Biosafety Cabinet
Added: (Thu Mar 03 2022)
Pressbox (Press Release) -
Biological safety cabinets are the primary barrier against exposure to aerosols. The purpose of a biosafety cabinet is to protect the operator and the surrounding environment from biological contaminants and other hazardous materials.
Biosafety Cabinets (BSCs) are enclosed workspaces with a ventilated hood that is designed to contain pathogenic microorganisms during microbiological processes.
The primary purpose of biosafety cabinets is to protect the laboratory personnel and the environment from the pathogenic microorganism as aerosols might be formed during the processing of such microorganisms.
Biosafety cabinets are only used for certain risk group organisms and for processes that might result in aerosol formation.
These cabinets are provided with HEPA-filters that decontaminate the air moving out of the cabinet.
Biosafety cabinets might be confused with the laminar hood as both of these pieces of equipment work as enclosed workspaces. But, laminar hood only provides protection to the sample and not to the personnel and the environment, whereas biosafety cabinets protect all three.
The use of biosafety cabinets or other such physical containment is not required in the biosafety level 1, but depending on the risk assessment, some processes might require such containment.
BSCs are an essential part of biosafety as they minimize the formation of aerosol, protecting the environment, the pathogen, and the laboratory personnel.
Besides, most BSCs also function to sterilize biological materials that are kept inside the cabinets.
1. Biosafety Cabinet Class I
Class I is the most basic biosafety cabinet that provides protection to the environment and the laboratory personnel.
It doesn’t, however, provide protection to the product as the unsterilized room air is drawn over the work surface.
Class I biosafety cabinets are typically used to either enclose specific equipment like centrifuges or for procedures like aerating cultures that might potentially generate aerosols.
Biosafety cabinets of this class are either ducted (connected to the building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory).
In the Class I BSC, the room air is drawn in through the opening that also allows the entry of the operator’s arm during work.
The air inside the cabinet then takes in the aerosol particles that may have been generated and moves it away from the operator towards the HEPA filter.
The air moving out of the cabinet is thus, sterilized via the HEPA filters before its discharge to the environment.
In this way, the cabinets protect the operator and the environment from the aerosol but not the sample.
2. Biosafety Cabinet Class II
BSC-Class II cabinets provide both kinds of protection (of the samples and the environment) since makeup air is also HEPA-filtered.
The principle of operation of Class II cabinets involves a fan mounted in the top of the cabinet that draws a curtain of sterile air over the workstation where the biological products are being handled.
The air then moves underneath the work station and back up to the top of the cabinet before passing through the HEPA filters.
The exhaust that moves out of the facility consists of air being drawn into the front of the cabinet underneath the work surface.
The air drawn in acts as a barrier against the potentially contaminated air coming back out to the operator.
Class II BSCs are further divided into five types depending on the exhaust system and the mechanism of work (recirculation of the exhaust air); Type A1, Type A2, Type B1, Type B2, and Type C1.