Agency Approval Scope

State environmental 

quality act 

Self-enforcing although local 

authority having jurisdiction 

(AHJ) has first opportunity to 

enforce

Approval or finding of no significant impact/ 

environmental agency having jurisdiction

Zoning Local zoning board Zoning approval/allows construction and 

operation at defined location

State accidental 

release prevention 

program

Local administering agency 

(for example county health or 

fire department) and U.S. EPA 

Approved submission or finding of nonapplicability/ requires an evaluation of the impact 

of the release of a regulated materials from the 

site and a plan in the event of a release
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The Permit Applicant

The administrative process for reviewing and approving projects may vary by jurisdiction but 

there are common elements. These basic elements are as follows:

1. Presubmittal review and feedback (optional but highly recommended)

2. Review and feedback to applicant

3. Formal submission of application 

4. Public meeting (on an as needed basis determined by both administrative law and the 

jurisdiction’s determination as to whether public input should be solicited)

5. Adjustments in the permit application (as needed) based on public input

6. Review of modified application and feedback to application

7. Resubmittal of modified application

8. Issuance of permit

9. Project construction

10. Site inspection to determine that project built as shown in final design plans

11. Periodic inspections to determine ongoing compliance.

The presubmittal review, although not typically required, is a critical step in this process. It

occurs at a time when significant problems could be identified and potentially averted. Examples 

of problems that could be averted are:

1. Identification of problems at the proposed site that the applicant is not aware of

2. Identification of requirements the project must meet that the applicant had not evaluated 

in the draft application

3. Any history of issues with similar projects in the jurisdiction.
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Permit Template and Example Permit

Template—Hydrogen Dispenser Added to Existing Fueling Station

For this template a single dispenser is added to an existing fueling station. The addition of a 

single dispenser still will trigger construction requirements. The dispenser will require at least 

the following elements:

• A dispensing platform

• Vehicle crash protection

• Electrical service

• Hydrogen storage or generation equipment or both for dispenser that has hydrogen 

generating and storage capability

• Lighting

• Compressors to compress the hydrogen to vehicle storage pressure

• Dispenser with fueling hose and nozzle

• Piping from the gaseous hydrogen storage system to the dispenser

• Fire protection system

• Maintenance system

• Unique construction requirements such as handicapped parking requirements.

Hydrogen Vehicle Infrastructure Codes and Standards Citations

This section lists codes and standards typically used for U.S. hydrogen vehicle and infrastructure 

projects. To determine which codes and standards apply to a specific project, identify the codes 

and standards currently in effect within the jurisdiction where the project will be located. Some 

jurisdictions also have unique ordinances or regulations that could apply. For example, the State 

of Michigan has state regulations that address hydrogen systems. These regulations would 

address the installation and operation of hydrogen fueling stations.

AHJs typically enforce the codes and standards in effect in their jurisdiction. However, many 

jurisdictions do not adopt the most recent building and fire codes. Jurisdictions cannot 

automatically reference the most current codes but instead must follow an administrative law 

process to update adoptions of codes and standards. There are costs associated with this process 

that may prevent jurisdictions from updating reference codes.

AHJs have the option of enforcing the most current code requirements to protect public safety.

For example, although there is not a reference to the NFPA 2 Hydrogen Technologies Code in 

the 2012 International Fire Code, an AHJ could enforce these requirements to protect public 

safety. The 2015 International Fire Code references the NFPA 2 Hydrogen Technologies Code.

There are also both equivalency and performance-based compliance options in fire codes. The 

equivalency option allows the use of alternative measures that provide an equal or greater level 
35

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of safety. The performance-based approach is similar but sets performance criteria that must be 

met in place of prescriptive code requirements. Both options require AHJ approval.

Find hydrogen vehicle and infrastructure codes and standards in these categories:

• Annual Inspections and Approvals

• General Station Requirements

• Gaseous Hydrogen Storage, Compression, and Generation Systems

• Liquefied Hydrogen Storage Systems

• Dispensing Systems

• Piping and Tubing for All Systems

• Valving and Fittings for All Systems

• Venting and Other Equipment

• Fire Safety

Annual Inspections and Approvals

Inspection Requirements

CGA G-5.4, Standard for Hydrogen Piping Systems at Consumer Locations (Compressed 

Gas Association, 2005)

• 7.0 Maintenance and Repair

CGA G-5.5, Hydrogen Vent Systems (Compressed Gas Association, 2004)

• 9 Maintenance 

International Fire Code (International Code Council, 2012)

• 406.2 Frequency (of employee training)

• 901.6 Inspection, Testing, and Maintenance 

• 901.6.2 Records (of systems inspection and maintenance)

• 2206.2.1.1 Inventory Control for Underground Tanks 

• 3204.5.2 Corrosion Protection

• 3205.4 Filling and Dispensing

Personnel Issues and Training

International Fire Code (International Code Council, 2009)

• 406 Employee Training and Response Procedures 

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 9.4 Operating Requirements for Attended Self-Service Motor Fuel Dispensing 

Facilities
36

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NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association, 2010)

• 4.6 Personnel Training

• 4.7 Fire Department Liaison

Operation Approvals—Dispensing

International Fire Code (International Code Council, 2009)

• 2204.2 Attended Self-Service Motor Fuel-Dispensing Facilities

• 2204.3 Unattended Self-Service Motor Fuel-Dispensing Facilities

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 6.2 General Requirements

• 6.3 Requirements for Dispensing Devices

Operation Approvals—Fire and Emergency Planning

International Fire Code (International Code Council, 2009)

