Common Specifications - Competing with Standards?

Both the MDR and IVDR introduce the concept of Common Specifications.

MDR and IVDR define common specifications as follows:

Definition: Common Specification

'"common specifications' [..] means a set of technical and/or clinical requirements, other than a standard, that provides a means of complying with the legal obligations applicable to a device, process or system."


Purpose of Common Specifications

EU Directives, such as the MDD and IVDD, as well as EU Regulations, such as the MDR and IVDR impose so-called general requirements on all medical device must meet. If the requirements are not met, manufactures must not place them on the market.

When conducting an audit or assessing the technical documentation, it should be possible to easily determine if these requirements are actually met. Therefore, clear decision criteria are helpful.

Standards contain such specific criteria. EU Regulations and Directives allow manufacturers to make use of harmonized standards for evidence. Where harmonized standards do not exist or are insufficient, specific criteria are lacking. It is these deficiencies that Common Specifications shall overcome.

The Commission may even lay down Common Specifications if "there is a need to address public health concerns" - ambiguous meaning.

Who implements Common Specifications?

The EU Commission perceives itself to be entitled to implement common technical specifications where no harmonized standards exist or where they are not sufficient.

Article 105 defines the tasks of the Medical Device Coordination Group (MDCG). One task, amongst others, is to contribute to the development of standards, common specifications and of scientific guidelines, including product specific guidelines.

Article 106 adds that expert panels and expert laboratories contribute to formulating and refining appropriate guidelines and common standards.

The MDR's preface says: "Common specifications ('CS') should be developed after consulting the relevant stakeholders and taking account of European and international standards."

Topics that Common Specifications might address

The EU Commission entitles itself to define Common Specifications for the following regulatory areas:

  • Clinical investigation, clinical evaluation and / or clinical follow-up after placing on the market
  • Risk management
  • Performance assessment and performance testing after having placed the device on the market
  • General safety and performance requirements, including physical and chemical characterization, microbiological and biocompatibility tests as well as mechanical, electric, electronic or non-clinical toxicology studies
  • Technical documentation
  • Processing (including verification, validation, quality management)
  • Reporting

The following topics are especially touched on:

  • Implantable devices
  • Products classified as class III
  • Products classified as class IIb intended to administer to or remove a medicinal product from the body
  • Certain groups of products for which a manufacturer claims only an aesthetic or another non-medical purpose, but which are similar to medical devices in terms of functioning and risks profile
  • Disposable products

Regulatory requirements

Requirements concerning the EU-Commission

The Commission keeps all its options open. According to Article 9, it can but doesn't need to lay down common specifications.

Requirements concerning manufacturers 

  • Compliance with common specifications
    Manufacturers must comply with Common Specifications (CS). Article 9 only allows for an exemption if manufacturers "can duly justify that they have adopted solutions that ensure a level of safety and performance that is at least equivalent thereto".
    In general, it will be impossible to provide such evidence. Thereby, common specifications take on a legal character.
  • Common specifications in declarations of conformity
    In their declaration of conformity, manufacturers must specify CS as well as the harmonized standards with which they comply (Appendix IV (7)).
  • Not only product requirements
    If necessary, manufacturers must not only pay attention to products' but also the quality management system's conformity with common specifications.
  • CS in the summary report
    The summary report on safety and clinical performance must indicate all harmonized standards and applied CS.
  • Plan for clinical follow-up
    The plan for clinical follow-up after the placing on the market, too, must contain references to all applicable common specifications and harmonized standards. 

Requirements concerning notified bodies

During audits and assessment of technical documentation, notified bodies must review compliance with common specifications even if the manufacturer does not reference them. This is laid down in Annex VII "4.5. Conformity assessment activities"The same applies to type-examinations.

Introduction of Common Specifications

It is not quite accurate to say that Common Specifications were introduced for the first time by the MDR and IVDR. In fact, Directive 98/79/EC already mentioned these Common Specifications. The IVDD lays down in Article 5 "Reference to standards" that conformity with general requirements is to be presumed if harmonized standards or these very common specifications are complied with.


With this concept, the EU Commission has given itself almost full discretion to strengthen requirements for medical devices. Thereby, it can put tremendous pressure on standardization bodies or bypass them if they don't act according to the Commission's will.

Neither the parliamentary nor the consensus building of international standardization bodies can limit the Commission's freedom. Expert panels and the Medical Device Coordination Group must only be heard and must cooperate. They are not competent to give a ruling.

It remains a mystery why the Commission believes to be more suited to define specifications than standardization bodies. Rule 11 may be an example for showing that there is nobody in their ranks who has ever developed and placed a medical device on the market themselves.

Once again, the impression is imposed that, under the guise of patient safety, requirements are raised to an extend that future products serving patients' health will be lacking.


2023-03-16: The following common specifications on MDR and IVDR are currently published in the official journal of the European Union:


Prof. Dr. Christian Johner

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