The ATEX technical file is the document in which all the engineering evidence that proves a piece of equipment's right to carry Ex marking is gathered. It shares the logic of the general CE technical file (see What Is the CE Technical File?) but contains additional sections specific to explosive atmosphere protection requirements. In this article we explain the file's content and the logic behind its preparation.
Contents of the ATEX Technical File
- General description: The product's description, intended use, and the targeted equipment group/category.
- Design and manufacturing drawings: Dimensioned drawings of critical parts such as the enclosure, gaskets and terminal connections.
- List of applied standards: The relevant harmonized EN/IEC 60079 series standards, and the justification for any deviation from them, if any.
- Ignition source analysis: The report in which all possible ignition sources are assessed and it is shown how the protection design controls them. See How Is ATEX Risk Analysis Carried Out?.
- Test reports: The results of relevant tests such as pressure resistance, temperature measurement, sealing, and energy limitation.
- EU-Type Examination Certificate: The certificate issued by the notified body for Category 1 and 2 equipment. See What Is Module B?.
- User manual: Installation, use and maintenance instructions, and any special conditions of use stated on the certificate (the "X" marking).
- EU Declaration of Conformity: The signed document in which the manufacturer declares conformity with all requirements.
Why Do Special Conditions of Use (the "X" Marking) Matter?
Some ATEX certificates prescribe additional conditions for the equipment's safe use — for example, not exceeding a certain ambient temperature range or using a specific cable type. If such conditions exist, the letter "X" is added to the end of the certificate number. Fully reflecting these conditions in the user manual is one of the most frequently overlooked yet most critical parts of the technical file, because failure to comply with these conditions in the field can effectively invalidate the protection documented by the certificate.
Keeping the File Up to Date
Even seemingly minor changes made to a product's design (material, gasket, cable entry, etc.) can affect the ignition source analysis and, consequently, the validity of the certificate. For this reason, the technical file and, if necessary, the certificate must be updated with every design revision; otherwise the product may end up in a state where it does not actually provide the protection stated on its label, while still carrying that label.
Retention Period and Accessibility
As under general CE legislation, the technical file must be kept accessible for generally 10 years from the manufacture of the last product. The ability to present the file quickly and completely during an audit or market surveillance action is an important assurance factor in the manufacturer's favor.
Frequently Asked Questions
Are the ATEX technical file and the CE technical file the same document?
Generally, a single integrated technical file is prepared for the same product, but this file must always include additional ATEX-specific sections.
Who is required to keep the technical file?
The obligation to keep the technical file belongs to the manufacturer or the manufacturer's authorized representative within the EU; the file must generally remain accessible for 10 years.
Why is the technical file requested during an audit?
Market surveillance authorities or notified bodies may examine the technical file to verify the product's declared conformity; an incomplete file can lead to serious sanctions.
Conclusion
The ATEX technical file is the document most frequently referenced during audits, proving the engineering justification behind a piece of equipment's Ex marking. Preparing the file completely, keeping it current, and ensuring it fully matches the product's actual design is essential both for legal compliance and for real safety in the field.
For more information, see our ATEX consultancy service.
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