After a long time revision, EU GMP Vol. 4 Annex 1 new version is now about to be issued. This European reference standard for sterile pharmaceutical manufacturing is thus about to change from a light and concise guideline to an improved, highly structured and detailed standard. A lot of new requirements, specifications and recommendations are included in the draft version so far shared by Eudralex, most of which will likely be an important challenge for many sterile manufacturers. Whether you can find more details about EU GMP vol.4 Annex 1 contents in other articles of this website, in this occasion we want to share some considerations and insights of one of the most challenging topics, Environmental Monitoring, and how the impact of Annex 1 guidelines can work as a leverage to get full knowledge and control of manufacturing.