What should I do if the Ex nameplate is missing or unreadable?

Treat the equipment as unverified. Without a readable Ex marking nobody can confirm that it suits the zone, gas group and temperature class of its location, so it is an inspection defect. Identify the item from site records and the manufacturer, obtain a replacement nameplate from the manufacturer, and if the item cannot be identified with certainty, replace it or take it out of service.

Short answer

• The marking is part of compliance. Directive 2014/34/EU requires equipment to be marked legibly and indelibly, and IEC 60079-0 requires the marking on the main part of the equipment.
• No readable marking means no verifiable suitability: EPL or category, gas or dust group, temperature class, ambient range and certificate number (with any X conditions) are all unknown.
• Identify before you act: asset register, serial number, purchase records, drawings, photographs from earlier inspections.
• A replacement plate must come from the manufacturer (or through a route the manufacturer authorises), because it belongs to a specific serial number and certificate. Never copy a label from a similar unit.
• If identity stays uncertain, the safe outcome is replacement or removal from service. Whether the equipment may stay energised while you investigate is a risk decision for the responsible person, not a default.

Why the nameplate matters

The nameplate is the only thing on the equipment that links it to a certificate. It carries the manufacturer, type, serial number, the Ex marking string and the certificate number. Under the ATEX product directive it also carries the CE marking, the year of construction and the group and category symbols. An inspector under IEC 60079-17 checks the equipment against the requirements of its location: protection level, group and temperature class. With the marking gone, every one of those checks fails by default.

Two look-alike enclosures can differ in gas group, temperature class or certificate conditions. A junction box from the same product family may be IIB in one version and IIC in another, or T6 at +40 °C and T5 at a higher ambient. That is why a label copied from a neighbouring unit is never acceptable.

Step by step: what to do

1. Record the finding as a defect in the inspection report, with location and tag number.
2. Check whether the marking is really gone. Paint, dirt or a sunshade may hide it; clean it gently. Some marking may be on another face. Note that empty enclosures certified as Ex components carry their Ex marking inside, by design (IEC 60079-1 and IEC 60079-7); the finished equipment should still carry its own external plate.
3. Identify the item from records. The equipment register, design documents, purchase orders and photographs from earlier inspections often give type and serial number. IEC 60079-17 requires up-to-date documentation, including a list and location of equipment and manufacturer's information, precisely so that this is possible.
4. Contact the manufacturer with type, serial number and photographs. A manufacturer who can trace the unit can confirm the certificate and supply a replacement nameplate for that unit. A repairer working under IEC 60079-19 may be involved if other work is needed.
5. Decide on the interim state. If the equipment's suitability for the zone cannot be shown, the responsible person decides whether it must be isolated now or can wait for identification, considering the zone, the type of protection and its condition.
6. Close out. Fit the replacement plate, update the register (store the certificate and a photo of the plate), and re-inspect. If no traceable identity can be established, replace the equipment.

Preventing the problem

• Photograph every nameplate at initial inspection and store it with the certificate in the equipment register. The Irish Health and Safety Authority's ATEX dossier checklist already asks for certificates of all equipment.
• Mask nameplates during painting and protect them in corrosive areas.
• Treat labels as a check item at each periodic inspection.

Common mistakes

• Making a new label from the drawing or a sister unit. A nameplate states what the manufacturer certified for that unit; it is not the user's to write.
• Assuming "same type, same rating" without checking the serial number against the certificate.
• Leaving the defect open because the equipment works. A missing marking is a compliance defect even when the equipment is in good condition.

Related on excodex

• How to read an Ex marking: decoding II 2 G Ex db IIC T4 Gb step by step
• Common Ex inspection findings and how to fix them
• What should I do if the nameplate marking differs from the Ex certificate?
• Where must the Ex marking be and must it stay visible after installation?
• Tool: Ex marking check; standards space IEC 60079-17

Standards and further reading

• Directive 2014/34/EU, Annex II section 1.0.5 (marking legibly and indelibly, minimum particulars): legislation.gov.uk
• IEC 60079-0, general requirements, marking clause (public copy of the 2004 edition; edition 8, 2026, is current): law.resource.org (PDF)
• IEC 60079-17, inspection and maintenance (edition 6, 2023); the documentation clause is visible in the preview of the 2002 edition: standards.iteh.ai (PDF)
• IEC 60079-1, annex on Ex component enclosures with internal marking (public copy of the 2014 edition): law.resource.org (PDF)
• IEC 60079-19, equipment repair, overhaul and reclamation (edition 5, 2025).
• Health and Safety Authority (Ireland), contents of an ATEX verification dossier: hsa.ie (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.