- Differential pressure (DP) it is maintained the air flow and prevent the cross contamination.
- Differential pressure (DP) is difference between atmospheric pressure between production area and its surrounding area.
- It is measured in pascal using mangnehlic pressure gauge.
- Differential pressure can greatly reduce operator error, improve process efficiency, protect expensive equipment, reduce training and reduce maintenance time.
- As per WHO guidelines 10-15 Pascals (Pa) of differential pressure is maintained between manufacturing area and surrounding area.
- Differential pressures is the difference in pressure between two points. This pressure differential is maintained by HVAC system.
- Air locks prevent the direct air flow from uncontrolled area to controlled area.
- AS per USP general chapter 797 (Pharmaceutical Compounding- Sterile Preparations)
Convert to pascal 5 Pa to 12.45 Pa.
Convert to mm 0.508 of WC to 1.27 of WC.
- Two types of Differential pressures
1.
Positive pressure :
- Inside higher pressure and outside lower pressure
- Aseptic area always be highly pressurized non aseptic area are low pressurized. This type system prevent the contamination other area.
- Inside lower pressure and outside higher pressure.
- Culture handling area, Cytotoxic handling area negative pressure was maintained because prevent the contamination of other area.
