The following interpretation of the Machinery Directive 2006/42EC has been published: Guide to application of the Machinery Directive 2006/42/EC 2. 2nd Edition June 2010, §72 4. Paragraph – New and used machinery: Clause 2.1:
"The Machinery Directive also applies to machinery based on used machinery that has been transformed or rebuilt so substantially that it can be considered as new machinery."
The undefined term "significant change" is also specified in an interpretation paper published by the Federal Ministry of Labour and Social Affairs (BMAS). This paper is only valid in Germany.
What does a significant change involve?
If the risk assessment finds that a significant change has taken place, the machine (product) must be assessed as a new machine (new product) in accordance with the Product Safety Act (ProdSG). This means that the requirements for placing the machine (product) on the market (conformity assessment procedure) must be met. This involves the user in a lot of work in terms of approval!
BMAS Interpretation Paper: "Significant change of machinery", published by BMAS on 09.04.2015, Az. IIIb5-39607-3 published in the Joint Ministerial Gazette GMBI, p. 183.