To control the bioburden in your cleanroom you will need to use disinfectants; these are chemicals that have properties that can kill micro-organisms. You will probably need to use two or more disinfectants in rotation, and this is why the process of killing micro-organisms in your cleanroom is called rotational cleaning.
Annex 1 – Manufacture of sterile medicinal products - Volume 4 EU Guidelines to Good Manufacturing Practice Medicinal Products for Human and Veterinary use, point 61, states the following:
“The sanitation of clean areas is particularly important. They should be cleaned thoroughly in accordance with a written programme. Where disinfectants are used, more than one type should be employed. Monitoring should be undertaken regularly in order to detect the development of resistant strains.”
"Annex 1: Manufacture of Sterile Medicinal Products," Good Manufacturing Practice (GMP) Guidelines (Brussels, Nov, 2008).