Section 1 Biosafety Requirements for Medical Laboratories

I. Classification and Grading of Biosafety in Medical Laboratories

1. Classification

1.1 BSL-1, BSL-2, BSL-3, and BSL-4 denote the corresponding biosafety containment levels of laboratories engaged solely in in vitro operations.

1.2 ABSL-1 (Animal Biosafety Level 1, ABSL-1), ABSL-2, ABSL-3, and ABSL-4 denote the corresponding biosafety containment levels of laboratories that include operations involving live animals.

1.3 Animal biosafety laboratories are divided into laboratories conducting experimental activities with vertebrate animals and those conducting such activities with invertebrate animals.

1.4 Based on differences in experimental activities, the personal protective equipment used, and the primary containment facilities, laboratories are classified as: (1) laboratories handling pathogenic biological agents generally considered not to be transmitted through the air; (2) laboratories in which routine quantities of airborne-transmitted pathogenic biological agents can be handled effectively using safety containment devices (e.g., Class II biosafety cabinets); (3) laboratories in which routine quantities of airborne-transmitted pathogenic biological agents cannot be handled effectively using safety containment devices; (4) laboratories in which routine quantities of airborne-transmitted pathogenic biological agents are handled using positive-pressure suits equipped with life support systems; and (5) laboratories in which routine quantities of airborne-transmitted pathogenic biological agents are handled using Class III biosafety cabinets.

2. Grading

2.1 According to the level of biosafety containment provided by the laboratory against pathogenic microorganisms and in accordance with the provisions of national biosafety standards for laboratories, laboratories are graded as Level 1 (Biosafety Level 1, BSL-1), Level 2 (BSL-2), Level 3 (BSL-3), and Level 4 (BSL-4).

2.2 Laboratories with a biosafety containment level of Level 1 are suitable for handling microorganisms that normally do not cause disease in humans or animals.

2.3 Laboratories with a biosafety containment level of Level 2 are suitable for handling microorganisms that can cause disease in humans or animals but generally do not pose a serious hazard to humans, animals, or the environment, present a limited risk of transmission, rarely cause serious disease following laboratory-acquired infection, and for which effective treatment and preventive measures are available. Depending on whether the laboratory is equipped with a mechanical ventilation system, BSL-2 laboratories are divided into conventional BSL-2 laboratories and enhanced BSL-2 laboratories.

2.4 Laboratories with a biosafety containment level of Level 3 are suitable for handling microorganisms that can cause serious disease in humans or animals and are relatively readily transmitted directly or indirectly between humans, from animals to humans, or between animals.

2.5 Laboratories with a biosafety containment level of Level 4 are suitable for handling microorganisms that can cause very serious disease in humans or animals, as well as microorganisms that have not yet been discovered in China or that have been declared eradicated.

II. Requirements for Medical Laboratory Facilities and Equipment

1. Laboratory Design Principles and Basic Requirements

1.1 The site selection, design, and construction of laboratories shall comply with the provisions and requirements of national and local construction plans, biosafety, environmental protection, and building technical codes.

1.2 Laboratory design shall ensure that the level of protection against biological, chemical, radiological, physical, and other hazard sources is controlled to an assessed and acceptable degree, so as to prevent hazards to the laboratory and the surrounding environment.

1.3 The building structure of the laboratory shall conform to the relevant national building regulations.

1.4 On the basis of fully considering the special requirements for the floors, walls, ceilings, pipelines, cabinets, and other parts of biosafety laboratories with respect to disinfection, cleaning, slip resistance, leak resistance, dust accumulation prevention, and other aspects, appropriate building materials meeting national standard requirements shall be selected through comprehensive consideration of energy conservation, environmental protection, safety, and economy.

1.5 Laboratory design shall give full consideration to such matters as operational convenience, rational workflows, and personnel comfort.

1.6 Indoor environmental parameters in the laboratory, such as temperature, humidity, illumination, noise, and cleanliness, shall meet work requirements as well as requirements for personnel comfort and hygiene.

1.7 Laboratory design shall, while meeting work and safety requirements, give full consideration to energy conservation and redundancy.

1.8 Corridors and passageways in the laboratory shall not impede the passage of personnel and materials.

1.9 Emergency evacuation routes shall be designed, and emergency exits shall bear conspicuous markings.

1.10 Room doors shall have viewing windows and, where required, be fitted with door locks; the locks shall allow rapid opening from the inside, and doors and windows shall incorporate corresponding measures to prevent the entry of arthropods and rodents.

