Essential requirements of directives and standards: the meaning of annex ZA, ZB or ZZ in harmonised standards
In order to monitor to what extend a European standard covers essential requirements of EU-directives and -regulations, these standards frequently include an informative annex. This annex determines the scope of requirements of an EU-directive covered by the standard. The European organizations of standardisation (ESOs) CEN and CENELEC denominate such an informative annex ZA, ZB or ZZ.1
This technical article describes this kind of annex of a standard and provides answers to the following questions:
- What information does a normative annex ZA, ZB or ZZ contain?
- What is it used for?
- What is the content-related structure of these annexes?
- What differences are expressed through the different abbreviations ZA, ZB or ZZ?
Creation of an annex ZA/ZZ for a harmonized standard
An answer to the question what information are provided by the above-mentioned annexes is given in the development process of a harmonized standard with presumption of conformity.
The legal acts of the European Commission (like the Machinery Directive or the Low Voltage Directive) contain requirements for products that fall under the scope of the respective directive or regulation. To clarify how the legal requirements can be implemented, “harmonized standards” can provide the technical details.
Within its annual work program, the EU-Commission issues so-called standardization mandates to the European organisations of standardisation. Within those mandates the Commission determines concrete requirements of its harmonization legislation. The organisations of standardization need to consider these requests when generating the harmonized standards.2
CEN and CENELEC pass the mandate on to the authorized technical committee which subsequently draws up the harmonized standard. For quite some time all harmonized standards must contain an informative annex (annex ZA, ZB or ZZ). Therein the responsible technical committee refers to the relationship between the sections of the legal requirements and the respective sections of the harmonized standard.3
The ESOs publish the newest version of a standard. In the following CEN and CENELEC verify together with the Commission to what extend the published standard corresponds to the original mandate and whether the “essential or other legal requirements ‘aimed to be covered’ are clearly indicated and covered by the standard.”4 Meanwhile, independent consultants are involved within this verification. These consultants assist the CEN/CENELEC technical committees as well as the EU-Commission and evaluate to what extend the directive’s requirements are represented within the harmonised standard. This includes a verification of the annex ZA/ZZ, which is commented in the scope of the consulting activity.5
If all requirements are fulfilled, the harmonised standard is published in the Official Journal of the EU for the respective harmonization legislation. This means that the sections contained within an annex ZA/ZZ of a harmonized standard trigger presumption of conformity with the requirements of the EU-directive and the regulations of the European Free Trade Association (EFTA).6
Content of informative annexes
A harmonized standard created on behalf of the Commission does not necessarily need to cover all essential requirements of the legal act. At least the standard needs to point out clearly which requirements in detail shall be covered. This may occur in a clearly arranged tabular manner within the annex ZA/ZZ.
Strictly speaking – according to the Blue Guide7 - when creating the informative annex ZA/ZZ, the standardization organizations can merely point out an intention which sections of a standard in their view belongs to the respective sections of a directive.
By listing the harmonized standard within the Official Journal of the EU the European Commission confirms this intention or, with a non-publication, rejects it.8
The CEN-Guide 414 contains specifications on how the informative annex can be structured:
In the first two paragraphs the standardisation mandate of the EU-Commission is summed up. furthermore, the relationship between the sections of a standard, the requirements of the directive as well as the EU Official Journal is disclosed.
The actual annex ZA, the correlation of a standard’s sections with the requirements of the underlying directive, appears in a follow-up passage or in a tabular form.
In concluding, the annex contains warning notices. They may indicate that the standard is subject to another legal act or that only when the listing in the Official Journal has occurred a user can take the presumption of conformity as granted.
Originally, the technical committees had been given more leeway in creating an informative annex as there had been more opportunities to set it up. The annex ZA, for instance, could be drawn according to Option A.1 and structured as follows:10
|Essential Requirements of Directive||Clause(s)/sub-clause(s) of this EN||Remarks/Notes|
|Option A.1: Within the limits of the scope all relevant essential requirements are covered||All normative clauses||For relation of normative clauses of this standard to significant hazards/relevant essential requirements of 2006/42/EC see informative annex XX „List of significant hazards“ of this standard in combination with annex D “Examples of significant hazards, hazardous situations, hazardous events and their relation to the Essential Requirements of the Machinery Directive 2006/42/EC” of CEN Guide 414 (https://boss.cen.eu/ref/CEN_414.pdf).|
Table 1: Option A.1 of an annex ZA9
Within a harmonized standard option A.1 would be structured as the following:
This kind of structure can be found only in more ancient standard.
