CE marking for replacement components: When does a retrofit require new certification?

Introduction

Continuous business operations are crucial in the industrial sector. Equipment undergoes wear and tear over time, necessitating repairs and upgrades. However, when replacement components are integrated or machines are modified, the fundamental question arises: does this modification require a new CE marking? The Machinery Directive 2006/42/EC sets clear, yet complex, frameworks for the safety of machines within the European Economic Area. This article examines the critical considerations for maintenance managers, safety officers and process engineers in the Benelux manufacturing industry, focusing on the legal and operational implications of component replacements and retrofits.

Scope and Applicability

The Machinery Directive 2006/42/EC defines a manufacturer not only as the original builder of the machine, but also as 'a natural or legal person who assembles, manufactures, assembles, packages or places on the market a machine or partially complete machine for his own use'. This means that when an existing machine is modified in such a way that it is considered a 'new machine', the party making the modification assumes the responsibility of the manufacturer. This responsibility includes carrying out a full risk assessment in accordance with NEN-EN-ISO 12100:2010, drawing up a technical construction file, issuing an EC declaration of conformity and applying a new CE marking.

A change is considered 'significant' if it meets one or more of the following criteria:

• The original function of the machine is fundamentally changed.
• New hazards are introduced or existing risks are increased, which were not covered in the original risk assessment.
• The performance limits of the machine (e.g. speed, power, pressure) are significantly exceeded.
• The change affects safety functions in a way that calls into question compliance with the Essential Health and Safety Requirements (ECVEs).

These guidelines apply to all machines installed or put into service within the European Economic Area, regardless of their age.

Key Requirements for CE Recertification after Retrofit

When a retrofit results in a 'new machine', the following essential steps apply:

Impact on MRO Operations

The consequences of a significant change extend beyond just the technical implementation. Maintenance strategies need to be revised as new components or functionalities require specific maintenance routines. The purchasing policy should ensure that replacement parts, even apparently simple components, meet the specifications of the recertified machine and applicable standards. This means a greater emphasis on the traceability and certification of purchased components.

Documentation management becomes more critical; the technical construction file must be up to date and easily accessible for both internal audits and external inspections. In addition, targeted training for operating personnel and maintenance technicians is essential to ensure the safe operation and maintenance of the modified machine. This proactive approach minimizes the risk of operational errors and accidents, which directly contributes to increased operational reliability and efficiency.

Component requirements

Not all replacement components require a separate CE mark as a standalone machine, but many do have specific certifications that are critical to overall machine compliance after a retrofit.

• Safety components: Components that perform a safety function, such as emergency stop buttons, light curtains, safety relays (e.g. from Pilz PNOZ series) or programmable logic controllers (PLCs) for safety systems, must comply with the Machinery Directive and often with NEN-EN-ISO 13849-1:2023 for Performance Level (PL) or NEN-EN IEC 62061:2021 for Safety Integrity Level (SIL). These components must have a CE marking and a self-declaration of conformity from the manufacturer of the safety component, specifying the safety characteristics such as PLr or SILCL.
• Pressure equipment: Pressurized components, such as fittings (e.g. ball valves PN16 DN50), valves, pressure vessels (e.g. 100 liters at 10 bar) or flexible hoses, are covered by the Pressure Equipment Directive (PED) 2014/68/EU. These components require CE marking under the PED, with a specific category classification (e.g. Category I, II, III, IV) depending on the pressure, content, and medium group. For example, a ball valve that processes process water (medium group 2) at 10 bar in a DN50 pipe may fall under Category I and requires a PED declaration of conformity.
• Components for potentially explosive atmospheres (ATEX): For machines and components used in environments with potentially explosive atmospheres (according to EN IEC 60079- series), the ATEX directive 2014/34/EU applies. Motors (e.g. IE3 motors for Zone 2), sensors, switches and lighting in these zones must be specifically ATEX certified for the relevant zone (e.g. Zone 1 gas, Zone 21 dust) and gas or dust group, including the temperature class (e.g. T3, T4). The certification often includes a type plate with 'Ex' marking and specific protection method.
• Electrical components: Transformers, motors, frequency converters (e.g. 400V 5.5kW), switchboards and cabling must comply with the Low Voltage Directive (2014/35/EU) and the EMC Directive (2014/30/EU). The harmonized standard NEN-EN 60204-1:2018 (Safety of machines - Electrical equipment of machines - Part 1: General requirements) is leading. The use of components that do not meet these standards can lead to malfunctions, overheating (e.g. due to insufficient cooling, resulting in component temperatures above 70°C), and fire hazard.

