The role of normative references in standards
Understanding normative references
Normative references are underlying standards incorporated as part of the main standard.
These references provide additional details, specifications, methods and requirements important for fully implementing the main standard. Therefore, to comply with the main standard, you must also consider the relevant parts of these normative references.
Normative references are convenient for ensuring all relevant aspects of safety, quality, and performance. These references allow a main standard to be built upon existing standards without unnecessary duplications or deviations.
An example
Consider the (main) standard EN IEC 62368-1, which covers the safety requirements of audio, video, information and communication technology equipment. This standard includes a very long list of normative references that cover specific aspects or parts, for instance:
- EN 60529, degrees of (ingress) protection provided by enclosures (IP Code);
- EN IEC 60730, automatic electrical controls;
- EN IEC 61558, safety of transformers, reactors, power supplies.
EN IEC 62368-1 refers to relevant parts of these referenced standards for requirements and test methods to establish compliance.
Dated and Undated
Normative references can be listed with and without a date. In the case of ‘dated’ normative references that version shall be applied, even if there is a newer version available. Unlike ‘undated’ normative references where the latest version shall be applied, even if that was published after the main standard.
Product compliance
For manufacturers and testing laboratories, interpretation and applying normative reference is indispensable to ensure compliance. When testing a product against a (main) standard, one must also consider those referenced standards. This approach ensures all potential risks are addressed.
In most cases, especially when dealing with well-known standards like EN IEC 62368-1, referencing the main standard should be sufficient, as testing laboratories are familiar with it and apply the relevant normative references. Often important normative references will be mentioned in the test report as well.
Possible approach
In most cases ProductIP does not include normative references in its requirement lists. Our policy is that testing laboratories know how to address these references. This may cause uncertainty about the applicability of an underlying standard.
To get certainty about a normative reference you either:
- Rely on the testing laboratory or get confirmation from them;
- Check the main standard and its normative references on CEN(ELEC), but it may be incomplete;
- Purchase the main standard and search for the clauses where normative references are mentioned.
Only the (main) standard itself provides a complete overview of normative references.
Even the information provided on the websites of European Standardization Organisations, such as CEN/CENELEC, is in their own words “purely indicative”.
