ISO 14687:2019

Hydrogen fuel quality - Product specification

This document specifies the minimum quality characteristics of hydrogen fuel as distributed for utilization in vehicular and stationary applications. It is applicable to hydrogen fuelling applications, which are listed in Table 1.

Qualité du carburant hydrogène — Spécification de produit

General Information

• Status: Published
• Publication Date: 26-Nov-2019
• ICS: 71.100.20 - Gases for industrial application
• Technical Committee: ISO/TC 197 - Hydrogen technologies
• Drafting Committee: ISO/TC 197/WG 27 - Hydrogen fuel quality
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 12-Feb-2025
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 14687:2025 - Hydrogen fuel quality - Product specification
• Effective Date: 06-Jun-2022
• Revises: ISO 14687-3:2014 - Hydrogen fuel - Product specification - Part 3: Proton exchange membrane (PEM) fuel cell applications for stationary appliances
• Effective Date: 05-Nov-2015
• Revises: ISO 14687-2:2012 - Hydrogen fuel - Product specification - Part 2: Proton exchange membrane (PEM) fuel cell applications for road vehicles
• Effective Date: 05-Nov-2015
• Revises: ISO 14687-1:1999 - Hydrogen fuel - Product specification - Part 1: All applications except proton exchange membrane (PEM) fuel cell for road vehicles
• Effective Date: 04-Nov-2015

Overview

ISO 14687:2019 - Hydrogen fuel quality - Product specification - defines the minimum quality characteristics for hydrogen fuel as distributed for vehicular and stationary applications. It consolidates and replaces the earlier ISO 14687 parts (‑1, ‑2, ‑3), updating impurity tolerances and test/verification approaches in light of modern PEM (proton exchange membrane) fuel‑cell developments. The standard covers gaseous, liquid and slush hydrogen and hydrogen‑based fuels and provides a framework for hydrogen fuelling, quality control and sampling.

Key Topics

• Classification and grades: hydrogen types (gaseous, liquid, slush) and grades (A–E). Notably, Grade D targets PEM fuel cells for road vehicles and Grade E targets PEM stationary applications.
• Fuel quality requirements: minimum purity and impurity‑specification approach for hydrogen used in PEM fuel cells and other applications.
• Analytical and sampling methods: requirements for laboratory and in‑field testing, sample size, selection of sampling points and procedures to verify compliance.
• Quality verification and control: production qualification tests, routine monitoring, reporting of results and the concept of a boundary point where supply responsibility transitions to the fuel cell system.
• Impurity effects and rationale: discussion on contaminants, reversible vs irreversible effects on fuel‑cell components, and guidance for acceptable impurity detection limits.
• Scope for fuel‑based mixtures: provisions for hydrogen‑based fuels (mixtures with a defined hydrogen index) used in stationary PEM applications.

Applications and Who Uses It

ISO 14687:2019 is intended for organizations involved in the hydrogen value chain that need to ensure consistent, reliable hydrogen fuel quality:

• Hydrogen producers and suppliers - to define product specifications and contracts.
• Hydrogen fuelling station operators - for on‑site quality control and sampling procedures.
• Automotive OEMs and fuel‑cell system integrators - to protect stacks, validate warranties and ensure vehicle reliability.
• Stationary power system manufacturers and operators - to set boundary‑point responsibilities and qualification tests.
• Regulators and certification bodies - for harmonized, safety‑and‑performance oriented regulations.

Benefits include improved fuel‑cell durability, predictable performance, interoperable supply chains and clearer supplier/customer responsibilities.

Related Standards (if applicable)

• ISO 19880‑8 - Gaseous hydrogen - Fuelling stations - Part 8: Fuel Quality Control (normative reference).
• ISO 21087 - Gas analysis - Analytical methods for hydrogen fuel - PEM fuel cell applications for road vehicles (normative reference).

