ISO LIMITS FOR clean room airchanges

Can any one provide me the information regarding the requirement of air changes per hour in clean rooms as per the grades.
Thanks in advance.



according the FDA “Guidance for Industry for Sterile Drug Products Produced by Aseptic Processing - Current Good Manufacturing Practice” :

“For Class 100,000 (ISO 8) supporting rooms, airflow sufficient to achieve at least 20 air changes per hour is typically acceptable. Significantly higher air change rates are normally needed for Class 10,000 and Class 100 areas.”

For non sterile, there is no minimum requrirement, it depends on the activity of the area (and the contamination generated by this activity)