Ante-rooms in hazardous drug facilities are:

• A. Always negative pressure
• B. Always positive pressure
• C. May be negative or neutral depending on design
• D. Not used

Answer: (C)

Ante-rooms serve as buffer spaces that help control airflow and provide a dedicated area for donning, doffing, and transferring materials when handling hazardous drugs. Their pressure relative to surrounding spaces isn’t fixed; it’s determined by the facility’s HVAC design and risk assessment. In some layouts, the ante-room is kept under negative pressure to aid containment when doors are opened and materials move in and out. In other designs, it is kept at neutral pressure to maintain the overall pressure cascade and minimize disruption to the surrounding zones. So, the status can be negative or neutral depending on design—there isn’t a universal rule that ante-rooms must always be one or the other.