Keywords: ISO 14687:2019, hydrogen fuel quality, fuel specification, PEM fuel cell, hydrogen fuelling, fuel quality control, hydrogen impurities, sampling, hydrogen suppliers.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14687
First edition
2019-11
Hydrogen fuel quality — Product
specification
Qualité du carburant hydrogène — Spécification de produit
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification and application . 3
4.1 Classification . 3
4.2 Application . 3
5 Hydrogen quality requirements for PEM fuel cell road vehicle application .4
5.1 Fuel quality specification . 4
5.2 Analytical method . 5
5.3 Sampling . 5
5.4 Hydrogen quality control . 5
6 Hydrogen and hydrogen-based fuels, quality requirements for PEM fuel cell
stationary applications . 6
6.1 Fuel quality specification . 6
6.2 Quality verification . 7
6.2.1 General requirements . 7
6.2.2 Analytical requirements of the qualification tests . 7
6.2.3 Report results . 8
6.3 Sampling . 8
6.3.1 Sample size . 8
6.3.2 Selection of the sampling point . 8
6.3.3 Sampling procedure . 8
6.3.4 Particulates in gaseous hydrogen . 8
7 Hydrogen quality requirements for applications other than PEM fuel cell road
vehicle and stationary applications . 8
7.1 Fuel quality specification . 8
7.2 Quality verification . 9
7.2.1 General requirements . 9
7.2.2 Production qualification tests .10
7.3 Sampling .10
7.3.1 Sample size .10
7.3.2 Gaseous samples .10
7.3.3 Liquid samples (vaporized).10
Annex A (informative) Guidance on the selection of the boundary point for PEM fuel cell
stationary applications .11
Annex B (informative) Rationale for the selection of hydrogen impurities to be measured
for PEM fuel cell stationary applications .14
Annex C (informative) Pressure swing adsorption and applicability of CO as an indicator
for PEM fuel cell stationary applications .16
Bibliography .17
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 197, Hydrogen technologies.
This first edition of ISO 14687 cancels and replaces ISO 14687-1:1999, ISO 14687-2:2012 and
ISO 14687-3:2014. It also incorporates the Technical Corrigenda ISO 14687-1:1999/Cor 1:2001 and
ISO 14687-1:1999/Cor 2:2008.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2019 – All rights reserved

