Drafting EN IEC standards for citation in the OJEU


This page provides guidance to Technical Bodies and Working Groups on horizontal aspects to be considered when preparing EN IEC harmonized standards, in support of EU harmonization legislation, intended to be cited in the Official Journal of the European Union (OJEU). Regulation (EU) No 1025/2012 on European standardization defines a harmonized standard as “a European standard adopted on the basis of a request made by the Commission for the application of Union harmonisation legislation”.

For the purpose of this page, the term 'Technical Body' (TB) refers to Technical Committees (TC), Sub-committees (SC), Reporting Secretariats (SR) and Task Force of the Technical Board (BTTF).



Under the Frankfurt Agreement, the standards are developed by IEC under parallel procedure with CENELEC (unless exempted from parallel procedures through a BT decision). Once the proposal is approved by the IEC P-Members of the IEC Technical Body, the corresponding work item is created by CCMC in the CENELEC Technical Body work programme. For further information, see the provisions of the Frankfurt Agreement – Day to Day management between IEC/CO and CCMC

The starting point for the development of a harmonized standard is to assess whether it is in the scope of relevant EU harmonization legislation and whether the standard is covered by a Standardization Request or Mandate which was accepted by CENELEC. If it is in its scope, the Technical Body Secretary shall contact the relevant CCMC Project Manager - to formally link the NWI to a Standardization Request (or mandate) work programme and to plan the next harmonization steps. CCMC keeps IEC informed on those work items that are intended to be cited in the OJEU.

The development of the EN IEC harmonized standard under parallel procedure follows the normal procedure as for the development of all other European Standards, with some additional considerations that are further detailed in this page.

The drafting of the EN IEC harmonized standard is carried out by the IEC Technical Body (see Frankfurt Agreement), therefore the CENELEC Technical Body must closely monitor the evolution of the work item at IEC level (and in the corresponding CENELEC Technical Body work programme). The Secretary is invited to contact the relevant CCMC Project Manager for advice and to trigger appropriate actions.



2.1 General rules for preparation of harmonized standards (hENs)

When drafting harmonized standards, it is strongly recommended that the generic checklist is used by the Technical Bodies. For specific European Commission's sectoral checklists see section 5 of this page.

2.1.1 General

The TC secretary shall confirm that the draft standard is covered by a standardization request (or mandate) and that the information is correctly displayed in Projex-online (“EC/EFTA relations” tab).  In case the information on Projex-Online on a Standardization Request, a Mandate or the EU legislation needs to be corrected, the TB Secretary contacts the CCMC Project Manager.

The harmonization process consists in the following:

  • WHAT: the goal is the citation of the reference to the EN IEC standard in the Official Journal of the European Union (OJEU).
  • WHY: once cited in the OJEU, manufacturers, economic operators or conformity assessment bodies can use the harmonized standard to demonstrate that products (or services and processes) comply with relevant EU legislation (presumption of conformity).
  • HOW: the citation of the reference to the EN IEC standard in the OJEU results from a ‘compliant assessment’ of the HAS consultant. A particular process is followed to achieve a ‘compliant assessment’: (1) assessments requests, (2) interactions with the HAS consultant and (3) evolution of the EN IEC draft standard.

Assessment requests

Assessments from the HAS consultants can be requested at 4 different stages (1st Working Draft, Enquiry Draft, Formal Vote Draft, Published EN). In consultation with the CCMC Project Manager, the TB secretary timely provides all the appropriate elements for assessment (in particular the Annex ZZ).

The HAS consultant delivers the assessment within a maximum of 35 days since the assessment request’s date (the assessments are requested by CCMC). The assessment can be found on the relevant LiveLink platform the TB secretary has access to (through https://sd.cen.eu).

The Technical Body shall answer all the comments from the HAS consultant at each assessment stage (FWD, Enquiry, Formal Vote or PUB). The feedback of the Technical Body shall be filled in the last column of the HAS assessment report (‘Observations of the secretariat’) to indicate how the comments of the consultant have been implemented or addressed.

