How IEC 60079-14 Redefines Flameproof Cable and Cable Gland Selection in Hazardous Areas

Incorrect cable and entry device selection can directly compromise the integrity of an Ex d installation. IEC 60079-14:2024 significantly increases the level of scrutiny applied to both. This whitepaper explains what has changed in the latest edition of IEC 60079-14, why it matters, and what organizations must do to respond.  

Executive Summary

IEC 60079-14:2024 (Edition 6) introduces a fundamental change in how cables and cable entry devices are selected for flameproof (Ex d) applications in hazardous areas. What was previously a component-based, largely prescriptive process has become a system-based, application-dependent assessment requiring deeper technical understanding, documented justification, and demonstrable personnel competence. 

This whitepaper examines the most significant changes affecting cable and cable gland selection for Ex d applications. It traces the evolution of the standard from the 2007 and 2013 editions, identifies the technical and organizational shortcomings those editions produced, and explains the revised methodology introduced in Edition 6 — including the new selection flowchart, the mandatory Annex C cable pressure test, and the shift in responsibility from installers to designers and engineers.

The key findings are:

• Two of the five major technical changes in Edition 6 relate directly to Ex d cable and cable entry device selection, indicating the scale of the revision in this area
• The 2013 edition's conditional requirements created an environment where formal compliance could be achieved without adequately addressing explosion safety risk; Edition 6 closes that gap
• Edition 6 requires cables and entry devices to be assessed together as an integrated system — neither can be selected in isolation
• The new flowchart links gland selection explicitly to gas group, cable length, enclosure volume, and demonstrable cable performance via normative Annex C
• Selection responsibility must move upstream from installers to the designers, engineers, and procurement professionals specifying the installation
• Organizations that continue to apply Edition 5 practices — particularly standardized non-barrier gland specifications without application-based assessment — face both non-compliance and increased explosion safety risk

The recommendations in this whitepaper are directed at the full range of stakeholders: designers and engineers, OEM equipment manufacturers, installers and contractors, inspectors, and end users. Each group faces specific obligations under Edition 6 that differ materially from previous practice.

Background: Cable and Gland Selection in Previous Editions

Previous editions of IEC 60079-14 approached cable and gland selection through prescriptive requirements and simplified decision tables. While this approach enabled consistency and ease of application, it also encouraged assumptions about cable behavior, gas migration, and sealing performance that were not always technically justified.

 

The Application-Based Framework of IEC 60079-14:2007 (Edition 4)

Edition 4 adopted a flowchart-based approach to cable entry device selection for flameproof enclosures. The framework explicitly considered key aspects of the application: the presence of internal ignition sources, hazardous area classification, equipment group, and enclosure volume. It provided a structured and transparent decision-making process, guiding users toward appropriate solutions based on the characteristics of the installation rather than prescriptive component criteria alone.

The 2007 methodology was widely regarded as intuitive and enforceable. It supported consistent interpretation across designers, manufacturers, installers, and inspectors, and its logic could be readily followed and justified during verification and inspection. The removal of this application-based flowchart in the 2013 edition was met with concern across the industry, including from the UK Health and Safety Executive, which directed practitioners to continue using the earlier edition.

 

The Legacy Approach Introduced in IEC 60079-14:2013 (Edition 5) 

Edition 5 replaced the flowchart with a set of conditional requirements intended to provide flexibility while maintaining safety. In practice, this change proved problematic. The revised requirements were widely regarded as difficult to interpret, inconsistently applied, and challenging to enforce.

For non-barrier cable glands used with non-mineral-insulated cables, compliance relied on three conditions: the gland being certified as Ex d to IEC 60079-1; a minimum cable length of 3 meters; and the cable meeting the construction requirements in Clause 9.3.2(a). Each condition had significant weaknesses in practice.

Non-barrier glands could be certified as Ex d based on a pressure test conducted on a steel mandrel rather than a representative cable. This demonstrated the mechanical integrity of the gland body and sealing system, but provided limited assurance of sealing performance with real cables of varying construction and deformation characteristics.

The 3-meter minimum cable length was straightforward to measure at installation but difficult to interpret during equipment design and system engineering. The standard did not clarify whether the 3 meters referred to cable inside or outside the enclosure, whether coiled cable qualified, or how the requirement applied where only a short run was exposed between enclosures.

The cable construction requirements in Clause 9.3.2(a) reduced in practice to a basic assessment of cable geometry — primarily whether the cable was round. Critical factors such as cable material behavior under pressure, gas migration pathways, and the specific gas group of the installation were not part of the assessment.

The net effect was an environment in which formal compliance could be achieved without adequately addressing explosion safety risk. Cable glands became interchangeable commodities, selected to satisfy minimum criteria rather than as safety-critical components requiring application-specific engineering assessment. These shortcomings directly informed the more rigorous revisions introduced in Edition 6.

