IEC 60079-0:2026 Changes and Impact on ATEX Certification

IEC 60079-0:2026 Changes and Impact on ATEX Certification

A Practical Comparison of IEC 60079-0:2017 Edition 7 and IEC 60079-0:2026 Edition 8

The publication of IEC 60079-0:2026 Edition 8 introduces an important technical revision to one of the core standards used for equipment intended for explosive atmospheres.

IEC 60079-0 establishes the general requirements for the construction, testing and marking of Ex Equipment and Ex Components. It is therefore one of the most widely applied standards in ATEX and IECEx product assessment.

For manufacturers with new products under development, the new edition can affect

• design decisions;

• technical documentation;

• test programmes; and

• Ex marking.

For manufacturers holding existing ATEX or IECEx certificates based on IEC 60079-0:2017 Edition 7, the most important question is different:

Does the publication of IEC 60079-0:2026 require changes to the product, additional testing or an update of the existing Ex certificate?

The answer cannot be determined simply from the publication of a new edition. A structured gap analysis between Edition 7 and Edition 8 is required, taking into account the actual product design, materials, protection concepts, marking, certificate conditions and existing test evidence.

This article provides a practical overview of the most important changes introduced by IEC 60079-0:2026 and their potential impact on ATEX assessment, testing and certification.

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What Is IEC 60079-0:2026?

IEC 60079-0:2026 is the eighth edition of the international standard that defines the general requirements for Ex Equipment and Ex Components intended for use in, or associated with, explosive atmospheres.

It replaces IEC 60079-0:2017 Edition 7 and constitutes a technical revision of the standard.

Because IEC 60079-0 is used together with many other protection-specific standards in the IEC 60079 and ISO/IEC 80079 series, changes in this general standard can affect a wide range of ATEX and IECEx products.

The IEC 60079-0:2026 covers fundamental requirements such as equipment grouping, temperature classification, constructional requirements, non-metallic materials, electrostatic risks, metallic enclosures, fasteners, cable entries, cells and batteries, documentation, type tests, routine tests, marking and instructions.

explosion proof manufacturers and certificate holders should review whether the new or modified requirements affect their product design, technical file, test evidence, marking, instructions or existing ATEX/IECEx certificates.

It is particularly important for manufacturers and certification bodies because not all changes require new testing or a modification to the product, while some may require a technical reassessment, an update of the documentation, additional testing, or a revision of the certificate.

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Significant changes in IEC 60079-0:2026 affecting ATEX/IECEx certification 

1- added NOTE 4 to clause 1 of the standard (scope) to address short-term thermal excursions.

clasue 1 (scope)

Type of the change: Minor and editorial

Although this change to the standard is classified as minor and editorial, in some equipment and conditions it could significantly impact the manufacturer's thermal assessment for equipment, the preparation of related technical documentation, and the interpretation of thermal test results by the certification body.

NOTE 4 Any short-term thermal excursions that occur as a result of electrical current excursions above normal rated currents, such as those that occur during the starting of motors, are not considered to create a significant possibility of ignition of an explosive atmosphere due to the relatively short duration of the event and the convection that occurs during the event.

the condition of NOTE 4 is occured in situations where

• the equipment has an acceptable temperature in normal operating mode,

but

• in a normal and very short-term occurence, due to current excursion, the temperature of a component or surface briefly rises above the steady-state value.

in addition, the applicability of NOTE 4 is when these conditions are met:

• The occurence to be truly short-term;

• to be caused by a predictable current excursion such as a start-up;

• does not develop into a continuous or recurring condition that causes heat buildup; and

• the duration and nature of the occurence are such that they do not create a significant possibility of ignition.

Examples of Note 4 applications

• Starting electric motors with high inrush current or starting current;

• Initial acceleration of rotating machines;

• Initial connection of inductive loads that produce short transient currents;

• Some transient current excursions that are part of normal and predictable equipment operation;

• Equipment that has a short thermal rise during energization or start-up, but then returns to a stable thermal state.

Considering the above, any condition that causes heat accumulation is not related to Note 4, such as:

• prolonged overload;

• locked rotor or stalled motor;

• rapid restarts;

• cooling system failure; and

• abnormal operation conditions outside the protection concept.

