The updated GMP EU Appendix 1 [1], dedicated to the production of sterile medicines, finally came about in August 2022. This has become a notable event for the pharmaceutical industry, since this application (old and new editions) is, in fact, the fundamental backbone for manufacturers of medicinal products. It is important to note that it is used not only for manufacturers of sterile medicinal products; after all, there is no secret that the notorious cleanliness grades of rooms A, B, C and D exist (and existed before) exclusively in this annex. In contrast, the same FDA guidelines for sterile medicines [3] perfectly dispense with the classification of clean rooms according to ISO and only during the operation state.