IEC 63360:2025

IEC 63360 ®
Edition 1.0 2025-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fluids for electrotechnical application – Specification of gases alternative to SF6
to be used in electrical power equipment

Fluides pour applications électrotechniques – Spécifications des gaz alternatifs
au SF6 destinés à être utilisés dans les matériels électriques

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IEC 63360 ®
Edition 1.0 2025-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fluids for electrotechnical application – Specification of gases alternative to

SF6 to be used in electrical power equipment

Fluides pour applications électrotechniques – Spécifications des gaz alternatifs

au SF6 destinés à être utilisés dans les matériels électriques

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.040.20  ISBN 978-2-8327-0161-4

– 2 – IEC 63360:2025 © IEC 2025
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 9
4 Requirements for gases . 9
4.1 General . 9
4.2 Compressed air . 10
4.3 Technical grade synthetic air . 10
4.4 Technical grade natural-origin gases . 10
4.5 Technical grade C F O (C5-FK) . 11
5 10
4.6 Technical grade C F N (C4-FN) . 12
4 7
5 Mixing ratio and tolerances . 12
6 Handling, storage and transportation . 13
6.1 Gas handling procedures . 13
6.2 Storage and transportation . 13
7 Environmental impact . 13
Annex A (informative) Environmental, health, and safety effects of gases . 14
A.1 General . 14
A.2 Physical hazards . 14
A.3 Hazard to human health . 14
A.4 Environmental hazard . 15
A.5 Ozone depletion . 16
A.6 Global warming/climate change (greenhouse effect) . 16
A.7 Reducing the environmental impact of the use of gases in electrical
power equipment . 17
Annex B (informative) On-site detection techniques . 18
Annex C (informative) Mole fraction (% mol) versus volume fraction (% vol) . 22
C.1 General . 22
C.2 Definitions of the fractions and compressibility factor . 22
C.2.1 Mole fraction (x) . 22
C.2.2 Volume fraction (Ф ) . 22
i
C.2.3 Mass fraction (w) . 23
C.2.4 Compressibility factor (Z) . 23
C.2.5 Names and symbols . 24
C.3 Examples % mol vs % vol for C4-FN / O / CO mixtures . 24
2 2
C.3.1 General . 24
C.3.2 Variation with pressure . 25
C.3.3 Variation with temperature . 25
Bibliography . 27

Figure C.1 – Shift between mole and volume fractions with pressure for two mixtures
containing 5 % mol and 3,5 % mol C4-FN, 13 % mol O and the rest in CO (20 °C) . 25
2 2
Figure C.2 – Shift between mole and volume fractions with temperature for two
mixtures containing 5 % mol and 3,5 % mol C4-FN, 13 % mol O and the rest in CO
2 2
(101,3 kPa) . 26

Table 1 – Requirements for compressed air for electrical power equipment . 10
Table 2 – Requirements for technical grade synthetic air . 10
Table 3 – Requirements for technical grade nitrogen . 11
Table 4 – Requirements for technical grade oxygen . 11
Table 5 – Requirements for technical grade carbon dioxide . 11
Table 6 – Requirements for technical grade C5-FK . 12
Table 7 – Requirements for technical grade C4-FN . 12
Table A.1 – Global warming potential (GWP) of components of the gases according to
IPCC AR6 [12] or [13] . 17
Table B.1 – Detection techniques for the analysis of synthetic air . 18
Table B.2 – Detection techniques for the analysis of compressed air . 19
Table B.3 – Detection techniques for the analysis of natural-origin gases mixtures . 20
Table B.4 – Detection techniques for the analysis of C5-FK mixtures . 20
Table B.5 – Detection techniques for the analysis of C4-FN mixtures . 21

– 4 – IEC 63360:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FLUIDS FOR ELECTROTECHNICAL APPLICATION −
SPECIFICATION OF GASES ALTERNATIVE TO SF
TO BE USED IN ELECTRICAL POWER EQUIPMENT

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
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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
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6) All users should ensure that they have the latest edition of this publication.
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 63360 has been prepared IEC technical committee 10: Fluids for electrotechnical
applications. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
10/1219/FDIS 10/1257/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 6 – IEC 63360:2025 © IEC 2025
INTRODUCTION
Considering the limited information for some of the data which appear in informative Annex A,
the reader should be aware that the information related with possible gases alternative to SF
are still a matter of study.
FLUIDS FOR ELECTROTECHNICAL APPLICATION −
SPECIFICATION OF GASES ALTERNATIVE TO SF
TO BE USED IN ELECTRICAL POWER EQUIPMENT

