SIST EN IEC 60079-45:2025

SLOVENSKI STANDARD
01-december-2025
Eksplozivne atmosfere - 45. del: Električni sistemi za vžig motorjev z notranjim
zgorevanjem (IEC 60079-45:2025)
Explosive atmospheres - Part 45: Electrical ignition systems for internal combustion
engines (IEC 60079-45:2025)
Explosionsgefährdete Bereiche – Teil 45: Elektrische Zündsysteme für
Verbrennungsmotoren (IEC 60079-45:2025)
Atmosphères explosives - Partie 45: - Systèmes d’allumage électrique pour les moteurs
à combustion interne (IEC 60079-45:2025)
Ta slovenski standard je istoveten z: EN IEC 60079-45:2025
ICS:
27.020 Motorji z notranjim Internal combustion engines
zgorevanjem
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60079-45

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2025
ICS 29.260.20; 43.060.50
English Version
Explosive atmospheres - Part 45: Electrical ignition systems for
internal combustion engines
(IEC 60079-45:2025)
Atmosphères explosives - Partie 45: Systèmes d'allumage Explosionsgefährdete Bereiche - Teil 45: Elektrische
électrique pour les moteurs à combustion interne Zündsysteme für Verbrennungsmotoren
(IEC 60079-45:2025) (IEC 60079-45:2025)
This European Standard was approved by CENELEC on 2025-10-01. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60079-45:2025 E

European foreword
The text of document 31/1880/FDIS, future edition 1 of IEC 60079-45, prepared by TC 31 "Equipment
for explosive atmospheres" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60079-45:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-10-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-10-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60079-45:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60079-14 NOTE Approved as EN IEC 60079-14
IEC 60079-15 NOTE Approved as EN IEC 60079-15
IEC 60079-18 NOTE Approved as EN 60079-18
IEC 60079-25 NOTE Approved as EN IEC 60079-25
IEC 60079-33 NOTE Approved as CLC/TR 60079-33
ISO 19879:2021 NOTE Approved as EN ISO 19879:2021 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60079-0 - Explosive atmospheres - Part 0: EN IEC 60079-0 -
Equipment - General requirements
IEC 60079-1 - Explosive atmospheres - Part 1: EN 60079-1 -
Equipment protection by flameproof
enclosures "d"
IEC 60079-7 - Explosive atmospheres - Part 7: EN 60079-7 -
Equipment protection by increased
safety "e"
IEC 60079-11 - Explosive atmospheres - Part 11: EN IEC 60079-11 -
Equipment protection by intrinsic safety
"i"
ISO 11565 - Road vehicles - Spark-plugs - Test - -
methods and requirements
1 2
ISO/IEC 80079-41 - Explosive atmospheres - Part 41: EN ISO/IEC 80079-41 -
Reciprocating internal combustion
engines
SAE J2031 - High-Tension Ignition Cable - -

Under preparation. Stage at the time of publication: ISO/IEC/CCDV 80079-41:2025.
Under preparation. Stage at the time of publication: prEN ISO/IEC 80079-41:2025.
IEC 60079-45 ®
Edition 1.0 2025-08
INTERNATIONAL
STANDARD
Explosive atmospheres -
Part 45: Electrical ignition systems for internal combustion engines
ICS 29.260.20; 43.060.50 ISBN 978-2-8327-0651-0

