A laboratory ventilation system should be designed and adjusted to maintain the lab under what kind of pressure?

Maintaining a laboratory under negative pressure is essential for safety and containment purposes. A negative pressure environment ensures that air flows into the lab from surrounding areas rather than allowing any potentially hazardous materials, fumes, or contaminants to escape into adjacent spaces. This is especially critical in laboratories handling hazardous substances, as it protects both the staff working inside and people in nearby areas from exposure to harmful chemicals or biological agents.

In a negative pressure system, the air pressure inside the lab is lower than that of the outside environment, which directs any airborne contaminants inward. This design is crucial for preventing the release of pathogens or toxic substances into the general environment, thereby ensuring compliance with safety regulations and standards.

In contrast, neutral or positive pressure systems are typically used in environments such as cleanrooms, where it is necessary to keep external contaminants out, or in operating rooms where the environment needs to remain sterile. A variable pressure system may not provide the consistent safety needed in a laboratory setting, which could lead to potential risks if not monitored continuously.