Drivers for Change in IEC 60079-14:2024 

The changes in Edition 6 reflect a growing recognition within IEC TC 31 that the historical simplifications in Edition 5 no longer adequately addressed the diversity of modern cable constructions, installation practices, and hazardous area applications. The revised methodology is based on empirical data compiled in IEC SC31J-SD-001:2021, a background document produced by a sub-working group of the standard's maintenance team. This document presents historical test data across a range of enclosures and cables to provide verifiable support for the new selection criteria.

The publication of Edition 6 represents the culmination of more than a decade of technical debate following the shortcomings identified in 2013. While the resulting methodology reflects a deliberate compromise between differing international technical perspectives, it prioritizes system integrity and application-based decision-making over simplified prescriptive compliance.

 

A Structural Shift: From Individual Components to System Assessment

One of the most significant changes in Edition 6 is the move away from treating cables and cable entry devices as independent components. The standard now explicitly states, in the section on cables for direct entries into flameproof enclosures, that "cables and cable entry devices should be considered together for direct entries into flameproof enclosures."

This is not a wording change — it is a structural one. Under Edition 5, the cable was assessed against one set of requirements and the gland against another. Under Edition 6, they are a system. The suitability of one cannot be assumed independently of the other.

This principle underpins the revised flowchart introduced in Edition 6 and shifts the center of gravity for selection work upstream — away from the installer and toward the designer and specifying engineer.

Risk-Based Differentiation by Gas Group and Cable Length

The flowchart's first decision point requires identification of the hazardous gas group, with particular focus on IIC and IIB + hydrogen atmospheres. These gases represent the highest explosion risk due to their ignition characteristics and flame propagation behavior.

To reflect this increased risk, minimum cable length thresholds differ by gas group:

• For IIC and IIB + hydrogen atmospheres: minimum cable length of 3 meters
• For all other gas groups (IIA and IIB): minimum cable length of 0.5 meters

Where these minimums cannot be met, a flameproof barrier-type entry device is mandatory. No further assessment is required, as risk mitigation is achieved through sealing at the point of entry.

Enclosure Volume Relaxation

For lower-risk gas groups (IIA and IIB), where the minimum cable length is satisfied, the flowchart introduces a further differentiation based on rated enclosure volume — specifically, whether it is below or above 2,000 cm³. Smaller enclosures generate lower explosion pressures and energies, reducing the likelihood of flame propagation through connected cable systems. Where the enclosure volume is below this threshold, and cable length criteria are met, the standard permits the use of a flameproof entry device with an elastomeric seal.

Enclosure volume data is not always readily available in published documentation. In such cases, designers and installers must obtain this information from the manufacturer or, where uncertainty remains, adopt the conservative assumption that the volume exceeds the threshold.

Evidence-Based Cable Performance: Normative Annex C

For installations where enclosure volume exceeds 2,000 cm³, or where it cannot be confidently established, the assessment moves to the most significant technical change in Edition 6: the requirement for demonstrable cable performance through normative Annex C.

The flowchart asks whether there is sufficient reliable evidence that the cable would meet the Annex C criteria. This is a decisive shift away from assumed cable suitability based on geometry or catalog descriptions alone. Where credible evidence exists — such as validated test data or equivalent substantiation — a flameproof entry device with an elastomeric seal may be used. Where such evidence is absent or insufficient, a barrier-type entry device is required.

The standard acknowledges that cable manufacturing variability can complicate reliance on a single test or data source. Catalog references alone may not constitute sufficient evidence, reinforcing the need for engineering judgement and documented justification.

 

Key Technical Changes Affecting Cable and Cable Gland Selection

Five linked changes underpin Edition 6. Two of the five major changes in this standard relate directly to Ex d cable and cable gland selection — indicative of the scale of revision in this area.

Revised selection flowchart for Ex d entry devices, Edition 5 Clause 10.2 + Table 10 is replaced by Edition 6 Clause 7.5.2 + Table 15. The new flowchart requires explicit consideration of equipment group, enclosure volume, cable length, and cable construction.

Normative cable testing via Annex C, Informative Annex E in Edition 5, is replaced by normative Annex C in Edition 6. In certain applications, cable testing is no longer optional — it is mandatory and forms a critical part of the selection process.

Cables and entry devices assessed together, Edition 5 Clause 10.6, is replaced by Edition 6 Clause 7.4.3, explicitly requiring cables and entry devices to be assessed together for direct entries into flameproof enclosures.

External influences and cable routing, Edition 6 Clause 7.3.2 expands on Edition 5 Clause 5.9, placing increased emphasis on external influences and cable routing and their impact on sealing integrity, material performance, and long-term reliability.