IEC 60079-45:2025-08(en)
IEC 60079-45:2025 © IEC 2025
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 System overview . 10
4.1 General . 10
4.2 Spark containment . 10
4.3 Spark prevention . 11
4.4 Spark detection/prevention . 11
4.5 Ignition system equipment . 11
4.6 Engine enclosed systems . 12
5 Construction and testing requirements . 12
5.1 General . 12
5.2 Impact . 12
5.3 Chemical compatibility . 12
5.4 Terminations and connections . 13
5.5 Power source . 13
5.6 Engine control module and ignition control unit . 13
5.7 Engine primary wiring. 13
5.8 Ignition coils . 14
5.9 Secondary leads . 14
5.9.1 General. 14
5.9.2 Flexible secondary lead . 14
5.9.3 Rigid secondary lead . 15
5.10 Spark plugs . 15
6 Spark containment . 16
7 Spark prevention . 16
7.1 General . 16
7.2 Terminations, connections, and enclosures . 16
7.3 Ignition coil requirements. 16
7.4 Spark plug well applications . 17
8 Spark detection/prevention . 17
8.1 General . 17
8.2 Design requirements . 17
9 Ex Equipment certificate . 17
10 Marking . 18
10.1 General . 18
10.2 Warning markings . 18
10.3 Example markings . 19
11 Manufacturer's instructions . 20
11.1 General . 20
11.2 Manufacturer’s instructions and installation drawings . 20
11.3 Warnings . 21
11.4 Commissioning checklist . 21
11.5 Maintenance . 22
IEC 60079-45:2025 © IEC 2025
12 Test procedures . 22
12.1 General . 22
12.2 Abrasion test for flexible secondary leads . 23
12.2.1 General. 23
12.2.2 Abrasive wheel test . 23
12.2.3 Emery cloth abrasion test . 24
12.3 Ignition coils, extensions or non-flexible secondary leads elevated
temperature exposure test . 25
12.4 Chemical compatibility . 25
12.4.1 General. 25
12.4.2 Chemical compatibility for non-flexible leads and equipment. 26
12.4.3 Chemical compatibility for flexible leads . 26
12.5 Vibration test . 27
12.6 Shielded secondary system tests . 28
12.6.1 General. 28
12.6.2 Explosion test exemption for metallic flexible leads . 29
12.7 Spark plug gas tightness test . 29
12.7.1 Spark plug gas tightness test (primary test) . 29
12.7.2 Spark plug gas tightness test (alternate test) . 30
12.8 Flashover tests . 30
12.8.1 General. 30
12.8.2 Rigid secondary lead test configuration . 31
12.8.3 Flexible lead test configurations . 32
12.9 Flexible Secondary lead bending and dielectric voltage withstand tests . 33
12.10 Spark prevention test . 34
12.11 Primary and secondary lead terminations pull test . 35
12.12 Flexible secondary lead insulation cut test. 35
12.13 Flexible secondary lead insulation pull test. . 36
Annex A (informative) Guidance for spark containment . 37
Annex B (informative) Guidance for spark prevention . 38
Bibliography . 43

Figure 1 – Components of an electrical ignition system . 11
Figure 2 – Warning "do not disconnect" pictogram . 19
Figure 3 – Abrasive wheel test apparatus . 24
Figure 4 – Emery cloth abrasion test apparatus . 25
Figure 5 – Vibration curve . 28
Figure 6 – Flexible lead example . 29
Figure 7 – Spark plug test apparatus . 30
Figure 8 – Rigid secondary flashover test apparatus . 31
Figure 9 – Flexible hybrid secondary flashover test apparatus . 32
Figure 10 – Flexible secondary flashover test apparatus . 33
Figure 11 – Flexible secondary dielectric voltage withstand test apparatus . 34
Figure 12 – Secondary lead or wiring insulation cut test apparatus . 36
Figure A.1 – Guidance flowchart for spark containment tests . 37
Figure B.1 – Guidance flowchart for spark prevention testing . 38
Figure B.2 – Terminations, connections and enclosures test . 39
IEC 60079-45:2025 © IEC 2025
Figure B.3 – Cut test . 40
Figure B.4 – Abrasion test . 40
Figure B.5 – Chemical compatibility test . 41
Figure B.6 – Pull test . 41
Figure B.7 – Ignition coils and rigid extenders test . 42
Figure B.8 – Spark prevention test . 42

Table 1 – List of critical parameters . 18
Table 2 – List of performance tests for spark containment and spark prevention . 22
Table 3 – Chemical compatibility . 27
Table 4 – Vibration test requirements . 28
Table 5 – Compositions of explosive test mixtures . 34

IEC 60079-45:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Explosive atmospheres -
Part 45: Electrical ignition systems for internal combustion engines