1 Scope
This document specifies the quality of gases alternative to SF (subsequently referred to as
gases) for use in electrical power equipment.
Detection techniques, applicable to the analysis of gases prior to their introduction into the
electrical power equipment, are also described in this document.
Information about gases by-products and the procedure for evaluating the potential effects of
gases and its by-products on human health are covered by IEC 63359 [1] and IEC 62271-4.
It is the responsibility of the gas manufacturer to make available sufficient information for safe
handling of gases and a risk assessment.
For gases not mentioned in this document, the electrical power equipment manufacturer and/or
gas manufacturer provides the information indicated in this document. It is the intention of this
document to include such gases in a next edition or in amendments to this edition. This
document provides information to prepare risk assessment associated with the use of gases. It
is the responsibility of the user of this document to establish appropriate health and safety
practices and determine the applicability of regulatory limitations prior to use.
NOTE 1 Throughout this document, the term "pressure" stands for "absolute pressure".
NOTE 2 If not otherwise specified in this document, concentration values (e.g. %, ppmv, µl/l) of gas components or
contaminants are given in volume fraction at 20 °C and 100 kPa. More information on temperature and pressure
dependance of mole fraction and volume fraction is given in Annex C.
NOTE 3 If gases for electrical power equipment are regulated, their designation and regulation origin can be found
in the IEC 62474 database [2] (available at https://std.iec.ch/iec62474 [viewed 2024-02-19]).
NOTE 4 Handling of gases is covered by IEC 62271-4:2022.
NOTE 5 Additional information is needed from gas manufacturer and/or electrical power equipment manufacturer
to perform a full risk assessment.
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.
IEC 60050-212, International Electrotechnical Vocabulary (IEV) – Part 212: Electrical insulating
solids, liquids and gases (available at http://www.electropedia.org)
IEC 60050-441, International Electrotechnical Vocabulary (IEV) – Part 441: Switchgear,
controlgear and fuses (available at http://www.electropedia.org)
___________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC 63360:2025 © IEC 2025
IEC 60050-826, International Electrotechnical Vocabulary (IEV) – Part 826: Electrical
installations (available at http://www.electropedia.org)
IEC 62271-4:2022, High-voltage switchgear and controlgear – Part 4: Handling procedures for
gases for insulation and/or switching
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in IEC 60050-212,
IEC 60050-441, IEC 60050-826 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1 Terms and definitions
3.1.1
electrical power equipment
any high-voltage or medium-voltage equipment containing gas for insulation and/or switching,
e.g. switchgear and controlgear, gas-insulated lines, transformers, instrument transformers,
etc.
3.1.2
single gas
gas made up of identical atoms or molecules
Note 1 to entry: A single gas could contain contaminants.
EXAMPLE CO (at standard atmospheric conditions) is a typical example of a single gas.
3.1.3
gas mixture
gas made up of a minimum of two single gases
Note 1 to entry: A gas mixture could contain contaminants.
EXAMPLE CO /O (at standard atmospheric conditions) is a typical example of a gas mixture of two single gases.
2 2
3.1.4
contaminant
foreign substance or material in an insulating liquid, gas or solid
[SOURCE: IEC 60050-212:2010, 212-17-27, modified – "which usually has deleterious effect
on one or more properties" has been deleted.]
3.1.5
by-product
contaminant which is formed by the degradation of the gas by electrical arcs, corona effect or
sparks, or formed by chemical reaction with other substances or materials
[SOURCE: IEC 62271-4:2022, 3.1.6]