Introduction
As mentioned in the Foreword, this document is a combination of three former standards for the
specifications of hydrogen fuel, ISO 14687-1, ISO 14687-2 and ISO 14687-3, incorporating their revisions
at the same time.
In recent years, PEM (proton exchange membrane) fuel cell technologies have shown a remarkable
progress such as lowering of platinum (Pt)-loading, thinned electrolyte membrane, operation with
high current density and operation under low humidity. With this progress, it has become necessary to
reconsider the tolerances of hydrogen impurities for the PEM fuel cells which were previously specified
in ISO 14687-2 and ISO 14687-3.
Therefore, this document has been mainly revised based on the research and development of PEM fuel
[1], [3] to [15]
cells focusing on the following items :
— PEM fuel cell catalyst and fuel cell tolerance to hydrogen fuel impurities;
— effects/mechanisms of impurities on fuel cell power systems and components;
— impurity detection and measurement techniques for laboratory, production and in-field operations;
— fuel cell vehicle demonstration and stationary fuel cell demonstration results.
The grade D and the grade E of this document are intended to apply to PEM fuel cells for road vehicles
and stationary appliances respectively. These aim to facilitate the provision of hydrogen of reliable
quality balanced with acceptable lower cost for the hydrogen fuel supply.
This document reflects the state of the art at the date of its publication, but since the quality
requirements for hydrogen technology applications are developing rapidly, this document may need to
be further revised in the future according to technological progress.
INTERNATIONAL STANDARD ISO 14687:2019(E)
Hydrogen fuel quality — Product specification
1 Scope
This document specifies the minimum quality characteristics of hydrogen fuel as distributed for
utilization in vehicular and stationary applications.
It is applicable to hydrogen fuelling applications, which are listed in Table 1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 19880-8, Gaseous Hydrogen — Fuelling stations — Part 8: Fuel Quality Control
ISO 21087, Gas analysis — Analytical methods for hydrogen fuel — Proton exchange membrane (PEM) fuel
cell applications for road vehicles
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
boundary point
point between the hydrogen fuel supply equipment (3.13)
and the PEM fuel cell power system (3.9) at which the quality characteristics of the hydrogen fuel are to
be determined
3.2
constituent
component (or compound) found within a hydrogen fuel mixture
3.3
contaminant
impurity that adversely affects the components within the fuel cell system (3.8), the fuel cell power
system (3.9) or the hydrogen storage system
Note 1 to entry: An adverse effect can be reversible or irreversible.
3.4
customer
party responsible for sourcing hydrogen fuel in order
to operate the fuel cell power system (3.9)
3.5
detection limit
lowest quantity of a substance that can be distinguished from the absence of that substance with a
stated confidence limit
3.6
determination limit
lowest quantity which can be measured at a given acceptable level of uncertainty
3.7
fuel cell
electrochemical device that converts the chemical energy of a fuel and an oxidant to electrical energy
(DC power), heat and other reaction products
3.8
fuel cell system
power system used for the generation of electricity on
a fuel cell vehicle
Note 1 to entry: The fuel cell system typically contains the following subsystems: fuel cell stack, air processing,
fuel processing, thermal management and water management.
3.9
fuel cell power system
self-contained fuel cell assembly used for the generation
of electricity which is fixed in a place in a specific location
Note 1 to entry: The fuel cell power system typically contains the following subsystems: fuel cell stack, air
processing, thermal management, water management and automatic control system. It is used in applications
such as: distributed power generation, back-up power generation, remote power generation, electricity and heat
co-generation for residential and commercial applications.
Note 2 to entry: For the purposes of the applications, the fuel cell power system does not contain a fuel processing
system due to the location of the boundary point (3.1).
3.10
gaseous hydrogen
hydrogen under gaseous form, purified to a minimum mole fraction as specified in tables in this
document
3.11
hydrogen-based fuel
gas containing a concentration of hydrogen as specified
in tables in this document used for PEM fuel cell for stationary applications
3.12
hydrogen fuel index
mole fraction of a fuel mixture that is hydrogen
3.13
hydrogen fuel supply equipment
equipment used for the transportation or on-site generation of hydrogen fuel, and subsequently for
the delivery to the fuel cell power system (3.9), including additional storage, vaporization and pressure
regulation as appropriate
3.14
irreversible effect
effect, which results in a permanent degradation of the fuel cell system (3.8) or the fuel cell power system
(3.9) performance that cannot be restored by practical changes of operational conditions and/or gas
composition
3.15
liquid hydrogen
hydrogen that has been liquefied, i.e. brought to a liquid state
2 © ISO 2019 – All rights reserved