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) 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 not 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 60079-45 has been prepared by IEC technical committee TC 31, Equipment for explosive
atmospheres. It is an International Standard.
ANSI/UL 122001 Standard for safety, General Requirements for Electrical Ignition Systems for
Internal Combustion Engines in Class I, Division 2 or Zone 2, Hazardous (Classified) Locations,
has served as a basis for the elaboration of this document.
Users of this document are advised that interpretation sheets clarifying the interpretation of this
document can be published. Interpretation sheets are available from the IEC webstore and can
be found in the "history" tab of the page for each document.
IEC 60079-45:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
31/1880/FDIS 31/1895/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.
A list of all parts in the IEC 60079 series, published under the general title Explosive
atmospheres, can be found on the IEC website.
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.
IEC 60079-45:2025 © IEC 2025
INTRODUCTION
This part of IEC 60079 also refers to IEC 60079-0 and its associated standards for the
construction, testing and marking requirements of suitable electrical Ex Equipment.
This document has been developed from ANSI/UL 122001 Standard for safety, General
Requirements for Electrical Ignition Systems for Internal Combustion Engines in Class I,
Division 2 or Zone 2, Hazardous (Classified) Locations.
The original content was developed primarily by the user community in response to operations
and maintenance problems arising from the use of shielded ignition systems (flameproof or
explosionproof) on reciprocating engines driving compressors and pumps handling flammable
materials and installed in hazardous areas. Experience has shown that these types of ignition
systems are subjected to significant dielectric stress due to being completely encapsulated in
grounded metallic raceways and suffer premature failure resulting in engine cylinder misfiring
and engine miss-operation and shutdown.
This document is intended to supplement ISO/IEC 80079-41 with the requirements for ignition
systems for reciprocating spark-ignited engines to be installed in hazardous areas for EPL Gc
applications. In addition, it is a standalone set of requirements for a complete ignition system
or for the individual components thereof to be installed on a reciprocating engine to meet EPL
Gc requirements in a repair or replacement activity.
Examples of reciprocating gas engines which typically need to be EPL Gc are:
a) Offshore oil and gas platforms that are typically crowded or congested by design and the
gas engine and driven equipment is required to achieve EPL Gc.
b) Onshore facilities where the gas engine and driven equipment assembly is located under a
shelter or in an enclosed building for environmental protection or noise suppression.
NOTE 1 Certified ignition systems can also be considered as an alternative replacement to non-Ex systems for
engines located in a non-hazardous area where the driven equipment is located in an EPL Gc area. This could
provide the additional explosion protection for larger than anticipated flammable releases.
NOTE 2 Ongoing inspection, maintenance and repair aspects also play an important role in control of hazardous
area installations and the user's attention is drawn to IEC 60079-17, IEC 60079-19 and manufacturer's instructions
for further information concerning these aspects.
NOTE 3 In any industrial installation, irrespective of size, there can be numerous sources of ignition apart from
those associated with electrical equipment. Precautions are necessary to ensure safety from other possible ignition
sources, but guidance on this aspect is outside the scope of this document.

