1 Overview
When the laboratory staff is dealing with pathogenic microorganisms, experimental materials containing the original microorganisms or parasites, the laboratory and animal laboratory are designed to ensure that the subjects do not pose biological hazards to humans, animals and plants, and to ensure that the surrounding environment is not contaminated. There are special requirements for construction. According to the degree of harm of the experimental object, the biosafety laboratory is generally divided into four levels, of which the requirement for biosafety isolation is low, and the fourth level is high. Levels 3 and 4 belong to other biosafety laboratories, sometimes referred to as biosafety clean rooms, commonly known as P3 and P4 laboratories.
2. Economic aspects
(1) For other biosafety laboratories, due to their high cost, it is not advisable to blindly build and avoid waste. Before establishing a biosafety laboratory, a thorough understanding of the main uses of the laboratory, basic performance indicators, and the purpose of the construction laboratory should be provided. The level of the biosafety laboratory should be determined according to the hazard of the test subject, and the high level cannot be blindly pursued, because the higher the level, the higher the construction and operation costs.
(2) To balance the relationship between initial investment and operating expenses, you should not only pursue low initial investment, choose cheap equipment or simple system form, but ignore running costs and avoid the cost of building. The situation. The life cycle cost analysis method should be carried out during design, and a reasonable and economical design plan should be selected after technical and economic analysis.
3. Carefully choose the design and construction unit
(1) Due to the increasing number of units that want to build biosafety laboratories, some companies that have little knowledge of biosafety laboratories also want to squeeze into the construction market of biosafety laboratories. However, due to the special nature of biosafety laboratories, especially a series of special requirements in terms of technology and biosafety, it is difficult to construct if there is no other biosafety laboratory built or the biosafety laboratory is not well understood. Qualified biosafety laboratories cause waste of manpower and material resources.
(2) At present, there are not many enterprises in China that have the ability to undertake the design and construction tasks of other biosafety laboratories. Therefore, users should be particularly cautious when selecting contractors. Companies that have designed or built other biosafety laboratories and are qualified should be responsible for themselves and for society. In particular, it should be emphasized that the air purification and vacuum control systems of biosafety laboratories are much more important than general heating, ventilation and air conditioning systems, and detailed design calculations must be performed.
(3) In recent years, some foreign companies have also built some three-level biosafety laboratories in China, some of which are successful, but there are some defects, mainly their technical points for biosafety laboratories. Not very clear. Therefore, although they use a lot of expensive building materials, they still do not meet the requirements.
4, the problem of the layout
Too cumbersome layout can only increase the inconvenience in use, and it can't really make much practical effect; copying the simple laboratory layout abroad is not in line with China's environmental characteristics and management level. Some practical projects have increased the initial investment and management difficulty due to the unreasonable layout of the layout, and some have affected the cleanliness of the air in the laboratory. Therefore, a sound and reasonable layout is very important, which requires owners and designers to have a full understanding of biosafety and full communication with each other.
5, air conditioning ventilation system
(1) Some designers are unclear about the concept of biosafety, resulting in unreasonable airflow organization in the biosafety laboratory and excessive dead space. The biosafety laboratory requires that the airflow must flow from the clean area to the contaminated area. The position of the indoor air supply and exhaust vents should be such that the airflow stagnation space is reduced to a small size, and the indoor air vents should be placed in the danger zone of the Zui, arranged on one side. There must be no obstacles. Some engineering air outlets blow against the biosafety cabinet , and the airflow and the protective airflow of the biological safety cabinet working window interfere with each other, which increases the leakage of the causative factors.
(2) Poor sealing performance, including the sealing of the laboratory envelope and the sealing of the air conditioning ventilation duct. The poor sealing performance of the retaining structure is mainly in the door and window parts, and some joints of the partition wall have poor sealing performance; the manufacturing process of the air conditioning ventilation duct does not meet the requirements, and the sealing material is unqualified. These are contrary to the basic principles of high biosafety laboratory requirements for good sealing.
(3) The installation position of the filter of the exhaust system is unreasonable, and the high-efficiency filter is installed at the positive pressure end of the exhaust fan, which cannot meet the requirement of negative pressure of the polluted exhaust section.