1.11 According to the needs associated with the different states of rooms or laboratory rooms—such as in use, out of service, under disinfection, and under maintenance—the laboratory shall adopt appropriate warning and access-restriction measures, such as warning signs, warning lights, warning lines, and access control.

1.12 Security of the laboratory shall conform to the safety management provisions and requirements of the relevant national authorities for laboratories of this level.

1.13 Corresponding physical security measures shall be adopted based on a risk assessment of the misuse, theft, and improper use of biological materials, specimens, pharmaceuticals, chemicals, confidential documents, and the like.

1.14 Facilities shall be purpose-designed to ensure the safety of storage, transport, collection, treatment, and disposal of test specimens and hazardous materials.

2. BSL-1 Laboratories

2.1 Sufficient space shall be provided for the installation, cleaning, maintenance, and safe operation of laboratory instruments and equipment.

2.2 The laboratory shall have sufficient space, benches, cabinets, and the like for placing laboratory equipment and articles.

2.3 Facilities for storing outer garments and personal effects shall be provided outside the laboratory work area; personal clothing and laboratory work clothing shall be stored separately.

2.4 Places for eating, drinking, and resting shall be located outside the laboratory work area.

2.5 Laboratory walls, ceilings, and floors shall be smooth, easy to clean, and leak-proof, and shall resist corrosion by chemicals and disinfectants. Floors shall be slip-resistant; carpets and hanging curtains shall not be installed inside the laboratory.

2.6 Laboratory benches (tables), cabinets, chairs, and the like shall be stable and sturdy, with rounded edges and corners. Laboratory bench tops shall be waterproof and capable of withstanding heat, organic solvents, acids and alkalis, disinfectants, and other chemical agents.

2.7 Laboratory equipment, benches, cabinets, and articles shall be arranged rationally according to the nature of the work and workflows, so as to avoid mutual interference and cross-contamination, and the arrangement shall not impede escape and emergency rescue. There shall be sufficient clearance between benches (tables), cabinets, and equipment to facilitate cleaning.

2.8 The laboratory shall be provided with handwashing sinks; faucet controls should be of the non-manual type and should be located near exits.

2.9 Laboratory doors shall have viewing windows and be lockable, and shall achieve an appropriate fire-resistance rating; door locks and the direction of door opening shall not impede the escape of personnel inside the room.

2.10 The laboratory may use natural ventilation, and windows that can be opened shall be fitted with insect-proof screens. If mechanical ventilation is used, contamination caused by airflow direction shall be avoided, and cross-contamination caused by contaminated airflow flowing between laboratories or between the laboratory and other areas shall be prevented.

2.11 Sufficient lighting shall be ensured inside the laboratory, and unnecessary reflections and glare shall be avoided.

2.12 For laboratory operations involving infectious, irritating, or corrosive substances, an eyewash station shall be provided within 30 m; where the risk is relatively high, an emergency shower shall be provided.

2.13 Where toxic, irritating, or volatile substances are used, appropriate exhaust hoods (fume hoods) shall be provided.

2.14 Where highly toxic, radioactive, or similar substances are used, corresponding safety facilities, equipment, and personal protective equipment shall be provided, in compliance with relevant national and local provisions and requirements.

2.15 Where compressed gases and combustible gases are used, safety measures shall be in place, in compliance with relevant national and local provisions and requirements.

2.16 A reliable and sufficient power supply shall be available to ensure electrical safety.

2.17 Emergency lighting shall be provided, with suitable installation locations considered, so as to ensure that personnel can leave the laboratory safely.

2.18 Sufficient fixed power sockets shall be provided to avoid multiple pieces of equipment sharing a single socket. A reliable grounding system shall be provided, and residual-current protection devices or monitoring and alarm devices shall be installed at key nodes.

2.19 The water demand required by the laboratory shall be met.

2.20 Water supply pipelines shall be fitted with backflow preventers or other effective devices for preventing backflow; the water supply and drainage systems shall be leak-free, and drains shall incorporate backflow-prevention designs.

2.21 Suitable emergency equipment shall be provided, such as fire-fighting equipment, accident-response equipment, and first-aid equipment.

2.22 Suitable communication equipment shall be provided.

2.23 Where necessary, appropriate disinfection and sterilization equipment may be provided.

3. BSL-2 Laboratories

3.1 Conventional BSL-2 Laboratories

3.1.1 Where applicable, the requirements of section 2 shall be met.

3.1.2 The door at the main entrance of the laboratory and the door of the laboratory room containing a biosafety cabinet shall be self-closing; the door at the main entrance of the laboratory shall incorporate access control measures.