IEC 60079-45:2025 © IEC 2025
1 Scope
This part of IEC 60079 is intended to enhance the safety of personnel by providing minimum
requirements for electrical ignition systems for spark-ignited reciprocating internal combustion
engines, parts of which provide Equipment Protection Level (EPL) Gc.
This document provides minimum construction and test requirements, in addition to
manufacturer installation and maintenance recommendations, for the safe operation of ignition
systems and components for spark-ignited reciprocating internal combustion engines providing
EPL Gc for equipment Group IIB+H , IIB or IIA. These requirements apply to systems rated for
normal operation with secondary voltages less than or equal to 60 kV.
This document applies only to the ignition systems or the individual ignition system components
used on reciprocating internal combustion engines that are stationary when in operation and
mobile machinery where the internal combustion engine can be potential source of ignition.
Applications addressed by the scope of this document include but are not limited to gas
compressors, electric power generators, forklift trucks, and pumps.
This document does not apply to:
a) Engine ignition systems that utilize a breaker point or magneto type ignition systems as
these would not be suitable for use in a hazardous area.
b) Road vehicles.
c) Low voltage parts and electrical installation that are not included in the ignition system, such
as various sensors and thermocouples, throttle actuator(s), fuel control valve(s), human
machine interface (HMI), respective harness and wiring and all the other items that might
belong to the integrated control system besides the ignition system.
This document supplements and modifies the general requirements of IEC 60079-0 and the
requirements of ISO/IEC 80079-41. Where a requirement of this document conflicts with
IEC 60079-0 or ISO/IEC 80079-41, the requirement of this document takes precedence.
NOTE See ISO/IEC 80079-41 for the requirements for explosion protection for EPL Gc reciprocating internal
combustion engines.
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 60079-0, Explosive atmospheres - Part 0: Equipment - General requirements, Edition 7.0
IEC 60079-1, Explosive atmospheres - Part 1: Equipment protection by flameproof enclosures
"d"
IEC 60079-7, Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
IEC 60079-11, Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"
ISO 11565, Road vehicles - Spark-plugs - Test methods and requirements
IEC 60079-45:2025 © IEC 2025
ISO/IEC 80079-41, Explosive atmospheres - Part 41: Reciprocating internal combustion
engines
SAE J2031, High-Tension Ignition Cable
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
ignition coil
inductive device used to convert primary voltage to secondary voltage intended to initiate
combustion
3.2
ignition control unit
ICU
component assembly that transforms energy from the ignition system power source and
provides it to the primary distribution system
Note 1 to entry: The ignition control unit is sometimes referred to as an ignition control module.
3.3
engine control module
ECM
electronic processor managing the timing relationship of the engine, transfer of data between
engine sensors, actuators, control elements, and information-storage and display units
3.4
ignition system
electrical system designed to produce and distribute electrical energy to initiate combustion
Note 1 to entry: An ignition system can be a part of integrated control system of the engine and hence connected
to the engine control module ECM. This can be any type of electrical system but is typically a capacitive or inductive
type system.
Note 2 to entry: A capacitive discharge ignition system is a type of ignition system, a charging circuit creates an
intermediate voltage on a capacitor, and at the instant of ignition timing applies the capacitor energy and voltage to
the ignition coil primary side which subsequently reflects to the secondary coil winding and spark plug.
Note 3 to entry: An inductive discharge ignition system is where the primary winding is directly connected to the
battery and stores energy while the primary winding conducts current from the battery. At the desired ignition timing,
the primary winding current is interrupted which drives a flyback event on the primary, which is reflected to the
secondary and generates a voltage high enough to ionize the spark plug gap. Following ionization of the spark plug
gap, most of the ignition coil energy is driven through the spark plug gap.
3.5
installation drawing
drawing or other document prepared by the equipment manufacturer that details the allowed
interconnections of ignition system components, indicates any Specific Conditions of Use,
provides initial parameters if required, and provides the necessary information for operational
use of the system or any component
___________
Under development. Stage at the time of publication: ISO/IEC/CCDV 80079-41:2025.
IEC 60079-45:2025 © IEC 2025
3.6
integral ignition coil
ignition coil with a rigid connection to the spark plug (coil on plug), on which no flexible cable
