Biosafety cabinet or microbiological safety cabinet is a necessity while working in laboratory. It provides with an enclosed safe ventilated space for working with any kind of contaminated or harmful pathogen. They act as a safety net to ensure contamination-free testing of the microorganism, without coming in contact,for the experimenter. Biosafety cabinet was first commercially launched in the year 1950, mainly keeping in mind the safety of all the lab workers, technicians and scientists working in the lab to avoid any unwanted health hazards. From that time every laboratory started using biosafety cabinet as a necessary addition in their workspace.These cabinets are mainly available in three categories, andunder these three categories there are few types they are differentiated in two ways: first, the level of environmental and personal safety and second is the product safety.
Class1 biosafety cabinet only provides protection to the user and the surrounding environment but doesn’t protect the sample. Class2 cabinets provides protection for the sample ,environment and user all at once, and are divided into four types A1,A2,B1,and B2.Class3 biosafety cabinet provide with the utmost protection the user it has it has a double door autoclave and provides with a tight enclosed gas chamber. All this cabinet are chosen keeping in mind the intensity of contamination from the sample.
Advantages of using biosafety cabinet
- Eliminating risk: One of the main purposes of the biosafety cabinet is to protect the user from any kind of contamination and expose to the pathogen. Another important factor to keep in mind before using a biosafety cabinet is to make sure all the part of the machine is functioning correctly as biosafety cabinet acts a barrier between the sample and the outer world if by any chance it gets out these would be hazardous for the rest of the staff working in the lab. So it is always necessary to check whether the filtration system is working or the cabinet is airtight or not before using.
- High efficiency particulate air filter: The exhausted polluted air from the cabinet is filtered by the HEPA filter. This filter traps all kind of harmful particles and infectious agents like virus, bacteria or any harmful microorganism.
- Inbuilt ventilation system: As HEPA provides a barrier against harmful agents and organism but it couldn’t stop any harmful gas or chemical emitted from the cabinet. Ventilationprotects the user from this harmful gas and chemical which can be extremely harmful for the lungs if breathed in.
- Airtight cabinet: Another safety measure of a biosafety cabinet is that it is built in airtight form so that no harmful contagions come out or goes inside the cabinet. The airtight cabinet also traps harmful gas emitted from the cabinet.
- Provide sterile environment: It also provide sterile environment to culture cell which is used in treatment of fatal disease and medicinal purpose.
- Provide a large variety of cabinet: As a safety cabinet is divided into three classes it provides a variety of range and features to the user which they can choose according to their requirement and pocket pinch. But the class2 cabinet are considered the most economical and versatile in nature and are used by most of the labs.
- Provides with rubber gloves: Biosafety cabinets provide rubber gloves and goggles which protect the experimenter against direct contact with the sample. If the pathogen is harmful direct contact with the hand and eye can cause serious health hazards for the user and can spread to the other stuff from the effected person.
Features of biosafety cabinet
All the features of the biosafety cabinets are divided into three classes of the cabinets.
Class 1 biosafety cabinet’s features
- Built in exhaust fan
- High efficiency particulate air filter(HEPA) /carbon filter
- A front opening aperture
Class 2 biosafety cabinets’ features
- A front opening with a continuous inward airflow
- Double high efficiency particulate filter(HEPA),vertical, dual directional airflow
- Inbuilt ventilation system
- Permits different airflow patters
Class 3 biosafety cabinets’ features
A class 3 biosafety cabinet is further divided into two types of cabinet-type A and type B:
- Down flow of high efficiency particulate filter
- 30% of the HEPA filtered air are released inside the lab or out in the environment(with or without thimble duct connection)
- 70% of the remaining air are re-circulated inside the cabinet
- Biologically contaminated plenum is surrounded by positive pressure in case of type A1 and negative pressure in case of type A2.
- HEPA filtered down flow
- 30% air is re-circulated in B1 type and no air is circulated in case of type B2
- Hard ducted cabinet in external ventilation system
All these cabinets have become an imperative part of the laboratory now as it protects the experimenter from the exposure of a number of viral and bacterial diseases causing agent. A lab without a biosafety cabinet cannot be imagined in present modern medical science.