3.1.3 Conditions for storing backup articles shall be provided outside the laboratory work area.

3.1.4 A pressure steam sterilizer or other appropriate disinfection and sterilization equipment shall be provided in the laboratory or in the building in which it is located; the disinfection and sterilization equipment provided shall be determined on the basis of risk assessment.

3.1.5 An eyewash station shall be provided in the laboratory work area and, where necessary, in each work room.

3.1.6 A Class II biosafety cabinet shall be provided in the laboratory area where pathogenic microorganism specimens are handled.

3.1.7 Biosafety cabinets shall be installed and used in accordance with the product design and the requirements of the instruction manual.

3.1.8 If a biosafety cabinet with ducted exhaust is used, the air shall be discharged through a duct independent of the other public ventilation systems of the building.

3.1.9 The laboratory entrance shall bear a biohazard sign, and the exit shall bear illuminated escape direction markings.

3.2 Enhanced BSL-2 Laboratories

3.2.1 Where applicable, the requirements of 3.1 shall be met.

3.2.2 An enhanced BSL-2 laboratory shall comprise an antechamber (buffer room) and a core work room.

3.2.3 The antechamber may double as a protective clothing change room. Where necessary, a preparation room and a decontamination room may be provided.

3.2.4 The doors of the antechamber should be interlockable. If interlocked doors are used, an emergency manual interlock-release switch shall be installed near the interlocked doors.

3.2.5 The laboratory shall be provided with handwashing sinks; faucet controls shall be of the non-manual type and should be located near exits.

3.2.6 A mechanical ventilation system shall be adopted. Outdoor air supply inlets and exhaust outlets shall be protected against rain, wind, debris, insects, and other animals, and the air supply inlets shall be located well away from the exhaust outlets. The exhaust system shall use HEPA filters.

3.2.7 The layout of air supply inlets and exhaust outlets in the core work room shall conform to the principle of directional airflow, helping to reduce eddies and stagnant-air zones within the room.

3.2.8 The core work room shall be at negative pressure relative to adjacent areas, with a pressure differential of no less than 10 Pa. At a conspicuous position at the entrance of the core work room, a pressure display device showing the negative-pressure status of the room shall be installed.

3.2.9 The stability of the laboratory pressure and pressure gradient shall be ensured through air supply and exhaust devices, such as exhaust fans or ventilating fans, or through automatic control measures.

3.2.10 Laboratory exhaust shall be interlocked with air supply: the exhaust shall start before the air supply and shut down after the air supply.

3.2.11 The laboratory shall have measures to prevent abnormal pressures harmful to personnel, and the containment structure/envelope shall be able to withstand the air pressure loads resulting from malfunction of the supply or exhaust fans.

3.2.12 The temperature in the core work room shall be maintained between 18°C and 26°C, and the noise level shall be below 68 dB.

3.2.13 An internally discharging pressure steam sterilizer and other suitable disinfection equipment shall be provided in the laboratory.

4. BSL-3 Laboratories

4.1 Where applicable, the requirements of section 3 shall be met.

4.2 Layout

4.2.1 The laboratory shall form an isolated zone of its own within the building or be a standalone building, and strict personnel access restrictions and controls shall be in place.

4.2.2 The laboratory shall clearly distinguish the auxiliary work area from the containment zone. Within the containment zone, the work room directly engaged in high-risk operations is the core work room, and personnel shall enter the core work room through an antechamber.

4.2.3 For laboratories handling pathogenic biological agents generally considered not to be transmitted through the air, the laboratory auxiliary work area shall at least include a monitoring room and a clean clothing change room; the containment zone shall at least include an antechamber and the core work room.

4.2.4 For laboratories in which routine quantities of airborne-transmitted pathogenic biological agents can be handled effectively using safety containment devices (e.g., biosafety cabinets), the laboratory auxiliary work area shall at least include a monitoring room, a clean clothing change room, and a shower room; the containment zone shall at least include a protective clothing change room, an antechamber, and the core work room. The core work room of the laboratory should not be directly adjacent to other public areas.

4.2.5 A transfer window (pass-through) may be installed as needed. If a transfer window is installed, its structural load-bearing capacity and airtightness shall meet the requirements of the area in which it is located, so as to ensure the integrity of the containment structure/envelope, and conditions shall be available for disinfecting the surfaces of articles inside the transfer window.

4.2.6 Full consideration shall be given to the need for large equipment such as biosafety cabinets and double-door pressure steam sterilizers to be moved into and out of the laboratory, and the laboratory shall be provided with an equipment door of sufficient size.

