What is a necessary feature for all HD compounding areas?

In sterile compounding, particularly in the preparation of hazardous drugs (HDs), a critical feature of compounding areas is that they must have fixed walls to ensure containment and a controlled environment. The use of fixed walls helps to establish a dedicated space that can be effectively sealed off to prevent contamination and exposure to hazardous substances. This is essential for the safety of both pharmacy personnel and patients, as it creates a barrier that minimizes the risk of cross-contamination and reduces environmental contamination.

Having dedicated areas with fixed walls allows for better control over the environment, including airflow, air pressure, and filtration systems necessary for compounding. This feature aligns with regulations and guidelines set by organizations such as the United States Pharmacopeia (USP), particularly USP <800>, which outlines the handling of hazardous drugs and emphasizes the importance of proper facilities.

Other options, while they may seem relevant, do not capture the fundamental necessity of structural integrity and containment that fixed walls provide in HD compounding areas.