1.1 When drafting standards, CENELEC technical bodies (TB) generally try to accommodate national regulation. However, this is not always possible. The national regulation may not be compatible with the solution that the standard offers, and the pace of evolution for national regulation may not be compatible with the timeframe of European standardization.

1.2 As each CENELEC member has the obligation to implement every EN by giving it the status of a national standard and withdrawing any conflicting national standard(s), if the content of an European Standard (EN) conflicts with the national regulations of a CENELEC Member, this will cause difficulties at national level.

1.3 To prevent such difficulties, the CENELEC system includes a mechanism for identifying the content of an EN that is incompatible with national legislation. This mechanism results in a derogation called an 'A-deviation'.

Examples of where A-deviations are justified include

  • products, service or practice specified by EN or HD which are banned in a given country;
  • national requirements which are more demanding than, or conflicting with the EN or HD;
  • binding precedents and jurisprudence.


2.1 If possible, when conflict with national legislation is identified, the draft should be amended to address the conflict, particularly if there is a number of countries requesting similar A-deviations.

When it is impossible to avoid A-deviations, all relevant information, i.e. clear identification of the national regulation concerned and of the clauses of the standard in conflict with the regulation, is laid down in an informative annex to the EN.

2.2 Only a CENELEC member with the conflicting national regulation, can ask for an A-deviation.

2.3 The exceptional aspect of the A-deviation should be taken into account as soon as possible, normally when a CENELEC member proposes new work and/or when a technical body drafts an EN.

2.4 In the case of harmonised standards, particular attention should be paid to those cases where the national regulation is in conflict with EU legislation.

2.4.1 In case the transition period (if any) of the EU legislation has not yet ended, A-deviations due to conflicting national regulation can be asked for and remain valid until the end of the transition period.

2.4.2 In case there is no transition period, or the transition period of the EU harmonization legislation has ended, no conflicting national regulation is allowed in EU (EEA) countries. If it is the case, the European Commission (EC) has to solve the problem.

2.5 A-deviations only apply to the normative provisions of a European Standard. In exceptional cases, an A-deviation may apply to all the normative provisions of the European Standard.

NOTE: Normative provisions of European Standards are called requirements. They are introduced by the modal verb "shall" or the use of the infinitive form. CEN and CENELEC publish documents other than European Standards, for instance Workshop Agreements, Technical Specifications or Technical Reports as national standards; there is no systematic implementation of such documents, hence a national difference due to a regulation is not a problem.

2.6 A-deviations do not release CENELEC members from their obligation to implement the relevant European Standard.

3 Special Cases

3.1 The product, service or practice specified by the European Standard is banned in a given country.

The banning of a product, service or practice in a member state does not prevent CEN or CENELEC from developing a related standard
This standard remains useful for national manufacturers since the product could still be produced in this country, even it's use is prohibited.  The same applies for services and practices specified by a European Standard. The European Standard can make users aware of the situation, by means of an A-deviation, covering all the requirements of the European Standard.

3.2 National regulation has requirements others than the European Standard

Such cases do not require any action of CEN and CENELEC, simply because compliance with regulations is mandatory and compliance with standards is voluntary. An A-deviation is not required. CENELEC National Committees  (NC) may draw attention to the additional national requirements in a national foreword.

3.3 Natinal regulation has requirements more demanding than the European Standard

As compliance with national regulation is mandatory in the respective country, an A-deviation makes standard users aware that compliance with the standard is not sufficient in this country.

3.4 National regulation has less requirements or requirements less demanding than the European Standard

When they exist, requirements in national regulation are often less precise or stringent than those of the European Standard. In the absence of contradiction, it is the user who makes the voluntary choice to comply only with the national regulation, or to implement the best practices embedded in the European Standard. NCs may draw attention to this in a national foreword. An A-deviation is not required.

3.5 Binding precedents and jurisprudence

The legal requirement faced by users is not limited to codified acts passed by the legislator or the executive, and can take the form of binding precedents, rulings or jurisprudence established by courts, which may form part of the national legal framework. Such compulsory requirements, if deemed contradictory to the European Standard, can be dealt with by means of an A-deviation provided it is fully, convincingly and verifiably documented.

3.8 CENELEC cannot challenge national regulation. For non-harmonized standards, A-deviations remain valid until the adjustment of the related national regulation or the standard is amended to address the conflict.  The review process will include a review of need for A-deviations.


4.1 Risks of conflicts between national regulation and a future EN shall be identified as soon as a new subject of work is proposed. An early notification allows the technical body to adapt its draft in order to avoid the request for an A-deviation.

CENELEC members should inform the relevant technical body of their need to request an A-deviation as soon as the drafting starts, and at the latest during the CENELEC Enquiry.

Although it is always useful to obtain this information, regardless of the stage of the standard's development, any late notification may require an amendment of the European Standard as soon as it is published. Nevertheless, it is understood that there may be cases where national regulation has changed or has been introduced in parallel with the development of the standard.

4.2 The request for a possible A-deviation shall contain: 

  • critical examination of the national situation in regard of the legal requirements of its national regulation;
  • a copy of the relevant part(s) of the national regulation (with an informal translation in the working language of the technical body);
  • the work item(s) affected by this request;
  • the clauses of the draft(s) concerned by this A-deviation.

The member presenting a request for A-deviation is invited to provide it in the working language of the technical body.

4.3 The technical body is responsible for assessing the material presented in support of the request for the A-deviation. The role of the technical body is restricted to verifying whether there is a conflict between the EN and national regulation, on the basis of the evidence provided by the CENELEC member requesting it, which needs to be fully documented,convincing and verifiable.

The technical body is not entitled to assess or even challenge national regulation.

Furthermore, the technical body is invited to verify, together with the relevant National Committe(s), that A-deviations are still relevant and valid when its deliverables undergo review.

4.4 Any technical body, when receiving such a request for an A-Deviation, should:

  • try to avoid the A-deviation (e.g. by adapting the draft);
  • verify (preferably by its Secretariat), if the regulation is impacting the EN, i.e. if there is actually a contradiction between (a) requirement(s) in the national regulation and (a) requirement(s) in the (pr)EN;

4.4.1 In case the regulation does not impact the EN, the technical body informs the notifying member about it.

4.4.2 When the regulation is impacting the EN, the technical body should:

  • document the result of the verification by a technical body;
  • draw the attention of the standards users, in the foreword of the EN, to the existence of deviation(s) from the content of the EN due to national regulation;
  • list the countries having such an A-deviation, with all relevant information (clear identification of the national regulation concerned and of the clauses of the standard in conflict with the regulation), in an informative annex to the EN;  
  • finalize the draft and send it to CCMC (production@cencenelec.eu) in order to start the Enquiry or Formal Vote procedure.

4.5 In justified cases, a modification to, or inclusion of, the A-deviation might be required after the Formal Vote.
Requests for, or modifications to an A-deviation, made after the standard has been voted upon or published, require BT approval (after TC advice) through a consultation by correspondence. The result is published as an Amendment to the standard if it has already been ratified. If the standard is not yet ratified, the results are incorporated into the text before publication.

4.6 Review

When reviewing an EN, the TB together with the concerned CENELEC member(s) should consider the validity of A-deviations. If an A-deviation is no longer valid, the EN shall be updated accordingly.


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