International Standards and Conformity Assessment for all electrical, electronic and related technologies

Developing a European Standard

The development of a European Standard (EN) is governed by the principles of consensus, openness, transparency, national commitment and technical coherence and follows several steps:

Proposal to develop an EN
Any interested party can introduce a proposal for new work. Most standardization work is proposed through the CENELEC Members.

Acceptance of the proposal
Once a project to develop an EN is accepted by the relevant Technical Body, or by the Technical Board, the member countries shall put all national activity within the scope of the project on hold. This means that they do not initiate new projects, nor revise existing standards at national level. This obligation is called 'standstill' and allows efforts to be focused on the development of the EN.

The EN is developed by experts within a Technical Body.

Enquiry – Public comment at national level & weighted vote
Once the draft of an EN is prepared, it is released for public comment and vote, a process known as the 'Enquiry'. During this stage, everyone who has an interest (e.g. manufacturers, public authorities, consumers, etc.) may comment on the draft. These views are gathered by the members who then submit a national position by means of a weighted vote and which is subsequently analyzed by the Technical Body. If the results of the Enquiry show a 100% approval for the EN then the European Standard will be published.

Adoption by weighted Formal Vote
If the results of the Enquiry show that the draft EN requires technical reworking, and the results of the Enquiry are not 100% approval then the Technical Body updates the draft and resubmit it for another weighted vote, called the Formal Vote.

Publication of the EN
Following the approval of the EN, either from the Enquiry or the Formal Vote, the EN then is published. A published European Standard must be given the status of national standard in all member countries, who also have the obligation to withdraw any national standards that conflict with it. This guarantees that a manufacturer has easier access to the market of all the member countries when applying European Standards and this also applies whether the manufacturer is based in a member's territory or not.

Review of the EN
To ensure that a European Standard is still current, it is reviewed within five years of its publication. This review results in the confirmation, modification, revision or withdrawal of the EN.


European Standards are made available in 3 official languages: English, French and German. National Committees can translate standards in their own language.

The shortest unambiguous reference to a European Standard is to use its number. The number of a European Standard consists of the capital letters EN followed by a space and a number in arabic numerals, without any space.

EN 50122-1:2011 (the part number is indicated by a hyphen, the year of availability of the EN is separated from the number by a colon)

The first two numerals indicate the origin of the standard:
- 40000 to 44999 cover domains of common CEN/CENELEC activities in the IT field
- 45000 to 49999 cover domains of common CEN/CENELEC activities outside the IT field
- 50000 to 59999 cover CENELEC activities i.e. standardization work undertaken purely at European level.
- 60000 to 69999 refer to the CENELEC implementation of IEC documents with or without changes.