What kind of pressure is maintained in a room that prevents contaminated air from leaving the space?

The correct answer is based on the principle of maintaining a specific environmental control within a sterile compounding area. In settings where contaminated air needs to be controlled, a negative pressure environment is established. This means that the air pressure inside the room is lower than the air pressure outside the room.

The purpose of maintaining negative pressure is to prevent contaminated air from escaping into adjacent areas. This is particularly important in environments where hazardous substances are handled, such as in oncology pharmacies, to ensure safety for both the employees and the surrounding areas.

In contrast, positive pressure environments are typically used in cleanrooms and aseptic areas, where the goal is to keep air from outside entering the space, thus protecting sterile products from contamination. High pressure and low pressure are not specifically relevant in this context, as they do not accurately describe the mechanism of air control used to prevent contamination in compounding spaces.