What is the purpose of a negative pressure isolation room?

• A. To prevent contamination of other rooms by exhaust air.
• B. To keep air from flowing out of the room.
• C. To contain airborne pathogens by keeping air from flowing out of the room and protecting others from exposure.
• D. To provide extra ventilation.

Answer: (C)

Controlling where the air goes is the essential idea. A negative pressure isolation room is kept at a lower pressure than surrounding areas, so air naturally flows into the room rather than out of it. The air inside is then exhausted away through a dedicated system (often with filtration) to prevent contaminated air from reaching other parts of the building. This setup contains airborne pathogens and protects others from exposure. Simply providing extra ventilation isn’t enough, and stopping flow without proper exhaust and filtration wouldn’t prevent spread.