What are the requirements for designing an animal laboratory?
Compared to ordinary biological laboratories, animal laboratories require stricter environmental control, more precise workflow layout, and more thorough disinfection and sterilization.
Regarding site selection and layout, animal laboratories should ideally be independently located or situated at the far end of a building, away from noisy and contaminated areas. The internal space needs to be strictly divided into three functional zones: the front area, the feeding and experimental area, and the auxiliary area. The front area includes quarantine rooms, offices, and storage rooms; the feeding and experimental area is the core functional area; and the auxiliary area includes disinfection rooms and waste disposal rooms. Personnel, material, and animal flows must be separated, following a unidirectional flow principle to avoid cross-contamination. This zoned management approach essentially aims to achieve clean-contamination separation—clean materials flow from clean areas to contaminated areas, not the other way around.
In terms of building decoration, the walls, floors, and ceilings of animal laboratories must be flat, smooth, corrosion-resistant, and easy to clean. Corners need to be rounded to eliminate unsanitary areas. This is more stringent than in ordinary laboratories because animal husbandry generates a large amount of dust, hair, and microorganisms, and any corner can become a source of contamination. For wall materials, rock wool cleanroom steel panels with a thickness of 50 mm and a steel plate thickness of at least 0.5 mm are recommended to ensure Class A fire resistance. For areas requiring frequent rinsing, such as disinfection rooms, magnesium oxide boards with superior moisture resistance should be used. PVC flooring should be laid on the floor and extended to the walls to form skirting boards, with a rounded transition to the wall surface for easy cleaning. Doors and windows also need to be equipped with measures to prevent insects, rodents, and escape of laboratory animals.
The air conditioning and ventilation system is a core challenge in animal laboratory design. The key is to ensure directional airflow—from clean areas to contaminated areas. Ordinary housing rooms need to maintain positive pressure to prevent external contaminants from entering; while laboratories involving infectious animal experiments must maintain negative pressure to prevent pathogen leakage. Sufficient air exchange is required to effectively reduce the concentration of ammonia produced by animals. Exhaust vents are usually located under the cages or at the bottom of the racks, so that polluted air produced by the animals can be directly drawn away, rather than allowing it to spread throughout the room. Exhaust air requires treatment before being released, commonly through high-efficiency filtration combined with activated carbon adsorption for odor removal, preventing unpleasant smells from affecting the surrounding environment.
The design of water supply, drainage, and disinfection systems is equally crucial. Drinking water for laboratory animals in barrier environments must meet sterility requirements, necessitating the installation of pure water preparation devices or autoclaves. Drainage pipes should be equipped with water seals and backflow prevention devices to prevent odors and microorganisms from flowing back into the environment. Wastewater from experiments and cage rinsing must undergo harmless treatment before being discharged into the municipal sewer system. Regarding disinfection facilities, ultraviolet lamps are used for air and surface disinfection, autoclaves for sterilizing cages, bedding, and drinking water, and chemical disinfectant sprays are used for routine environmental disinfection. These disinfection methods must be used in combination to ensure a sterile environment in the animal laboratory.
Electrical and fire protection design has its own specific requirements. Animal laboratories must be equipped with dual power supplies or backup generators, because in the event of a power outage, the ventilation system will stop operating, and animals may die from hypoxia or overheating. Lighting systems need to differentiate between animal illumination and working illumination. Animal illumination should mimic the natural diurnal rhythm, typically using a 12-hour on/12-hour off cycle. Regarding fire safety, automatic sprinkler systems are prohibited in the barrier-free cleanroom area, as water spraying can damage the clean environment, harm delicate equipment, and potentially cause animal death. Instead, the cleanroom should employ a gaseous fire suppression system, such as heptafluoropropane or IG541, or be equipped with handheld fire extinguishers.
Waste disposal, while a crucial final step in animal laboratory design, is equally important. Animal carcasses, waste bedding, laboratory supplies, and wastewater all require thorough treatment before removal from the experimental area. Animal carcasses are temporarily stored in dedicated freezers and periodically incinerated; waste bedding is autoclaved and treated as medical waste; wastewater is disinfected before discharge. For facilities involving infectious animal experiments, a dedicated live virus wastewater treatment system is also required to ensure the complete inactivation of pathogens.
Ultimately, animal laboratory design is a systematic project. It's not just about choosing materials and equipment; it's a projection of a complete management logic onto the building space. From changing clothes and air showers for personnel entering, to quarantine and isolation for animals, and sterilization of waste upon departure, every step needs to be carefully considered during the design phase. Post-construction operation and maintenance are equally important—regularly monitoring temperature, humidity, pressure differential, air exchange rate, and ammonia concentration; regularly replacing high-efficiency filters; and maintaining the integrity of all sealed components. Only when design, construction, and operation are all handled properly can an animal laboratory truly be considered a safe and reliable research platform.