What is considered a primary engineering control in the context of sterile hazardous drug (HD) compounding?

• A. Class II BSC
• B. Class I BSC
• C. Fume hood
• D. Laminar flow hood

Answer: (A)

In sterile hazardous drug compounding, the device that directly contains the work and provides filtered air to protect both the practitioner and the product is the primary engineering control. A Class II biosafety cabinet is designed for this role: it creates inward airflow to contain hazards, delivers downward laminar air over the work surface to protect the product, and uses HEPA filtration on both the inflow and the exhaust to prevent contamination from escaping into the room. This combination ensures containment of hazardous drugs while maintaining a clean, sterile work environment.

A Class I biosafety cabinet offers personnel and environmental protection but does not provide product protection through filtered inflow/downs; a fume hood is intended for volatile chemicals and does not provide adequate containment for HD; a laminar flow hood protects the product but does not protect the operator from exposure to hazardous drugs and lacks containment features.