It is essential that purchasing departments check required certifications and source components from reliable suppliers who can provide full traceability and compliance documentation. One wrong component can make the entire machine unsafe, regardless of the original certification.

Compliance Checklist for Maintenance Managers

This checklist provides a practical framework to ensure compliance with CE marking requirements after a retrofit, directly applicable to safety officers and maintenance managers:

1. Assess the change: Objectively determine whether the planned retrofit qualifies as a 'significant change' based on the criteria listed above.
2. Carry out risk assessment: Carry out a new, comprehensive risk assessment in accordance with NEN-EN-ISO 12100:2010 for the modified machine and document all identified hazards and risk reduction measures.
3. Identify hazards: Identify any new and potentially changed hazards (mechanical, electrical, thermal, ergonomic, etc.) introduced by the retrofit, for example vibration levels of 0.5 mm/s² that may increase to 1.5 mm/s².
4. Check safety functions: Evaluate whether the existing safety functions are still sufficient for the new situation and validate the Performance Level (PL) or Safety Integrity Level (SIL) in accordance with NEN-EN-ISO 13849-1 or NEN-EN IEC 62061.
5. Prepare technical construction file: Collect or create all necessary technical documentation, including revised diagrams (electrical, pneumatic, hydraulic), calculations, test reports, and component certificates.
6. Obtain declaration of conformity: Ensure that all individually CE-marked components (e.g. a CE-marked safety relay) have a valid declaration of conformity or declaration of incorporation from the manufacturer.
7. Select suppliers: Only purchase critical components from suppliers who can provide full product documentation and certifications (e.g. TÜV certificate, ATEX compliance).
8. Apply a new CE marking: If required, apply a new CE marking with the details of the 'new manufacturer' and the year of recertification.
9. Update user manual: Adapt the manual to the new situation and risks. This also includes detailed instructions for maintenance and possible malfunctions, for example new error codes.
10. Revise maintenance procedures: Integrate the new components and functions into the preventive maintenance schedules. For example, specify inspection intervals for new bearings (every 2000 operating hours).
11. Training personnel: Ensure adequate training of operating and maintenance personnel on the modified machine, including safety procedures and emergency stops, in accordance with NEN-EN-ISO 12100 paragraph 6.2.2.
12. Internal audit: Perform an internal audit to verify full compliance before returning the machine to service. Use a checklist based on the EGVEs.
13. Registration and archiving: Record all steps and keep the technical construction file and the EC declaration of conformity for the required period (at least 10 years after the machine was last placed on the market).
14. Periodic inspections: Schedule regular, legally required inspections (e.g. NEN 3140 for electrical installations) to ensure continued safety and compliance.
15. Monitor regulatory updates: Stay proactively informed of changes to relevant guidelines and harmonized standards to anticipate future compliance requirements.

Common Non-Compliance Issues

Auditors and inspection services, such as the Dutch Labor Inspectorate and the FAMHP in Belgium, frequently identify various non-conformities in machines that have undergone a retrofit. The most common problems are:

• Insufficient or no risk assessment: The retrofit is carried out without a re-evaluation of the risks, leaving new or changed hazards undetected. For example, adding a faster drive (from 1500 to 3000 RPM) can lead to higher kinetic energy and therefore a greater risk of safety device failure, which requires a detailed reassessment of braking systems.
• Missing or incomplete technical construction file: The file of the modified machine is incomplete, not updated, or not traceable, thus missing the burden of proof of conformity. This often includes the lack of updated electrical diagrams or software version control.
• Use of unsuitable components: Replacement parts that do not meet specific safety, pressure or explosion protection requirements, such as installing a standard (non-ATEX) frequency converter in an ATEX Zone 2 environment. An engine designed for ambient conditions up to 40°C and then installed in a 60°C environment can fail 50% faster than expected (taking into account the Arrhenius equation), posing risks of overheating and fire.
• No or incorrect CE marking: Despite a significant change, no new CE marking is applied, or the marking is incorrect, which is misleading to users and inspectors.
• Lack of training: Personnel are not trained on the new or modified machine functions and safety procedures. This leads to a higher risk of operator errors and accidents, as the human factor plays a critical role.
• Outdated documentation: Original manuals and diagrams are not updated, which can lead to incorrect maintenance, repairs and incorrect diagnosis of faults.

Sanctions and Liability

Non-conformity with the Machinery Directive and related legislation can have serious legal and financial consequences for companies and individual managers in the Benelux. The costs of non-compliance can far exceed the initial investment in adequate compliance.

• Fines: In the Netherlands, the Dutch Labor Inspectorate can impose significant fines, ranging from €3,000 to €50,000 per violation, depending on the severity, frequency and impact on safety. For very serious violations, especially those that lead to injury, these fines can rise to several hundreds of thousands of euros. In Belgium, similar sanctions can be imposed by the Federal Public Service Employment, Labor and Social Dialogue.
• Criminal liability: In the event of accidents resulting in injury or death, drivers, managers and even maintenance technicians may be held personally criminally liable. This can result in prison sentences and high personal fines, as laid down in the Working Conditions Act in the Netherlands or the Code on Well-Being at Work in Belgium. A fatal accident can lead to a criminal case with prison sentences of up to several years.
• Civil liability: Accident victims can hold the 'new manufacturer' or operator civilly liable for damages suffered, including medical costs, loss of income and damages. This can lead to claims of hundreds of thousands of pounds depending on the severity of the injury.
• Insurance issues: Commercial liability insurance policies may refuse to pay out claims for damages arising from failure to comply with legal safety requirements and certification obligations. This results in uncovered costs, which can mean a significant loss of operating capital.
• Corporate reputation and shutdown: An incident resulting from non-compliance can seriously damage corporate reputation, which has a long-lasting impact on customer confidence and business relationships. Furthermore, the inspection may order the shutdown of machines or even entire production until compliance is restored, leading to significant production loss and financial damage.

Conclusion

Correctly handling CE marking in retrofits is not an optional consideration, but a legal and ethical obligation. It not only ensures the safety of your staff, but also protects your company against significant fines, liability claims and reputational damage. By proactively following the Machinery Directive and investing in certified components, you build a resilient and safe production environment. For certified, compliant components that meet the strictest industry standards, see the UNITEC-D E-Catalog.

References

• European Commission. Machinery Directive 2006/42/EC. Directive of the European Parliament and of the Council on machinery and amending Directive 95/16/EC. Official Journal L 157, 9.6.2006, pp. 24–86.
• NEN. NEN-EN-ISO 12100:2010. Safety of machinery – General design principles – Risk assessment and risk reduction.
• NEN. NEN-EN 60204-1:2018. Safety of machinery - Electrical equipment of machinery - Part 1: General requirements.
• NEN. NEN-EN-ISO 13849-1:2023. Safety of machinery – Safety related parts of control systems – Part 1: General design principles.
• European Commission. Pressure Equipment Directive (PED) 2014/68/EU. Directive on the harmonization of the laws of the Member States relating to the making available on the market of pressure equipment. Official Journal L 189, 27.6.2014, pp. 164–259.
• European Commission. ATEX Directive 2014/34/EU. Directive on the harmonization of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres. Official Journal L 96, 29.3.2014, pp. 309–331.
• Dutch government. Working Conditions Act (Arbowet).
• Dutch government. Commodities Act.