3.16
particulate
solid or liquid such as oil mist that can be entrained somewhere in the production, delivery, storage or
transfer of the hydrogen fuel to a fuel cell system (3.8) or a fuel cell power system (3.9)
3.17
reversible effect
effect, which results in a temporary degradation of the fuel cell system (3.8) or the fuel cell power system
(3.9) performance that can be restored by practical changes of operational conditions and/or gas
composition
3.18
slush hydrogen
hydrogen that is a mixture of solid and liquid at the eutectic (triple-point) temperature
3.19
system integrator
integrator of equipment between the PEM fuel cell
power system (3.9) and the hydrogen supply
4 Classification and application
4.1 Classification
Hydrogen fuel shall be classified according to the following types and grade designations:
a) Type I (grades A, B, C, D and E): gaseous hydrogen and hydrogen-based fuel.
b) Type II (grades C and D): liquid hydrogen.
c) Type III: slush hydrogen.
4.2 Application
Table 1 characterizes representative applications of each type and grade of hydrogen fuel.
Table 1 — Hydrogen and hydrogen-based fuel classification by application
Type Grade Category Applications Clause
Gaseous hydrogen; internal combustion engines for
A ― transportation; residential/commercial combustion 7
appliances (e.g. boilers, cookers and similar applications)
Gaseous hydrogen; industrial fuel for power generation and
B ― 7
heat generation except PEM fuel cell applications
Gaseous hydrogen; aircraft and space-vehicle ground
I
C ― 7
support systems except PEM fuel cell applications
Gas
a,b
D ― Gaseous hydrogen; PEM fuel cells for road vehicles 5
PEM fuel cells for stationary appliances 6
1 Hydrogen-based fuel; high efficiency/low power applications
E
2 Hydrogen-based fuel; high power applications
3 Gaseous hydrogen; high power/high efficiency applications
a
Grade D may be used for other fuel cell applications for transportation including forklifts and other industrial trucks if
agreed upon between supplier and customer.
b
Grade D may be used for PEM fuel cell stationary appliances alternative to grade E category 3.
Table 1 (continued)
Type Grade Category Applications Clause
Aircraft and space-vehicle on-board propulsion and
II
C ― 7
electrical energy requirements; off-road vehicles
Liquid
a,b
D ― PEM fuel cells for road vehicles 5
III Aircraft and space-vehicle on-board propulsion
― ― 7
Slush
a
Grade D may be used for other fuel cell applications for transportation including forklifts and other industrial trucks if
agreed upon between supplier and customer.
b
Grade D may be used for PEM fuel cell stationary appliances alternative to grade E category 3.
NOTE Biological sources of hydrogen can contain additional constituents (e.g. siloxanes or mercury) that can
affect the performance of the various applications, particularly PEM fuel cells. However, these are not included in
most of the following specifications due to insufficient information.
5 Hydrogen quality requirements for PEM fuel cell road vehicle application
5.1 Fuel quality specification
The quality of hydrogen at dispenser nozzle for grade D hydrogen (see Table 1) shall meet the
requirements of Table 2. The fuel specifications are not process-dependent or feed-stock-specific. Non-
listed contaminants have no guarantee of being benign.
NOTE ISO 19880-8:2019, Annex A provides the rationale for the selection of the impurities specified in
Table 2.
Table 2 — Fuel quality specification for PEM fuel cell road vehicle application
a
Type I, Type II
Constituents
(assay)
grade D
b
Hydrogen fuel index (minimum mole fraction) 99,97 %
Total non-hydrogen gases (maximum) 300 μmol/mol
Maximum concentration of individual contaminants
Water (H O) 5 μmol/mol
c
Total hydrocarbons except methane 2 μmol/mol
(C1 equivalent)
Methane (CH ) 100 μmol/mol
Oxygen (O ) 5 μmol/mol
Helium (He) 300 μmol/mol
a
For the constituents that are additive, such as total hydrocarbons and total sulphur compounds, the sum of the
constituents shall be less than or equal to the acceptable limit.
b
The hydrogen fuel index is determined by subtracting the "total non-hydrogen gases" in this table, expressed in mole
percent, from 100 mole percent.
c
Total hydrocarbons except methane include oxygenated organic species. Total hydrocarbons except methane shall be
measured on a C1 equivalent (μmol/mol).
d
The sum of measured CO, HCHO and HCOOH shall not exceed 0,2 μmol/mol.
e
As a minimum, total sulphur compounds include H S, COS, CS and mercaptans, which are typically found in natural gas.
2 2
f
All halogenated compounds which could potentially be in the hydrogen gas [for example, hydrogen chloride (HCl) and
organic chlorides (R-Cl)] should be determined by the hydrogen quality control plan discussed in ISO 19880-8. Halogenated
compounds shall be measured on a halogen ion equivalent (μmol/mol).
g
Particulate includes solid and liquid particulates comprises of oil mist. Large particulates can cause issues with vehicle
components and should be limited by using filter as specified in ISO 19880-1. No visible oil shall be found in fuel at a nozzle.
4 © ISO 2019 – All rights reserved