• 404 Fire Safety and Evacuation Plan

• 406 Employee Training and Response Procedures

• 407 Hazard Communication

• 906 Portable Fire Extinguishers

• 907 Fire Alarm and Detection Systems

• 2209.3.2.6.2 Fire-Extinguishing Systems

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

• 2209.5.1 Protection from Vehicles

• 2209.5.2 Emergency Shutoff Valves

• 2209.5.3 Emergency Shutdown Controls

• 2209.5.4 Venting of Hydrogen Systems

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 7.3.5 Fixed Fire Protection

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 6.3.7 Requirements for Dispensing Devices
37

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General Station Requirements

Site Requirements for Fueling Stations

NFPA 2 Hydrogen Technologies Code (National Fire Protection Association, 2011)

• 6.6.1 Weather Protection- Classification of Weather Protection as an Indoor 

Versus Outdoor Area

• 6.12 Gaseous Hydrogen Detection Systems

• 6.17.1 Mechanical Exhaust Ventilation

Canopy Tops

International Building Code (International Code Council, 2009)

• 406.5.2.1 Canopies use to support gaseous hydrogen systems

International Fire Code (International Code Council, 2009)

• 2209.3.2.6 Canopy Tops

• 2209.3.3 Canopies

Fuel Delivery

International Fire Code (International Code Council, 2009)

• 105.6.8 Compressed Gases

• 105.6.10 Cryogenic Fluids

• 2205.1 Tank Filling Operation for Class I, II, or IIIA Liquids

• 3205.4 Filling and Dispensing

Vehicle Access

International Fire Code (International Code Council, 2009)

• 105.6.8 Compressed Gases

Weather Protection

International Fire Code (International Code Council, 2009)

• 2209.3.2.2 Weather Protection

• 2704.13 Weather Protection

General Safety Requirements

International Fire Code (International Code Council, 2009)

• 2209.5 Safety Precautions

• 2211.7 Repair Garages for Vehicles Fueled by Lighter-than-Air Fuels

• 2211.8 Defueling of Hydrogen from Motor Vehicle Fuel Storage Containers

• 3003 General Requirements

• 3203 General Safety Requirements

• 3503 General Requirements
38

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Repair Facilities

International Fire Code (International Code Council, 2012)

• 2211.7 Repair Garages for Vehicles Fueled by Lighter-than-Air Fuels

• 2211.8 Defueling of Hydrogen from Motor Vehicle Fuel Storage Containers

Gaseous Hydrogen Storage, Compression, and Generation Systems

NFPA 2 Hydrogen Technologies Code (National Fire Protection Association, 2011)

• 7.1.1.3 Building Occupancy Classification for Hydrogen Storage

• 7.1.3 Listed and Approved Hydrogen Equipment

• 7.1.4 Metal Hydride Systems (including systems on industrial trucks)

• 7.1.5 Containers, Cylinders, and Tanks (this section refers to both the ASME BPB 

Section XIII or Transport Canada, Transportation of Dangerous Goods 

Regulations)

• 7.1.5.5 Pressure-Relief Devices

• 7.1.6 Labeling Requirements

• 7.1.6.4 Piping Systems

• 7.1.7 Security (including physical protection and securing containers)

• 7.1.8 Valve Protection

• 7.1.9 Separation from Hazardous Conditions

• 7.1.10 Service and Repair

• 7.1.11 Unauthorized Use

• 7.1.12 Containers, Cylinders, and Tanks Exposed Fire

• 7.1.13 Leaks, Damage, or Corrosion

• 7.1.14 Surfaces (on which containers would be placed)

• 7.1.15 Piping (including reference to ASME B31.12, Process Piping)

• 7.1.16 Valves (required accessibility)

• 7.1.17 Vent Pipe Termination

• 7.1.18 Cathodic Protection

• 7.1.19 Transfer (reference to CGA P-1 Safe Handling of Compressed Gases in 

Containers)

• 7.1.21 Emergency Shut-off Valves

• 7.1.22 Excess Flow Control (requirements for leak detection and emergency shutoff or excess flow control)
39

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• 7.1.23 Ignition Control

• 7.2 Nonbulk GH2

• 7.2.1 Nonbulk GH2 General (separation from incompatible materials)

• 7.2.2 Nonbulk GH2 Storage (includes separation distances for nonbulk GH2 

storage systems, systems 5,000 scf or less)

• 7.2.3 Nonbulk GH2 Use

• 7.2.4 Nonbulk GH2 Handling

• 7.3 Bulk GH2 Systems

• 7.3.1 Bulk GH2 Systems General Requirements

• 7.3.2 Bulk GH2 Systems Storage (contains Table 7.3.2.3.1.2 (a), (b), and (c) for 

above ground system separation distances)

• 7.3.3 Bulk GH2 Systems Use

• 7.3.4 Handling of Bulk GH2 Systems

International Fire Code (International Code Council, 2009)

• 2209.5 Safety Precautions

• 3003 General Requirements

• 3503 General Requirements

Storage Containers

CGA PS-20, Direct Burial of Gaseous Hydrogen Storage Tanks (Compressed Gas 

Association, 2006)

CGA PS-21, Adjacent Storage of Compressed Hydrogen and Other Flammable Gases 

(Compressed Gas Association, 2005)

International Fire Code (International Code Council, 2009)

• 2703.2.1 Design and Construction of Containers, Cylinders, and Tanks

• 3003.2 Design and Construction

• 3503.1.2 Storage Containers

Compression Systems and Equipment

International Fire Code (International Code Council, 2009)

• 2209.2 Equipment

• 2209.3 Location on Property

• 2209.5.3.1 System Requirements

• 2209.5.4.2.1 Minimum Rate of Discharge
40

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Design of Gaseous Storage Systems—Barrier Walls

International Fire Code (International Code Council, 2009)

• 2209.3.1.1 Barrier Wall Construction – Gaseous Hydrogen

On-Site Hydrogen Production

International Fire Code (International Code Council, 2009)

• 2209.3.1 Separation from Outdoor Exposure Hazards

International Fuel Gas Code (International Code Council, 2009)