Therefore IEC 60079-0 does not require that any momentary, short-term thermal excursion resulting from a current excursion is automatically considered to be an effective ignition hazard.

the additional Note 4 can directly affect the interpretation of the temperature requirements in Clauses 5.3.1 and 5.3.2 and the thermal type tests specified in Clause 26.5.1, particularly Clauses 26.5.1.1 and 26.5.1.3.

Note 4 does not introduce a new requirement or test method. It clarifies how short-term thermal excursions resulting from temporary electrical current excursions above normal rated currents, such as those occurring during motor starting, should be interpreted in relation to ignition risk, temperature requirements and thermal type testing.

Type of relationship	Related clause	Relevance to Note 4	Practical impact
Scope / interpretation	Clause 1, Note 4	Direct	Short-term thermal excursions caused by current excursions, such as motor starting, are not necessarily considered to create a significant possibility of ignition.
Requirement	5.3.1 – Determination of maximum surface temperature	Very direct	Affects the determination of which temperature condition should be considered as the maximum surface temperature.
Requirement	5.3.2 – Limitation of maximum surface temperature	Direct	Affects comparison of the relevant effective temperature with the applicable temperature class or maximum surface temperature limit.
Documentation	24.1 – Schedule drawings	Indirect but important	Relevant operating conditions, electrical ratings and limitations affecting the thermal assessment should be clearly documented.
Type test	26.5.1.1 – General temperature measurement	Very direct	Affects interpretation of temperature-test conditions and the distinction between a short transient excursion and the final or stabilized temperature.
Type test	26.5.1.2 – Service temperature	Relevant	May affect assessment of components for which service temperature is significant, where transient operating conditions influence thermal behaviour.
Type test	26.5.1.3 – Maximum surface temperature	Very direct	Affects determination of the temperature used as the basis for temperature classification or maximum surface temperature marking.

 

Some essential steps that must be taken by the manufacturer:

Manufacturers should therefore:

• distinguish short-term thermal excursions caused by temporary current excursions, such as motor starting currents

from

• temperature conditions that are relevant to the determination of the maximum surface temperature.

This distinction should be supported by

• the product operating characteristics,

• electrical ratings and

• relevant technical documentation.

Where such transient conditions are relevant, the manufacturer should clearly define:

• the normal rated current,

• expected transient current,

• duration and frequency of the event, and

• the associated thermal behaviour in the technical documentation.

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2- added standards and technical specifications supplementing and modifying IEC 60079-0:2026 added to clause 1 (scope) of it, including: 

• IEC TS 60079-46

• IEC TS 60079-47

• IEC 62784 

• ISO 80079-37

clasue 1 (scope)

Type of the change: Minor and editorial

The change: 

• does not normally introduce new IEC 60079-0 type-test requirements for ordinary Ex equipment.

• provides more clearly connection the general requirements of IEC 60079-0:2026 to the above-mentioned technical specifications and standards.

• formally integrates the above-mentioned technical specifications and standards into the framework assessment and certification of relevant explosion-proof products which was formally based on only IEC 60079-0 in the previous revision.

• improves the structural completeness and clarity of the standard rather than correcting a previous technical deficiency.

• more clearly connects the general requirements with additional specific standards for

  • equipment assemblies (IEC TS 60079-46): its inclusion does not introduce new assessment requirements, as IEC TS 60079-46 was already applicable to Ex equipment assemblies. The practical effect is the explicit recognition of equipment assemblies within the framework of standards applied together with IEC 60079-0, removing the previous lack of a direct link between the general requirements and the specific assessment route for assemblies;

  • 2-WISE intrinsically safe Ethernet systems (IEC TS 60079-47);

  • Vacuum cleaners and dust extractors with EPL Dc for collection of combustible dusts (IEC 62784): the specialist route explicitly places the assessment of vacuum cleaners and dust extractors designed to collect flammable dust within the scope of IEC 60079-0;

  • non-electrical types of protection (ISO 80079-37):  its inclusion does not introduce new requirements for non-electrical Ex equipment. The practical effect is to formally connect IEC 60079-0 with the existing protection concepts “c”, “b” and “k”, providing a more complete and explicit framework for the assessment of non-electrical equipment under the general requirements of IEC 60079-0;

• provides a reliable technical justification for certification bodies to include the above technical specifications and standards in the scope of certification for related explosion-proof products in ATEX and IECEx certification schemes; and 

• formalizes the acceptance of issued certificates including the aforementioned standards in the explosion-proof product marketplace.