Personnel competence embedded in the scope, Edition 6 Clause 1 (Scope), Clause 5.5, and Annex A make clear that correct application cannot be achieved through documentation alone. Demonstrable, up-to-date competence is now a formal requirement of the standard.

 

Impact on Industry Stakeholders

Designers and Engineers

The most consequential Organizational change in Edition 6 is that cable entry device selection must move upstream. This work used to be handled at installation, often by whoever was tightening the glands. The Edition 6 flowchart requires knowledge of gas group, enclosure volume, and cable construction — all design-stage information. Designers must now engage more deeply with cable behavior, enclosure characteristics, and installation conditions, and must be trained on Edition 6 requirements before making selection decisions.

OEM Equipment Manufacturers

Manufacturers who ship equipment with cable glands pre-fitted now risk incompatibility with the cables connected by the end customer or downstream integrator. Since cables and glands must be assessed together under Edition 6, a pre-fitted gland cannot be assessed for suitability until the cable is known. Manufacturers should review whether pre-fitted glands remain appropriate, or whether their documentation should instead specify gland requirements for the customer to meet during installation.

Installers and Contractors

Historic installation practices based on Edition 5 specifications may no longer be sufficient. Site specifications written 10 or 20 years ago that standardize on non-barrier glands regardless of gas group, enclosure volume, or cable construction should be reviewed. Training must extend beyond installers to whoever is designing, selecting, and purchasing cable entry devices. Where Annex C testing is required to support non-barrier gland selection, this must be planned into the project schedule and not left as a retrospective activity.

Inspectors and Verifiers

Inspection under Edition 6 is more than confirming a gland carries Ex d certification. Inspectors should check that the selection flowchart has been followed, that Annex C evidence is available and specific to the cable construction used where non-barrier glands are installed, and that enclosure volume has been verified where the small-volume exception applies. Inspectors who have not reviewed Edition 6 in detail should do so before inspecting installations designed for it.

End Users and Operators

End users face increased exposure where legacy specifications, pre-2024 equipment, or insufficient competence in the selection team lead to non-compliant installations. Non-compliance can arise from a lack of knowledge of the new requirements, site specifications written to Edition 5 that have not been updated, or equipment manufactured and shipped before Edition 6 came into force. Reviewing standard glanding philosophies and purchasing specifications against Edition 6 is a priority action. Element's global hazardous location compliance whitepaper and hazardous location equipment markings guide provide further context on how certification obligations vary across ATEX, IECEx, UKEX, and HazLoc schemes.

 

Transitional Considerations and Global Adoption

Although IEC standards are formally voluntary, their adoption as national and regional standards makes transition management critical. The IEC edition of Edition 6 was approved by all member countries with the exception of the UK. At the time of writing (early 2026), several EN editions have been released. The BS EN version was pending approval of a National Foreword addressing issues unrelated to cable or cable entry device selection. Organizations working to international specifications should apply the IEC version now and monitor the BS EN publication timeline for formal UK adoption.

 

Frequently Asked Questions

Q: What is IEC 60079-14:2024 and why does it matter? 

IEC 60079-14:2024 is the sixth edition of the international installation standard for electrical equipment in hazardous areas. It covers the design, selection, installation, and initial inspection of electrical Ex equipment. Edition 6 matters because it fundamentally changes how cables and cable entry devices are selected for flameproof (Ex d) applications — replacing a decade of ambiguous, component-based guidance with a mandatory, application-based system that ties gland selection to gas group, cable length, enclosure volume, and demonstrable cable performance.

 

Q: What are the five major technical changes in IEC 60079-14:2024?

Edition 6 identifies five major technical changes: an updated standard title reflecting its broader scope; revised requirements for simple apparatus in intrinsically safe (Ex i) applications; a new mandatory flowchart for Ex d cable entry device selection; normative Annex C, making cable pressure testing mandatory in certain applications; and updated initial inspection tables. Two of the five — the flowchart and Annex C — relate directly to Ex d cable and gland selection, which signals how significant the revision is in this area.

Q: Does IEC 60079-14:2024 require barrier glands for all Ex d installations?

No. The Edition 6 flowchart routes users through four decision points before a barrier gland becomes mandatory. For IIA and IIB gas groups where the cable is at least 0.5 meters long, and the enclosure volume is below 2,000 cm³, a non-barrier gland with an elastomeric seal is permitted without further cable assessment. Where enclosure volume exceeds 2,000 cm³ or cannot be confirmed, Annex C evidence is required before a non-barrier gland can be used. For IIC and IIB + H₂ atmospheres with cables shorter than 3 meters, a barrier gland is mandatory regardless of other factors.