3.1.6
gas container
vessel (cylinder) suitable for the containment of pressurized gases either in gaseous or liquid
phase, according to local and/or international safety and transportation regulations
[SOURCE: IEC 60480:2019 [3], 3.2, modified − "gas" has been added to the term.]
3.1.7
compressed air
air suitable for electrical power equipment processed in accordance with Table 1
3.1.8
technical grade natural-origin gas
technical grade nitrogen (N ), technical grade oxygen (O ) or technical grade carbon dioxide
2 2
(CO ) or their mixtures in any combination
3.1.9
technical grade nitrogen
nitrogen (N ) for electrical power equipment in accordance with Table 3
3.1.10
technical grade oxygen
oxygen (O ) for electrical power equipment in accordance with Table 4
3.1.11
technical grade carbon dioxide
carbon dioxide (CO ) for electrical power equipment in accordance with Table 5
3.1.12
technical grade synthetic air
gas mixture for electrical power equipment in accordance with Table 2
Note 1 to entry: Technical grade synthetic air is a fixed gas mixture of technical grade natural-origin gases.
3.1.13
technical grade C5-FK
C5-FK for electrical power equipment in accordance with Table 6
3.1.14
technical grade C4-FN
C4-FN for electrical power equipment in accordance with Table 7
3.2 Abbreviated terms
ppmv parts per million by volume
ppmw parts per million by weight
4 Requirements for gases
4.1 General
The technical specifications enclosed are based on achieving required technical performance
with commercially available gases. Therefore, the level of impurity can vary for different gases.
The accuracy of the measuring devices/methods shall be considered when checking the quality
of the gas.
– 10 – IEC 63360:2025 © IEC 2025
NOTE Detection techniques applicable for on-site verification of concentrations and acceptable level of impurities
are given in Annex B.
4.2 Compressed air
Compressed air shall fulfil the requirements given in Table 1.
The responsibilities of the manufacturer lie with the party compressing the air for use in
electrical power equipment.
NOTE Table 1 is necessary to define requirements for compressed air for use in electrical power equipment
because not all ambient air, when compressed, is suitable for this application.
Table 1 – Requirements for compressed air for electrical power equipment
Substance Concentration/size
N 77 % to 80,5 %
O 19,5 % to 22 %
Ar ≤ 1 %
a
CO
≤ 5 000 µl/l (ppmv)
b
H O
≤ 450 µl/l (ppmv)
Other gases ≤ 100 µl/l (ppmv)
Mineral oil < 10 mg/kg (ppmw)
c
Solid particles
≤ 1 µm
The substance concentrations sum to 100 %.
a
The CO2 level corresponds to the maximum average workplace concentration and has a negligible impact on
dielectric performance.
b
This value is equivalent to −28 °C frost point at 100 kPa and can be reduced with the use of drying agent.
c
This value can be achieved using a compressor equipped with suitable particle filters.

4.3 Technical grade synthetic air
Technical grade synthetic air shall fulfil the requirements given in Table 2.
Table 2 – Requirements for technical grade synthetic air
Substance Concentration
O 20 % ± 2 %
N 80 % ± 2 %
Other gases ≤ 0,4 %
a
H O
≤ 200 µl/l (ppmv)
The substance concentrations sum to 100 %.
a
This value is equivalent to −36 °C frost point at 100 kPa.

4.4 Technical grade natural-origin gases
Technical grade natural-origin gases (nitrogen (N ), oxygen (O )) and carbon dioxide (CO ) or
2 2 2
any mixture of them shall fulfil the requirements given in Table 3, Table 4 and Table 5.

Table 3 – Requirements for technical grade nitrogen
Substance Concentration
N ≥ 99,7 %
a
≤ 0,3 %
Other gases
b
H O
≤ 200 µl/l (ppmv)
a
Typically, the main other gas is O2.
b
This value is equivalent to −36 °C frost point at 100 kPa.

Table 4 – Requirements for technical grade oxygen
Substance Concentration
O ≥ 99,5 %
a
≤ 0,5 %
Other gases
b
H O
≤ 200 µl/l (ppmv)
a
Typically, the main other gas is N2.
b
This value is equivalent to −36 °C frost point at 100 kPa

Table 5 – Requirements for technical grade carbon dioxide
Substance Concentration
CO ≥ 99,5 %
a
≤ 0,5 %
Other gases
b
H O
≤ 200 µl/l (ppmv)
NOTE The kind and quantities of specific contaminants depend on the production process.
a
Typically, the main other gases are N and O .
2 2
b
This value is equivalent to −36 °C frost point at 100 kPa.

4.5 Technical grade C F O (C5-FK)
5 10
Technical grade C F O shall fulfil the requirements given in Table 6.
5 10
Technical grade C F O is usually used in a mixture with one or more technical grade carrier
5 10
gases (N , CO and/or O ).
2 2 2
NOTE 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-2-butanone, also described as CF -C(O)-CF-(CF ) or C F O
3 3 2 5 10
is a Fluoroketone. For easier naming, reference and identification, it is also named C5-FK (FK = Fluoroketone). There
are other molecules with the same formula (C F O) which do not have the same spatial structure.
5 10
– 12 – IEC 63360:2025 © IEC 2025
Table 6 – Requirements for technical grade C5-FK
Substance Concentration
CF -C(O)-CF-(CF ) ≥ 99,5 %
3 3 2
a
≤ 0,5 %
Other gases
b
H O
≤ 270 µl/l (ppmv)
NOTE The kind and quantities of specific contaminants depend on the production process.
a
Typically, another gas is 1,1,1,2,3,3,3-heptafluoropropane.
b
This value is equivalent to −33 °C frost point at 100 kPa.

