What is the minimum pressure required in pharmaceutical working rooms as per guidelines?

[Awad (Dr. Ahmed Mohamed Awad)]

@Awad

differential pressure generally should have upper limit even in non open product areas because turbulence caused by high differential pressure reduces cleaning efficiency of HVAC

A 5 - 20 pa range I think is a very safe acceptance range between areas of the same grade (e.g grade d) since this range is mentioned in WHO and ISO

Regarding minimum DP Limit between different grades it is 10 Pascal as per WHO and FDA