What is the primary feature of a closed system transfer device (CSTD)?

The primary feature of a closed system transfer device (CSTD) is that it prevents the escape of hazardous drug concentrations. CSTDs are designed to minimize the risk of drug exposure to healthcare workers and the environment by providing a sealed system that contains the hazardous substances during the transfer process. This is especially important in sterile compounding where handling chemotherapeutic agents and other hazardous drugs can pose significant health risks.

By maintaining a closed system, CSTDs effectively limit the potential for aerosolization or leakage of these dangerous drugs into the environment, thereby protecting both the compounding personnel and patients. This safety feature is crucial in ensuring that hazardous drugs are managed responsibly and in accordance with safety regulations.

The other features mentioned, while they may be present in various devices or practices, do not encapsulate the primary and critical role of CSTDs in safeguarding against drug exposure.