• 703.1 General Requirements

Natural Gas

ASME B31.8, Gas Transmission and Distribution Systems (American Society of 

Mechanical Engineers, 2003)

Liquefied Hydrogen Storage Systems

NFPA 2 Liquefied Hydrogen Requirements

NFPA 2 Hydrogen Technologies Code (National Fire Protection Association, 2011)

• 8.1.2 Containers – Design, Construction, and Maintenance (refers to ASME BPV, 

Rules for Unfired Pressure Vessels and Transport Canada Transportation of 

Dangerous Goods Regulations)

• 8.1.3 Design (of systems)

• 8.1.3.1 Piping Systems (refers to ASME B31.3 Process Piping)

• 8.1.4 Pressure Relief Devices (refers to CGA S-1.1 through 1.3)

• 8.1.5 Pressure Relief Vent Piping

• 8.1.6 Marking (refers to NFPA 704 Standard System for the Identification of the 

Hazards of Materials for Emergency Response)

• 8.1.7 Security

• 8.1.8 Separation from Hazardous Conditions

• 8.1.9 Electrical Wiring and Equipment (general reference to NFPA 70 National 

Electrical Code)

• 8.1.10 Service and Repair

• 8.1.11 Unauthorized Use

• 8.1.12 Leaks, Damage, and Corrosion

• 8.1.13 Lighting

• 8.1.14 Emergency Shutoff Valves

• 8.1.15 Dispensing Areas

• 8.1.16 Operations (for mobile fueling equipment)
41

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• 8.2 Nonbulk LH2 (storage, handling and use shall be in accordance with Chapter 

1–6 and 8 as applicable)

• 8.3 Bulk LH2 Systems (cutoff is = or > 150 liters)

• 8.3.1.2.1.1 Fire Resistance for Steel Supports

• 8.3.1.2.1.2 Container Marking

• 8.3.1.2.2 Vent System Requirements (including reference to CGAG-5.5)

• 8.3.1.2.3 Piping, Tubing, and Fittings (including reference to ASME B31.3 

Process Piping)

• 8.3.1.2.4 Equipment Assembly (including location of emergency shutoff valves)

• 8.3.1.2.5 LH2 Vaporizers

• 8.3.1.2.6 Electrical Systems (sets electrically classified areas and refer to NFPA 

70)

• 8.3.1.2.7 Bonding and Grounding

• 8.3.1.2.8 Stationary Pumps and Compressors

• 8.3.1.2.9 Emergency Shutdown System

• 8.3.2 Bulk LH2 Systems Storage

• 8.3.2.1.3 Placarding Site

• 8.3.2.1.4.1 Construction of the Inner Vessel

• 8.3.2.1.4.2 Construction of the Vacuum Jacket (Outer Vessel)

• 8.3.2.1.4.3 Nonstandard Containers (can be used with AHJ approval)

• 8.3.2.1.4.4 Concrete Containers

• 8.3.2.1.4.5 Foundations and Supports

• 8.3.2.2 Indoor Storage

• 8.3.2.2.2 Detaching Buildings (including requirements for explosion control)

• 8.3.2.3 Outdoor Storage

• 8.3.2.4 Aboveground Tanks

• 8.3.2.4.2 Physical Protection

• 8.3.2.4.3 Flood Protection

• 8.3.2.4.4 Drainage

• 8.3.2.4.5 Siting Locations (Including Table 8.3.2.4.5.1 Minimum Distance from 

Liquefied Hydrogen Systems to Exposures)

• 8.3.2.5 Underground Tanks
42

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• 8.3.3 Bulk LH2 Systems Use

• 8.3.3.1.5 Inspection (requirements for annual inspection and recordkeeping)

• 8.3.4 Bulk LH2 Systems Handling

• 8.3.4.2 Carts and Trucks

• 8.3.4.4 Closed Containers

• 8.3.4.5 Cargo Transport Unloading

• 8.3.4.6 Overfilling

Liquid Hydrogen Storage—Equipment Location

International Fire Code (International Code Council, 2009)

• 2209.3 Location on Property

• 3203.5.4 Physical Protection

• 3203.6 Separation from Hazardous Conditions

• 3204.3.1.1 Location

• 3204.4.2 Location

• 3504 Storage

Liquid Hydrogen Storage—Storage Containers

International Fire Code (International Code Council, 2009)

• 2703.2 Systems, Equipment, and Processes

• 3203.1 Containers

• 3203.5 Security

• 3203.6 Separation from Hazardous Conditions

• 3204.3.1 Stationary Containers

• 3204.4 Underground Tanks

Dispensing Systems

NFPA 2 Hydrogen Technologies Code (National Fire Protection Association, 2011)

• 10.2.1 System Approvals

• 10.3.1.1 System Component Qualifications

• 10.3.1.4 Pressure Relief Devices

• 10.3.1.5 Pressure Gauges

• 10.3.1.6 Pressure Regulators

• 10.3.1.7 Fuel Lines and Piping Systems
43

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• 10.3.1.8 Hose and Hose Connections

• 10.3.1.9 Valves

• 10.3.1.10 System Testing

• 10.3.1.11 System Maintenance

• 10.3.1.12 Equipment Security and Vehicle Protection

• 10.3.1.13 Compressed and Gas Processing Systems

• 10.3.1.14 Vehicle Fueling Dispenser System Operation

• 10.3.1.15 Vehicle Fueling Connection

• 10.3.1.16 Installation of Electrical Equipment

• 10.3.1.17 Stray or Impressed Currents and Bonding

• 10.3.1 18 Installation of Emergency Shutdown Equipment

• 10.3.1.19 Fire Protection

• 10.3.2.2.3.1.3 Separation Distances for Outdoor Gaseous Hydrogen Dispensing 

Systems

Vaporizers

International Fire Code (International Code Council, 2009)

