Key takeaways:
The text explains when a machine modification becomes “substantial” within the meaning of Regulation (EU) 2023/1230 and sets out the consequence: a renewed conformity assessment.
- Regulation (EU) 2023/1230 introduces a formal definition of a “substantial modification” of a machine or related product
- A substantial modification is a physical or digital change not envisaged by the manufacturer that affects safety.
- It involves creating new hazards or increasing risk where significant protective measures are required.
- This results in an obligation to carry out a new conformity assessment before placing it on the market again or putting it back into service.
- Directive 2006/42/EC did not define the term explicitly, which led to ambiguity and disputes over interpretation.
“Significant modification” is a term that has been used in the machinery sector for years, but until recently it had no formal legal definition. Only Regulation (EU) 2023/1230 on machinery of the European Parliament and of the Council, repealing Directive 2006/42/EC, establishes a clear framework for this concept, stating that a significant modification is a change to a machine that requires substantial protective measures and affects compliance with the essential health and safety requirements. As a result, every significant modification requires a new conformity assessment before the machine is placed on the market again or put back into service.
Definition of a significant modification
The definition of a significant modification under Regulation (EU) 2023/1230 of the European Parliament and of the Council is as follows:
“significant modification” means a change of a machine or related product, by physical or digital means after that machine or related product has been placed on the market or put into service, which was not foreseen or planned by the manufacturer and which affects the safety of the machine or related product by creating a new hazard or increasing an existing risk, requiring:
(a) the addition of guards or protective devices to that machine or related product the operation of which requires the modification of the existing safety-related control system; or
(b) the adoption of additional protective measures to ensure the stability or mechanical strength of that machine or related product;“
Accordingly, any change that requires new protective measures or affects the risk assessment qualifies as a significant modification of machinery, which means that a repeat conformity assessment is required.
Previously, Directive 2006/42/EC of the European Parliament and of the Council on machinery did not refer directly to this term, which led to considerable uncertainty in interpretation. In some cases, the guide to the Machinery Directive suggested that conformity assessment was necessary after major changes, but it did not clearly define which modifications should be regarded as significant.
In the Guide to Machinery Directive 2006/42/EC, “significant modification” was not explicitly defined, but references to the concept suggested that any modification to a machine that affects the level of safety or introduces a new risk requires a repeat conformity assessment. This was linked to the requirement that machines which had undergone significant changes should be treated as new machines and therefore had to comply with all applicable safety and risk assessment requirements. This approach to significant modifications was based on interpretations set out in the guide rather than on a clear, formal definition.
However, the guide was only a supporting document, not a legally binding act. As a result, whether a change constituted a significant modification was often disputed and depended on the interpretation of both the manufacturer and the market surveillance authorities.
Examples of a significant modification
- Adding new control systems that affect safety.
- Changing protective mechanisms, such as guards, where this requires modification of the existing safety-related control system.
- Introducing autonomous elements into a machine that was previously operated manually.
- Changing the control system from pneumatic to electrical, which requires appropriate protective measures to be implemented.
- Upgrading mechanical components, such as introducing a new type of drive, where this affects the risk assessment.
Examples of non-significant upgrades or modifications
- Replacing standard guards with newer models that do not affect the existing level of safety.
- Adding a cooling system that does not affect the functionality of the machine’s protective features.
- Changing the control panel to a more intuitive one, without affecting the machine’s safety function.
- Improving lighting in the machine’s working area, increasing operator comfort without affecting the risk assessment.
- Replacing mechanical components with newer ones having the same technical parameters, without changing the machine’s functionality.
Any of these changes may make a conformity assessment process necessary in order to ensure user safety and compliance with Regulation (EU) 2023/1230 of the European Parliament and of the Council.
Examples of Correct Practice in the Case of Significant Modifications
- Introducing a New Sensor System: If you add a new safety sensor system to a machine and it must be integrated with the existing control system, a full assessment is required to verify that the addition does not affect the reliability or operation of other protective components.
- Adapting a Machine to Handle a New Product: If a machine is modified so it can handle a new product, for example one with different physical properties (e.g. heavier or requiring a different operating speed), there is a risk that the change will affect operator safety or the integrity of the machine. Such changes must be analysed from a safety perspective, including machine stability.
- Changing the Drive to a Different Type: Converting a drive from pneumatic to electric may introduce new electrical shock hazards. In such cases, appropriate protective measures must be implemented, such as additional insulation or electric shock protection.
Role of Users and Manufacturers in the Context of Modifications
The responsibilities associated with carrying out a significant modification of machinery lie with both machine manufacturers and users. The manufacturer is responsible for designing and supplying solutions that minimise risk at the production stage, while the user is responsible for ongoing maintenance and monitoring the machine’s safety condition. The decision to modify a machine should be made jointly, taking into account the manufacturer’s technical knowledge and the user’s experience from operation under real working conditions.
Where a modification results in the machine being treated as newly placed on the market or put back into service, it may also trigger updated formal obligations, including the EU Declaration of Conformity for machinery, the preparation of technical documentation, and verification of the CE nameplate requirements.
This is particularly important when the modified equipment falls within categories discussed under particularly hazardous machines or when the modification affects the conditions for placing machinery on the market.
Links
Regulation (EU) 2023/1230 on machinery: https://eur-lex.europa.eu/legal-content/PL/TXT/PDF/?uri=CELEX:32023R1230
Substantial modification of machinery
This is a change to a machine or related product (physical or digital), made after it has been placed on the market or put into service, that was not foreseen by the manufacturer and affects safety. Such a change creates a new hazard or increases an existing risk and requires significant protective measures.
When it requires adding guards or protective devices whose operation entails modifying the existing safety-related system. Or when additional protective measures are needed to ensure stability or mechanical strength.
Yes, any substantial modification requires a new conformity assessment before the machine is placed back on the market or put back into service. This is because the changes may affect compliance with the essential health and safety requirements.
For example, adding new control systems that affect safety, changing guards in a way that requires modification of the safety system, or introducing autonomous elements into a previously manual machine. A change to the drive system (e.g. from pneumatic to electric) or a mechanical upgrade that affects the risk assessment may also be considered substantial.
For example, replacing components with newer ones of the same technical specifications without changing functionality, improving lighting, or changing the control panel without affecting safety functions. Such actions should not alter the safety level or the risk assessment.