Guidance on the selection of biosafety cabinets 2/2

III biosafety cabinet is applicable to laboratories with Class III or Class IV biosafety level.
3. Ventilation connection of biosafety cabinet
Class II A1 type and A2 type outdoor biological safety cabinets are connected with "sleeve type" or "umbrella type exhaust hood type". The casing is installed on the exhaust pipe of the safety cabinet to lead the gas discharged from the safety cabinet into the exhaust system of the building. An opening with a diameter difference of 2.5 cm is left between the sleeve and the exhaust pipe of the safety cabinet, so that the air in the laboratory can be pumped into the exhaust system of the building together. The ventilation capacity of the building must meet the requirements for ventilation in rooms and cabinets. The sleeve must be removable or designed to operate and test the biosafety cabinet. Generally, the fluctuation of building air flow will not have a great impact on the function of the biosafety cabinet with sleeve connection.
Class II B1 and B2 biosafety cabinets are firmly connected to the ventilation system of the building through hard pipes, that is, without any openings, or to the special ventilation system. The exhaust air volume and static pressure of the building exhaust system must be exactly consistent with the requirements of the manufacturer. It takes more time to certify a hard piped biosafety cabinet than to recirculate air back to the room or use a jacketed biosafety cabinet.
4. Selection of biosafety cabinet
When purchasing a biosafety cabinet, consider whether the biological protection provided is for the operator or for the test sample; If the protection is aimed at operators, it should be clear whether it is aimed at pathogenic microorganisms, toxic chemicals or both. If it is aimed at pathogenic microorganisms, the biological hazard level of microorganisms should also be emphasized; For toxic chemicals, the following principles can be followed: volatile or toxic chemicals are not allowed to operate in Class I or Class II Type A biosafety cabinets. Class II B1 type biosafety cabinet can only be used for the operation of a small amount of volatile or toxic chemicals, and Class II B2 type biosafety cabinet must be used for the operation of a certain amount of volatile or toxic chemicals. Different types of biosafety cabinets have different exhaust characteristics