Interactions with the HAS consultant

Technical bodies are encouraged to interact with the assigned HAS consultant. Interactions can take place either before the HAS consultant has delivered the assessment (to proactively clarify any relevant point) or once the TC has received the assessment. CCMC facilitates this process. It is crucial to ensure, as early as possible, a common understanding of any potential compliance issue between the HAS consultant and the TC (the main compliance issues are described hereafter). Throughout the standardization process lead by the IEC TC, the EN IEC draft will have to evolve in a way that addresses any compliance issue in order to be cited in the OJEU.

Evolution of the EN IEC standard

In the case of EN IEC harmonized standards, the relationship between the CENELEC Technical Body and the IEC Technical Body is of particular importance to ensure that the compliance-related comments from the HAS consultants) are addressed by subsequent versions of the IEC draft. This connection can be made through the CLC TB secretary, providing the relevant assessment elements to the IEC WG’s European experts (which NCs are member of CENELEC), and inviting them to take them into consideration. The CLC TB secretary may also contact directly the IEC convenor, as relevant.

2.1.2 Scope

The scope of the harmonized standard shall be concise and clear and worded as a series of statements of facts. In line with CEN-CENELEC Internal Regulations Part 3 (and ISO/IEC Directive Part 2), the scope shall not include requirements, permissions or recommendations. The scope shall be consistent regarding content covered by the standard.

However, the scope of the standard could be broader than the relationship between the standard and the requirements of the EU legislation.

2.1.3 Requirements

The EN IEC standard shall contain objectively verifiable requirements and test methods – in line with the CEN-CENELEC Internal Regulations Part 3 and the ISO/IEC Directives Part 2: “Expression in the content of a document conveying objectively verifiable criteria to be fulfilled and from which no deviation is permitted”.

Only those requirements which can be verified shall be included. Phrases such as “sufficiently strong” or “of adequate strength” shall not be used because they are subjective statements.

Furthermore, technical requirements that are not linked to the EU legislation’s essential requirements shall be covered in separate clauses in the standard. Similarly, separate EU-related requirements (e.g. EMC and LVD) shall be covered in separate clauses. This particular point of attention may require some evolutions in the structure of some EN IEC standard.

2.1.4 Normative references

The CEN-CENELEC Internal Regulations – Part 3 include provisions on the use of normative references.

The standards listed in Clause 2 are normatively referenced within the text of the standard. The normative references in Clause 2 of the EN IEC standard and in the body of the standard shall be dated, active and published. This is the role of the CENELEC Annex ZA, which links normative references to international publications to their corresponding European publications. Most often, the normative references are not dated in the IEC standard, therefore they must be dated through the Annex ZA.  

Non-dated normative references are exceptionally possible if:

  • The normative reference is not relevant for compliance with essential requirements or
  • The normative reference is relevant for compliance with essential requirements but the implications of modifications to the referenced document for the compliance with essential requirements have been duly considered (to be explained in a dedicated Technical Body justification, which will have to be provided to the HAS consultant).

As a general principle, all normative references must be EN, ISO or IEC standards. If EN, ISO and IEC standards do not exist, exceptionally, other standards could be used under certain conditions:

  • The references must comply with the ISO/IEC Directives Part 2
  • The document needs to be available for possible consultation by the HAS consultant or the European Commission.

The process for handling the Annex ZA by the CENELEC Technical Committee is described in BT Decisions D160/020 and D160/021.

2.1.5 Risk reduction

If a harmonized product standard deals with safety aspects, the relevant hazards must be identified and the risks reduced. This particularly applies in the case of the Low-Voltage Directive, for which a risk assessment shall be provided together with the Annex ZZ for assessment purposes. There is no particular template for such a risk assessment, however it must rely on the CENELEC Guide 32 ‘Guidelines for safety related risk assessment and risk reduction for low voltage equipment’. See also an example on how CLC/TC 23E uses CENELEC Guide 32 for its risk analysis and self-assessment.

