By Cybelle Guerrero, North American Sales Director; Deborah Thibodeaux, Science Director; and Cheri Gaudet, Marketing Specialist.
With the recent Ebola outbreak, many hospitals are looking to use a biological safety cabinet to contain any possibly-infectious samples drawn from patients for identification. Although a biosafety cabinet is typically considered a laboratory device, it is being considered for use in a clinical setting to protect hospital workers from becoming infected with diseases such as Ebola virus, because it provides protection to personnel from aerosol-generating items or procedures inside the work area. Additionally, a biological safety cabinet provides a sterile work environment that separates samples from one another, preventing cross-contamination and false positive test results.
When considering installing a biosafety cabinet, hospitals may want to ask many of the same questions that are considered in a laboratory setting. Below is provided as a set of general issues to consider. Please seek the support of your local area infection control group for your hospital’s particular needs.
The most basic question to ask yourself is whether or not the procedures you expect to be performed within this setting require a biosafety cabinet. In varying degrees, a laminar flow biological safety cabinet is designed to provide three basic types of protection:
It is important to assess whether these procedures will produce agents that can be harmful to the user and surrounding environment. For example, procedures requiring venal puncture, throat swabs, and skin or wound samples can all generate aerosolized particles and droplets during processing, and therefore may require the containment properties a biosafety cabinet is designed to provide. Conversely, if blood will be centrifuged, the use of sealed safety cups may obviate the need for a biological safety cabinet. As with any application, however, it is critical to perform an assessment of the risk associated with the procedure, as well as to include appropriate personnel in the evaluation of those procedures (e.g., environmental health and safety officers, biosafety officers, etc.).
If room dimensions are not sufficient to support the safe operation and use of a biological safety cabinet, containment and personnel protection may be compromised. Some manufacturers design biosafety cabinets to meet minimum safety standards, but they lose their containment capabilities under real-life work conditions in a dynamic, day-to-day work environment. Ensure that your biosafety manufacturer provides maximum containment even if room conditions are not ideal. Data to request include the performance envelope for your particular cabinet model, which should exceed the minimum standards required by NSF/ANSI 49. (Always check any data you receive from a manufacturer against the standards employed at your hospital.)
The position of any room air supply vent may also conflict with the placement of the biosafety cabinet. What if the best location for the biosafety cabinet is directly beneath the room air supply vent? The local sales or service representative for your biosafety cabinet manufacturer can usually help you with this situation.
We do not recommend placement of the biological safety cabinet in the anteroom spaces to the isolation suites. Anterooms are intended to be non-contaminated spaces, and placement there could compromise entry and egress points.
Some equipment and tools that may be used inside a biosafety cabinet include microplates and microtubes, small centrifuges, microscopes and other analytical instruments. It is important to confirm whether the size, heat load or vibration characteristics of the equipment will interfere with the safe operation of the biosafety cabinet, thereby compromising its ability to delivery optimum performance and adequately contain any aerosols that might be generated within. Ask your sales or service representative for the results of microbiological testing done with the type of instrument you want to use (and again, check them against your hospital’s standards).
Restrictions on personnel movement must be rigorously applied for the biosafety cabinet to be operated safely. This applies both to movement inside and outside the cabinet. Follow recommended procedures for working safely inside a biosafety cabinet, such as these in the Biosafety in Microbiological and Biomedical Laboratories (BMBL). Restricting personnel movement outside the cabinet helps to prevent turbulence that can compromise containment and worker safety.
Personal protective equipment may be different depending whether the disease is unidentified or identified. The CDC has recently issued a new PPE protocol for working with infectious agents, and the Greater New York Hospital Association has produced a video to describe dressing and disrobing when working with Ebola virus.
For guidance on compounds that are effective against Ebola virus, read this document and this page. Always review Safety Data Sheets prior to using any compound. It is important to consider whether any compound that you plan to use consistently will affect the material components of the biosafety cabinet work area. Check with the manufacturer of your biosafety cabinet to be sure.
It is imperative that you consult your biosafety cabinet manufacturer before attempting any modifications to your cabinet. Modifications may compromise the performance of the cabinet, often resulting in excess turbulence, which can compromise containment and place personnel at serious risk when working with infectious diseases. In most cases, a discussion with the manufacturer will shed light on the risks that your proposed modification may cause, and you may be able to explore possible ways to mitigate those risks.
Additionally, always follow CDC and WHO guidance on the use of PPE (see link below). Compliance may seem inconvenient or expensive, but it is never worth risking the life or health of your personnel.
To learn more about infection control (including information specific to Ebola), the following links may be useful:
If you have specific questions about the placement and operation of Baker biological safety cabinets in point of care areas, or questions about the effects of decontamination compounds, please contact Baker’s Science Director, Deborah Thibodeaux.
(Updated 10/31/14 to include link to Ebola 2014 article)