• 2209.2 Equipment

• 2209.3 Location on Property

• 3203.1.3 Foundations and Supports

• 3203.2.2 Vessels or Equipment Other than Containers

• 3203.5.3 Securing of Vaporizers

International Fuel Gas Code (International Code Council, 2009)

• 708 Design of Liquefied Hydrogen Systems Associated with Hydrogen 

Vaporization Operations

Dispensing, Operations, and Maintenance Safety—Gaseous Hydrogen

CGA G-5.5, Hydrogen Vent Systems (Compressed Gas Association, 2004)

• 9 Maintenance

International Fire Code (International Code Council, 2009)

• 2204 Dispensing Operations

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 9.2.2 Tank Filling and Bulk Delivery
44

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• 9.4 Operating Requirements for Attended Self-Service Motor Fuel Dispensing 

Facilities

• 9.5 Operating Requirements for Unattended Self-Service Motor Fuel Dispensing 

Facilities

Dispensing, Operations, and Maintenance Safety—Liquid Hydrogen

CGA G-5.5, Hydrogen Vent Systems (Compressed Gas Association, 2004)

• 9 Maintenance

International Fire Code (International Code Council, 2009)

• 2204 Dispensing Operations

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages (National 

Fire Protection Association, 2003)

• 9.2.2 Tank Filling and Bulk Delivery

• 9.4 Operating Requirements for Attended Self-Service Motor Fuel Dispensing 

Facilities

• 9.5 Operating Requirements for Unattended Self-Service Motor Fuel Dispensing 

Facilities

Piping and Tubing for All Systems

ASME B31.12, Hydrogen Piping and Pipelines (American Society of Mechanical 

Engineers, 2012)

ASME B31.3, Process Piping (American Society of Mechanical Engineers, 2006)

• F323.4(5) Specific Material Considerations—Metals

• IX K305 Pipe

CGA G-5.4, Standard for Hydrogen Piping Systems at Consumer Locations (Compressed 

Gas Association, 2005)

• 3.1 General

• 3.2 Piping Materials

• 5.0 Installation

• 5.1 Piping Installation General

• 5.2 Piping Installation Above Ground Installation

• 5.3 Piping Installation Underground Installation

International Fuel Gas Code (International Code Council, 2012)

• 101.2.1 Gaseous Hydrogen Systems

• 704 Piping, Use, and Handling
45

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705 Testing of Hydrogen Piping Systems CGA H-3 Cryogenic Hydrogen Storage 

(Compressed Gas Association, 2006)

• 10.0 External Piping

Valving and Fittings for All Systems

ASME B31.3, Process Piping (American Society of Mechanical Engineers, 2006)

• IX K306 Fittings, Bends, and Branch Connections

• IX K307 Valves and Specialty Components

CGA G-5.4, Standard for Hydrogen Piping Systems at Consumer Locations (Compressed 

Gas Association, 2005)

• 3.3.2 Isolation Valves

• 3.3.3 Emergency Isolation Valves

• 3.3.4 Excess Flow Valves

• 3.3.5 Check Valves

• 3.3.7 Gasket and Sealing Materials

• 3.3.8 Additional Requirements

• 5.0 Installation

• 5.1 Installation General

Venting and Other Equipment

CGA G-5.5, Hydrogen Vent Systems (Compressed Gas Association, 2004)

• 6.0 Vent System

• 6.2 Sizing

• 6.3 Design

• 6.4 Materials

• 6.5 Components

• 7 Installation

International Fire Code (International Code Council, 2009)

• 2209.5.4 Venting of Hydrogen Systems

• 2211.8.1.2 Atmospheric Venting of Hydrogen from Motor Vehicle Fuel Storage 

Containers

• 3003.16.8 Connections

• 3005.5 Venting

• 3203.3 Pressure Relief Vent Piping
46

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• 3204.4.5 Venting of Underground Tank

Fire Safety

Construction

International Fire Code (International Code Council, 2009)

• 911 Explosion Control

• 2209.5 Safety Precautions

International Fuel Gas Code (International Code Council, 2009)

• 706.3 Outdoor Gaseous Hydrogen Systems

NFPA 52, Vehicular Gaseous Fuel Systems Code (National Fire Protection Association, 

2010)

• 9.12 Stray or Impressed Currents and Bonding

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association, 2010)

• 7.1.6 Separation from Hazardous Conditions

Equipment

International Fire Code (International Code Council, 2009)

• 404 Fire Safety and Evacuation Plan

• 406 Employee Training and Response Procedures

• 407 Hazard Communication

• 906 Portable Fire Extinguishers

• 907 Fire Alarm and Detection Systems

• 2209.4 Dispensing into Motor Vehicles at Self-Service Hydrogen Motor FuelDispensing Facilities

• 2209.5 Safety Precautions

Signage

International Fire Code (International Code Council, 2009)

• 2204.3.5 Emergency Procedures

• 2209.5.2.1 Identification

CGA H-3 Cryogenic Hydrogen Storage (Compressed Gas Association, 2006)

• 6.0 Tank Design and Manufacturing Criteria

• 7.0 Inner Vessel

• 8.0 Outer Jacket
47

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Stationary and Portable Fuel Cell Systems Codes and Standards Citations

This section lists codes and standards typically used for stationary and portable fuel cell systems

projects. To determine which codes and standards apply to a specific project, you need to 

identify the codes and standards currently in effect within the jurisdiction where the project will 

be located. Some jurisdictions also have unique applicable ordinances or regulations.