4.3 Containment Structure/Envelope

4.3.1 The laboratory should be classified as a Category A building, and its fire-resistance rating shall conform to the requirements of relevant standards.

4.3.2 The inner surfaces of the containment structure/envelope within the laboratory containment zone shall be smooth, corrosion-resistant, crack-free, and waterproof; all joints at gaps and penetrations shall be reliably sealed, and the surfaces shall be easy to clean and disinfect.

4.3.3 Floors within the laboratory containment zone shall be leak-proof, intact, smooth, slip-resistant, corrosion-resistant, and dust-free.

4.3.4 All doors in the laboratory shall be self-closing and, where required, shall be fitted with observation windows; the direction of door opening shall not impede escape.

4.3.5 All windows in the laboratory shall be sealed windows, and the glass shall be impact-resistant and shatter-proof.

4.3.6 The height of the laboratory and equipment rooms shall meet equipment installation requirements, and space for maintenance and cleaning shall be available.

4.3.7 No access hatches or similar openings shall be provided in the ceiling of the laboratory containment zone.

4.3.8 When the tightness of the containment structure/envelope within the laboratory containment zone is checked by the smoke test method under normal operating conditions of the ventilation system, no visible leakage shall occur at any gap.

4.4 Ventilation and Air-Conditioning System

4.4.1 An independent laboratory air supply and exhaust system shall be installed to ensure that, while the laboratory is operating, air flows from low-risk areas toward high-risk areas and that laboratory air is discharged outdoors only after filtration through HEPA filters.

4.4.2 The design of the laboratory air-conditioning system shall give full consideration to the cooling, heating, and moisture loads of equipment such as biosafety cabinets, centrifuges, carbon dioxide incubators, refrigerators, pressure steam sterilizers, and emergency showers.

4.4.3 The layout of air supply inlets and exhaust outlets in rooms within the laboratory containment zone shall conform to the principle of directional airflow, helping to reduce eddies and stagnant-air zones within the rooms; air supply and exhaust shall not affect the normal function of other equipment, and no air supply inlet shall be located above the working opening of a biosafety cabinet or above other locations where aerosols are generated.

4.4.4 Air exhausted from the laboratory containment zone shall not be recirculated, and equipment that recirculates and treats indoor air, such as split-type air conditioners, shall not be installed within the laboratory containment zone.

4.4.5 Biosafety cabinets and their exhaust duct systems shall be installed in accordance with the product design requirements and instructions for use.

4.4.6 Laboratory supply air shall be filtered through primary-efficiency and intermediate-efficiency filters and HEPA filters.

4.4.7 The outdoor exhaust outlet of the laboratory containment zone shall be located downwind of the prevailing wind, at a straight-line distance greater than 12 m from the fresh-air intake, and at least 2 m above the roof of the building in which it is located; it shall incorporate wind-, rain-, rodent-, and insect-proof design but shall not impede discharge of air into the upper atmosphere.

4.4.8 HEPA filters shall be installed as close as possible to the supply air duct (at the supply air outlet end inside the laboratory) and the exhaust duct (at the exhaust air outlet end inside the laboratory).

4.4.9 It shall be possible to disinfect and leak-test exhaust HEPA filters in situ.

4.4.10 Where HEPA filter units are used outside the laboratory containment zone, their structure shall be robust and capable of withstanding a pressure of 2500 Pa; the overall airtightness of the HEPA filter unit shall be such that, with all passageways closed and the temperature inside the chamber maintained stable, when the air pressure is maintained at 1000 Pa, the amount of air leaking from the chamber per minute shall not exceed 0.1% of the net chamber volume.

4.4.11 Sealing valves shall be installed at key nodes of the air supply and exhaust ducts of the laboratory containment zone and shall, where necessary, be capable of being fully closed.

4.4.12 Laboratory exhaust ducts shall be made of corrosion-resistant, aging-resistant, non-water-absorbent materials, and stainless steel ducts are preferred. The supply air and exhaust ducts through which sealing valves connect to the laboratory containment zone shall be robust, airtight, and easy to disinfect; the duct airtightness shall be such that, with all passageways closed and the temperature inside the ducts maintained stable, when the air pressure is maintained at 500 Pa, the amount of air leaking from the ducts per minute shall not exceed 0.2% of the net duct volume.

4.4.13 Exhaust fans shall be configured as one operating and one standby. The length of the positive-pressure section of the exhaust duct downstream of the exhaust fans shall be minimized, and this duct section shall not pass through other rooms.

