BioSafety Cabinets – How they function and best practices
How a BioSafety Cabinet (BSC) functions
There are different types of biosafety cabinets, each designed to handle specific kinds of work. The most common are Class II biosafety cabinets, often used in microbiological studies, cell culture, and pharmaceutical procedures. It is important to understand the class and type of BSC you use. These cabinets work by creating a controlled environment with a protective air barrier. The air is drawn from the room into the cabinet and mixed with recirculating air; the air then separates; some gets pushed back into the room through an exhaust filter, and some is pushed through a supply HEPA Filter downward onto the work surface, creating a contamination-free zone.
Biosafety cabinets (BSCs) are essential in maintaining a safe and contaminant-free environment in laboratories.
When used correctly, these cabinets provide three primary protections:
- Personnel protection: to protect workers from harmful agents inside the cabinet.
- Product protection: to avoid contamination of the work, experiment, or process within the BSC.
- Environmental protection: to protect the laboratory and space surrounding the BSC from contaminants within the cabinet.
Precautions Before Using Biological Safety Cabinets
Always wear the necessary personal protective equipment (PPE), including a lab coat, gloves, and safety glasses. Place all materials and equipment inside the cabinet before starting work to minimize disruptions and maintain the cabinet’s integrity.
Follow these steps to start up a biological safety cabinet safely:
- Turn off the ultraviolet sterilizer (if equipped) upon entering the room.
- Turn on all blowers and cabinet illumination lights.
- Allow the cabinet to operate for at least 5 minutes to purge the system and check flow alarms.
- Decontaminate accessible interior surfaces with an appropriate disinfectant.
To maintain airflow and ensure safety while operating a BSC:
- Ultraviolet (UV) light Never use UV light while working inside the cabinet to avoid eye and skin damage.
- Avoid disrupting airflow by minimizing movements in and out of the cabinet.
- Do not block the front grill or rear vents with arms or materials.
- Maintain a distance of at least 4 inches from the front vent edge.
- Correct sash height Never work in a biosafety cabinet when the sash is not at the correct height. An alarm sounds and flashes when the sash is opened too high or closed too low. The alarm can be silenced for five minutes at a time to allow the loading of large equipment and for cleaning.
- Separate Clean & Dirty Items Never mix clean and dirty items inside the cabinet. Instead, take care to use a systematic process (e.g., left to right, or front to back) to separate clean items from dirty to avoid contamination. Limiting items inside the cabinet to only the most essential is also a good preventive measure.
- Keep the Top of the Biosafety Cabinet Clear Class II Type A biosafety cabinets that are not connected to an exhaust system use an air diffuser that also protects the exhaust HEPA filter. This filter is very fragile and easily damaged. Make sure the diffuser is installed correctly and not blocked. Keep the top of the cabinet clear.
- Ensure the BSC has the correct airflow, most BSCs have airflow alarms or Magnehelic gauges.
Proper airflow is crucial in Biosafety Cabinets (BSCs):
Biosafety Cabinets use HEPA-filtered unidirectional airflow to keep contaminants out. Overcrowding can obstruct this airflow pattern, leading to pockets of stagnant air where contaminants can accumulate or spread. These can be visualized with smoke studies. Overcrowding can lead to contamination of experiments and pose risks to users. Proper spacing around any object within the cabinet ensures that air can flow freely, and contaminants are continuously removed from the work area and away from the user.
Decontamination, Testing and Certification of Biosafety Cabinets
The exact circumstances of a laboratory will determine when and how often a BSC should be decontaminated, however, there are five basic reasons why it should be carried out:
- Prior to any operation or experiment that requires access to areas of the BSC (such as the fan or filters) that may have become biologically compromised.
- Prior to the relocation of a BSC from one room or building to another, in order to avoid contaminating the external environment during the transition
- After the accidental spillage of a potentially hazardous substance or microorganism in the vicinity of the BSC working area
- If a different biological substance is being used inside the BSC or if operational procedures undergo a fundamental change
- As part of a routine decontamination protocol
Biosafety Cabinets MUST be certified when installed, whenever they are moved and at least annually. BSC’s must be decontaminated at the end of their lifespan before disposal. Venture Forward Partners can certify, test, maintain, and decontaminate your biosafety cabinets.
Best Practices:
To maintain optimal performance, it’s recommended that the items placed in the BSC be limited to those necessary for the immediate task. Regular cleaning and decontamination of the work area, as well as following the manufacturer’s guidelines for equipment placement, are essential.
Do not store chemicals in the biosafety cabinet overnight or when you are not being actively used. Always store chemicals in an approved chemical storage cabinet.
Shut the sash: To conserve energy, the biosafety cabinet’s sash should always be closed when not in use.
Venture Forward Lab Partners is always ready to certify, repair and properly maintain your Biosafety Cabinets.
Venture Forward Lab Partners is a full-service Laboratory Planning, Project Management and Lab Services company for life science and biotech laboratories in Greater Boston. From site selection and lab relocations to setting up and maintaining your lab, we provide a broad range of services and solutions to support your lab operations. Our team possesses unparalleled energy and enthusiasm toward the work we do, and we have the expertise, training, hands-on lab experience and industry connections to ensure your lab’s success. Whatever your lab needs – we make it happen.