European Standards and conformity assessment

This document provides guidance on the drafting of European Standards addressing conformity assessment aspects.


Conformity assessment covers activities carried out by a specific entity (1st, 2nd or 3rd party) to demonstrate that products, processes, services, persons, systems and bodies meet specified requirements. These activities can include testing, inspection, evaluation, examination, auditing, assessment, declarations, certification, accreditation, peer assessment, verification and validation


2.1 The CEN policy on conformity aspects in standards is based on the neutrality principle, which requires that all documents shall be written in a way such that conformity with the specified requirements can be assessed by a manufacturer or supplier (first party), a user or purchaser (second party), or an independent body (third party) - see Clause 33 of the CEN-CENELEC Internal Regulations, Part 3.

2.2 Standards, whether harmonized or non-harmonized, shall give all the necessary information allowing the evaluation of conformity of the subject of the standard to the requirements specified in the standard. Any other requirement, not pertaining to the subject of the standard itself, but to parties involved in manufacturing, testing or assessing it shall not be part of the standard. Such conformity assessment requirements shall be drafted in a separate document (e.g. a separate document in a series or a separate Part) provided that this document can be applied independently. For example, requirements specifying or implying that a particular party (1st, 2nd, 3rd) is to carry out the conformity assessment shall be drafted in a separate document.


  • Part 1: Product requirements
    Part 1 sets out the requirements for the product and can be applied independently with no reference to Part 2.
  • Part 2: Conformity assessment requirements
    Part 2 sets out the requirements for assessing whether the given product conforms with the requirements specified in Part 1.


3.1 TC secretaries/WG convenors should check their draft standards for compliance with this policy at the earliest possible stage, or at the latest prior to sending them to the CEN-CENELEC Management Centre (CCMC) for Enquiry.

The appearance of the following words in the draft may indicate conformity assessment implications - the committee should check whether the draft is in line with the CEN policy on conformity aspects in standards outlined in this guidance:

  • Accreditation
  • Approval
  • Auditing
  • Calibration
  • Certificate
  • Certification
  • Conformity
  • Conformity assessment bodies
  • Conformity assessment
  • Declaration
  • Evaluation
  • Inspection
  • Laboratory management
  • Qualifications
  • Registration
  • Sampling
  • Surveillance
  • Testing
  • Uncertainty
  • Validation, and
  • Verification 

3.2 Committees should note that CEN-CLC/JTC 1 as a technical committee can provide advice on the standards within its scope, i.e. ISO/IEC 17000 series. CEN-CLC/JTC 1 is not responsible for implementing the drafting rules in accordance with the CEN-CENELEC Internal Regulations, Part 3. Regarding Clause 33 of the CEN-CENELEC Internal Regulations, Part 3, i.e. the neutrality principle, CEN CLC/JTC 1 can only provide general advice and is unable to review whole drafts or provide editing/(re)drafting services. Committees who have a conformity assessment query can submit it to CEN-CLC/JTC 1 (via its Secretary) by filling in the dedicated form prior to sending the draft to CCMC.

Helpful information to understand the concept on which this Guidance is based, is provided in the document Philosophy behind the concept.

Detailed guidance on good drafting practices with regard to conformity assessment is provided in the ISO brochure Conformity assessment for standards writers – do's and don'ts.

3.3 In the past, several standards were published containing conformity assessment aspects, mainly due to a lack of clear understanding of the policy. Therefore, all TCs are instructed to check the content of their published standards for the presence of such aspects and if some are discovered, a revision should be started as soon as possible.

3.4 Where committees wish to specify requirements regarding conformity assessment, they shall consult the requirements given in Clause 33.2 and 33.3 of the CEN-CENELEC Internal Regulations, Part 3.
For further guidance, see ISO/IEC 17007, Conformity assessment – Guidance for drafting normative documents suitable for use for conformity assessment.


4.1 In the context of mandates related to certain EU Directives or EU Regulations, the inclusion of requirements for conformity assessment in standards may be requested. This may typically be the case for items such as 'factory production control'.

In this case derogation from the CEN policy is allowed for the inclusion of conformity aspects required in the mandate. However, all derogation requests should be approved by CEN/BT.

4.2 Because of some specific particularities of the former Construction Products Directive (CPD) and its related Mandates, the Technical Board (BT) has approved a derogation related to factory production control (resolution BT 57/1999, confirmed by resolutions BT 71/1999 and BT 67/2000). This remains valid for standards harmonized under the Construction Products Regulation (CPR).


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Conformity is the fulfilment of requirements specified for a particular object, e.g. a product, process, service, system, installation, project, data, design, material, claim, person, body, organisations, or any combination thereof.

The applicable requirements are specified needs or expectations that are stated in standards, technical specifications, regulations, contracts, programmes, codes of practice, or other normative documents. They can be detailed (e.g. “2 m ± 5 cm” or “at least 300 h watertight”) or general (e.g. “safe” or “not harmful to health”).

Conformity assessment is the demonstration that specified requirements are fulfilled through the completion of defined functions: selection (planning, preparation, sampling), determination (evidence gathering), review (suitability, adequacy, effectiveness of evidence), decision (conforming / not conforming object), attestation (statement of conformity).

Both concepts relate to the fulfilment of requirements and are not necessarily different.

In some contexts, a differentiation between the adherence to legal provisions (compliance) and the fulfilment of technical requirements (conformity) is made. In that sense, technical conformity, as determined and attested by a conformity assessment body, can be a precondition for legal compliance.

A conformity assessment body is a legal entity providing conformity assessment activities.

Standards for conformity assessment bodies include requirements for their technical competence, impartiality, and consistent operation. For example:

  • EN ISO/IEC 17025 for testing laboratories,
  • EN ISO/IEC 17020 for inspection bodies,
  • EN ISO/IEC 17029 for validation/verification bodies,
  • EN ISO/IEC 17021-1 for certification bodies of management systems,
  • EN ISO/IEC 17024 for certification bodies of persons,
  • EN ISO/IEC 17065 for certification bodies of products, processes and services.

Conformity assessment bodies can be in-house facilities as well as independent third parties. Certification is defined as third party activity.

Accreditation is a means of recognising conformity assessment bodies for demonstrating their fulfilment of the applicable standard (e.g. EN ISO/IEC 17025 for testing laboratories or EN ISO/IEC 17065 for product certification bodies). Accreditation is laid down in a so called “scope of accreditation” that identifies the specific conformity assessment activities (if applicable, including specific technical areas) for which the body has demonstrated competence, impartiality and consistent operation.

Accreditation bodies are independent legal entities, demonstrably fulfilling an applicable standard themselves, EN ISO/IEC 17011. Within the EU legal framework, accreditation is provided by a national accreditation body and considered as the preferred means of demonstrating the technical competence of conformity assessment bodies (see Regulation (EC) No 765/2008).

Notified bodies are conformity assessment bodies which have been officially designated by their national authority to carry out the procedures for conformity assessment within the meaning of applicable Union harmonisation legislation when a third party is required.

The so-called New Legislative Framework (NLF) consist of:

  • Regulation(EC) No 765/2008 setting out the requirements for accreditation and market surveillance relating to the marketing of products and Decision No 768/2008/EC on a common framework for the marketing of products.
  • Regulation (EU) 2019/1020 on market surveillance and compliance of products and amending Directive 2004/42/EC and Regulations (EC) No 765/2008 and (EU) No 305/2011.

It provides the regulatory basis for the notification process, accreditation, conformity assessment procedures, CE marking and market surveillance in the EU (see also the “Blue Guide” on the implementation of EU products rules).


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