4.5 Water Supply and Gas Supply Systems

4.5.1 Non-manual handwashing facilities shall be provided within the laboratory containment zone near the exit of the laboratory room; if the laboratory does not have water supply conditions, a non-manual hand-disinfection device shall be provided.

4.5.2 A backflow-prevention device or other effective device for preventing backflow contamination shall be installed between the laboratory water supply and the municipal water supply system, and such devices shall be located outside the containment zone, preferably at the boundary of the containment structure/envelope.

4.5.3 Liquid and gas pipeline systems entering and leaving the laboratory shall be robust, leak-free, rust-resistant, pressure-resistant, temperature-resistant (cold or hot), and corrosion-resistant. Sufficient space shall be available to clean, maintain, and repair exposed pipelines inside the laboratory, and shut-off valves, backflow-prevention devices, or HEPA filters shall be installed at key nodes.

4.5.4 If gas (liquid) supply cylinders or the like are provided, they shall be placed outside the laboratory containment zone in positions that are easy to replace and maintain and shall be securely installed; incompatible gases or liquids shall not be placed together.

4.5.5 If a vacuum system is provided, measures shall be taken to prevent contamination of the interior of the vacuum system; the vacuum system shall not be installed outside the laboratory premises.

4.6 Waste Treatment and Disinfection Systems

4.6.1 A pressure steam sterilizer meeting biosafety requirements shall be provided within the laboratory containment zone. A biosafety-type double-door pressure steam sterilizer is preferred; its main body shall be installed in a position that is easy to maintain, and the junction with the containment structure/envelope shall be reliably sealed.

4.6.2 Other disinfection and sterilization measures shall be available for articles within the laboratory containment zone that cannot be sterilized by pressure steam.

4.6.3 The installation position of the pressure steam sterilizer shall not affect the airflow of safety containment devices such as biosafety cabinets.

4.6.4 A liquid transfer trough (dunk tank) for passing articles may be provided as needed. If provided, it shall be made of corrosion-resistant material of adequate strength and shall facilitate replacement of the disinfectant; the junction between the trough and the containment structure/envelope shall be reliably sealed.

4.6.5 The floor liquid collection system shall incorporate devices to prevent liquid backflow.

4.6.6 Drainage pipelines should be surface-mounted, and sufficient space shall be available to clean, maintain, and repair exposed pipelines inside the laboratory. To limit the extent of contamination in the event of an accident and facilitate equipment inspection and maintenance, shut-off valves shall be installed at key nodes.

4.6.7 If a drainage system exists within the laboratory containment zone, it shall be completely isolated from the building drainage system; drainage shall lead directly to a wastewater treatment system dedicated to this laboratory.

4.6.8 All drainage pipelines shall have sufficient slope and discharge capacity to ensure that no water remains in the pipelines; at key nodes of the pipelines, backflow-prevention devices, traps (of a depth suitable for changes in air pressure differential), or sealing valves shall be installed as needed; the drainage system shall meet the corresponding requirements for pressure resistance, heat resistance, and chemical corrosion resistance, shall be securely installed and leak-free, and shall be easy to maintain, clean, and inspect.

4.6.9 The laboratory drainage system shall be provided with a separate vent, and the vent shall be fitted with a HEPA filter or other reliable disinfection device, while good ventilation at the vent shall be ensured. If the vent is fitted with a HEPA filter, the HEPA filter shall be capable of being disinfected and leak-tested in situ.

4.6.10 Based on risk assessment, the laboratory shall determine the disinfection method for sewage (including waste) from the laboratory containment zone; the disinfection effect shall be monitored periodically to ensure the effectiveness of each disinfection.

4.6.11 Sewage from the laboratory auxiliary area shall be treated to meet the discharge standards before it may be discharged into the municipal pipe network.

4.6.12 Conditions shall be available for disinfecting the laboratory containment zone, its facilities and equipment, and the pipelines directly connected to it.

4.6.13 Portable disinfection devices shall be provided in areas within the laboratory containment zone where biological contamination may occur (e.g., near biosafety cabinets and centrifuges), and an adequate supply of suitable disinfectants shall be kept on hand. In the event of an accident, disinfection shall be carried out promptly.

4.7 Power Supply System

4.7.1 Power shall be supplied according to the first-level (Class I) load requirement to meet the laboratory's electricity demand, with redundancy.

4.7.2 Biosafety cabinets, supply and exhaust fans, lighting, automatic control systems, and monitoring and alarm systems shall be equipped with uninterruptible backup power, and the power supply shall be maintained for at least 30 min.