Meanwhile the EU-Commission accepts explicitly informative annexes with the type “option C” of the CEN-Guide. This version determines that essential requirement of a directive listed in a column assigns to a section of a harmonized standard:11
|Essential Requirements of Directive||Clause(s)/sub-clause(s) of this EN||Remarks/Notes|
|Option C:[Per row: an essential requirement]||[The relevant normative clauses linked to the individual essential requirement]|
Table 2: Option C of an annex ZA12
This means that when creating a standard, technical committees can explicitly hand in an annex ZA/ZZ with this detailed frame at CEN/CENELEC. The European Organisations of Standardisation can then give the generated standard including its annex over to the commission for a further examination. An example is given here:13
An important note is stated in warning 1: it underlines that only the listing within the Official Journal of the EU triggers presumption of conformity.
Denominations of annexes - ZA, ZB, ZZ…?
When a CEN technical committee creates a harmonized standard, the informative annex is named ZA, in the case of CENELEC it is named ZZ.
If a harmonized standard shall cover the requirements of several legal acts, the denomination is changed into ZA/ZB (CEN) and ZZA/ZZB (CENELEC), respectively. This is primarily the case if a legal act undergoes a revision and the requirements that shall be met have changed.
A special case emerges if globally applicable standards from the international organisations of standardization ISO and IEC are adopted into the European standardization. In this case annex ZA always covers the normative references of international publications with the corresponding European publications. The informative annex that covers the requirements of EU-directives and its corresponding sections of standards is renamed into Annex ZB for CEN-standards.
Information for Safexpert users
Once a successor standard is published for a standard contained in an IBF data package, the standard is adopted with the status “adopted/ratified, intended to be published as harmonised standard” into the safexpert database.
This illustrates that issuer CEN/CENELEC expects a listing of the standard within the Official Journal of the EU, but it has not occurred yet. Hence the sections listed in annex ZA do not (yet) trigger presumption of conformity.
When the harmonized standard ist published within the Official Journal, the IBF experts change the status and take note of the legal base (Commission Implementing Decision) and means of publication (EU-Official Journal) in the bibliographical data of the data set.
With the Safexpert Change Assistant Safexpert offers an analytical tool on a sectional level of standards. Whenever you apply a section of a standard as a measure within your project, you can easily display, verify and even change the respective section via mouse click with the section of the successor document.
The informative annexes ZA, ZB, ZZ, … initiated by the EU-Commission can be regarded as a useful help. Engineers can herby see rapidly which essential safety and health requirements of a legal act are covered by the standard.
In the case of newer editions of standards users are provided an exact comparison of sources of information of single requirements and the appropriate sections of a standard.
1See 2016/C 272/01: Commission Notice — The ‘Blue Guide’ on the implementation of EU products rules 2016
2See Regulation (EU) No. 1025/2012 of the European Parliament and of the Council of 25 October 2012 on European standardisation
3See CEN/CENELEC-Webinar: 'Harmonized Standards under the Machinery Directive' (https://www.cencenelec.eu/media/CEN-CENELEC/Events/Webinars/2021-10-18_webinar_harmonized_standards_machinery_directive.pdf )
4See 2016/C 272/01: Commission Notice — The ‘Blue Guide’ on the implementation of EU products rules 2016
5See KAN Brief 3/10: “Serving the quality of standards: CEN/CENELEC Consultants“ (https://www.kan.de/en/publications/kanbrief/the-eu-and-standardization/serving-the-quality-of-standards-cencenelec-consultants )
6See EN ISO 13857:2019, Annex ZA
7See 2016/C 272/01: Commission Notice — The ‘Blue Guide’ on the implementation of EU products rules 2016
8See 2016/C 272/01: Commission Notice — The ‘Blue Guide’ on the implementation of EU products rules 2016
9CEN Guide 414 - Safety of machinery – Rules for the drafting and presentation of safety standards Edition 3, 2017-10-11
10See EN 13378:2001+A1:2013-01- Pasta processing plants - Pasta presses - Safety and hygiene requirements
12See CEN Guide 414 - Safety of machinery – Rules for the drafting and presentation of safety standards Edition 3, 2017-10-11
13See EN ISO 13854:2019 - Safety of machinery - Minimum gaps to avoid crushing of parts of the human body (ISO 13854:2017)
Posted on: 2021/12/15
Johannes Windeler-Frick, MSc ETH
Managing Director of IBF Solutions AG, the Swiss subsidiary of IBF in Zürich. Johannes is a trainer for both the Machinery Directive (MD) as well as the Low Voltage Directive (LVD). He studied electrical engineering at ETH Zürich with a specialization in energy systems.