Glossary · Existing plants and retrofit
Retrofit under the Machinery Regulation
Also known as: Machinery retrofit, Modification of machinery in use
Under the EU Machinery Regulation (EU) 2023/1230, a retrofit of machinery in use is legally either a repair or modification that remains the operator's matter, or a substantial modification: a change not foreseen by the manufacturer that creates a new hazard or increases an existing risk so that new guards or protective devices requiring changes to the safety control system, or additional measures for stability or mechanical strength, become necessary. Whoever makes a substantial modification is considered a manufacturer under Article 18.
- Compliance
- EU
- Technical documentation
In one sentence
A retrofit stays the operator's matter unless it is a substantial modification; then the modifier becomes the manufacturer (Article 18).
Example
An operator replaces the obsolete PLC of a press with a current controller and the same functions — a retrofit without new hazards; adding a robot loader with a new light curtain changes the safety control system and is assessed as a substantial modification.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Timeline: The Machinery Regulation applies from January 20, 2027. Until then the Machinery Directive 2006/42/EC applies, which does not define the term; in Germany the BMAS interpretation paper on substantial modification of machinery fills the gap, and Article 3(16) of the regulation largely follows its approach.
- The test: Start with the risk assessment of the change. Does it create a new hazard or increase an existing risk? If so, can the existing protective measures handle it, or are new guards or protective devices that change the safety control system, or new measures for stability or strength, needed? Only the last case is a substantial modification. Repair and maintenance that do not affect compliance are not. Record the reasoning in every case.
- Assemblies: If the change affects only one machine within an assembly of machinery, the manufacturer obligations apply to the affected part, as shown in the risk assessment. Line-wide requirements such as the stop controls of the assembly still have to work for the whole line.
- Operator duties: Whether or not the retrofit is substantial, the operator updates its own risk assessment under the BetrSichV and, where explosive atmospheres are involved, the explosion protection document under the GefStoffV. There is no grandfathering for these documents.
- Technical documentation: A substantial modification requires a conformity assessment, technical file, declaration of conformity, CE marking and updated instructions for the modified machinery. For a non-substantial retrofit, update the operator's documents, circuit diagrams and as-built documentation.
Retrofit vs. substantial modification
Retrofit describes what is done — modernizing an existing machine. Substantial modification describes a legal consequence of some retrofits. Most retrofits are not substantial modifications, but every retrofit needs the assessment that shows it. Naming a retrofit "like for like" does not replace that assessment.