4.7.3 A dedicated distribution box shall be installed at a safe location in the laboratory auxiliary work area; its placement shall take into account the risks of personnel misoperation and malicious damage, as well as the risks of exposure to moisture and flooding.

4.7.4 Power supply outlets shall be configured as needed.

4.8 Lighting System

4.8.1 The illumination in the core work room of the laboratory shall be no less than 350 lx, and the illumination in other areas shall be no less than 200 lx; ceiling-mounted, sealed, waterproof, clean-room type luminaires are preferred.

4.8.2 Excessively strong light and light reflections shall be avoided.

4.8.3 An emergency lighting system and illuminated emergency evacuation direction markings shall be provided.

4.9 Automatic Control, Monitoring, and Alarm Systems

4.9.1 The laboratory automatic control system shall consist of a computerized central control system, communication controllers, field controllers, and the like. It shall provide both automatic and manual control functions; emergency manual control shall have priority and shall incorporate hardware interlocks.

4.9.2 The laboratory automatic control system shall ensure correct directional airflow and stable pressure and pressure differentials within the laboratory containment zone.

4.9.3 The interlock control sequence for the laboratory ventilation system shall start the exhaust first and then the air supply; on shutdown, the air supply and sealing valves shall be closed first, followed by the exhaust and sealing valves.

4.9.4 The ventilation system shall be interlocked with local exhaust equipment such as biosafety cabinets and exhaust hoods (fume hoods) to ensure stable laboratory operation and to maintain an orderly pressure gradient during startup and shutdown of the laboratory ventilation system.

4.9.5 When the exhaust system fails, the supply fan shall be shut down first, and the supply fan shall be restarted only after the standby exhaust fan has started, so as to avoid positive pressure in the laboratory.

4.9.6 When the air supply system fails, the laboratory negative pressure shall be effectively controlled within an acceptable range, so as to avoid compromising the safety of laboratory personnel, the normal operation of safety containment devices such as biosafety cabinets, and the safety of the containment structure/envelope.

4.9.7 It shall be possible to continuously monitor the resistance of the HEPA filters in the supply and exhaust systems.

4.9.8 At a conspicuous position at the entrance of rooms subject to pressure control, a device displaying the room pressure shall be installed.

4.9.9 The central control system shall be capable of real-time monitoring, recording, and storage of parameters subject to control requirements within the laboratory containment zone—such as pressure, pressure gradient, temperature, and humidity—as well as the operating status of key facilities and equipment such as exhaust fans and supply fans and the current status of the power supply. A historical record archive system shall be provided so that historical records can be viewed at any time; historical data should preferably be presented as trend curves combined with text records.

4.9.10 The signal acquisition interval of the central control system shall not exceed 1 min, and the various parameters shall be easy to distinguish and identify.

4.9.11 Laboratory automatic control system alarms shall be divided into general alarms and emergency alarms. General alarms are those that do not immediately affect safety and under which experimental activities may continue, such as increased filter resistance or deviation of temperature and humidity from normal values; emergency alarms are those that affect safety and require termination of experimental activities, such as positive pressure in the laboratory, sustained loss of the pressure gradient, fan switchover failure, power outage, and fire. General alarms shall be display alarms, whereas emergency alarms shall be audible-and-visual alarms and display alarms; the emergency alert may be displayed simultaneously to personnel inside and outside the laboratory, and an emergency alarm button shall be provided in the core work room.

4.9.12 At the entrance of the antechamber to the core work room, there shall be a device indicating the working status of the core work room and, where necessary, an interlock mechanism restricting entry into the core work room.

4.9.13 The laboratory shall be equipped with closed-circuit television monitoring, with cameras installed at key positions to monitor and record in real time the activities in the laboratory and the surroundings of the laboratory. The monitoring equipment shall have sufficient resolution and image storage capacity.

4.10 Laboratory Communication System

4.10.1 A facsimile machine or other electronic equipment for transmitting documents and data to the outside shall be provided within the laboratory containment zone.

4.10.2 Voice communication systems shall be installed in the monitoring room and inside the laboratory. If an intercom system is installed, a selective communication mode is preferred, in which incoming calls into the laboratory are controlled while outgoing calls are uncontrolled.

4.11 Laboratory Access Control Management System

4.11.1 The laboratory shall have an access control management system that ensures that only authorized personnel may enter the laboratory and that can record personnel entry and exit.

4.11.2 The laboratory shall be provided with a door interlock system, and an emergency manual interlock-release switch shall be installed near the interlocked doors so that, when needed, the door interlock can be released immediately.

