Proper set-up and maintenance of laboratory vacuum lines are important to protect the central vacuum system as well as facility maintenance staff who service this equipment. The vacuum system should be protected by a HEPA filter, particularly when used to manipulate biohazardous materials, and an overflow container should be present and managed vigilantly. Lab materials should never reach the main vacuum pump and potentially expose maintenance staff to biohazardous/chemical agents.
For activities conducted in biosafety cabinets/tissue culture hoods the recommended aspiration set-up is illustrated below. The set-up includes a collection or suction vessel (A), an overflow collection vessel (B), and a vacuum protection in-line HEPA filter (C) placed immediately before the valve (D) (Figure 2).
Sufficient chemical disinfectant is placed in the primary collection and overflow vessels to inactivate biological agents as they are collected. Spargers (or tubes, as shown in B) in the vessels are also recommended to minimize aerosols being directly sucked into the vacuum line without being disinfected. An example of a commonly selected HEPA filter is the Whatman® VACU-GUARD. Primary collection flasks should be disposed of daily, or more often as necessary; HEPA filters should be placed in a periodic inspection and replacement schedule. Collections flasks should be labeled with the universal biohazard sign; if collection flasks are stored on the floor, secondary containment should be used.