How does a negative air machine work?

A negative air machine is designed to create a controlled environment by removing contaminated air from a space and discharging it outside. This process is crucial during asbestos abatement and other hazardous material removal procedures, as it helps to maintain air quality in the work area while preventing the spread of contaminants to surrounding spaces.

The machine operates by using a fan to draw air from the containment area, which is then passed through filters that capture particulates, including asbestos fibers. Once the air is filtered, it is safely released outside, resulting in negative air pressure within the containment area. This negative pressure prevents air from leaking in from outside, thereby minimizing the risk of cross-contamination.

The other choices do not accurately capture the primary function of a negative air machine. Circulating air within the room does not effectively remove contaminants and could lead to air quality issues. Adding fresh air to the work area would not address existing contamination and could even spread it. Increasing pressure in the containment area contradicts the purpose of maintaining negative pressure, as the goal is to keep contaminants confined within the workspace.