What pressure differential should exist between the ISO 7 buffer room and the ante room?

The appropriate pressure differential between the ISO 7 buffer room and the ante room is crucial for maintaining the integrity of sterile compounding environments. A positive pressure of +0.02 inches water column is typically required to ensure that any airborne contaminants from the ante room do not infiltrate the cleaner ISO 7 buffer area.

This positive pressure helps to establish a controlled environment where the clean air flows outward from the buffer room to the ante room, thereby minimizing the risk of contamination in the critical sterile areas where compounding occurs. Maintaining this differential is vital to comply with standards set by organizations such as USP (United States Pharmacopeia), as it enhances the safety and sterility of compounded preparations.

When considering other options, a pressure differential that is too high or too low can lead to problems. A higher positive pressure could potentially lead to excessive air movement that disrupts the laminar flow needed in sterile areas, while a negative pressure would increase the risk of contaminants entering the ISO 7 space. Thus, the +0.02 inches water column is the correct standard to uphold a safe and effective sterile compounding environment.