4.11.3 In an emergency, all doors fitted with interlock functions shall be capable of being opened.

4.12 Parameter Requirements

4.12.1 The containment structure/envelope of the laboratory shall be able to withstand the air pressure loads resulting from malfunction of the supply or exhaust fans.

4.12.2 For laboratories handling pathogenic biological agents generally considered not to be transmitted through the air, the pressure differential between the (negative) pressure in the core work room and the outdoor atmospheric pressure shall be no less than 30 Pa, and the (negative) pressure differential relative to adjacent areas shall be no less than 10 Pa; for laboratories in which routine quantities of airborne-transmitted pathogenic biological agents are handled effectively using safety containment devices, the pressure differential between the (negative) pressure in the core work room and the outdoor atmospheric pressure shall be no less than 40 Pa, and the (negative) pressure differential relative to adjacent areas shall be no less than 15 Pa.

4.12.3 The minimum air change rate of each room in the laboratory containment zone shall be no less than 12 ACH.

4.12.4 The laboratory temperature should be controlled within the range of 18°C to 26°C.

4.12.5 Under normal conditions, the relative humidity in the laboratory should be controlled within the range of 30% to 70%; under disinfection conditions, the relative humidity in the laboratory shall meet the technical requirements for disinfection.

4.12.6 With the biosafety cabinet operating, the noise level in the core work room shall not exceed 68 dB.

4.12.7 The at-rest cleanliness level of the laboratory containment zone shall be no lower than Class 8.

5. BSL-4 Laboratories

5.1 Types

5.1.1 BSL-4 laboratories are divided into positive-pressure-suit laboratories and cabinet-type laboratories.

5.1.2 In a cabinet-type laboratory, all operations involving microorganisms are carried out in a Class III biosafety cabinet. In a positive-pressure-suit laboratory, personnel shall wear positive-pressure protective suits equipped with life support systems.

5.1.3 Where applicable, the requirements of section 4 shall be met.

5.2 Layout

5.2.1 The laboratory shall form an isolated zone of its own within the building or be a standalone building, and personnel access control shall be in place.

5.2.2 The containment zone of a BSL-4 laboratory shall at least include the core work room, an antechamber, an outer protective clothing change room, and the like, and the outer protective clothing change room shall be an air lock. The auxiliary work area shall include a monitoring room, a clean clothing change room, and the like.

5.2.3 The containment zone of a positive-pressure-suit BSL-4 laboratory shall include the core work room, a chemical shower room, an outer protective clothing change room, and the like. The chemical shower room shall be an air lock and may double as an antechamber. The auxiliary work area shall include a monitoring room, a clean clothing change room, and the like.

5.3 Containment Structure/Envelope

5.3.1 The containment structure/envelope of the laboratory containment zone shall be located as far as possible from the external walls of the building.

5.3.2 The core work room of the laboratory shall, as far as possible, be located in the central part of the containment zone.

5.3.3 The airtightness of the containment structure/envelope of the laboratory containment zone shall be such that, with all passageways of the tested room closed and the temperature inside the room maintained stable, after the air pressure in the room rises to 500 Pa, the natural pressure decay within 20 min is less than 250 Pa.

5.3.4 A transfer window (pass-through) may be installed as needed. If a transfer window is installed, its structural load-bearing capacity and airtightness shall meet the requirements of the area in which it is located; where necessary, a transfer window meeting air-lock requirements and providing disinfection conditions shall be provided.

5.4 Ventilation and Air-Conditioning System

5.4.1 Laboratory exhaust air shall be treated through two stages of HEPA filters before being discharged.

5.4.2 It shall be possible to disinfect and leak-test the supply and exhaust HEPA filters in situ.

5.5 Life Support System

5.5.1 A positive-pressure-suit laboratory shall also be equipped with emergency backup gas cylinders, and the gas supply duration of the emergency backup cylinders shall be no less than 60 min per person.

5.5.2 The life support system shall have uninterruptible backup power, and the continuous power supply duration shall be no less than 60 min.

5.5.3 The pressure, flow rate, oxygen content, temperature, humidity, and content of harmful substances in the breathing gas shall meet occupational safety requirements.

5.5.4 The life support system shall be equipped with the necessary alarm devices.

5.5.5 According to the work situation, personnel entering the laboratory shall be provided with properly fitting positive-pressure protective suits that meet work needs, and the laboratory shall be equipped with positive-pressure suit leak-test apparatus and maintenance tools.