4.6 Technical grade C F N (C4-FN)
4 7
Technical grade C F N shall fulfil the requirements given in Table 7.
4 7
Technical grade C F N is usually used in a mixture with one or more technical grade carrier
4 7
gases (N , CO and/or O ).
2 2 2
NOTE 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-propanenitrile, also described as (CF ) CFCN or C F N, is a
3 2 4 7
Fluoronitrile. For easier naming, reference and identification, it is also named C4-FN (FN = Fluoronitrile). There are
other molecules with the same formula (C F N) which do not have the same spatial structure.
4 7
Table 7 – Requirements for technical grade C4-FN
Substance Concentration
(CF ) -CF-CN ≥99,3 %
3 2
a
≤ 0,7 %
Other gases
b
H O
≤ 270 µl/l (ppmv)
NOTE The kind and quantities of specific contaminants depend on the production process.
a
Typically, another gas is 1,1,1,2,3,3,3-heptafluoropropane and/or CF -CF -CF -CN.
3 2 2
b
This value is equivalent to −33 °C frost point at 100 kPa.

5 Mixing ratio and tolerances
Except for technical grade synthetic air and compressed air, additional information on the
accuracy of the concentration of each component of the gas mixture is required. The tolerance
of mixing ratio is specified by the electrical power equipment manufacturer. For gas mixtures
used in electrical power equipment, the required concentration of each component of the
mixture is based on:
• the minimum temperature, to avoid partial liquefaction,
• physical and chemical properties,
• the dielectric, thermal and/or switching performances.
The absolute tolerance on high concentrations can be larger than for low concentrations, which
results in an impact of the mixing ratio in the achievable accuracy. In addition, for practical
reasons, the achievable accuracy of the gas mixing equipment and of the gas analyser shall be
considered, to avoid requirements which cannot be fulfilled with state-of-the-art equipment.

6 Handling, storage and transportation
6.1 Gas handling procedures
The need to handle gases in accordance with the present document arises when:
• the gas container is connected to the filling device,
• the gas or gases are introduced into electrical power equipment or a gas container,
• the gas pressure is topped-up in closed pressure systems,
• the gas is drawn from an electrical power equipment or a gas container for analysis.
Further information concerning handling procedures for gas and gas mixtures is provided in
IEC 62271-4.
6.2 Storage and transportation
Information concerning gas storage and transportation is provided in IEC 62271-4.
7 Environmental impact
Gases can have an environmental impact. Gases other than compressed air and natural-origin
gases shall be handled carefully to prevent release into the atmosphere.
More detailed information concerning environmental impact is reported in Annex A.

– 14 – IEC 63360:2025 © IEC 2025
Annex A
(informative)
Environmental, health, and safety
effects of gases
A.1 General
Components of the gases could be non-intentionally released to the atmosphere during
operation (normal leakage, abnormal leakage or sudden release), maintenance and end of life.
For environmental issues, health and safety, major aspects to consider are described in
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) [4] part 3 and
part 4. The main information is in Section 11 (Toxicological information) and Section 12
(ecological information) of each safety data sheets (SDS) of gases and is described in
ISO 11014:2009, Annex A [5]. Additionally, physical hazards are also mentioned.
NOTE Environmental effects of SF and its mixtures are detailed in IEC 60376:2018, Annex B [6].
A.2 Physical hazards
This clause provides a concise but complete description of the different kinds of physical
hazards. Typical physical hazards to be considered when using a gas in electrical power
equipment are:
• explosion;
• corrosion;
• fire. This hazard can result from high surface temperature of electrical power equipment or
sparks during operation, maintenance, or flames during operation, maintenance, or failure;
• gases under pressure. This hazard is considered in IEC 62271-1 [7] or
IEC TS 62271-5:— , Clause 12 [8], in relevant applications (e.g. IEC 62271-200 [9] or
IEC 62271-203 [10]) and local regulations.
A.3 Hazard to human health
Hazard to human health is described in Section 11 of the SDS from the gas manufacturer and
provides a concise but complete description of the various considered toxicological (health)
effects, and where to find the available data used to identify those effects. The relevant hazards
to be considered are:
a) acute toxicity that describes serious adverse health effects (i.e. lethality) of a substance
occurring after a single exposure or from multiple exposures in a short period of time;
b) skin corrosion/irritation which refers to the production of irreversible/reversible damage to
the skin occurring after exposure to a substance or mixture;
NOTE 1 "Skin corrosion" is synonymous with "skin burning".
c) serious eye damage which refers to the production of tissue damage in the eye, or serious
physical decay of vision, which is not fully reversible, following the exposure of the eye to a
substance or mixture. Eye irritation refers to the production of changes in the eye, which
are fully reversible, following the exposure of the eye to a substance or mixture;
___________
Under preparation. Stage at the time of publication: IEC/BPUB TS 62271-5:2024.