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3- Making the definition of reverse charging terms more general and precise:

clause 3 Terms and definitions - subclause 3.7.10 reverse charging

Type of the change: Minor and editorial

In the 2017 edition, the definition effectively related reverse charging to a condition that “generally” occurs when the polarity of a worn cell in a series battery is reversed.

However, in the 2026 edition, the definition has been made more general and precise:

Reverse charging is the forced flow of current through a primary or secondary cell in the direction of the normal discharge current under polarity reversal conditions.

The explanation that this condition can occur in a expired cell in a series battery has been moved from the definition itself to Note 1 to entry.

The main change is that the 2017 edition tied the cause of the occurrence too much to a specific scenario; but the 2026 edition focuses the definition on the electrical nature of the phenomenon and keeps the expired cell scenario merely as an illustrative example.

The change does not introduce new design, assessment or type-test requirements, but reduces the risk of interpreting reverse charging as being limited to one specific battery-failure scenario.

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4- added figure to typical battery compartment

clause 3 Terms and definitions - subclause 3.7.14 battery compartment

Type of the change: Minor and editorial

A new illustrative figure (Figure 2) has been added to show a typical battery compartment construction, together with a corresponding reference in Note 3 to entry. The definition itself has not been technically changed.

The added figure clarifies the relationship between the equipment, the battery compartment and the cell, battery or replaceable battery pack. The change does not introduce new design, technical documentation, assessment or type-test requirements.

The newly added figure does not prescribe a mandatory design or a normative construction detail. The figure is titled “Typical battery compartment”; therefore, the manufacturer is not required to design the battery compartment exactly as shown in Figure 2. The figure merely clarifies the conceptual boundaries between the equipment, the battery compartment, and the cell, battery or replaceable battery pack.

From the practical perspective of a certification body, the figure may support a more precise classification of certain parts of the equipment during the assessment. For example, it may help determine whether a cover, an internal space, or the location in which a battery is installed actually forms part of the battery compartment. However, this effect is interpretative in nature and does not introduce any new requirement.

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5- added brush discharge definition 

clause 3 Terms and definitions - subclause 3.8 brush discharge

Type of the change: Minor and editorial

brush discharge
electrostatic discharge between a rounded (as opposed to sharp) earthed conductor and a charged insulating surface

What is the purpose of adding this definition?

In the 2017 edition, the term brush discharge was used frequently in requirements related to static electricity, but it did not have a separate definition.

In the 2026 edition, the above official definition has now been added which eliminates any disagreement in the standard's interpretation of what exactly brush discharge means.

This definition does not in itself create a new design requirement but it makes the requirements of Chapter 7 of the standard relating to charged insulating surfaces more precisely interpreted and therefore makes it necessary to provide the required technical information to be included by the manufacturer in the technical file in more detail to strengthen the documentation of static electricity risk assessment based on the following arrangements and details.

