Which statement describes buffer-room requirements?

• A. Fixed walls, negative pressure, at least 60 ACPH
• B. Fixed walls, positive pressure, at least 30 ACPH
• C. Flexible walls, negative pressure, at least 30 ACPH
• D. Fixed walls, negative pressure, at least 30 ACPH

Answer: (D)

Buffer-room requirements hinge on enclosing the space, maintaining negative pressure, and providing enough air exchanges to quickly dilute and remove contaminants. The room must be a dedicated area with fixed walls to create a stable, contained environment. Negative pressure relative to surrounding spaces ensures that air flows into the room rather than out, helping to keep hazardous drug aerosols contained. To protect both staff and the compounding process, the system must achieve a minimum rate of air exchanges per hour; 30 ACPH is the standard minimum. The best description matches all three elements: fixed walls, negative pressure, and at least 30 ACPH. Descriptions with flexible walls or positive pressure fail containment principles, and stating a higher minimum like 60 ACPH goes beyond the standard minimum.