Table 2 (continued)
a
Type I, Type II
Constituents
(assay)
grade D
Nitrogen (N ) 300 μmol/mol
Argon (Ar) 300 μmol/mol
Carbon dioxide (CO ) 2 μmol/mol
d
Carbon monoxide (CO) 0,2 μmol/mol
e
Total sulphur compounds 0,004 μmol/mol
(S1 equivalent)
d
Formaldehyde (HCHO) 0,2 μmol/mol
d
Formic acid (HCOOH) 0,2 μmol/mol
Ammonia (NH ) 0,1 μmol/mol
f
Halogenated compounds 0,05 μmol/mol
(Halogen ion equivalent)
g
Maximum particulate concentration 1 mg/kg
a
For the constituents that are additive, such as total hydrocarbons and total sulphur compounds, the sum of the
constituents shall be less than or equal to the acceptable limit.
b
The hydrogen fuel index is determined by subtracting the "total non-hydrogen gases" in this table, expressed in mole
percent, from 100 mole percent.
c
Total hydrocarbons except methane include oxygenated organic species. Total hydrocarbons except methane shall be
measured on a C1 equivalent (μmol/mol).
d
The sum of measured CO, HCHO and HCOOH shall not exceed 0,2 μmol/mol.
e
As a minimum, total sulphur compounds include H S, COS, CS and mercaptans, which are typically found in natural gas.
2 2
f
All halogenated compounds which could potentially be in the hydrogen gas [for example, hydrogen chloride (HCl) and
organic chlorides (R-Cl)] should be determined by the hydrogen quality control plan discussed in ISO 19880-8. Halogenated
compounds shall be measured on a halogen ion equivalent (μmol/mol).
g
Particulate includes solid and liquid particulates comprises of oil mist. Large particulates can cause issues with vehicle
components and should be limited by using filter as specified in ISO 19880-1. No visible oil shall be found in fuel at a nozzle.
5.2 Analytical method
The analytical methods for measuring constituents in Table 2 shall meet the requirements of ISO 21087.
5.3 Sampling
Guidance on hydrogen sampling methods for gaseous hydrogen fuelling stations is available in
ISO 19880-1.
5.4 Hydrogen quality control
The means of assuring that the hydrogen quality meets the specification in 5.1 shall be based upon
ISO 19880-8.
6 Hydrogen and hydrogen-based fuels, quality requirements for PEM fuel cell
stationary applications
6.1 Fuel quality specification
The quality of hydrogen and hydrogen-based fuels, supplied to stationary PEM fuel cell appliances,
shall meet the requirements of Table 3 at the boundary point set between the hydrogen fuel supply
equipment and the PEM fuel cell power system.
NOTE 1 Annex A provides guidance for the selection of the boundary point.
NOTE 2 Annex B provides the rationale for the selection of the impurities specified in Table 3.
Type I, grade E hydrogen and hydrogen-based fuels, for PEM fuel cell applications for stationary
appliances, specify the following subcategories in order to meet the needs of different stationary
applications, depending on the requirements specified by the manufacturer:
— Type I, grade E, category 1 (hydrogen-based fuel; high efficiency/low power applications).
— Type I, grade E, category 2 (hydrogen-based fuel; high power applications).
— Type I, grade E, category 3 (gaseous hydrogen; high power/high efficiency applications).
Table 3 — Fuel quality specification for PEM fuel cell stationary applications
a
Constituents Type I, grade E
(assay) Category 1 Category 2 Category 3
b
Hydrogen fuel index
50 % 50 % 99,9 %
(minimum mole fraction)
Total non-hydrogen gases
50 % 50 % 0,1 %
(maximum mole fraction)
Non-condensing at any Non-condensing at any Non-condensing at any
c
Water (H O)
ambient conditions ambient conditions ambient conditions
d
Maximum concentration of individual contaminants
Total hydrocarbons except
e
methane
10 μmol/mol 2 μmol/mol 2 μmol/mol
(C equivalent)
Methane (CH ) 5 % 1 % 100 μmol/mol
Oxygen (O ) 200 μmol/mol 200 μmol/mol 50 μmol/mol
Sum of nitrogen (N ),
argon (Ar) and helium (He) 50 % 50 % 0,1 %
(mole fraction)
a
For the constituents that are additive, such as total hydrocarbons and total sulphur compounds, the sum of the
constituents shall be less than or equal to the acceptable limit.
b
The hydrogen fuel index is determined by subtracting the "total non-hydrogen gases" in this table, expressed in mole
percent, from 100 mole percent.
c
Each site shall be evaluated to determine the appropriate maximum water content based on the lowest expected
ambient temperature and the hig
...