Sustainability is becoming increasingly important in pharmaceutical manufacturing. For some time now, there have been discussions about making sustainability a relevant factor for the marketing authorization. In this context, energy efficiency in manufacturing is becoming increasingly important. In the manufacture of sterile preparations in particular, clean rooms are responsible for a high proportion of energy consumption. This makes them central to the optimisation of energy consumption. ISO 14644-16 is a useful standard for optimising energy consumption in cleanrooms. This raises the question of how ISO 14644-16 and the regulatory requirements of EU GMP, Annex 1 can be combined in practice. The presentation provides one possible answer to this question. At the same time, it will show how risk management plays a central role in this and how critical thinking is essential for some of the measures in
implementation.