For further information, see the CENELEC Webinar: https://www.cencenelec.eu/news/videos/Pages/VIDEO-2019-029.aspx

2.1.6 Neutrality principle

For compliance purposes, the draft standard (as developed by the IEC TB) must respect the neutrality principle – in line with the ISO/IEC Directives Part 2, clause 33.1.

The standard shall not contain clauses imposing requirements or obligations on or between certain economic operators (e.g. requirements are set to an economic operator and its competence or resources instead of to product design and product properties).

The standard shall not contain clauses imposing first, second- or third-party conformity assessment.

2.1.7 Annex ZZ

For the drafting of the informative Annex ZZ, the latest template shall be used (see Forms and Templates - Annex ZZ).

The rows shall be placed in the order of the legal requirements.

If a legal requirement is claimed as covered in the Annex ZZ, this requirement shall be clearly addressed by a clause/sub-clause of the standard.

If a standard deals with aspects which are outside the scope of the EU legislation, clauses/sub-clauses dealing with these aspects shall not be referred to in the informative Annex ZZ.

In case the standard covers different EU Directives/Regulations, separate Annexes ZZ shall be prepared.

For further information on the drafting of Annex ZZ, see the Webinar on Annexes ZA/ZZ to CEN/CENELEC Harmonized Standards.

2.1.8 Further specific rules

Specific rules and requirements can apply to specific sectors/directives. Those are reproduced in dedicated sectorial “checklists”, which the Technical Body needs to take into account when developing harmonized standards. These checklists are used by the HAS consultant when assessing the standard, which the consultant provides with its assessment.



3.1 Drafting EN up to Enquiry

The drafting stage for harmonized standards is identical to the drafting of EN IEC standards up to Enquiry stage (i.e. parallel CDV). The IEC TC drafts the standard. Therefore, the CENELEC Technical Body needs to closely monitor the standard’s development at IEC level. It can be monitored notably through the relevant page on the IEC website, which provides the planning for the development of the IEC standard (see standards development – technical committees and subcommittees – and then relevant standards from the IEC Technical Body). Some information is also reflected in Projex-Online working area.

Note: CCMC is working with the IEC on the alignment of the data for parallel EN IEC standards. To ensure the citation of the standard, it is of upmost importance to start the harmonization process as soon as possible, with an assessment of the “first working draft (FWD)” from IEC (the CENELEC FWD is understood as the equivalent to the IEC CD). This assessment will be requested by CCMC upon the request of the CENELEC Technical Body secretary. The CD (or CDs) stage(s) do not formally appear in the CENELEC Technical Body’s work programme. The secretary is invited to liaise with the CCMC Project Manager to coordinate on the elements that need to be provided as part of the FWD assessment.

To trigger the assessment on the FWD, the CENELEC secretary notifies production@cencenelec.eu together with the draft and the completed transmission notice. The option ‘document is to be submitted to HAS Consultant for indicative assessment’ shall be filled by the TB secretary to trigger the request. The CENELEC TB secretary shall include the CCMC Project Manager in copy when providing these elements.

CCMC will begin the necessary preparation of a draft Annex ZA (as far as possible at this stage), since it is recommended that the FWD include a draft Annex ZA, but it is not mandatory at this stage. It is also recommended to include in the assessment ‘package’ a first draft Annex ZZ, or an indication of how the Essential Requirements are intended to be covered.

The FWD HAS assessment is optional, but strongly recommended to ensure early involvement of the HAS Consultant in the process, so that the Consultant can flag at an early stage any potential compliance issue.

In terms of good practice, the CENELEC secretary (with the relevant experts) is invited to contact the HAS consultant as soon as the assessment is requested (this is valid for all assessment stages) and before the assessment is finalised. The CCMC Project Manager notifies the CENELEC TB secretary when the assessment is formally triggered, so that the HAS 'comment resolution meeting' can be anticipated.

The assessment will be uploaded in a specific section in LiveLink (in case the secretary does not have access, they must contact the CCMC Project Manager).The CENELEC secretary shall share the assessment with the Technical Body to address future actions.