No.	Headings to be included in the technical file	Brush Discharge Risk / Subject to be Assessed	Applicable Clause(s) of          IEC 60079-0:2026	Method of Compliance Required Technical File Content	Evidence to be Included	Description of the relation with the topic of "brush discharge"
1	Electrostatic Hazard Assessment, including Brush Discharge Risk Assessment	Possibility of an ignition-capable brush discharge occurring between a charged insulating surface and a rounded earthed conductor under normal or reasonably foreseeable conditions	3.8, 7.4.1, 7.4.2 and 7.4.2.1	Perform and document an electrostatic hazard assessment identifying charging mechanisms, possible discharge paths, surrounding explosive atmosphere and the effectiveness of the selected protective measures.	Electrostatic hazard assessment report; product description; operating conditions; installation conditions; photographs or drawings.	These clauses define brush discharge, establish the applicability of electrostatic requirements and require electrostatic ignition hazards associated with external insulating surfaces to be addressed.
2	Identification of External Insulating Surfaces	External plastic parts, coatings, labels, windows, films, foils, glass, ceramics and other surfaces capable of retaining electrostatic charge	7.4.1	Identify every relevant external insulating or non-conductive surface and record its material, dimensions, exposed area, location and accessibility.	Parts list; material list; marked-up drawings; photographs; surface-area calculations; coating specifications.	Clause 7.4.1 determines which external parts and surfaces fall within the scope of the electrostatic hazard assessment.
3	Justification that the Brush Discharge Hazard Is Eliminated or Acceptably Controlled	Whether each identified insulating surface can accumulate sufficient charge to produce a hazardous brush discharge	7.4.2.1 and applicable provisions of 7.4.2.2	Provide a technical justification demonstrating either that hazardous charging cannot occur or that one or more permitted protective methods have reduced the risk to an acceptable level.	Design calculations; resistance measurements; test reports; material properties; technical justification report.	These provisions require the electrostatic ignition hazard to be prevented through suitable design measures or controlled by recognized compliance methods.
4	Description of Protective Measures against Electrostatic Charging	Charge accumulation and brush discharge from exposed insulating parts, coatings or isolated conductive components	Applicable method(s) under 7.4.2.2	Specify the selected measure such as limitation of surface area, control of surface resistance, dissipative/conductive materials, coating thickness limitation, earthing, bonding or conductive screening.	Design specifications; bonding details; earthing diagrams; resistance test reports; material certificates.	Clause 7.4.2.2 contains acceptable design approaches for avoiding hazardous electrostatic charge accumulation.
5	Material Data Sheets and Electrical Properties of Non-metallic Parts	Ability of the selected material to retain, dissipate or conduct electrostatic charge	7.1.2, applicable requirements of 7.2 and 7.3, and selected compliance method under 7.4.2.2	Define the material and document all properties used to demonstrate compliance.	Manufacturer's data sheet; certificates; surface/volume resistance reports.	Compliance with electrostatic requirements depends on controlled material characteristics.
6	Identification of Conductive and Insulating Parts on Drawings	Location and extent of insulating surfaces, nearby earthed conductors, isolated metallic parts, bonding connections and earthing points	7.4.1, applicable provisions of 7.4.2.2, and 24.1	Show all relevant insulating and conductive parts on controlled drawings.	Schedule drawings; assembly drawings; bonding and earthing diagrams.	The drawings provide objective design information needed to verify compliance with Clause 7.
7	Electrostatic Risk Assessment for Cleaning, Wiping, Dust Accumulation, Handling and Maintenance	Charging caused by dry wiping, friction, cleaning, personnel contact, dust, handling, installation and maintenance	7.4.2.1 together with relevant notes associated with 7.4.1	Evaluate reasonably foreseeable charging scenarios and determine whether they can create a charged insulating surface and possible discharge.	Risk assessment matrix; maintenance analysis; intended use; environmental conditions.	These activities can generate electrostatic charge and therefore must be considered.
8	User Instructions and Safety Warnings Related to Electrostatic Hazards	Residual electrostatic risks depending on installation, cleaning, maintenance or user behaviour	Applicable provisions of 7.4.2.2 together with Clause 30	State all necessary precautions such as cleaning with a damp cloth, avoiding dry rubbing and maintaining bonding connections.	Instruction manual; installation instructions; maintenance instructions; warning labels.	Where electrostatic safety depends on user action or installation conditions, precautions shall be communicated in the instructions.

 

What equipment is most affected?

This change is most significant for equipment containing Plastic body, Thick paint coating, Powder coating, Polycarbonate window, Acrylic windo, Plastic len, GRP Enclosure, FRP, Rubber Cove, Plastic Handle, Plastic Labe, Plastic Membrane, Film, Coatin, as all of these can create a charged insulating surface.

Therefore, if the insulating surface becomes charged due to rubbing, cleaning, air movement, dust, transportation, and separation of materials, and then a grounded metal piece is placed near it, electrostatic energy may be discharged in the form of a brush discharge, which can be a source of ignition in some gas groups.

The real impact of the addition of Definition 3.8 in Edition 8 is not that it has created a new test or design requirement, but rather that the certification body can no longer be satisfied with simply examining "Surface Resistance" or "Surface Area". 
The manufacturer is now expected to explicitly demonstrate in the Technical File that the brush discharge hazard has been identified, assessed and controlled.

