What is required of single or combined mechanical exhaust systems for environmental air?

Single or combined mechanical exhaust systems for environmental air must be separate from all other exhaust systems to ensure proper ventilation and avoid contamination of the air being handled. This separation is crucial for maintaining the integrity of air quality management within a facility.

By keeping exhaust systems distinct, it helps to prevent potential cross-contamination between different types of exhaust streams, especially those that may contain hazardous pollutants or other harmful substances. This is especially important in settings such as laboratories or industrial environments where fumes from one source could adversely affect air quality in another space.

Other options suggest dependencies, combinations, or operational constraints that may compromise the effectiveness and safety of the ventilation systems. Ensuring dedicated exhaust systems for environmental air protects both the quality of the air circulated within a space and the health of individuals using those spaces.