This technical information report primarily addresses routine monitoring for viable particles (i.e., microorganisms) to demonstrate the suitability of microbiological control in controlled environments used to produce healthcare products that are intended to be terminally sterilized. Where applicable, routine monitoring for non-viable particles is addressed, however ISO 14644 series should be used as the main source of information for non-viable particles. As required by the current applicable quality system regulations, if the conditions for the work environment can have an adverse effect on product quality, the organization shall document the requirements for the work environment and the procedures to control and monitor the work environment (per clause 6.4.1 in ISO 13485:2016).