A clean room (GMP cleanroom), in my mind are a combination of engineering design, fabrication, finish and operational controls (control strategy) that are required to convert a “normal” room to a “clean room”. In this blog I will attempt to explain the necessary characteristics of a regulated company clean room not producing potent chemicals or active or hazardous biologicals. If there are significant containment requirements, the requirements would be outside the scope of a “simplistic” blog like this. In a pharmaceutical sense, clean rooms are those rooms that meet the code of GMP requirements as defined in the sterile code of GMP, i.e. Annex 1 of both the EU and PIC/S Guides to GMP and other standards and guidance as required by local health authorities.