Substantial modification of machinery under Regulation 2023/1230 (Article 18)

The definition (Article 3(16))

A substantial modification is a modification of machinery or a related product, by physical or digital means, after it has been placed on the market or put into service, which:

• is not foreseen or planned by the manufacturer, and
• affects safety by creating a new hazard or increasing an existing risk, and
• requires either (a) the addition of guards or protective devices whose processing needs a change to the existing safety control system, or (b) additional protective measures to ensure stability or mechanical strength.

What Article 18 says happens

• The person who makes the substantial modification is considered a manufacturer and is subject to the manufacturer obligations in Article 10, for the whole machinery, or only for the affected machinery if the modification affects the safety of just one part of an assembly, as shown by the risk assessment.
• That person must ensure and declare, on their sole responsibility, that the machinery conforms with the applicable requirements, and apply the conformity assessment procedure in Article 25(2), (3) and (4).
• A non-professional user who modifies their own machinery for their own use is not considered a manufacturer.

Related rule for importers and distributors (Article 17)

An importer or distributor is treated as a manufacturer if it places a product on the market under its own name or trademark, or modifies a product already on the market in such a way that compliance with the applicable requirements might be affected.

Checklist for a retrofit or upgrade

• Write down what changes: mechanics, guards, safety controls, software or configuration.
• Test the change against the definition: new hazard or higher risk? Does it need new protective devices that alter the safety control system, or added stability or strength measures?
• If yes, update the risk assessment and decide whether the whole machine or only one part of an assembly is affected.
• Select the conformity assessment route under Article 25 and apply it.
• Draw up the technical documentation and an EU declaration of conformity in your name, and affix the marking.
• Update the instructions and keep the records for the required period.

General information, not legal advice or certification. Source: Regulation (EU) 2023/1230, Articles 3(16), 17 and 18, on EUR-Lex.

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