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6- Clarifying the definition for "bushing to be an insulating device"

clause 3-Terms and definitions

sub-clause 3.10 bushing

Type of the change: Minor and editorial

Bushing: insulating device carrying one or more conductors, insulated or bare, through an internal or external wall of an enclosure.

The new definition of Bushing is primarily a clarification change and, contrary to its appearance, does not typically create new design, testing or documentation requirements.

Impact of the change

The addition of the word “insulating” clarifies that, for the purposes of IEC 60079-0, a bushing is specifically an insulating device used to carry one or more insulated or bare conductors through an internal or external wall of an enclosure.

This is a minor and editorial clarification intended to distinguish a bushing from other conductor pass-through arrangements or metallic feed-through components.

It does not introduce a new design principle, but it makes the intended nature of the component more explicit.

Impact on conformity assessment and the Technical File

No new mandatory Technical File document is introduced solely because of this wording change. However, where a component is identified as a bushing, the manufacturer should ensure that:

• it is actually an insulating device in accordance with the revised definition;

• its insulating material and relevant electrical characteristics are correctly specified;

• drawings, the bill of materials (BOM) and component descriptions use consistent terminology;

• any applicable creepage, clearance, dielectric-strength or protection-type requirements are addressed under the relevant clauses of the standard.

Impact on type tests

The change does not introduce any new type test, test method or acceptance criterion.

Existing tests remain applicable only where required by the relevant protection concept, voltage rating, insulation system or construction of the equipment.

Conclusion

The practical effect is limited to terminology and classification clarity.

Products already using correctly specified insulating bushings should not require redesign, additional testing or new Technical File documentation solely as a result of this amendment.

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7- Note 1 to entry for coating added to definition of coating

clause 3-Terms and definitions

sub-clause 3.14 coating

Type of the change: Minor and editorial

Note 1 to entry: With respect to explosive atmospheres, this term is used more broadly than the definition in IEC 60050-212:2010, 212-11-61 that is specific to coatings applied to surfaces to improve resistance to tracking, and is also often applied for other purposes such as corrosion protection or lowering surface resistivity to reduce the possibility of electrostatic discharge.

In the 2017 edition, the definition of Coating was only given as a general definition, but in the 2026 edition, a part of the above-added note says "with respect to explosive atmospheres, this term is used more broadly..."

This Note clarifies two important points:

• The definition of Coating in IEC 60079-0 is not limited to the definition in IEC 60050-212, it means in IEC 60050, coating mainly refers to insulating coatings to increase tracking resistance, however, in IEC 60079-0, The term Coating also includes any type of functional coating.

• The standard provides more diverse examples of these coatings, thus broadening the scope of the meaning of Coating. such as:

  • Corrosion protection;

  • Surface resistance reducing coating;

  • Antistatic coating; and 

  • Other coatings with protective function

This Note does not create any new requirements for design, testing or certification, but rather

• clarifies the scope of the coating concept for applications related to explosive atmospheres; and

• allows for the documentation and evaluation of functional coatings to be carried out with greater accuracy and uniformity.

Are the requirements for preparing a Technical File affected?

If the equipment does not have any specific coating, no changes are required, However, if the equipment has a functional coating, it is better to more detailed describing for thr coating in technical documentation.

For example, if the equipment has an anti-corrosion coating, specify more clearly:

• Type of coating

• Thickness

• Location

• Coating function

If the coating is to reduce surface resistance, specify more clearly: 

• Target surface resistance

• Type of material

• Application method

• Durability of the coating

 and If the coating is antistatic, specify its relation with electrostatic relevant clauses in the standard.

If in the drawings only general information of the coating is sspecified such as Paint or Surface treatment, it is not enough and better to specify the type of coating, for example epoxy coating, conductive coating, anti-static coating, corrosion resistant coating, zinc-rich coating or etc.

if the coating has a functional role, specify in the BOM:

• Material type

• Brand name

• Coating code

• Technical specifications

The impact of such a change on the assessment of the certification body could be to check whether the used coating is not effective in explosion protection (e.g. decorative) or whether it is considered as a part of the explosion protection. For example, an anti-static coating.

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