In clean room design, the buffer room must meet ISO class air quality.

• A. Anteroom
• B. Main clean room
• C. Buffer room
• D. Storage room

Answer: (C)

Clean room design hinges on zones with defined ISO air cleanliness, and the buffer room acts as the controlled transition between less clean areas and the main clean room. Because it sits between outer spaces and the sterile-processing area, the air in the buffer room must meet a specified ISO class to prevent contaminants from entering when doors open or when materials and personnel move through. This ISO-class air quality helps maintain the proper pressure differentials and directional airflow that protect the integrity of the main clean room, where the highest level of cleanliness is required. The other spaces serve different roles, but the buffer room specifically is the transitional zone that must meet ISO-class air quality to safeguard the clean room.