Find stationary and portable fuel cell systems codes and standards in these categories:

• Balance of Plant

• Compressed Hydrogen Gas Storage

• Design

• Electrical Equipment

• Equipment Safety

• Fire Safety

• Fuel Lines

• Operation Approvals

• Periodic Inspections

• Setbacks and Footprints

• Transportation

Balance of Plant

ANSI/CSA America FC 1-2004, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2012)

• Metallic Piping

• Flue Gas Venting Systems

• 1.11.2.1 Shut-off Valves

• 1.11.2.2 Supply Fuel Valves

International Fire Code (International Code Council 2012)

• 5003.2.2 Piping, Tubing, Valves, and Fittings

• 5003.3 Release of Hazardous Materials

• 5303.3 Pressure Relief Devices

• 5303.4.3 Piping Systems

• 5303.6 Valve Protection

• 5305.3 Piping Systems

• 5305.4 Valves

• 5305.5 Venting

International Fuel Gas Code (International Code Council 2012)

• 703.3 Pressure Relief Devices
48

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• 704 Piping, Use and Handling

International Mechanical Code (International Code Council 2012)

• 305 Piping Support

• 401 General

• 501 Exhaust Systems

• 502 Required Systems

• 510 Hazardous Exhaust Systems

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2013)

• 7.3.1.3 Piping Systems

• 7.3.1.4 Valves

• 10.2.3 Hydrogen-Venting Systems

• 10.2.3.1 Venting Requirements

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 6.4.1 Gaseous Hydrogen Storage

• 6.4.3 Hydrogen Piping

• 6.4.3.6 Ventilation Air

• 7.1.1 General

• 7.2.2 When Natural Ventilation Permitted

• 7.3 Exhaust Systems

Compressed Hydrogen Gas Storage

International Building Code (International Code Council 2012)

• 414.4 Hazardous Materials Systems

International Fire Code (International Code Council 2012)

• 5003.2 Systems, Equipment, and Processes

• 5003.2.1 Design and Construction of Containers, Cylinders, and Tanks

• 5003.2.4 Installation of Tanks

• 5003.2.5 Empty Containers and Tanks

• 5003.4 Material Safety Data Sheets

• 5003.9.2 Security

• 5003.9.3 Protection from Vehicles
49

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• 5003.9.9 Shelf Storage

• 5004 Storage

• 5303.1 Containers, Cylinders, and Tanks

• 5303.2 Design and Construction

• 5303.4.1 Stationary Compressed Gas Containers, Cylinders, and Tanks

• 5303.4.2 Portable Containers, Cylinders, and Tanks

• 5303.5 Security

• 5303.6.1 Compressed Gas Container, Cylinder, or Tank Protective Caps or Collars

• 5303.10 Unauthorized Use

• 5303.12 Leaks, Damage, or Corrosion

• 5303.13 Surface of Unprotected Storage or Use Areas

• 5303.14 Overhead Cover

• 5304 Storage of Compressed Gases

• 5305.1 Compressed Gas Systems

• 5803.1.2 Storage Containers

• 5803.1.3 Emergency Shutoff

• 5803.1.4 Ignition Source Control

International Fuel Gas Code (International Code Council 2012)

• 303 Appliance Location

• 409 Shutoff Valves

• 703.2 Containers, Cylinders, and Tanks

• 703.5 Security

International Mechanical Code (International Code Council 2012)

• 303 Equipment & Appliance Location

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2010)

• 7.1.4 Listed and Approved Hydrogen Equipment

• 7.1.6 Containers, Cylinders and Tanks

• 10.3.2 Location of Gaseous Hydrogen Systems

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 6.4.1 Gaseous Hydrogen Storage

• 6.4.3 Hydrogen Piping
50

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

• 6.4.3.1 Hydrogen Piping Shutoff Valve

• 6.4.3.2 Hydrogen Piping

• 6.4.3.5 Hydrogen Piping

• 6.4.3.7 Hydrogen Piping

Design

ANSI/CSA America FC 1-2004, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2004)

• 1.2 Power Systems Design

• 1.3 Physical Environment and Operating Conditions

• 1.4 Selection of Materials

• 1.6 Cabinets

International Building Code (International Code Council 2012)

• 307.1.1 Maximum Allowable Quantities

• 414.1 General

• 414.2 Control Areas

• 1609 Wind Loads

• 1612 Flood Loads

• 1808 Foundations

International Fire Code (International Code Council 2012)

• 5003.1.1 Maximum Allowable Quantities per Control Area

• 5003.1.3 Quantities Not Exceeding the Maximum Allowable Quantity per Control 

Area

• 5003.1.4 Quantities Exceeding the Maximum Allowable Quantity per Control Area

• 5003.2.8 Seismic Protection

• 5003.8 Construction Requirements

• 5003.8.1 Buildings

• 5003.8.2 Required Detached Buildings

• 5003.8.3 Control Areas

• 5003.8.4 Gas Rooms

• 5003.8.5 Exhausted Enclosures

• 5003.8.6 Gas Cabinets

• 5003.8.7 Hazardous Materials Storage Cabinets
51

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• 5004.12 Outdoor Storage

International Fuel Gas Code (International Code Council 2012)

• 301 General

• 302 Structural Safety

• 633 Stationary Fuel Cell Power Systems

• 635 Gaseous Hydrogen Systems

International Mechanical Code (International Code Council 2012)

• 301 General

• 302 Protection of Structure

• 924 Stationary Fuel Cell Power Systems

• 926 Gaseous Hydrogen Systems

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association, 2010)

• 7.1.4 Listed and Approved Hydrogen Equipment

• 10.2.2 Piping Systems

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 4.2 Prepackaged, Self-Contained Fuel Cell Power Systems

• 4.3 Pre-Engineered Fuel Cell Power Systems

• 4.4 Engineered and Field-Constructed Fuel Cell Power Systems

• 5.1.1 (2) General Siting

• 6.4.1 Gaseous Hydrogen Storage

Electrical Equipment

ANSI/CSA America FC 1-2004, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2004)