d) respiratory or skin sensitization.
Respiratory sensitization refers to hypersensitivity of the airways following inhalation of a
substance or a mixture.
Skin sensitization refers to an allergic response following skin contact with a substance or
a mixture;
e) germ cell mutagenicity which refers to heritable gene mutations, including heritable
structural and numerical chromosome aberrations in germ cells following the exposure to a
substance or mixture;
f) carcinogenicity which refers to the induction of cancer or an increase in the incidence of
cancer following the exposure to a substance or mixture. Substances and mixtures which
have induced benign and malignant tumours in well performed experimental studies on
animals are considered also to be presumed or suspected human carcinogens unless there
is strong evidence that the mechanism of tumour formation is not relevant for humans;
g) reproductive toxicity which refers to adverse effects on sexual function and fertility in adult
males and females, as well as developmental toxicity in the offspring, following exposure to
a substance or mixture;
h) STOT (specific target organ toxicity) single exposure which refers to specific, non-lethal
toxic effects on target organs following a single exposure to a substance or mixture. All
significant health effects that can impair function, both reversible and irreversible, immediate
and/or delayed and not specifically addressed in items a) to g) and j) are included;
i) STOT repeated exposure which refers to specific toxic effects on target organs following
repeated exposure to a substance or mixture. All significant health effects that can impair
function, both reversible and irreversible, immediate and/or delayed and not specifically
addressed in a) to g) and j) are included;
j) aspiration hazard, which refers to severe acute effects such as chemical pneumonia,
pulmonary injury or death following aspiration of a substance or mixture.
NOTE 2 "Aspiration hazard" is synonymous with "inhalation hazard".
In case of mixture, the toxicological data should describe the mixture. If that information is not
available, the toxicological properties of each component should be provided.
NOTE 3 Components can interact with each other in the body, resulting in different rates of absorption, metabolism
and excretion. As a result, the overall toxicity of the mixture can be different from the toxicity of each single
component.
A.4 Environmental hazard
The information provided in this clause contains information on possible environmental effects,
behaviour and fate of the substance or mixture if released to the environment.
Environmental hazard is described in Section 12 of the SDS from the gas manufacturer and
provides information on possible environmental effects:
a) Toxicity
Information on toxicity can be provided using data from tests performed on aquatic and/or
terrestrial organisms. This includes relevant available data on both acute and chronic
aquatic toxicity for fish, crustaceans, algae and other aquatic plants. In addition, toxicity
data on other organisms (including soil micro- and macro-organisms) such as birds, bees
and plants, can be included when available. Where the substance or mixture has inhibitory
effects on the activity of micro-organisms, the possible impact on sewage treatment plants
should be mentioned;
– 16 – IEC 63360:2025 © IEC 2025
b) Persistence and degradability
Persistence and degradability is the potential for the substance or the appropriate
constituents of a mixture to degrade in the environment, either through biodegradation or
other processes, such as oxidation or hydrolysis. If degradation half-lives are quoted, it shall
be indicated whether these half-lives refer to mineralization or to primary degradation. The
potential of the substance or certain constituents of a mixture to degrade in sewage
treatment plants should also be mentioned;
c) Bioaccumulative potential
Bioaccumulation is the potential for the substance or certain constituents of a mixture to
accumulate in biota and, possibly, pass through the food chain;
d) Mobility in soil
Mobility in soil is the potential of a substance or the constituents of a mixture, if released to
the environment, to move under natural forces to the groundwater or to a distance from the
site of release;
e) Other adverse effects, such as environmental fate (exposure), endocrine disrupting
potential, ozone depletion potential, photochemical ozone creation potential, and global
warming potential are described in Clause A.5 and Clause A.6.
A.5 Ozone depletion
