Biological Safety sterilizer (biological safety cabinet BSC) is a negative pressure safety device for air purification that can prevent the aerosol escape of some dangerous or unknown biological particles in the process of experimental operation and treatment. It is widely used in microbiology, biomedicine, genetic engineering, biological products and other fields of scientific research, teaching, clinical testing and production, is the basic safety protection equipment in the primary protection barrier of laboratory biosafety.
1.The working principle of biological safety sterilizer
The working principle of the biological safety sterilizer is to pump the air in the chamber outwards to keep the negative pressure in the chamber and protect the staff through the vertical air flow. The outside air is filtered through the high-efficiency particulate air filter (HEPA filter) and then into the chamber to avoid contaminant of the sample; The air in the chamber also needs to be filtered by a HEPA filter and then discharged into the atmosphere to protect the environment.
2.Structure of biological safety sterilizer
The biological safety sterilizer is generally composed of two parts: the cabinet body and the scaffold. The cabinet body mainly includes the following structure:
1)Air filtration system
The air filtration system is the main system to ensure the performance of the equipment. It is composed of a driving fan, an air duct, a circulating air filter and an exhaust air filter. Its main function is to continuously make clean air into the chamber, so that the flow rate of downdraft (vertical airflow) in the working area is not less than 0.3m/s, to ensure that the cleanliness of the working area reaches 100 levels. At the same time, the exhaust air is also purified to prevent environmental pollution.
The core component of the system is the HEPA filter, which adopts special fireproof material as the frame, the frame is separated into a grid with corrugated aluminum sheet, which is filled with emulsified glass fiber subparticles, the filtration efficiency can reach 99.99%~100%. The pre-filter cover or pre-filter of the air inlet enables the air to enter the HEPA filter after pre-filtration and purification, which can prolong the service life of the HEPA filter.
2)Outlet exhaust bellows system
The exhaust bellows system is composed of an exhaust bellows shell, a fan and an exhaust pipe. The outer exhaust fan provides the exhaust power, the unclean air in the chamber is extracted, And by the exhaust filter to purify the unclean air and protecting the sample and experimental items in the cabinet chamber. Because of the outer exhaust, the chamber is under negative pressure to prevent the air in the working area from escaping, and to protect the operators.
3.Sliding front window drive system
Sliding front window drive system is composed of front glass door, door motor, traction mechanism, drive shaft and limit switch. The main function is to drive or traction each door shaft, so that the front glass door will in the normal position during the equipment is running.
Biosafety is never just about individuals. In addition to preventing laboratory workers from becoming infected, biosafety is also about preventing infectious materials or strains from leaving the laboratory.
The following is the biosafety level of the laboratory for your reference:
According to the risk of infectious microorganisms, it is divided into four levels:
Hazard rating 1 (low individual hazards , low group hazards)
Biological factors such as bacteria, fungi, viruses and parasites that do not cause illness in health workers and animals.
Hazard rating 2 (medium individual hazards, limited group hazards)
Pathogens that cause disease in humans or animals but generally do not cause serious harm to health workers, populations, livestock or the environment. Laboratory infections do not cause serious disease, effective treatment and prevention measures are available, and the risk of transmission is limited.
Hazard rating 3 (high individual hazards , low group hazards)
Pathogens that causes serious disease in humans or animals, or causes serious economic damage, but is not normally transmitted from one person to another by casual contact, or can be treated with antibiotic and antiparasitic drugs.
Hazard rating 4 (high individual hazards , high group hazards)
Pathogens that causes a very serious disease in humans or animals, generally incurable, and is easily transmitted directly, indirectly or by casual contact from person to person, or from animal to human, or from human to animal, or from animal to animal.
Therefore, the operation of microorganisms with different dangerous levels needs to be carried out in laboratories of certain safety levels (BSL1-4 level laboratories).
In fact, the biological safety sterilizer focuses more on the protection of operators and the environment, to prevent the spread of pathogenic microorganisms caused by personnel injury and environmental pollution.