Animal laboratories, also known as vivariums, are specialized facilities dedicated to the breeding, housing, and research involving experimental animals. These facilities are categorized into four distinct levels: Ordinary, Clean, SPF (Specific Pathogen-Free), and GF (Germ-Free), each with corresponding standards that ensure the appropriate environmental controls are in place.

: These facilities house general-purpose animals with no special microbial control, except for the exclusion of zoonotic pathogens and a few specific highly infectious agents. To maintain the reliability and reproducibility of experimental results, certain preventive measures are employed to control the spread of infectious diseases during breeding and housing.

: In addition to the requirements of the Ordinary Level, Clean Level facilities must exclude the pathogens responsible for major animal infectious diseases.

: Building upon the Clean Level, SPF laboratories must further exclude specific pathogens as outlined in the regulatory standards. Disinfection and sterilization methods commonly used include HEPA filtration, ultraviolet sterilization, triethylene glycol vapor spraying, and lithium chloride solution spraying.

: GF laboratories are designed for housing germ-free animals, which must be completely free of any detectable microorganisms. Gnotobiotic animals, which host one or more known microorganisms, are also maintained in these highly controlled environments.

The design of animal laboratories varies according to the level of environmental control required. Animals free from specific pathogens or maintained in a sterile state must be housed in environments that minimize contamination risks, commonly referred to as barrier environments. These environments utilize physical barriers to isolate animals from external contaminants, ensuring conditions akin to a sterile womb environment.

From a microbiological control perspective, these environments are categorized into five primary systems:

: This system involves housing animals within enclosed containers equipped with operational gloves, suitable for maintaining germ-free and gnotobiotic animals. The interior of the isolator is maintained at a Class 100 cleanliness level, though the surrounding rooms and personnel are not required to meet sterile room standards.

: Used for long-term housing and breeding of SPF animals, barrier systems utilize sterile cleanrooms with cleanliness levels ranging from Class 10,000 to Class 100,000. Strict protocols, such as mandatory showers and clothing changes, are enforced for personnel entering these areas.

: This system loosens some of the entry and exit protocols of the Barrier System while maintaining a similar overall layout.

: In this system, animal cages are placed within horizontal laminar airflow to maintain cleanliness. It is often used for small-scale breeding but carries a risk of contamination when used in standard rooms. This system can serve as a supplement to semi-barrier environments.

: This system does not enforce stringent contamination controls on personnel, materials, or air entering and exiting the facility but does maintain a basic level of cleanliness management.

: Animal laboratories should be constructed in clean, quiet areas with good drainage, ventilation, and reliable water and electricity supplies. They should be situated away from factories, residential areas, slaughterhouses, livestock farms, and regions prone to disease and pollution.

: The facility's design should include provisions for clean preparation rooms, clear separation of clean and contaminated zones, and the use of appropriate construction materials to prevent microbial contamination. Walls, floors, and ceilings must be designed with smooth, durable, and easy-to-clean surfaces that resist corrosion from disinfectants.

: Proper ventilation and pressure differentials between rooms are essential to maintain the desired cleanliness levels. The use of sealed doors and windows, as well as controlled access between barrier and non-barrier areas, helps prevent contamination.

: Floors, walls, and ceilings must be constructed from materials that are resistant to wear, water, chemicals, and microbial contamination. Rounded corners and smooth transitions between surfaces are recommended to avoid the accumulation of dirt and microorganisms.

: The layout should facilitate logical and efficient movement of personnel, animals, and materials, with strict separation of clean and contaminated areas to ensure the health of both humans and animals and to maintain the integrity of experimental data.

Animal laboratory facilities typically consist of various rooms for housing, health observation, quarantine, and specialized laboratories for surgical procedures, post-operative care, disease diagnosis, and more. Additionally, support areas such as storage, sterilization, and staff amenities must be integrated into the design. The layout should prioritize operational efficiency while maintaining strict adherence to cleanliness standards to protect the accuracy of experimental results and the well-being of laboratory personnel.