Which statement best defines a closed system transfer device (CSTD)?

• A. A disposable workstation for routine chemical transfers
• B. A closed system transfer device
• C. A device for open air transfers
• D. A portable incubator for drug testing

Answer: (B)

A closed system transfer device is designed to keep hazardous drug transfers contained, providing a sealed pathway during preparation and transfer to minimize exposure to the worker and the surrounding environment. This protective barrier is the key feature that defines a CSTD, ensuring that drug-containing aerosols or spills do not escape into the work area.

That is why describing it as a closed system transfer device is the best answer: it directly states the essential purpose and function of the device. Other options refer to equipment that either doesn’t guarantee a closed barrier (a disposable workstation used for routine transfers) or describes open-air transfers or unrelated equipment (open-air transfer tools, incubators), which do not fit the concept of a device designed to maintain containment during hazardous-drug handling.