What is the key principle behind using negative pressure in hazardous drug areas?

The key principle behind using negative pressure in hazardous drug areas is to ensure that potentially contaminated air is contained. Negative pressure environments are vital in areas where hazardous drugs are prepared or handled because they help prevent the escape of harmful particulates and vapors into adjacent areas. By maintaining lower air pressure within the hazardous drug handling zone compared to surrounding areas, any air that may be contaminated is effectively drawn into the room and filtered instead of being released into the general environment. This containment is critical for protecting both healthcare workers and patients from potential exposure to hazardous substances.

While other options may involve considerations relevant to workplace design and employee safety, they do not reflect the primary purpose of negative pressure environments in the handling of hazardous drugs.