is used
3.7
maximum secondary peak output circuit voltage
maximum open circuit voltage produced by the ignition system with the
secondary lead disconnected from the spark plug
3.8
normal operation
operation of equipment conforming electrically and mechanically with its design specification
and used within the limits specified by the manufacturer
Note 1 to entry: For electrical ignition systems, this can include:
• supply voltage, current, and frequency;
• environmental conditions;
• minimum and maximum engine operating and cranking speeds;
• all removable parts in place; and
• all operator-accessible adjustments at their most unfavourable settings within the normal range.
[SOURCE: IEC 60079-0:2017, 3.62, modified – replacement of Notes to entry.]
3.9
engine driven power source
power source that relies on mechanical energy from the engine for conversion to ignition system
electrical energy
3.10
external power source
power source that relies on energy from a source other than the engine for
ignition system electrical energy
3.11
primary distribution system
components that deliver the primary voltage (low voltage) and current from the power supply
and ignition control unit to the ignition coil, including the coil primary terminations
3.12
primary wire
insulated conductor interconnecting the ignition control unit and the ignition coil
3.13
primary voltage
voltage produced across the primary of the ignition coil under normal operating conditions
3.14
primary wiring harness
group of wires transporting voltage to the primary of the ignition coil
3.15
raceway
enclosure for routing, protecting, and supporting wires or cables
IEC 60079-45:2025 © IEC 2025
3.16
secondary distribution system
component assembly that electrically interconnects the ignition coil and the spark gap, including
the coil secondary terminations
3.17
secondary lead
part of the secondary distribution system, either rigid or flexible, electrically interconnecting the
coil and the spark plug
Note 1 to entry: Often referred to as secondary lead assembly.
3.18
secondary voltage
open circuit voltage produced across the spark gap
3.19
spark gap
space between two conductors across which electrical energy is discharged
3.20
spark plug
electromechanical device that provides a spark gap intended to ignite a fuel mixture
3.21
flashover
electric breakdown between conductors in a gas or a liquid or in vacuum, at least partly along
the surface of solid insulation
Note 1 to entry: Where a spark occurs from the internal live wires of the ignition system to an external metal surface
such as the secondary lead to surrounding metallic surface.
[SOURCE: IEC 60050-212:2010, 212-11-47, modified – addition of Note 1 to entry.]
3.22
end gas knock
autoignition of the unburned air fuel mixture ahead of the flame front
4 System overview
4.1 General
Any portion of an ignition system providing EPL Gc during normal operation is intended to not
produce arcs, sparks, or heat that could ignite a surrounding flammable atmosphere. This may
be achieved through conformance with the construction requirements of Clause 5 and utilizing
at least one of the types of protection indicated in 4.2, 4.3 or 4.4, or any combination thereof
(see 4.5). The portions of the ignition system which operate at voltage levels of 15 kV and less
may use other Types of Protection defined in the IEC 60079 series (considering the voltage
restrictions allowed within the specific part of the series).
4.2 Spark containment
Any portion of the ignition system providing EPL Gc shall be constructed such that arcs or
sparks that could occur under normal operating conditions are contained in a manner that
precludes ignition of a surrounding flammable atmosphere. See Clause 6 for requirements for
spark containment. Refer to Annex A for a flowchart providing guidance on test sequencing.
IEC 60079-45:2025 © IEC 2025
4.3 Spark prevention
Any portion of the ignition system providing EPL Gc shall be constructed such that arcs or
sparks under normal operating conditions do not occur outside of the combustion chamber. See
Clause 7 for requirements for spark prevention. Refer to Figure B.1 through Figure B.8 of
Annex B for a flowchart providing guidance on test sequencing.
4.4 Spark detection/prevention
Any portion of the ignition system providing EPL Gc shall be designed and constructed such
that conditions leading to arcs or sparks in any portion of the ignition system outside of the
engine are detected and remedied before such sparks occur. See Clause 8 for spark detection
and prevention requirements.
4.5 Ignition system equipment
Ex Components and Ex Equipment of ignition systems can be examined separately for
conformance with the applicable requirements of this document or other types of protection
defined in other IEC 60079 series standards.
The parties assembling the completed ignition system are responsible for total system
documentation and demonstrating conformance of the completed ignition system to this
standard.
Ex Components and Ex Equipment shall be marked as detailed in Clause 10.
A typical ignition system is illustrated in Figure 1.

