Substantial modification

A machine is placed on the market once, with its manufacturer’s declaration of conformity and CE marking. If it is later changed in such a way that this assessment no longer holds, it counts as new machinery. Whoever carries out or arranges the change then has the duties of a manufacturer.

In Germany the threshold is described by the interpretation paper of the Federal Ministry of Labour on the substantial modification of machinery. It does not ask how extensive the modification is but what effect it has on safety.

First question: does the change create a new hazard or increase an existing risk? If not, the modification is not substantial. Second question: are the existing protective measures sufficient for the new situation as well? If so, it is not substantial.

Third question: can the risk be eliminated or adequately reduced with simple guards or protective devices? If so, the modification is again not substantial. Only if that fails too is it a substantial modification. Every answer rests on a documented risk assessment – the result has to be traceable, not merely asserted.

Replacing a component with an equivalent one does not change the risk. A higher rated capacity, greater reach, higher speed or a new function generally does – then the second and third questions decide. A new control system that affects safety functions is a frequent borderline case.

A new gripper is a topic of its own: load handling attachments are products in their own right with their own conformity assessment. What remains to be checked is whether the hoist works within its design limits with the new attachment.

The modified machine undergoes a conformity assessment procedure like a new one.

If the modification stays below the threshold, the operator is not released from duty. The German Industrial Safety Regulation requires the risk assessment to be reviewed when work equipment is changed, and an assessment of whether the change requires inspection. The decision “not substantial” is filed with its reasoning.

From 20 January 2027 the EU Machinery Regulation 2023/1230 applies. For the first time it defines substantial modification in the legal text itself and expressly assigns the manufacturer’s obligations to whoever carries it out.