Can old equipment marked 'EEx' still be used in a hazardous area?

Usually yes. EEx is simply the marking used for equipment built to the old European (CENELEC) standards of the EN 50014 series. Equipment that was lawfully placed in service may remain in use, provided it is still suitable for the zone, gas group and temperature class, is in safe condition, and is covered by the site's risk assessment and inspection regime. The old marking alone is not a reason to remove it, but it cannot be supplied today as new equipment.

Short answer

• EEx meant compliance with the European standards EN 50014 to EN 50020 and related parts. When EN 60079-0 replaced EN 50014 (withdrawal date 1 October 2008), the marking changed from EEx to Ex as an editorial change.
• The EU product directive (2014/34/EU, formerly 94/9/EC) governs placing products on the market. It does not force existing, lawfully installed equipment out of service.
• UK HSE guidance states that any safe product in service in the EU on or before 30 June 2003 may remain in service indefinitely, whether European or non-European certified.
• Conditions: suitable for the current area classification, correct group and T-class, intact protection features, legible marking, documentation available, regular inspection.
• Moving the equipment to another site, reselling it, or modifying it can bring other rules into play.

What EEx tells you

A marking such as EEx d IIB T4 or EEx ia IIC T6 has the same structure as today's marking without the equipment protection level (EPL):

Two generations exist. Pre-ATEX equipment carries EEx and often the hexagon mark of the earlier directives, but no category. Equipment certified under ATEX to the EN 50014 series, before it was withdrawn on 1 October 2008 and EN 60079-0:2009 introduced EPLs, carries both but no EPL, for example II 2 G EEx d IIB T4. Where a category is shown, it gives the zone directly. Where it is not, the type of protection does: ia for Zone 0, the other common types for Zone 1, and the type "n" variants (EEx nA and similar) for Zone 2 only.

The legal position in the EU

The European Commission's ATEX Guidelines state that used products placed on the market and used in the EU before 2014/34/EU came into force are not covered by it, as long as they are not modified in a way that affects their health and safety characteristics. For equipment older than ATEX, the workplace directive 1999/92/EC (Article 9) required that work equipment already in use before 30 June 2003 meets the minimum requirements of its Annex II, Part A, and gave existing workplaces three years to comply with the directive.

In other words, the employer must show that the old equipment is safe where it is used. HSE's guidance on existing equipment adds, for a DSEAR review of older plant, that there is no obligation to bring old equipment fully up to current standards, but simple changes that improve safety may be expected.

How to decide in practice

1. Check suitability. Compare the type of protection (or category), gas group and T-class with the current area classification. Zones change over a plant's life; the equipment must fit today's zones, not the original ones.
2. Check condition. Flamepaths, gaskets, glands, cover fasteners, intrinsically safe barriers and seals must be intact. An EEx enclosure with corroded flamepaths is unsafe for the same reasons a new one would be.
3. Inspect against the right standard. IEC 60079-17 notes that for older installations the equipment and installation details should be checked against the standards applied when they were installed, which may not have been IEC standards.
4. Keep documentation. Certificates, special conditions ("X"), entity parameters for intrinsically safe loops and drawings are often hard to find for old equipment. Without them, specific conditions of use cannot be verified.
5. Repair with care. Repairs follow IEC 60079-19 and the original certification documents. HSE warns that a repair affecting the essential safety requirements may be a substantial modification, after which the product needs a new conformity assessment.
6. Plan replacement where spares, documentation or suitability are missing. Replacement equipment will carry today's marking, for example Ex db instead of EEx d.

Common mistakes

• Removing sound equipment only because it says EEx. The marking is outdated, the equipment may not be.
• Reinstalling old equipment at a new site without checking the rules. HSE notes that equipment brought into service at a new site in Great Britain must comply with the directives that applied when it was first supplied or put into service, and the design of second-hand equipment must be reviewed and verified as fit for purpose.
• Ignoring a zone change. Reclassification is the most common reason old equipment becomes unsuitable.

Related on excodex

• How to read an Ex marking: decoding II 2 G Ex db IIC T4 Gb step by step
• Inspection of Ex installations under IEC 60079-17: initial, periodic, visual, close and detailed
• Why do newer markings say 'Ex db' or 'Ex eb' instead of 'Ex d' or 'Ex e'?
• What should I do if the Ex nameplate is missing or unreadable?
• Tools: Ex marking check; standards spaces IEC 60079-17, IEC 60079-19

Standards and further reading

• IEC 60079-17:2023, inspection and maintenance of electrical installations: preview
• IEC 60079-19:2025, equipment repair, overhaul and reclamation.
• HSE, existing equipment issues under DSEAR and the 2016 equipment regulations: hse.gov.uk
• Directive 1999/92/EC, Article 9, existing work equipment and workplaces: legislation.gov.uk
• European Commission, ATEX 2014/34/EU Guidelines, 6th edition (January 2026), used and second-hand products: ec.europa.eu (PDF)
• ExNB clarification sheet ExNB/10/388/CS, EN 50014 to EN 60079-0 and the change from EEx to Ex: prestations.ineris.fr (PDF)

This article is general technical information prepared by the excodex editorial team. It does not replace the applicable standards, the equipment certificates and instructions, national regulations or the assessment of a competent person.