• 1.12 Electrical Safety

International Fire Code (International Code Council, 2009)

• 5003.9.4 Electrical Wiring and Equipment

• 5003.9.5 Static Accumulation

• 5303.8 Wiring and Equipment

• 5803.1.5 Electrical

International Fuel Gas Code (International Code Council 2012)

• 703.4 Venting
52

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• 703.6 Electrical Wiring and Equipment

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2007)

• 8.1.3 Electrical Equipment and Components

Equipment Safety

ANSI/CSA America FC 1-2004, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2004)

• 1.3.3 Physical Environmental 

• 1.3.6 System Purging

• 1.3.7 Vibration, Shock and Bump

• 1.3.8 Handling, Transportation, and Storage

• 1.3.9 Protection against Fire and Explosion Hazards

International Building Code (International Code Council 2012)

• 414.6 Outdoor Storage, Dispensing, and Use

International Fire Code (International Code Council 2012)

• 5003.1 Hazardous Materials

• 5003.2.3 Equipment, Machinery, and Alarms

• 5003.2.9 Testing

• 5003.9 General Safety Precautions

• 5003.9.1 Personnel Training and Written Procedures

• 5003.9.8 Separations of Incompatible Materials

• 5003.12 Outdoor Control Areas

• 5005 Use, Dispensing, and Handling

• 5303.7 Separations from Hazards

• 5305 Use and Handling of Compressed Gases

• 5305.2 Controls

• 5305.6 Upright Use

• 5305.7 Transfer

• 5305.9 Material-Specific Regulations

• 5305.10 Handling

• 5805 General Use
53

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International Fuel Gas Code (International Code Council 2012)

• 705 Testing of Hydrogen Piping Systems

• 706 Location of Gaseous Hydrogen Systems

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2013)

• 7.1.11 Separation from Hazardous Conditions

• 7.6 Flammable Gases

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 5.1.1 General Siting

• 5.1.2 General Siting

• 5.2 Outdoor Installations

• 9.2 Outdoor Installations

Fire Safety

ANSI/CSA America FC 1-2004, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2012)

• 1.5 General Requirements

• 1.6 Cabinets

• 1.16 Marking, Labeling, and Packaging

• 1.16.2 FC Power System Marking

• 1.19.4.2 Installation Manual

International Building Code (International Code Council 2012)

• 907 Fire Alarms and Detection Systems

International Fire Code (International Code Council 2012)

• 401 General Emergency Planning and Preparedness

• 406 Employee Training and Response Procedures

• 5003.9.1.1 Fire Department Liaison

• 5303.4 Gas Marking

• 5303.11 Exposure to Fire

• 5303.16.13 Accessway

• 5503.4 Liquid Marking

International Fuel Gas Code (International Code Council 2012)

• 305 Installation
54

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International Mechanical Code (International Code Council 2012)

• 304 Installation

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2010)

• 7.1.8 Labeling Requirements

• 10.2.1 Marking

• 10.6.1.2 Fire Protection

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 5.1.3 General Siting

• 5.2 Outdoor Installations

• 6.1.2 General

• 8.1.2 Fuel Cell Fire Protection and Detection

• 9.2 Outdoor Installations

• 9.5 Fire Protection

Fuel Lines

ANSI/CSA America FC 1-2012, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2004)

• 1.8.1 Metallic Piping

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 20103

• 7.3.1.3 Piping Systems

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 6.4.1 Gaseous Hydrogen Storage

• 6.4.3 Hydrogen Piping

Operation Approvals

ANSI/CSA America FC 1-2012, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association, 2004)

• 1.16.1 Marking, Labeling and Packaging

• 1.16.2 FC Power System Marking

• 1.16.4.2 Installation Manual
55

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CGA P-1, Safe Handling of Compressed Gases in Containers (Compressed Gas 

Association 2008)

• 4.4 Regulating Authorities of Employee Safety and Health

International Fire Code (International Code Council 20012

• 105.6.8 Compressed Gases

• 404.3.2 Fire Safety Plans

• 406 Employee Training and Response Procedures

• 5003.5 Hazard Identification Signs

• 5003.6 Signs

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2013)

• 4.7 Personnel Training

• 4.8 Fire Department Liaison

• 7.1.8 Labeling Requirements

• 10.2.1 Marking

• 10.3.2 Location of Gaseous Hydrogen Systems

• 10.6.1.2 Fire Protection

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 6.1.2 General

• 6.4.1 Gaseous Hydrogen Storage

• 6.4.3 Hydrogen Piping

• 8.2 Fire Prevention and Emergency Planning

Periodic Inspections

ANSI/CSA America FC 1-2012, Stationary Fuel Cell Power Systems (American National 

Standards Institute and Canadian Standards Association 2004)

• 1.16.4.5 Maintenance Manual

International Fire Code (International Code Council 2012)

• 5003.2.6 Maintenance

• 5303.9 Service and Repair

International Fuel Gas Code (International Code Council 2012)

• 707 Operation and Maintenance of Gaseous Hydrogen Systems
56

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Setbacks and Footprints

International Fire Code (International Code Council 2012)

• 5003.7 Separations from Hazards

• 5003.9.8 Separations of Incompatible Materials

• 5004 Storage of Compressed Gases

International Fuel Gas Code (International Code Council 2012)

• 706 Location of Gaseous Hydrogen Systems

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2013)

• 10.3.2 Locations

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems (National 

Fire Protection Association 2010)

• 6.4.1 Gaseous Hydrogen Storage

Transportation

CGA P-1, Safe Handling of Compressed Gases in Containers (Compressed Gas 

Association 2008)

• 4.1 Transportation Regulating Authorities

• 4.2 Container Regulations

• 4.3 Container Filling Regulations

• 6.2 Flammable Gases

International Fire Code (International Code Council 20012

• 105.6.8 Compressed Gases

• 404.3.2 Fire Safety Plans

• 5005 Use, Dispensing, and Handling

• 5305.7 Transfer

• 5805 General Use

NFPA 55, Compressed Gases and Cryogenic Fluids Code (National Fire Protection 

Association 2013)

• 7.3 Use and Handling

• 8.3.5 Overfilling

• 10.3.2 Location of Gaseous Hydrogen Systems
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Example Permit

Section 1 of the permit application requires basic identifying information be submitted.

