1) What is the New Legislative Framework (NLF) and the Blue Guide ?
Harmonised standards are a unique form of standards, and work differently than typical voluntary standards. They are part of the New Legislative Framework (NLF), a European system created to make sure products (like AI systems) meet compliance to essential legal requirements, with a balance of flexibility and guidance.
The NLF is built on a few key ideas:
Essential requirements vs. technical details
EU laws (like the AI Act) define essential requirements : they define the results that must be achieved by the products (example : an AI system must be transparent – Article 13). However, they don’t specify the “how”. The market, represented in standardisation bodies, is invited to define the “how” : harmonised standards provides one way to achieve that transparency, but manufacturers could use other methods if they can prove they meet the same legal requirements. This means harmonised standards are not mandatory.
They are tools to help manufacturers comply with the law, but companies can choose other approaches if they can demonstrate equivalent compliance.
The role of harmonised standards
They are developed by CEN, CENELEC, or ETSI in response to a standardisation request from the European Commission. If a product complies with a harmonised standard listed in the Official Journal of the EU (OJEU), it is presumed to meet the relevant legal requirements. Only harmonised standards published in the OJEU provide that presumption of conformity.
This is why the process for developing harmonised standards is more rigorous than traditional standardisation. Every clause must clearly map to an essential requirement in the legislation, and this mapping is documented in Annex ZA.
The Blue Guide: your manual to understand the purpose of harmonised standards
The Blue Guide on the Implementation of EU Product Rules is the European Commission’s official reference for how harmonised standards work in practice. It helps understand the differences between a harmonised standard and a traditional standard, mainly by expliciting how presumption of conformity works.
It is recommended that stakeholders involved in harmonised standards within JTC 21 read the Blue Guide, especially the following parts :
4.1.2.1. Definition of a harmonised standard
4.1.2.2. Role of harmonised standards
4.1.2.3. The Presumption of conformity
4.1.2.4. Withdrawal, restriction or prevention of the presumption of conformity
4.1.2.5. Revision of harmonised standards
4.1.3. Conformity with the essential requirements: other possibilities
Link to the Blue Guide : https://single-market-economy.ec.europa.eu/news/blue-guide-implementation-product-rules-2022-published-2022-06-29_en
Why does this matter for AI standards?
The AI Act is one of the first major EU laws to apply the NLF to digital technologies on this scale. If the standard has insufficiently clear ways to give presumption of conformity, it could be legally invalid, and the market would have to turn to more burdensome processes to obtain the right to commercialize their AI product in the EU.
Standardisation request
This request is the legal foundation of the standards. It defines the scope, the essential requirements, and the deadline for delivery.
In harmonised standards, Annex ZA is where you map each clause of the standard to the essential requirements of the legislation (AI Act), making it clear which technical mean can be used to reach presumption of conformity.
What happens if Annex ZA is unclear or incomplete?
- Market surveillance authorities may challenge the standard’s validity.
- The European Commission may refuse to publish the standard’s reference in the OJEU, meaning it won’t provide the presumption of conformity.
The HAS Consultant is the third-party reviewer
Before a harmonised standard is published in the OJEU, it undergoes a HAS (Harmonised Standards) assessment by a HAS Consultant. For the JTC 21, the HAS Consultant is a member of the AI Office. The consultant checks whether the standard fully aligns with the standardisation request and the AI Act, that the Annex ZA is complete and accurate and whether the standard avoids prescriptive language.
OJEU publication
A harmonised standard only provides a presumption of conformity once its reference is published in the Official Journal of the EU (OJEU). Until then, it’s just a draft. A standard can be :
- fully cited,
- partially cited,
- or rejected.
A partially cited standard means that only a fraction of its content is sufficient to give presumption of conformity, and that the market will need to use another method for requirements that are not covered by the OJEU citation.
Key differences between traditional and harmonised standards
| Traditional standards | Harmonised standards | |
| Purpose | Provide technical guidance or best practices. | Provide a legal tool for manufacturers to demonstrate compliance with EU law. |
| Development trigger | Industry need, market demand, or technological advancement. | A standardisation request (mandate) from the European Commission. |
| Legal weight | Voluntary; no presumption of conformity. | Presumption of conformity if published in the OJEU. |
| Review process | Peer review, public consultation. | HAS assessment by a HAS Consultant + approval by the European Commission. |
| Stakeholder involvement | Experts, industry representatives. | Legal experts, HAS Consultants, and the European Commission are involved. |
2) Writing harmonised standards for AI in practice
A few steps that can help you write standards that can be accepted as harmonised standards :
1) Deeply understanding the standardisation request
2) Draft the standard with Annex ZA in mind
3) Involve legal experts early
4) Understand the HAS Checklist to understand how the assessment is done (https://boss.cen.eu/developingdeliverables/pages/en/pages/has_assessment_process/)
5) Keep post-market monitoring in mind : the Blue Guide emphasises that manufacturers must keep their technical documentation updated if the standard is revised or if new risks emerge. Authorities can also challenge the presumption of conformity if they find evidence of non-compliance.
What can happen to a harmonised standard ?
- Partial coverage of essential requirements
This happens when a harmonized standard only covers part of the essential requirements relevant to an AI product or addresses certain aspects incompletely. This reduces its usefulness for manufacturers/providers, who rely on the standard to demonstrate compliance and market surveillance authorities, who need clarity to assess conformity.
Consequences : This reduces the legal certainty, as manufacturers/providers and authorities cannot rely on the standard for compliance. Legal uncertainty then increases the burden on manufacturers/providers, as they must develop alternative technical solutions or provide additional evidence of compliance.
- Ambiguities in the standard
Sometimes, it can happen that standards contain ambiguous language, leading to misinterpretations of requirements.
- Formal Objection Procedure
If a Member State or the European Parliament believes a harmonized standard does not entirely satisfy the requirements it aims to cover, they can initiate a formal objection under Article 11 of Regulation (EU) No 1025/2012.
Process:
- A Member State or the European Parliament notifies the European Commission that the standard is deficient.
- The Commission consults Member States and assesses whether the objection is justified.
- If the objection is valid, the Commission may:
- Refuse to publish the standard’s reference in the OJEU (preventing presumption of conformity).
- Publish the reference with restrictions (e.g., limiting its scope).
- Withdraw an existing reference from the OJEU (removing presumption of conformity).
- If the standard’s reference is not published or withdrawn, manufacturers lose the presumption of conformity for the requirements it aimed to cover.
- Manufacturers must then:
- Use alternative technical solutions (e.g., ISO standards, proprietary methods), with detailed technical documentation to prove compliance.
- Undergo third-party conformity assessments if required by the applicable legislation.
Flowchart 1
The role of harmonised standards in complying with relevant essential requirements identified by a manufacturer – a generic philosophy for cases where a manufacturer needs to identify relevant essential requirements1. Causes of Failure in Harmonized Standards (from the Blue Guide)
➡️ Here are 2 quick quizzes to assess your understanding of this article : first steps in standardisation and writing standards for beginners
➡️ For advanced users, here is a quiz to assess your understanding of standardisation : writing standards – advanced