Components of the gases listed in this document do not contribute to the destruction of the
stratospheric ozone layer because they contain neither chlorine nor bromine.
A.6 Global warming/climate change (greenhouse effect)
Both manmade and natural greenhouse gases contribute to the greenhouse effect if released
to the atmosphere. The Kyoto Protocol [11] is an international agreement to control the emission
of manmade greenhouse gases.
The greenhouse gases to be monitored according to the Kyoto Protocol are carbon dioxide
(CO ), methane (CH ), nitrous oxide (N O), hydrofluorocarbons (HFCs), perfluorocarbons
2 4 2
(PFCs), nitrogen trifluoride (NF ) and sulphur hexafluoride (SF ). The latter four substances
3 6
are fluorinated greenhouse gases (F-gases).
The concentrations of different gases relevant to the environment including those in the Kyoto
Protocol are regularly monitored by several scientific bodies. In particular, the
Intergovernmental Panel on Climate Change (IPCC) periodically prepares assessment reports,
updating the existing information on emissions and evaluating their potential future impact on
the environment according to different hypothesis of their emission trends.
The report provides the global warming potential (GWP) of each gas which is calculated over a
time period of 100 years, warming potential of 1 kg of a gas referred to 1 kg of CO . Table A.1
gives the global warming potential (GWP) of components of the gases according to IPCC AR6
[12] or [13].
Table A.1 – Global warming potential (GWP) of
components of the gases according to IPCC AR6 [12] or [13]
Name of the gas GWP
Compressed air/synthetic air 0
N 0
O 0
CO 1
C5-FK (C F O) 0,29 [13]
5 10
C4-FN (C F N) 2 750 [12]
4 7
A.7 Reducing the environmental impact of the use of gases in electrical
power equipment
Major failures causing sudden gas releases are rare as records from 50 years of experience
show for SF and its mixtures. The quantities released in such extreme cases are again very
limited by the fact that the design of products containing higher quantity of gas is
compartmented, limiting the fault to the place where it originates. The gas quantities concerned
are subsequently small fractions of the total gas banked in a substation.
The electric industry utilizes manmade gases in a closed cycle, banking it for example in gas-
insulated switchgear (GIS), medium-voltage and high-voltage gas circuit-breakers, high-voltage
gas-insulated lines (GIL), gas-insulated voltage transformers (GVT) and gas-insulated power
transformers (GIT). To avoid any deliberate release of manmade gases to the environment, gas
recovery has the highest priority.
The environmental impact of any electrical power equipment should be evaluated using the life
cycle assessment (LCA) approach, for example, according to IEC TS 62271-320 [14].
To reduce the overall environmental impact, the approach is to:
• design equipment with reduced amount of materials and lower leakage rates. Refer to
IEC 62271-1:2017;
• improve handling processes and handling equipment for all life cycle stages. Refer to
IEC 62271-4;
• minimise emissions of manmade gases during testing, manufacturing, installation, operation
and maintenance of electrical power equipment;
• recover gases other than compressed air and natural-origin gases at the equipment's end
of life according to IEC 62271-4;
• design more compact electrical power equipment which results in less material consumption
and/or design main current path to have low ohmic resistance to reduce power losses during
operation of electrical power equipment.

___________
Under preparation. Stage at the time of publication: IEC/CD TS 62271-320:2023.

– 18 – IEC 63360:2025 © IEC 2025
Annex B
(informative)
On-site detection techniques
The analytical methods described in this annex refer to on-site measurement of the gas quality.
On-site measurement is typically performed with mobile analysers. Gas samples can also be
taken and sent to the laboratory for more detailed analysis and higher accuracy. All listed
measurement methods for on-site measurement can also be performed in the laboratory in
addition to other recognized laboratory measurement techniques such as GC-MS and infrared
absorption.
Measurement methods are constantly evolving, and new methods/techniques of on-site
detection can become commercially available for the analysis of gases. Therefore, the listed
detection methods from Table B.1 to Table B.5 are not exhaustive.
Table B.1 – Detection techniques for the analysis of synthetic air
Substance Detection technique Typical measurement range Typical accuracy
N
...