Section 2 of the permit application identifies which code requirements need to be complied with 

depending on whether the dispenser is being added to an existing station or whether the 

dispenser is at a new stand-alone station. 

The technical installation requirements address the following specific elements of station safety:

• Approval/listing and labeling requirements

• Piping code compliance 

• Storage vessel stamps/approval.

Section 3 consists of a standard certification statement that could be modified as needed by the 

jurisdiction. By signing the certification statement the applicant agrees to comply with the 

standard permit conditions and other applicable requirements. This consent would give the 

jurisdiction the option of allowing the applicant to proceed with installation and operation of the 

dispensing equipment. 

Section 4 of the document gives an example of a checklist the jurisdiction could develop to track 

key information on the application. The example under Section 4 contains only a few items of 

the many that the jurisdiction might wish to track.

This permit package also includes a schematic drawing depicting a typical installation (Figure 2). 

The purpose of the schematic is only to show how the station equipment could be arranged and is 

not intended to convey any permit requirements. 

Section 1. Basic Identifying Information

Jurisdiction of __________________, _____________(state)

Building/Fire Permit For Hydrogen Dispensing Installation 

Compliance with the following permit will allow the construction and operation of a hydrogen dispensing 

installation in the _________________ jurisdiction. This permit addresses the following situations:

1. The addition of a hydrogen dispensing and storage system to an existing fueling station

2. TBD

This permit contains a general reference to the fire and building codes or equivalent codes used in the 

jurisdiction. All work and installed equipment will comply with the requirements of XXXX code used in the 

jurisdiction. The jurisdiction maintains the authority/responsibility to conduct any inspections deemed 

necessary to protect public safety.

57 
58

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Section 2. Sample Permit Structure

Topic Permit Requirements

Siting Do storage and dispenser systems meet 

separation distance requirements?

Mechanical Is equipment listed or approved?

• Valves

• Pressure relief devices

• Piping

• Containers

• Hoses

• Nozzles

Electrical Is equipment proximate to dispenser classified?

Maintenance Have maintenance requirements been defined in 

permit application?

Is there documentation required?

Emergency response Are E-stops accessible?

Do they have a plan?

Are personnel trained?

Is communication with the fire department and 

other emergency responders clearly defined?

Sensors Do sensors detect releases or upset conditions?

Is the information from sensors conveyed to the 

process equipment, operators, and fire 

department?
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Section 3. Owner Responsibility Statement

Section 4. Jurisdiction Checklist

I hereby certify that the electrical work described on this permit application shall be/has been installed 

in compliance with the conditions in this permit and the codes and standards currently adopted and 

enforced within the jurisdiction of installation. By agreeing to the above requirements, the licensee or 

owner shall be permitted to construct and operate the charging station.

Signature of Owner Date

Information each jurisdiction would add to permit such as:

1. Unique requirements in the jurisdiction such as seismic requirements

2. Summary of Risk Management Plan (RMP) analysis if subject to RMP

3. Summary of compliance with environmental regulations if applicable. 

59 
60

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Figure 2. Schematic of a typical hydrogen dispensing station with single dispenser with gaseous 

and liquid hydrogen storage
61

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References

Austin, G. (1984). Shreve's Chemical Process Industries. New York: McGraw-Hill, Inc.

Cramer, S.D.; Covino, B.S., Jr. (2003). Corrosion: Fundamentals, Testing, and Protection. ASM 

Handbook Volume 13a. Materials Park, OH: ASM International.

Larminie, J.; Dicks, A. (2003). Fuel Cell Systems Explained. Chichester, West Sussex, England: 

John Wiley & Sons Ltd.

Lewis, R.J., Sr. (2001). Hawley’s Condensed Chemical Dictionary. New York: John Wiley & 

Sons, Inc.

McCarty, R.D.; Hord, J.; Roder, H.M. (1981). Selected Properties of Hydrogen (Engineering 

Design Data). Washington, DC: U.S. Department of Commerce, National Bureau of Standards.

National Fire Protection Association. (1963). NFPA 567 Gaseous Hydrogen Systems at 

Consumer Sites. Boston: National Fire Protection Association.

Ramachandran, R.; Menon, R.K. (1998). “An Overview of Industrial Uses of Hydrogen.”

International Journal of Hydrogen Energy (23:7); pp. 593-598.

Rigden, J.S. (2003). Hydrogen: The Essential Element. Boston: Harvard University Press.

U.S. Census Bureau. (2012). “Transportation.” Statistical Abstract of the United States: 2012. 

Washington, DC: U.S. Census Bureau.

Wolff, D. (2008). “Expanding Use of Onsite UHP Hydrogen Production Improves Safety, 

Quality and Productivity in Epitaxy Operations.” 41st International Symposium on 

Microelectronics 2008 (IMAPS 2008); November 2-6, 2008, Providence, Rhode Island. 