Key
1 Power source
2 Primary wiring
3 Ignition coil
4 Secondary leads
5 Spark plug
6 Ignition control unit
7 Engine control module
NOTE 1 The order and arrangement of components in an ignition system can be different; only basic ignition system
components are shown in this diagram.
NOTE 2 Ground conductors can be insulated conductors or part of a metallic frame.
Figure 1 – Components of an electrical ignition system
IEC 60079-45:2025 © IEC 2025
4.6 Engine enclosed systems
For any ignition system components that are contained completely within an enclosed volume
of the engine that is subject to the positive pressure from the crankcase are by definition not
exposed to a flammable atmosphere, therefore the requirements for explosion protection
outlined in this document do not apply.
NOTE For additional information concerning the enclosed volumes of engines and their possibility of having an
explosive mixture internally, see ISO/IEC 80079-41.
5 Construction and testing requirements
5.1 General
Ignition systems shall be constructed to withstand the service temperatures to which they will
be exposed in normal operation. Different service temperature ratings may apply to separate
devices of an ignition system. Maximum surface temperature of all equipment within the ignition
system shall be determined in accordance with the test procedures as defined by maximum
surface temperature in IEC 60079-0, modified for a system input voltage of ±25 % of rated for
DC powered systems, or ±10 % of rated for AC powered systems, or as specified by the
manufacturer. The equipment shall be marked as specified in Clause 10.
Ignition systems shall be constructed to withstand the effects of vibration levels they are likely
to encounter during normal operation such that they are prevented from becoming a potential
source of ignition. The test in 12.11 demonstrates conformance with this requirement.
For all types of protection, the complete test program for the system and component level is
defined in Table 2.
5.2 Impact
All parts of the ignition system that can be exposed to impact and intended for installation in a
hazardous area shall meet the high-level Resistance to Impact Test as specified for Group II in
IEC 60079-0.
5.3 Chemical compatibility
Enclosures and insulating materials shall provide protection to prevent deterioration and
corrosion that could adversely affect the suitability of the parts of the equipment intended to be
installed in a hazardous area. The list of compounds in Table 3 includes chemicals
representative of those to which ignition systems would likely be exposed in normal operation.
All non-metallic enclosure materials, secondary leads, secondary lead assembly, or secondary
lead harness, and insulation compounds associated with the ignition system utilized on the
exterior of the engine, shall comply with the chemical compatibility tests of 12.4. Test chemicals
in Table 3 shall be included in the test. One or more of the test chemicals may be omitted from
the test if the manufacturer’s instructions prepared in accordance with Clause 10 states that
the equipment is not suitable for use in locations where the omitted test chemical is present. If
one or more of the test chemicals is excluded, the certificate number shall include the suffix "X"
to indicate this Specific Condition of Use according to IEC 60079-0. The manufacturer of the
device shall make available information necessary to determine if critical materials of
construction are compatible with substances not included in Table 3 that might be present in
an installation area.
IEC 60079-45:2025 © IEC 2025
5.4 Terminations and connections
Electrical terminations and connections for the secondary lead system intended to be installed
in a hazardous area shall be mechanically secured against unintentional disconnection.
Terminations shall be constructed such that, when connected as specified on the installation
drawing, a separating force of at least that specified in the pull test described in 12.11 is
required for disconnection. Terminations shall also maintain continuity when subjected to the
vibration test specified in 12.5. The vibration test shall be completed as a prerequisite to the
pull test described in 12.11.
The pull test in 12.11 is not required for terminations that:
a) have a threaded interconnection, or
b) require the use of a tool such as a key, screwdriver or wrench to remove, or
c) requires two independent actions for separation.
All electrical terminations and connections for the primary wiring system intended to be installed
in a hazardous area that are subject to vibration, shall be secured against unintentional
disconnection except for intrinsically safe circuits (IEC 60079-11). These electrical terminations
and connections shall be designed in accordance with IEC 60079-7 and shall be subject to the
vibration test as detailed in 12.5.
5.5 Power source
When the power source is located in the hazardous area, it shall be explosion protected and
meet the appropriate requirements of IEC 60079-0. Ignition systems shall operate at a voltage
of ± 25 % of rated for DC powered systems, or ± 10 % of rated for AC powered systems, or as
specified by the manufacturer. Engine driven power source requirements (if required) shall be
indicated on the manufacturer’s instructions.
NOTE Measurements by the manufacturer ar
...