IEC GUIDE 104:2019

IEC GUIDE 104 ®
Edition 5.0 2019-07
GUIDE
colour
inside
The preparation of safety publications and the use of basic safety publications
and group safety publications
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IEC GUIDE 104 ®
Edition 5.0 2019-07
GUIDE
colour
inside
The preparation of safety publications and the use of basic safety publications

and group safety publications
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020 ISBN 978-2-8322-7196-4

– 2 – IEC GUIDE 104:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 HORIZONTAL SAFETY FUNCTIONS and GROUP SAFETY FUNCTIONS . 8
4.1 Assignment of HSF or GSF to a TC . 8
4.2 Preparation of BSP or GSP with the assigned HSF or GSF . 9
4.3 Monitoring of the assigned HSF or GSF . 10
5 Development of SAFETY publications . 11
5.1 General . 11
5.1.1 Categories of BASIC SAFETY PUBLICATIONs and GROUP SAFETY
PUBLICATIONs . 11
5.1.2 References to other publications. 12
5.1.3 SAFETY during the life of equipment . 12
5.2 BASIC SAFETY PUBLICATION . 12
5.2.1 Objective and object of a BASIC SAFETY PUBLICATION . 12
5.2.2 Development of a BASIC SAFETY PUBLICATION . 12
5.2.3 Scope of a BASIC SAFETY PUBLICATION . 13
5.2.4 Revision of a BASIC SAFETY PUBLICATION . 13
5.3 GROUP SAFETY PUBLICATIONS . 13
5.3.1 Objective and object of a GROUP SAFETY PUBLICATION . 13
5.3.2 Development of a GROUP SAFETY PUBLICATION . 13
5.3.3 Scope of a GROUP SAFETY PUBLICATION . 13
5.3.4 Revision of a GROUP SAFETY PUBLICATION . 14
5.4 PRODUCT SAFETY STANDARD . 14
5.4.1 SAFETY objectives and scope of a PRODUCT SAFETY STANDARD (PSS) . 14
5.4.2 Development of a PRODUCT SAFETY STANDARD . 15
6 Responsibilities of TCs with HORIZONTAL SAFETY FUNCTIONs or GROUP SAFETY
FUNCTIONs. 15
6.1 Co-operation and liaison with other TCs . 15
6.2 Requests from PRODUCT TCs for new work . 15
7 Responsibilities of PRODUCT TCs . 16
7.1 General . 16
7.2 Application of BASIC SAFETY PUBLICATIONs . 16
7.3 Application of GROUP SAFETY PUBLICATIONs . 16
7.4 New work requests to TCs with SAFETY functions . 16
Annex A (informative) Structure of IEC SAFETY publications . 18
Bibliography . 19

Figure 1 – Assignment of an HSF or GSF to a TC . 9
Figure 2 – Development of the first BASIC or GROUP SAFETY PUBLICATION . 10
Figure 3 – Monitoring of HSF and GSF . 11
Figure A.1 – Structure of IEC SAFETY publications . 18

INTERNATIONAL ELECTROTECHNICAL COMMISSION
__________
THE PREPARATION OF SAFETY PUBLICATIONS AND
THE USE OF BASIC SAFETY PUBLICATIONS AND
GROUP SAFETY PUBLICATIONS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This fifth edition of IEC Guide 104 has been prepared, in accordance with ISO/IEC Directives,
Part 1, Annex A, by the IEC Advisory Committee on Safety (ACOS). This Guide is a
mandatory Guide in accordance with SMB Decision 136/8.
This fifth edition cancels and replaces the fourth edition published in 2010.
The main changes with respect to the previous edition are as follows:
– alignment with terms and definitions of ISO/IEC Guide 51:2014;
– reference to IEC Guide 108 in the introduction;
– creation of BASIC SAFETY PUBLICATION and GROUP SAFETY PUBLICATION subcategories to
clarify the different types of document (requirements, guidance, mandatory test
procedures and reference data);
– improved structure: new titles and subclauses;