Washington, DC: International Microelectronics and Packaging Society (IMAPS); pp. 405-412.
62

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Informational Websites

DOE Hydrogen and Fuel Cells Program: 

http://www.hydrogen.energy.gov/

DOE Alternative Fuels Data Center:

http://www.afdc.energy.gov/

DOE Fuel Cell Technologies Office Safety, Codes and Standards:

http://energy.gov/eere/fuelcells/safety-codes-and-standards

NREL Hydrogen and Fuel Cell Research: 

http://www.nrel.gov/hydrogen/

Sandia National Laboratories Hydrogen and Fuel Cells Program:

http://energy.sandia.gov/energy/renewable-energy/hydrogen

Pacific Northwest National Laboratory Hydrogen and Fuel Cells:

http://www.pnnl.gov/fuelcells/
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Appendix A. NREL Process Hazard Analysis on a 

Representative Hydrogen Fueling Station

The National Renewable Energy Laboratory (NREL) conducted a process hazard analysis (PHA) 

on a representative hydrogen fueling system (Figure A-1) to better understand the relative risks 

of the pieces of the system. The following analysis gives a picture of the components of most 

concern in a hydrogen fueling system.

Figure A-1. Schematic of a representative hydrogen station

A PHA was conducted on the representative station shown in Figure A-1. The analysis was 

performed by NREL staff familiar with operating hydrogen fueling stations and component 

safety and performance issues. NREL employed PHAWorks 5, a spreadsheet software package 

designed to perform risk analyses.
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This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

The analysis was based on the assumption that the system complied with the requirements of 

codes and standards typically used in the United States. These documents include the following:

• NFPA 2 Hydrogen Technologies Code

• International Fire Code—addresses hydrogen applications

• International Building Code—general construction requirements

• ASME B31.12 Hydrogen Pipelines and Piping Code—hydrogen piping design

• ASME BPV Code Section XIII and X Pressure Vessels

• CGA S-1.1-3 Pressure Relief—hydrogen storage systems

• NFPA 70 National Electric Code—classified electrical areas.

Table A-1 shows the preliminary results of the PHA. Figure A-2 and Table A-2 show the hazard 

assessment and frequency categories used in the PHA. The system was broken down into the 

eight nodes shown in Table A-1. Undesirable outcomes were identified based on defining 

variations at nodes. Safety measures were identified for these undesired outcomes. The residual

risk was then defined for each undesirable outcome. The residual risk is based on assigning a 

consequence and probability using the rating system shown in Table A-2. The combination of 

consequence and probability produces a risk rating as determined by the risk matrix.

Table A-1. Risk Value Frequencies

Node/Parameter HR MR LR RR Sum

Node 1 Dispensing Nozzle 0 0 5 1 6

Flow 0 0 5 1 6

Temperature 0 0 0 0 0

Node 2 Dispensing Hose 0 2 3 0 5

Flow 0 2 3 0 5

Node 3 Dispenser Cabinet 0 0 0 0 0

Flow 0 0 0 0 0

Node 4 Cascade tanks to Dispenser 0 0 2 5 7

Flow 0 0 0 1 1

Temperature 0 0 2 4 6

Node 5 Compression to Cascade Tanks 0 0 7 9 16

Pressure 0 0 7 9 16

Node 6 Cryogenic Storage to Compressors 0 0 0 1 1

Temperature 0 0 0 1 1

Node 7 Air System 0 0 0 5 5

Flow 0 0 0 5 5

Node 8 Control Electronics 0 0 2 4 6

Level 0 0 2 4 6

PROJECT TOTAL 0 2 19 25 46
65

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

The PHA used the risk evaluation system shown in Figure A-2. This matrix integrates event severity and event frequency to produce 

four categories of risk. These categories are High Risk (HR), Medium Risk (MR), Low Risk (LR), and Routine Risk (RR).

Probability

Consequences

Category Descriptive

Word

A

Frequent

B

Reasonably

Probable

C

Occasional

D

Remote

E

Extremely

Remote

F

Impossible

I Catastrophic

Hose rupture

II Critical

Nozzle leak

III Marginal

Compressor 

failure

IV Negligible

High Risk Moderate Risk Low Risk Routine Risk

Figure A-2. NREL risk matrix
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This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table A-2. NREL Event Probability Classification Table

Probability (Probability that the potential consequence occurs)

Level Annual Probability Potential Consequences

A Frequent > 1.0 Likely to occur many times during the life cycle of the 

system (test/activity/operation)

B Reasonably Probable 1.0 to 

0.1

Likely to occur several times during the life cycle of the 

system

C Occasional 0.01 to 0.1 Likely to occur sometime during the life cycle of the system

D Remote 0.0001 to 0.01 Not likely to occur in the life cycle of the system, but 

possible

E Extremely Remote 0.000001 to 

0.0001

Probability of occurrence cannot be distinguished from zero

F Impossible < 0.000001 Physically impossible to occur

Consequence

Category Description (Est. $ Lost) Potential Consequences

I Catastrophic (equipment loss > 

$1,000,000)

May cause death or system loss.

II Critical ($100,000 to 

$1,000,000) 

May cause severe injury or occupational illness, or minor 

system damage.

III Marginal ($10,000 to 

$100,000)

May cause minor injury or occupational illness, or minor 

system damage.

IV Negligible (< $10,000) Will not result in injury, occupational illness, or system 

damage.

The preliminary results shown in Table A-1 were weighted on a 1 to 4 system with High Risk 

(HR) = 4 and Routine Risk (RR) = 1 to develop a total relative risk at each node. The results of 

this process are shown in Table A-3.
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Table A-3. Total Risk at Node

Node Node Description HR MR LR RR

Node 

Total 

Risk

5 Compressor to Cascade 

Tank

0 0 7 9 23

2 Hose 0 2 3 0 12

1 Nozzle 0 0 5 1 11

4 Cascade Tanks to 

Dispenser

0 0 2 5 9

8 Control Electronics 0 0 2 4 8

7 Air System 0 0 0 5 5

6 Cryo Storage to 

Compressor

0 0 0 1 1

3 Dispenser Cabinet 

(evaluated under control 

electronics)

0 0 0 0 0

HR - High Risk

MR - Medium Risk

LR - Low Risk

RR - Routine Risk