KANBrief 1/10

Caution: presumption of conformity!

Users of harmonized standards need to be fully aware of which provisions in directives are supported by the standards concerned, and which are not1. Users relying solely upon the normative parts of harmonized standards and assuming that they will thereby observe all requirements of the directives are on dangerous ground. It is therefore advisable to examine precisely how far the presumption of conformity actually extends.

Ultimately, the presumption of conformity2 is no more than a reversal of the burden of proof. This means that a product complying with the relevant standards may be challenged, for example by the market surveillance authority, only if actual evidence can be produced that the manufacturer has violated the requirements of the directives. In individual cases, this may well be possible. In addition, the presumption of conformity applies solely to the provisions of directives that are actually covered by harmonized standards the titles of which have been published in the Official Journal of the EU.

The function of Annex Z armonized standards which support Single Market directives must contain an informative Annex Z (ZZ in the case of CENELEC standards) which indicates clearly which essential requirements of the relevant directives are addressed within them. In the opinion of the European Commission, this annex should preferably take the form of detailed tables in the case of standards issued by CEN; these tables should indicate which sections of the standard support which requirements of the directives. Should it not be possible for all relevant requirements to be addressed in a standard, owing to a lack either of knowledge or of a consensus, clear indication should be provided in such cases of which essential requirements are covered, and which are not.

Accordingly, at the request of the Commission, the European standards organizations formulated clear rules for themselves for the entire area affected by the New Approach3. These rules were then confirmed by the European Commission in formal correspondence to CEN and CENELEC and by the Member States in Committee 98/34/EC, “Standards and technical regulations”4.

Particular issues relating to machinery

Standards pursuant to the Machinery Directive are also subject to CEN Guide 4145. In Sections 5.3 and, this guide requires that information important to the user in that it indicates the extent to which the requirements of the directives have been addressed in the standard must also be stated clearly in the scope. Owing to time pressure, many standards have until now been adapted only formally to the new 2006/42/ EC Machinery Directive. For this and other reasons, some standards the titles of which have been listed in the Official Journal of the EU as being pursuant to the new Machinery Directive contain the information in Annex Z that a considerable number of essential requirements are not covered. Application of these standards therefore gives rise to the presumption of conformity to a very limited degree only. Consequently, the manufacturer must in addition be able to demonstrate how he has complied with the relevant provisions in the directives.

Unfortunately, despite the requirement to this effect in CEN Guide 414, the users of such standards are only very rarely informed in the scope of these deficits. It must therefore be feared that many users are not even aware of them. Since machines which are manufactured solely in accordance with such standards may exhibit safety deficits, this situation must be rectified as soon as possible.


It should be completely transparent to the user whether all relevant essential health and safety requirements are actually covered by a standard. For this reason, it is absolutely essential that the standards organizations observe the rules referred to above. Wherever possible, the standards committees should also ensure that harmonized standards consider all requirements of the directives relevant to the product concerned.

Users of standards should not rely solely upon the publication of their title in the Official Journal, but should in addition always examine all available information concerning their completeness. Furthermore, a risk assessment should be performed in accordance with the relevant directives: not only because it is a requirement, but also in order to avoid nasty surprises.

Corado Mattiuzzo mattiuzzo@kan.de