 

Q: What is the Annex C pressure test in IEC 60079-14:2024?

Annex C is a normative cable pressure test that determines whether a cable's internal construction would allow flame to propagate through it under explosion conditions. A 0.5-meter cable sample is fitted to a 5,000 cm³ test enclosure, pressurized to 0.3 kPa, and the pressure is isolated for 5 seconds. If the pressure does not drop by more than 50%, the cable passes. Where the Edition 6 flowchart routes to this test, the result — or equivalent documented evidence — is required before a non-barrier entry device can be used.

 

Q: Who is responsible for cable and gland selection under Edition 6?

Edition 6 does not name a specific role, but the assessment requires knowledge of gas group, enclosure volume, and cable construction — all design-stage information. This makes the responsibility clear: it belongs with the designer or specifying engineer, not the installer. Organizations that have historically left this decision to installers need to restructure that responsibility and ensure the relevant people are trained on Edition 6 before making selection decisions.

Q: Do existing site specifications and glanding philosophies need to be updated?

Yes, in most cases. Specifications written to Edition 5 that standardize on non-barrier glands regardless of gas group, enclosure volume, or cable construction are no longer technically adequate for new work. They should be reviewed and updated before being applied to new installations or extensions to existing ones. The risk of not doing so is that contractors continue to apply out-of-date practices, resulting in non-compliant installations that may not be identified until inspection.

 

Q: Does IEC 60079-14:2024 apply in the UK?

The IEC version was approved by all member countries except the UK. The BS EN version had not been published as of early 2026, pending a National Foreword on matters unrelated to cable and gland selection. UK practitioners should be aware of the technical content and direction, particularly where they work to international specifications. Organizations should monitor the BS EN publication timeline for formal UK adoption.

 

Q: Can Element conduct Annex C testing?

Yes. Element can conduct the Annex C pressure test and issue a third-party test certificate. A certificate from an accredited laboratory carries significantly more weight as sufficient reliable evidence than internal records, particularly for installations subject to independent inspection or where an end user requires formal assurance.  

Conclusions and Recommendations

IEC 60079-14:2024 represents a decisive move toward more rigorous, system-based explosion safety engineering. The 2013 edition's ambiguities allowed Organizations to achieve formal compliance without adequately addressing explosion safety risk. Edition 6 closes that gap through a mandatory, application-based flowchart, normative cable testing, and an explicit requirement for demonstrable personnel competence.

Organizations that fail to adapt risk non-compliance, compromised safety, and increased liability. The following recommendations apply across stakeholder groups:

• Designers and engineers must be trained on the Edition 6 flowchart and take ownership of cable and gland selection decisions at the design stage
• OEM manufacturers should review the suitability of pre-fitted cable entry devices in light of the system-assessment requirement
• Installers and contractors must review historic specifications and extend selection training beyond the installation team
• Inspectors must be briefed on Edition 6 before inspecting installations designed to it, and should check for flowchart compliance and Annex C evidence as standard
• End users should update their standard glanding philosophies and purchasing specifications before applying them to new work

Where Organizations intend to use non-barrier glands and require Annex C evidence, third-party testing by an accredited laboratory produces the most robust form of sufficient reliable evidence. Element can conduct the Annex C pressure test and issue a third-party certificate.

Element is an internationally accredited testing and certification body with laboratory facilities across Europe, North America, and the UK, providing explosive atmosphere testing and certification across ATEX, IECEx, UKEX, and HazLoc schemes. Find out more about Element.

Download the PDF version of this whitepaper for offline reference and sharing with your engineering and compliance teams.

 

References and Supporting Documents 

1. IEC 60079-14:2007 (Edition 4) — Explosive atmospheres: Electrical installations design, selection and erection
2. IEC 60079-14:2013 (Edition 5) — Explosive atmospheres: Electrical installations design, selection and erection
3. IEC 60079-14:2024 (Edition 6) — Explosive atmospheres: Electrical installation design, selection and installation of equipment, including initial inspection
4. IEC SC31J-SD-001:2021 — Background to flameproof cable gland requirements in IEC 60079-14: a review of the history and technical factors associated with cable gland selection for flameproof (Ex d) enclosures. Available at: https://assets.iec.ch/public/sc31j/IEC%2060079-14%20cable%20glands%20requirements.pdf
5. IEC 60079-1:2014 — Explosive atmospheres: Equipment protection by flameproof enclosures (Ex d)

Jonathan Hichens BSc IEng MIMechE is Director of InsightEx, an explosive atmospheres training and consultancy business working in partnership with Element's Connected Technologies & Mobility group. He has worked in the Ex industry since 2012 across R&D, product certification, and training. He represented the UK on the IEC TC 31 committee that developed Edition 6 of IEC 60079-14.