Dunk Tank Pass box: high efficiency disinfection and goods transfer system for biosafety laboratory

Liquid transfer box, commonly known as the aqueduct, is an important safety equipment in the laboratory, which is used to disinfect and safely dispose of dangerous organisms during the experiment. It is a special form of transmission window equipped with a disinfectant basin. It is mostly used in high-level biosafety laboratories. It is usually installed between two laboratories or laboratories and corridors to transfer items through dunk tank. The two doors are interlocked to ensure that the air does not produce direct convection in the two rooms and does not produce interactive pollution between the rooms.

Level 3 and Level 4 biosafety laboratories has inactivation or destruction effect on living tissues, microorganisms and articles made of certain materials. In this case, only the pass box with fumigation and disinfection function or the transmission window with liquid medicine can be used for transmission. The dunk tank with disinfection function needs to be connected with disinfection equipment, and the space requirements for disinfection should be considered in the overall design of the laboratory. The operating space requirements for disinfectant replacement shall be considered for the liquid medicine pass box.

The delivered articles are disinfected by chemical disinfectant during the transfer from the core workshop to the isolation corridor. The aqueduct is filled with disinfectant liquid. The articles that are not sterilized by high temperature and high pressure or radiation are disinfected by the disinfectant liquid liquid, and then the disinfectant liquid is discharged to the outside by the drain valve. The aqueduct is equipped with liquid level detection, liquid level display and low level alarm functions. For larger aqueducts, article transfer devices can be installed.

1.Principle

Biosafety dunk tank is mainly to disinfect by disinfectant. During the experiment, the items that need to be disinfected are put into the biosafety aqueduct, an appropriate amount of disinfectant is added, and then the aqueduct door is closed. The disinfectant solution is effective in killing harmful organisms and dissolving them in the solution. At the same time, the biosafety aqueduct can also be equipped with a waste liquid treatment system to prevent the leakage and spread of harmful viruses.

2. Role

biosafety aqueduct is to disinfect and safely dispose of dangerous organisms through the liquid during the experiment. Because some items in the laboratory are not disinfected by high temperature and high pressure or ultraviolet rays, they cannot be disinfected by ordinary transfer windows through high temperature and high pressure or ultraviolet lamps, so biosafety transfer windows with aqueducts have appeared. It can effectively kill harmful organisms that may exist in the laboratory and ensure that the laboratory personnel and other organisms will not be harmed during the experiment. At the same time, it can also prevent the leakage and spread of harmful organisms and protect the safety of the laboratory and the surrounding environment.

3. Structure and design requirements

The structural design of the biosafety aqueduct has strict requirements and must comply with relevant national standards and regulations. It is usually composed of a soaking tank box, a cover plate, and a drain valve component. The cover plate (side door) is a symmetrical mechanical compression type or inflatable air-tight door. The aqueduct is interlocked by interlocking device, so that the two cover plates of the aqueduct cannot be opened at the same time, so as to ensure that the airflow on both sides does not flow with each other. Among them, the stainless steel shell must have the characteristics of corrosion resistance and high temperature resistance. The disinfectant basin needs to be equipped with a variety of disinfectants to meet different disinfection needs. The material can be 304 stainless steel or 316 stainless steel. In addition, safety factors and durability requirements need to be considered in the design.

4. The advantages of integrated use of biosafety transfer windows and aqueducts

● Compact design concept, save the use of the environment;

● Solve different operation processes in the same area;

● respectively with interlocking function, in line with GMP standards;

● Higher level of air tightness protection;

6. Suppression inspection requirements

Airtightness of dunk tank: refer to the standard of pass box, under the condition that the initial pressure of aqueduct cavity is -500Pa, the airtightness test is carried out by pressure attenuation method, and the natural attenuated air pressure within 20min is not less than -250PA.

7. Application Scenarios

Biosafety aqueduct is mainly used in high-level biosafety laboratories that need to carry out animal and plant epidemic prevention and control, human health protection and other fields, and is generally used in biosafety level 3 laboratories and biosafety level 4 laboratories. For example, in virology, bacteriology, immunology, etc. laboratories, there is a need for disinfection and safe handling of possible pests. For example, in some virology laboratories, biosafety aqueducts are used to disinfect and safely handle virus samples, ensuring the safety of laboratory personnel and other organisms. In addition, in food processing enterprises, biosafety aqueducts are also used to sterilize and safely treat food that may contain harmful organisms to ensure food safety.

References

National Certification and Accreditation Standardization Technical Committee. GB 19489-2008 Understanding and implementation of general requirements for laboratory biosafety. Beijing: China Standard Press, 2010

[2] China Academy of Building Research, Technical Code for Biosafety Laboratory Building: GB 50346-2011. Beijing: China Building Industry Press, 2012

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