(4) The exhaust system does not add a high-efficiency filter, but uses high-altitude emissions, which is also not allowed. Some design or construction units have problems understanding high-speed emissions. They believe that high-speed discharge means that the wind speed in the exhaust pipe should exceed 13 m / s. As a result, the exhaust resistance is large, and the required exhaust air volume is not achieved. It is difficult to maintain indoors. The required negative pressure. Or the exhaust fan head is enlarged, and the noise and power consumption are also increased.
(5) High-efficiency filter replacement and leak detection problems, especially high-efficiency exhaust filters. Exhaust air-efficient filters must be sterilized prior to replacement. Disinfection must be considered during design and installation, and replacement is easy. In order to ensure environmental safety, exhaust air efficient filters should also consider the possibility of leak detection, or take other measures to ensure that no leakage is observed.
(6) Indoor installation of split air conditioner or vertical cabinet air conditioner, which is not allowed in the biological clean room, because the heat exchanger in the air conditioner is actually a microbial breeding device, which seriously pollutes the laboratory environment. Some construction units do not install split air conditioners or cabinet air conditioners in the laboratory, but install them in adjacent rooms and use air ducts for air supply. However, because other biosafety laboratories must use DC wind, the heat exchangers of ordinary air conditioners are designed according to indoor circulating winds, which can not meet the large turbulence requirements of DC winds. In addition, in order to reduce the cost, the equipment capacity is not rich, fundamentally The required indoor temperature is not reached. Experimenting in other biosafety laboratories requires special protective clothing, sometimes it is necessary to wear multiple layers. If the temperature does not meet the requirements, the experimenter's feelings will be imaginable.
In addition, if the third-level biosafety laboratory is built into a positive pressure laboratory, the fire damper is not installed according to the regulations, the purification workbench is used instead of the biological safety cabinet, and the air exhaust of the safety cabinet is used instead of the room exhaust. Serious mistakes. The general purification workbench and the biological safety cabinet work completely differently, and it is very dangerous to protect the human body from microbial infection.
6, equipment standby problem
(1) No backup power is set. For example, a three-level biosafety laboratory requires two independent power supplies, or a standby generator set, and a four-stage biosafety laboratory requires a third backup power source. If the condition is not available, an uninterruptible power supply is required. The power supply capacity of the uninterruptible power supply is not less than 45 minutes. Some three-level biosafety laboratories use only ordinary municipal power supply, and there is no backup measure, which obviously does not meet the requirements.
(2) Alternate problems with exhaust fans. In order to ensure that the laboratory maintains negative pressure under any circumstances, the exhaust system of the third- and fourth-level biosafety laboratories requires the installation of a spare exhaust fan, but many projects are not set. What's more, there is no spare fan in the exhaust system, but the air supply has a spare fan.
7, system adjustment and control functions
System adjustment and control functions. In order to strictly ensure the pressure difference and pressure gradient in various areas of the laboratory, the necessary air volume adjustment devices should be installed on the air supply and exhaust system, and cannot be replaced by ordinary control valves. Some engineering biosafety cabinets and room exhausts have not undergone rigorous design calculations, and the pressure gradients required by the design cannot be met during system commissioning, or the pressure gradient is unstable. The lack of a sound self-control system and the lack of capacity to respond to emergencies are also a major problem in the completed laboratories. Although the pressure gradient of each area can be adjusted to meet the requirements during completion acceptance, in the actual operation process, the laboratory without the automatic control system cannot ensure the pressure gradient due to the change of high-efficiency filter resistance and the lack of professional operation management personnel. Therefore, we must pay attention to the automatic control system of the biosafety laboratory.
8, should pay attention to engineering testing
After the biosafety laboratory is completed, it should first be tested by a nationally authorized testing agency. This is an important part. The content of the test should include the rigor of the laboratory, the negative pressure between each room, the flow of air flow, high-efficiency filter leak detection, cleanliness level, and automatic control system.
9, other matters needing attention
It is strictly forbidden to build a biosafety laboratory into a positive pressure laboratory. Fire dampers should be installed according to the regulations. It is strictly forbidden to use the purification workbench instead of the biological safety cabinet. It is strictly forbidden to use the air exhaust of the safety cabinet instead of the room exhaust.
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