What is a Biosafety Cabinet?

What is a Biosafety Cabinet?

Biosafety cabinets are cabinets used for safe and healthy work on pathogens and microorganisms that may be contagious. Biosafety cabinets are designed with various exhaust air filters to get rid of harmful bacteria and viruses. Biosafety cabinets have 2 different types that differ from each other in order to protect the environment and personnel, and to protect the experiment. Biosafety cabinets allow robotic studies in microbiological processes. Vented Biosafety cabinet is generally used in diseases such as tuberculosis and tuberculosis, while Cytotoxic Biosafety cabinet is used in the field of drug making.

What are the Biosafety Cabinet Types?

Biosafety cabinet can be designed in different ways due to usage areas and purposes. Biosafety cabinets can come in three different designs with safety equipment and other features. What classifies the cabins is the protection equipment they have. As the class increases, the level of protection increases in direct proportion.

Class I Biosafety Cabinet

These are the cabins that provide user and environmental protection. There is no product protection. While the user is protected by the air drawn into the cabin, the environment is protected by passing the inhaled air out through the filter.

Class II Biosafety Cabinet

They are cabinets that provide user, environment and product protection. It is suitable to work with agents with risk groups 1,2 and 3. Thanks to the air drawn in from the front, the user, the product as the air coming from the ceiling to the working area passes through the filter, and the environment is protected as the air that is expelled passes through the filter. It is divided into 4 classes within itself.

Class II A1 Biosafety Cabinet

These are the cabins with a recirculation rate of 70% and an exhausted air rate of 30%. Front air intake velocities are minimum 75 fpm (0,38 m/s). Since the polluted plenum with positive pressure is not surrounded by negative pressure, it is no longer preferred today.

Class II A2 Biosafety Cabinet

These are the cabins with a recirculation rate of 70% and an exhausted air rate of 30%. Front air intake velocities are minimum 100 fpm (0,51 m/s). Biocontaminated plenum is under negative pressure or surrounded by negative pressure.

Class II B1 Biosafety Cabinet

These are the cabins with 40% re-circulation rate and 60% expelled air rate. Front air intake velocities are minimum 100 fpm (0,51 m/s). All biocontaminated compartments are negative to the room or surrounded by negative pressure compartments. Flue connection is mandatory.

Class II B2 Biosafety Cabinet

There is no recirculation. All of the incoming air is thrown out without recirculation (100% – total exhaust). Front air intake velocities are minimum 100 fpm (0,51 m/s). All biocontaminated compartments are negative to the room or surrounded by negative pressure compartments. B2 type cabinets can be used when working with chemicals and toxic substances. Flue connection is mandatory.

Class III Biosafety Cabinet

It is completely impermeable. Hazardous biological agents are taken to the work area from a covered compartment. The operator performs his operations through the gloves on the windshield. It is also called as glove box. The cabin is kept under negative pressure and supply air is taken from the HEPA filters. Suitable for working with risk group 4 agents.

Today, Class II A2 and Class II B2 type cabins are preferred.

“What is a biosafety cabinet?” Now that we have found the answer to the question, we can examine its features;

biosafety cabinets,

It prevents the micro-organisms and bacteria being studied from spreading around with the ventilation filter.
It prevents employees from being affected by the microorganisms or bacteria they work on.
Since it is quite safe in drug preparation processes, it is indispensable for pharmaceutical companies.
It offers more inspection opportunities against the examined microorganisms and bacteria with its light equipment.
• It can find a place for itself in almost every laboratory with its designs with various dimensions.

What environmental conditions and equipment are required for virus studies?

• Biosafety Cabinet Class IIA and Class IIB class cabinets should be used for such highly pathogenic and viral contagious samples. Such cabinets provide user, environment and specimen protection. Esco Biosafety cabinets provide a clean air environment at ISO Class 3 level by filtering particles down to 0.1 microns using ULPA filter technology instead of standard HEPA filters.

What should be considered before and during the work?