The Technical Body shall consider the outcome of the assessment and the comments of the HAS Consultant. In case of Lack of Compliance, it is recommended that the Technical Body interacts with the HAS consultant (in writing or by calling for a meeting).

The European experts involved in the CENELEC and IEC Technical Bodies are strongly advised to ensure that the items mentioned in the FWD HAS assessment reports under ‘1.2 Critical findings leading to a lack of compliance’ are duly considered before prEN IEC is submitted to Enquiry (CDV).  In case those findings cannot be considered and addressed by the IEC TB, experts from European NCs in the IEC TB together with the CLC TB shall consider the preparation, as early as possible, of European Common Modifications.

Requesting a HAS assessment at Public Enquiry (CDV in IEC) is mandatory in the process. Before the start of the Public Enquiry, the CENELEC Technical Body provides the necessary European elements for harmonization: Annex ZA, Annex ZZ, risk assessment (as relevant) and the Technical Body responses (“observations from the secretariat”) to the previous assessment (i.e. on the FWD). Annex ZA is formally prepared by CCMC (and checked by the TB); all other elements are the responsibility of the TB.

At the start of the parallel Enquiry (at the very latest), the CENELEC TB secretary provides these European elements to production@cencenelec.eu with the transmission notice to trigger the formal assessment at Enquiry stage. The CENELEC secretary shall also include the CCMC Project Manager in copy to this correspondence. At this stage, the HAS consultant is not allowed to perform an assessment if the Annex ZZ is not available. CCMC notifies the CENELEC TB secretary when the assessment has been formally triggered.

At all stages, the HAS consultant has 35 days to deliver the assessment.

For further information, see the Frankfurt Agreement Day2Day management, notably clause

3.2 After Enquiry and before Formal Vote

If the outcome of the Enquiry HAS assessment is 'lack of compliance', it is again recommended to organise a meeting (or at least written exchanges) with the HAS consultant to clarify the comments and agree on a way forward (in view of the next standardization step: the parallel FDIS, i.e. the CENELEC Formal Vote).

In view of the assessment request at the Formal Vote stage, the Technical Body shall ensure that the adequate elements are timely provided to CCMC. The CENELEC TB secretary is notified by CCMC when the IEC final draft is ready to proceed to parallel FDIS (i.e. Formal Vote). At this moment, the CENELEC Technical Body secretary, in consultation with the relevant TB officers and members, shall submit to CCMC the following documents (to production@cencenelec.eu with the transmission notice and the CCMC Project Manager in copy):

  • Annex ZZ (even if unchanged compared to the ENQ assessment);
  • Annex ZA (even if unchanged);
  • Risk assessment (as relevant);
  • The enquiry HAS assessment report with the last column ‘Observations of the secretariat’ filled with the Technical Body comments on how the consultant comments were addressed.


For further information, see the Frankfurt Agreement Day2Day management, notably clause

Resolving ’lack of compliance’ assessments at Formal Vote

It has to be noted that, unlike CENELEC homegrown standards, where the start of the Formal Vote is suspended in case of ‘lack of compliance’ assessment (so that the Technical Body can modify the final draft before it is submitted to Formal Vote), this is not possible in the case of EN IEC standards.  

Therefore, the FV assessment is requested at the start of the Formal Vote (IEC FDIS) at the latest. When the IEC FDIS approval procedure has started, the EN IEC could not be modified anymore (except through Common Modifications). If modifications are required on the Annex ZA or Annex ZZ only, the CENELEC Technical Body can proceed with such modifications. Those new Annexes will then have to be approved by the BT before they can be made available by CENELEC. The Technical Body shall fill the HAS assessment report with the last column ‘Observations of the secretariat’ to indicate the feedback of the Technical Body to the HAS consultant’s comments and if these comments can still be addressed.

Based on these considerations, the Technical Body could organise a meeting with the HAS Consultant to find an agreement on the way forward. For the practicalities, the Technical Body is invited to contact the CCMC project manager.

In such case, the Technical Body records the outcome of the meeting and asks the Consultant for feedback, i.e. asks whether the consultant's comments were sufficiently addressed. This can be done either via email or at the end of the meeting with the consultant. In the latter case, the confirmation should be reflected in writing.