– 4 – IEC GUIDE 104:2019 © IEC 2019
– addition to the responsibilities of the technical committees (TCs) with HORIZONTAL SAFETY
FUNCTION: development of their publications in collaboration with customer TCs and
monitoring the use of their SAFETY publications;
– replacement of Annex A and the associated text by reference to IEC Guide 116;
– shortened status statement for publications with BASIC SAFETY PUBLICATION designation;
– addition of the scope items of a PRODUCT SAFETY STANDARD.
The text of this IEC Guide is based on the following documents:
Four month’s vote Report on voting
C/2145/DV C/2173/RV
Full information on the voting for the approval of this Guide can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this document, terms in UPPERCASE are defined in Clause 3.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
Technical committees dealing with subjects relating to SAFETY for the whole, or for a specific
part, of their activities, are required by SMB Decision 136/8 to follow the provisions of this
document, which is to be used in conjunction with the ISO/IEC Directives and with the Guides
listed under Clause 2.
The objective of this document is to improve the consistency of the SAFETY requirements
across IEC publications. For this purpose, mandatory procedures are defined in this document
for limiting overlaps and contradictory SAFETY requirements. Consequently, this document can
be considered as complementary to ISO/IEC Directives.
Depending on the situations, RISK reduction can be analysed and implemented by different
approaches. Therefore, technical guidance about SAFETY aspects and RISK analysis is in
principle optional and detailed in other non-mandatory Guides. However, ISO/IEC Guide 51
and IEC Guide 116 are referenced in this document for specific essential requirements for
achieving SAFETY.
In this document, the term "technical committees", hereinafter referred to as TCs, also
includes subcommittees. The term "publication" includes International Standard, Technical
Report, Technical Specification, Publicly Available Specification and Guide. In addition, the
term "product" includes individual product, process, service and combinations thereof,
commonly known as "systems".
This document follows the principles of IEC Guide 108 with specific additions for SAFETY
aspects.
– 6 – IEC GUIDE 104:2019 © IEC 2019
THE PREPARATION OF SAFETY PUBLICATIONS AND
THE USE OF BASIC SAFETY PUBLICATIONS AND
GROUP SAFETY PUBLICATIONS
1 Scope
This mandatory Guide defines procedures for the development of SAFETY publications,
including the preparation and use of BASIC SAFETY PUBLICATIONs and GROUP SAFETY
PUBLICATIONs. It also describes the procedures for the assignment of HORIZONTAL SAFETY
FUNCTIONs or GROUP SAFETY FUNCTIONs to TCs, their relationship with PRODUCT TCs and their
respective responsibilities.
In the context of this document, "SAFETY" relates to the SAFETY of persons, domestic animals,
livestock and property.
This document does not cover:
– requirements and guidance for the inclusion of general SAFETY aspects in standards, which
are covered by ISO/IEC Guide 51;
– guidance for SAFETY related RISK assessment and RISK reduction to be taken into account
when developing SAFETY publications for low voltage equipment, which are covered by
IEC Guide 116.
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/lEC Guide 51:2014, Safety aspects – Guidelines for their inclusion in standards
IEC Guide 116:2018, Guidelines for safety related risk assessment and risk reduction for low
voltage equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC Guide 51 and
the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
basic safety publication
BSP
publication on a specific SAFETY aspect, applicable to many electrotechnical products and of
crucial importance to ensure the coherence amongst publications.

3.2
group safety publication
GSP
publication covering all SAFETY aspects primarily for a specific group of products within the
scope of two or more PRODUCT TCs
Note 1 to entry: GSPs are primarily intended to be stand-alone PRODUCT SAFETY STANDARDs, but may also be
used by TCs as source material in the preparation of their publications, as detailed in 7.3.
3.3
product safety standard
PSS
standard covering all SAFETY aspects of one or more products within the scope of a single
PRODUCT TC
Note 1 to entry: Product includes equipment, software, installation and service.
3.4
product TC
technical committee with a scope which covers a specific family or group of products
3.5
horizontal safety function
HSF
BASIC SAFETY PUBLICATIONs within its scope
task assigned to a TC to prepare one or more
3.6
group safety function
GSF
task assigned primarily to a PRODUCT TC to prepare one or more GROUP SAFETY PUBLICATIONs
within its scope
3.7
normal condition
condition in which all means of protection are intact
3.8
single fault condition
condition in which there is a fault of a single protection (but not a reinforced protection) or of a
single component or a device
Note 1 to entry: If a SINGLE FAULT CONDITION results in one or more other fault conditions, all are considered as
one SINGLE FAULT CONDITION.
Note 2 to entry: Reinforced protection is defined in IEC 60050-903:2013, 903-02-08.
3.9
harm
injury or damage to the health of people, or damage to property or the environment
[SOURCE: ISO/IEC Guide 51:2014, 3.1]
3.10
hazard
potential source of HARM
[SOURCE: ISO/IEC Guide 51:2014, 3.2]

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3.11
risk
combination of the probability of occurrence of HARM and the severity of that HARM
Note 1 to entry: The probability of occurrence includes the exposure to a hazardous situation, the occurrence of a
hazardous event and the possibility to avoid or limit the HARM.
[SOURCE: ISO/IEC Guide 51:2014, 3.9]
3.12
safety
freedom from RISK which is not tolerable
[SOURCE: ISO/IEC Guide 51:2014, 3.14]
4 HORIZONTAL SAFETY FUNCTIONS and GROUP SAFETY FUNCTIONS
4.1 Assignment of HSF or GSF to a TC
The assignment of HORIZONTAL SAFETY FUNCTIONs (HSFs) and of GROUP SAFETY FUNCTIONs
(GSFs) is the responsibility of the Advisory Committee on Safety (ACOS), subject to
confirmation by the SMB (Standardization Management Board).
Any TC may request an assignment of an HSF or a GSF to ACOS. The TC proposing an HSF
or GSF shall provide to ACOS for review:
– the clear definition of the HSF with the safety aspects or the GSF with the group of
products,
– a demonstration of the common benefits to several TCs, and
– a drafted scope of the first intended project of BSP or GSP according to 4.2.
The assignment of an HSF or a GSF to a TC is made with the purpose of:
– ensuring the consistency of IEC publications relating to safety aspects common to a
number of TCs by avoiding duplication of work and contradictory requirements;
– reducing the size and cost of lEC publications by avoiding duplication of texts;
– improving mutual understanding among engineers of different technical disciplines.
The assignment gives mandate to the TC having:
– an HSF to develop associated BSPs;
– a GSF to develop associated GSPs.
For the structure of IEC SAFETY publications see Annex A.
The assignment process is shown in Figure 1.

Figure 1 – Assignment of an HSF or GSF to a TC
4.2 Preparation of BSP or GSP with the assigned HSF or GSF
To ensure the consistency of the intended BSP or GSP with the HSF or GSF, its scope and
the essential SAFETY requirements, guidance, mandatory tests or reference data of the first
publication under a new assignment
...