• It is recommended to perform UV light sterilization for about 15 minutes without opening the cabinet glass, especially before the sample studies with a high risk of biological and contamination. After UV sterilization, cleaning the entire work surface and side walls with 80% alcohol solution before opening the cabinet glass and placing the equipment. Cleaning the surfaces of the devices used in the cabin with alcohol solution, if any, helps to prevent contamination that may arise from the previous work.
In addition, disinfecting the equipment with alcohol solution again while being taken into the cabin will be beneficial in terms of preventing contamination.

What to pay attention to after work?

• After your analysis and studies are completed, as in the preparation process, the cabin equipment should be disinfected with 80% alcohol solution when taking it out. Afterwards, it is recommended to clean the cabinet, side walls and work surfaces, and the surfaces of the interior devices, if any, with 80% alcohol solution. After the cabin windshield is completely closed, the UV light sterilization process must be performed for 15 minutes and used to neutralize the pathogens and viruses remaining in the cabin.

The biosafety cabinet can be used in all industries that include laboratories. These industries are usually;

Food
Agriculture
Petrochemical
Medicine
Veterinary Medicine
Hospital
Medicine
Environment
Chemical

	Biosafety Levels vs. Risk Groups
Risk Group	Biosafety Level	Laboratory Type	Laboratory Applications	Safety Group Equipments
1	Basic Biosafety Level 1 (BSL-1)	– Basic teaching lab. – Researching lab.	-Good Lab. Applicatons (İLU)	No required
2	Basic Biosafety Level e 2 (BSL-2)	– Public safety lab. – Clinic microbiological lab. – Researching lab.	With İLU; -Biological warning sign -Wearing protection clothes	Biosafety cabinets for potential aerosol next to the open counter (BGK)
3	Basic Biosafety Level 3 (BSL-3)	– Specigic detect lab. – Researching lab.	Addition to BSL-2; -Special protection clothes -The controlled in-out -Single way air flow/negative pressure	BGK or other primary protection equipment for all activities
4	Maximum Isolation Biosafety Level 4 (BSL-4)	-Dangerous patogen working lab.	Addition to BSL-3; -İnlet of locked air -Out of shower -Special drain system	Positive pressure special protective clothing with Class III/BGK or Class II/BGK

The microbiological safety cabinet should be located away from indoor fresh air systems, doors and windows, and where traffic is least. The microbiological safety cabinet must be made of materials resistant to water, humidity and chemicals to be used. The air circulation system in the biosafety cabinet must be capable of providing continuous airflow and be operational for 24 hours. Electrical installation and equipment and mechanical installation and equipment must be isolated from each other. Electrical sockets and switches must be protected. Burners and heaters that can generate excessive heat can damage Hepa filters, so care should be taken to use them in the biosafety cabinet, flame burners should not be opened more than necessary and should not be brought closer to the filters. There should be no obstructive materials and vehicles in front of the suction grilles. The front of the air intake and outlet grilles should always be open. Before starting to work in the biosafety cabinet, necessary safety precautions should be taken.

Human errors are often caused by lack of knowledge and carelessness. Despite all the precautions taken, there should be a first aid team in the institution, taking into account the accidents that may occur in the laboratory environment. Microbiology, biochemistry, cytotoxic drug preparation etc. A sterile cabinet should be used when working in areas or working with carcinogenic substances. Biosafety cabinets must be connected to an earth-protected electrical installation. The ventilation fan must be activated before the front cover of the biosafety cabinet is opened. According to the model, it should be waited for a certain period of time for the air circulation inside to complete its cycle and work should be started after the sterilization of the interior is ensured. Although this time varies by model, it is at least five minutes. When the microbiological safety cabinets are not in use, the front vertical cover must be kept in the closed position. During operation, the windshield cover should be lowered to the lowest possible level. In this way, the connection of the indoor environment with the outside will be minimized. In some studies, users may need to wear extra masks and protective lab goggles.