A cleanroom is typically kept clean by using filtered air supplies and large air change rates to replace the air within the cleanroom many times per hour. The filtration can be High Efficiency Particulate Air (HEPA) filters depending on the cleanroom requirements and classification. These filters are certified to ensure that there is no leakage of air which by-passes the filter, therefore all air entering the facility is filtered. In addition, the materials used to construct the cleanroom are also non-shedding and do not add to the particulate load within the facility.
