Clean room suite configuration used in compounding sterile hazardous drugs must include an anteroom and a buffer room. What ISO class air quality must these spaces meet?

• A. ISO 5 and ISO 7
• B. ISO 7 and ISO 7
• C. ISO 7 and ISO 5
• D. ISO 8 and ISO 8

Answer: (B)

Air cleanliness in the spaces you pass through before reaching the actual work area must meet ISO 7. In a sterile hazardous-drug compounding setup, the anteroom and the buffer room serve as transition spaces where gowning, hand hygiene, and material transfers occur, so they need to be clean enough to protect the more critical work zone. The actual compounding work occurs in a primary containment device that is maintained at ISO 5 air quality, providing the highest level of cleanliness for aseptic preparation. Keeping both the anteroom and the buffer room at ISO 7 ensures a consistent, sufficient barrier of clean air as products and personnel move toward the ISO 5 environment. Options suggesting ISO 5 or ISO 8 for these spaces don’t align with this transition-role requirement.