National regulations – Possible conflict with CEN work (A-deviations)

This document gives guidance to the CEN technical bodies as well as to the CEN-CENELEC Management Centre (CCMC) on how to handle requests for A-deviations in ENs, keeping in mind that A-deviations should be considered as exceptional.


Most of the time, European Standards are developed outside specific efforts of European legislative harmonization. This is the case for 80% of European Standards. In such cases, there is the possibility that one country or several countries has/have a piece of national regulation not necessarily compatible with the provisions of a European Standard in the course of preparation.

National regulation comprises legal acts that are enforceable as law in a CEN member country. Due to differing legal systems and languages in Europe, such legal acts can have different forms and names (law, decree, order, binding precedent) and include jurisprudence. Dispositions not directed to all, not sanctioned or of a contractual nature are not considered as regulation.

Technical committees generally try to accommodate such national regulation, but it is not always possible, as the national regulation may not always be compatible with the optimal solution that the standard offers. Of course, such national regulation may later be withdrawn or modified. However, the pace of evolution for national regulation is not necessarily compatible with the timeframe of European standardization.


An essential objective of the CEN System is to obtain harmonization of national standards at European level. This harmonization is considered to be achieved when products or services in compliance with the national standards of one CEN member can be regarded, without modifications, as complying with the national standards of the other CEN members and vice versa.

The most effective way to reach this objective is to develop a European Standard (EN). Indeed, each CEN member has the obligation to implement the EN by giving it the status of a national standard and withdrawing any conflicting national standard(s).

The CEN rules foresee the case where a CEN member is confronted with a situation where it has to implement an EN that is not compliant with the regulation of its country. It is then the full right of this CEN member, and this right cannot be denied, to ask for derogation from the application of the standard in its country. This derogation is exercised through the application of an A-deviation.


3.1 When it is impossible to avoid A-deviations, all relevant information concerning them (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.

3.2 A-deviations are only based on conflicting national regulation. They are out of the competence of CEN members in charge of implementing ENs as national standards. It is the reason why only the NSBs concerned by conflicting national regulation, can ask for an A-deviation. An A-deviation is not a privilege granted to a CEN member; it reflects a national problem with national regulation.

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

3.4 Attention should be paid in particular to those cases where the national regulation in question is in conflict with EU harmonization legislation:

  • in case the transitional period (if any) of the EU harmonization legislation has not yet ended, A-deviations due to conflicting national regulation can be asked for and remain valid until the end of the transitional period;
  • in case there is no transitional period or the transitional 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.

It should always be borne in mind that monitoring the implementation EU harmonization legislation remains within the responsibility of EU institutions.

3.5 CEN members have the obligation to implement European Standards. A CEN member may face difficulties with the application of a European Standard because some of its requirements are not compliant with its country's regulation. The response of CEN is to include this information in an annex to the European Standard, called A-deviation. Such deviations only apply to the normative provisions of a European Standard. In exceptional cases, an A-deviation may also apply to all the requirements 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.

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

3.7 Special cases

3.7.1 The product, service or practice specified by the European Standard is banned in a given country
The common endeavour of most CEN members does not necessarily need to stand still because of a ban in a single country. In such cases, the national regulation does not allow to place in the market or to use products, specified in the European Standard, in a CEN member country. However, the standard remains useful for national manufacturers since the product could still be produced in this country even it is not allowed to use it there. This applies analogously also to 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.

3.7.2 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.

3.7.3 National 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.

3.7.4 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.

3.7.5 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 CEN cannot go against national regulation even if they are wrong and not correct. Moreover, when ENs are produced in fields that are not covered by EU harmonization legislation, A-deviations remain valid until the adjustment of the related national regulation.  


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.

CEN National 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 CEN 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:

  • a 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;
  • 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 an informal translation into 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 NSB requesting it, which needs to be:

  • fully documented,
  • convincing
  • verifiable

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

Furthermore, the technical body is invited to verify that A-deviations are still relevant and valid when its deliverables undergo systematic review.

4.4 Any technical body, when receiving such a request, should:

  • try to avoid the A-deviation (e.g. by adapting the draft);
  •  verify (preferably by its Secretariat) whether or not the regulation is relevant, i.e. whether there is actually a contradiction between (a) requirement(s) in the national regulation and (a) requirement(s) in the (pr)EN;
  • in case the regulation is considered irrelevant, inform the notifying member about it;
  • when the regulation is relevant:
    - document the result of the verification by a Technical Committee (TC) decision;
    - 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, all relevant information concerning them (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 via E-Trans to CCMC in order to start the Enquiry or Formal Vote procedure.
  • In justified cases, a modification to or inclusion of the A-deviation might be required after the formal vote.
  • Requests for -or modifications to- A-deviation made after the standard has been voted upon or published require BT approval (after TC advice with the support of the relevant WG Convenor) through a vote by correspondence according to IR2 6.1.4. The result is published as an Amendment if the standard has already been made available. If the standard is not yet published, the results are incorporated into the text before publication.

4.5 A-Deviation and Systematic Review

A question concerning the validity of A-deviations is included in the 5-year systematic review balloting.

If an A-deviation is no longer valid, the EN shall be updated accordingly (through an amendment, even if the standard is older than 4 years, or revision).


Our use of cookies

We use necessary cookies to make our site work. We'd also like to set optional analytics cookies to help us improve it. We won't set optional cookies unless you enable them. Using this tool will set a cookie on your device to remember your preferences.

Necessary cookies enable core functionality such as security, network management, and accessibility. You may disable these by changing your browser settings, but this may affect how the website functions.

We'd like to set Google Analytics cookies to help us to improve our website by collecting and reporting information on how you use it. The cookies collect information in a way that does not directly identify anyone.

I accept all cookies