5.6 Waste Treatment and Disinfection Systems

5.6.1 A biosafety-type pressure steam sterilizer shall be provided in the core work room of the laboratory; if a double-door pressure steam sterilizer is provided, the room in which its main body is located shall be at negative indoor pressure, and it shall be installed in a position within the laboratory containment zone that facilitates replacement and maintenance.

5.6.2 The chemical shower disinfection device shall remain usable even when no power is supplied, and the capacity of the disinfectant reservoir shall meet the disinfectant consumption demand under all circumstances.

5.6.3 The surfaces of all articles, or their packaging, that need to be transported out of the laboratory from within the containment zone shall be reliably sterilized and meet safety requirements.

5.7 Parameter Requirements

5.7.1 The indoor pressure in all areas within the laboratory containment zone shall be negative; the pressure differential between the (negative) pressure in the core work room and the outdoor atmospheric pressure shall be no less than 60 Pa, and the (negative) pressure differential relative to adjacent areas shall be no less than 25 Pa.

5.7.2 A cabinet-type laboratory shall handle pathogenic biological agents inside a Class III biosafety cabinet or an equivalent safety containment device; at the same time, it shall be provided with article transfer equipment matched to the safety containment device and with a biosafety-type pressure steam sterilizer.

III. Medical Laboratory Waste Disposal

Waste refers to all articles that are to be discarded.

Within the laboratory, the ultimate method of waste disposal is closely related to the degree to which contamination has been removed. For routine laboratory supplies, very little contaminated material actually needs to be removed from the laboratory or destroyed. Most glassware, instruments, and laboratory coats can be reused or recycled. The primary principle of waste disposal is that all infectious materials must be decontaminated and autoclaved within the laboratory.

For all laboratory items used to handle potentially infectious microorganisms or animal tissues, the main questions to be considered before they are transported out of the laboratory are:

(1) Whether prescribed procedures have been followed to effectively decontaminate or disinfect these items.

(2) If not, whether they have been packaged in the prescribed manner for on-site incineration or transport to another location equipped with incineration facilities for treatment.

(3) Whether the handling of decontaminated items will pose any potential biological or other hazards to personnel directly involved in discarding them or to personnel who may come into contact with the discarded items outside the facility.

(4) Whether any potential hazard to the environment will arise.

1. Decontamination

Autoclaving (pressure steam sterilization) is the preferred method of decontamination. Items that require decontamination and destruction shall be placed in containers and autoclaved. Alternative methods capable of removing and/or killing microorganisms may also be used.

2. Procedures for Handling Contaminated Materials and Waste

Infectious substances and their packaging shall be identified and handled separately, and the relevant work shall comply with relevant national regulations. Waste can be divided into the following categories:

(1) Non-contaminated (non-infectious) waste that can be reused or recycled, or that can be treated as ordinary "household" waste.

(2) Contaminated (infectious) sharps—hypodermic needles, scalpels, other sharp instruments, and broken glass; this waste shall be collected in lidded, puncture-resistant containers and treated as infectious waste.

(3) Contaminated materials that are reused or recycled after decontamination by autoclaving and washing.

(4) Contaminated materials that are incinerated after autoclaving.

(5) Contaminated materials that are incinerated directly.

3. Contaminated (Potentially Infectious) Materials Reused After Autoclaving

Contaminated (potentially infectious) materials to be reused after autoclaving shall not be washed beforehand; any necessary washing or repair must be carried out after autoclaving or disinfection.

4. Discarded Contaminated (Potentially Infectious) Materials

Apart from sharps, which are handled according to the method above, all other contaminated (potentially infectious) materials shall be placed in leak-proof containers and autoclaved before being transported out of the laboratory. After autoclaving, the items are packaged as required, placed in medical waste bins in the medical waste storage room, and disposed of collectively by a designated agency. If the laboratory is equipped with an incinerator, autoclaving may be dispensed with: contaminated materials shall be placed in designated containers (such as color-coded bags) and transported directly to the incinerator. Reusable transport containers shall be leak-proof and have tight-fitting lids. These containers shall be disinfected and cleaned before being returned to the laboratory for reuse.

Containers and wide-mouth jars for waste, preferably unbreakable ones (such as plastic items), shall be placed on each workbench. When a disinfectant is used, the waste shall be brought into full contact with the disinfectant (i.e., no air bubbles shall block contact), and an appropriate contact time shall be maintained depending on the disinfectant used. Waste containers shall be autoclaved and cleaned before reuse.

Incineration of contaminated materials must obtain approval from the public health and environmental protection authorities as well as the laboratory biosafety management department.