In practice, if the text of the EN IEC standard needs updates, the EN IEC will not be offered for citation: as the text cannot be modified anymore. The CENELEC Technical Body will have to consider the development of Common Modifications to address the remaining compliance issues (leading to different EN and IEC standards) or the Technical Body should wait for a future amendment/revision at IEC level to address the remaining compliance issue.

The possibility to develop Common Modifications can be an appropriate interim solution, allowing the citation of the (modified EN IEC) standard, and pending a future amendment/revision at IEC level that would possibly integrate the necessary elements for compliance.

If the consultant provides:

  • Positive feedback to the Technical Body: the EN will be published and offered to the European Commission for citation in the OJEU;
  • Negative feedback to the Technical Body: the standard will not be offered for citation by CENELEC.
  • No feedback: Technical Committees need to assess 3 different options and decide on a way forward:

Option 1: the Technical Body concludes, with the support of CCMC, that the standard includes all the comments (in practice through the modification of the Annex ZA or Annex ZZ) from the HAS consultant and therefore the HAS assessment is “resolved”. The standard can proceed to Publication and will be offered to the EC for citation.

Option 2: the Technical Body, with the support of CCMC, Project Manager concludes that the reworked standard includes all the remarks from the HAS consultant. CCMC can request a Publication assessment (PUB HAS assessment) prior to publication to have a formal ‘validation’. The PUB assessment should only be requested by CCMC, on the advice of the CENELEC TB, in limited cases for a final check.

Option 3: the Technical Body concludes that harmonization is not possible and takes a decision to request BT to remove the link to legislation, either temporarily or permanently. If BT approves the request, the standard (without Annex ZZ) will proceed to Publication and the CCMC Project Manager informs the EC about the “de-harmonization” of the standard.

3.3 After Formal Vote and before publication

This step will follow Option 2 as presented above. Exceptionally, after the Formal Vote stage, a Technical Body could request a HAS assessment at Publication stage (PUB HAS assessment). This shall be considered an exceptional request and this procedure can only be applied if the FV HAS assessment outcome was lack of compliance.

Considering that technical comments cannot be taken into account after the Formal Vote stage, this procedure shall only be followed for limited cases, e.g. final assessment on the new version of the Annex ZZ/ZA.

If the PUB HAS assessment is 'lack of compliance', the Technical Committee will have to analyse the comments from the HAS consultant and agree on the way forward (i.e. considering Common Modifications or waiting for a new amendment or revision at IEC level).

3.4 Ratification and making available

Harmonized standards that at this stage still have an assessment outcome showing 'lack of compliance', the CLC/BT will be consulted on the ratification and publication of the standard. This consultation to CLC/BT will be initiated at earliest possible moment, even before the IEC publication has taken place.

When there are no obstacles for ratification at European level, CCMC triggers the process for making the related EN project available in CENELEC. The finalized EN is then submitted to the responsible Technical Body secretariat for the proofing period. During this period and at least by the deadline, the secretary shall respond to any questions from CCMC and confirm the Technical Body’s approval to make the EN available.

When the secretariat has given its approval, CCMC makes  the EN available in the three official language versions of CENELEC and distributes the files for implementation to the CENELEC members.

In case the standard:

  • Has received a 'compliant assessment': it will be offered by CCMC to the European Commission for citation (i.e. CCMC provides the standards and their references to the European Commission for final validation).
  • Has received a ‘lack of compliance’ assessment, it will not be offered by CCMC to the European Commission for citation. In such case, the CENELEC Technical Body will have to consider European Common Modifications to address the compliance issues or wait for the next amendment or revision cycle at IEC to address those.


This section lists available horizontal training material.

This section lists available horizontal training material.



This section lists some sectoral guidance documents and training material to support Technical Bodies and Working Groups in the drafting of harmonized standards in support of EU legislation.


Besides information on the HAS assessment process and interactions with the HAS consultant, there are two key charts on the HAS system:


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