Bio safety Cabinet one of the most useful scientific instruments which designed to protect humans from hazardous chemicals. Moreover, it can also define as an engineering control device. Whose sole purpose is to protect and secure the laboratory workers. The environment of the laboratory equipment, along with the work materials. That easily exposed to harmful, infectious, and hazardous aerosols. 


These splashes might generate while manipulating certain materials that comprise infectious agents such as diagnostics specimens, stock, and primary cultures. 

It is therefore integral that the Bio Safety Cabinets (BSC) must be annually certified after their repairs, maintenance, and moving. 

PURPOSE OF Bio Safety Cabinet:

Also known as a Microbiological Safety Cabinet, this instrument serves the following purpose:

  • Product Protection
  • Personal Protection
  • Environmental Protection 


While using any device which might be prone to some chemicals, it is often recommended to consider some guidelines while its usage. Follow these Guidelines below to ensure safety in the BSC:

  1. The Microbiological Safety Cabinet results in contaminated cultures. It can also expose the operators to infectious diseases, if it is used improperly.
  2. The right usage will direct the curtain of room air to enter the grill at the very front surface of the device, therefore acting as a protective barrier. 
  3. The curtain of room air mixes with an air stream which is re circulating and passes along the HEPA Filter. The flow is downwards towards the work surface thereby creating a contamination-free environment. 
  4. The purpose of these guidelines is to secure the delicate air barriers, securing both the research product as well its researcher. 
  5. Keep only the necessarily required supplies or equipment inside the Bio Safety Cabinet 
  6. Before beginning your work, take the following precautions:
  • Wear protective equipment (PPE)
  • Gloves
  • Safety Glasses
  • Place the materials inside the cabinet before commencing the procedure 



There are three types of Bio Safety Cabinet. Let us understand the difference and working mechanism for all the three types:


This is the first and a very simply designed cabinet, which offers protection to the personnel and environment. However, it doesn’t offer product protection. These types of cabinets are compatible to be used with Risk Group 1, Risk Group 2, Risk Group 3, Risk Group 4, biological materials. 

C:\Users\Dell\Downloads\class 1.jpg
Working Style:
  1. The curtain of room air filled through the front opening. The minimum range of velocity is 0.38 m/s. 
  2. The operator can reach the work surface through the front surface inside the cabinet. 
  3. The operator can examine the work surface through the glass surface 
  4. The window is flexible enough to be fully raised, by offering access to the work surface for cleaning purposes. 


This cabinet ventilated, which offers personnel, environment, and product protection. It commonly used within research as well as clinical laboratories. It works along with the infectious agents in the Risk Groups 4, 3, and 2 and also the tissue culture.  Operating conditions and Specific installation are necessary for this type of cabinet to function correctly. 

C:\Users\Dell\Downloads\cl;ass 2.jpg
Working Style:
  1. The working mechanism of Class II Bio Safety Cabinet depends on its various types such as Type A2 and B1. 
  2. The flow of air is inward for personnel protection. 
  3. The HEPA Filtered Laminar Airflow is downward, over the work surface for the product protection.
  4. The curtain air and the re-circulated air HEPA Filtered before passing down over the work surface. 
  5. These cabinets exhausted directly into the contaminated zone, with the help of a hard ducted connection which depends on its types. 


This type of cabinet known for its highest level of protection provided to the personnel and used for the Risk 4 Agents. It is most compatible to work within Bio safety Level 3 as well as 4 laboratories. 

Working Style:
  1. This cabinet type enclosed. 
  2. Its procedure takes place under pressure to ensure that no particles have room to leak from it within the room. 
  3. The supplied air filtered through HEPA. Moreover, the exhausted air further discharged into the air through two HEPA Filters.
  4. Numerous glove boxes combined to expand the work surface.
  5. These cabinets must comprise a pass-through box which is attached, sterilized and equipped with HEPA Filtered Exhaust. 


  1. The chemicals used may damage the HEPA Filter 
  2. The Bio Safety Cabinet Fans are not spark-proof. The chemical usage may lead to fire or explosion
  3. Avoid using the Bunsen Burners or Flames. It can affect the airflow and damage the HEPA filters. 
  4. HEPA Filters do not retain the volatile filters. 

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