2022-01-04

Human & Animal Health Laboratories Design BSL3

BSL3 Levels

• BSL1 - agents not known to cause disease (no or low individual and community risk).
• BSL2 - agents that cause human or animal diseases with moderate individual or low community risk (e.g. blood borne 
  diseases).
• BSL3 - indigenous/exotic agents associated with human disease and with potential for aerosol transmission - high individual risk (respiratory) low community risk)
• BSL4 - dangerous/exotic agents of life threatening nature – serious diseases readily transmitted.

Biosafety level requirement

System/Equipment	Bio safety level
	1	2	3	4
Isolation of Laboratory	NO	NO	YES	YES
Room sealable for decontamination	NO	NO	YES	YES
Ventilation
- Inward Air flow	NO	DESIRABLE	YES	YES
- Controlled ventilation system	NO	DESIRABLE	YES	YES
- HEPA filtered air exhaust	NO	NO	YES / NO	YES
Double door entry	NO	NO	YES	YES
Airlock	NO	NO	NO	YES
Air lock with shower	NO	NO	NO	YES
Ante room	NO	NO	YES	-
Effluent Treatment	NO	NO	YES \ NO	YES
Autoclave
- On site	NO	DESIRABLE	YES	YES
- In Laboratory room	NO	NO	DESIRABLE	YES
- Double ended	NO	NO	DESIRABLE	YES
Bio logical safety cabinets	NO	DESIRABLE	YES	YES
Personal safety monitoring	NO	NO	DESIRABLE	YES

Biosafety and Biosecurity laboratory design criteria

Laboratory location, Wipe clean surfaces, Heating ventilation and air conditioning ( HVAC) system, Directional air flow and 
cascade negative pressure, Laboratory furniture and equipment, Laboratory rooms sizes and orientation, sample reception, 
Double door autoclave and decontamination chamber for solid waste material, water supply and sewage system and Electrical 
system.

Essential building principles

• Primary containment barrier is the first barrier between agent and man (such as gloves, gowns, masks, biosafety 
  cabinets, respiratory protection etc.)
• Secondary containment barrier is the barrier between agents and environment (airtight rooms, air handling and
  filtration, air locks, showers, laundry, sewage treatment, waste disposal, sterilisers, redundant services as well as 
  equipment and material niches.
• Tertiary containment barrier represents an additional organisational barrier with the physical operation with items 
  such as walls, fences, security, quarantine and animal exclusion zones.

Workflow consideration.

During the programming phase it is essential to define how various elements are processed, including animals (clean and dirty), 
people, wastes (carcasses, solid, other), samples from animals, laundry, feed and bedding (if used).

Ventilation

Issues related to ventilation in containment facilities include: directional airflow, airflow velocities, pressure differential between 
adjacent spaces and air exchange rates.

Directional airflow is used to create zones of hazard by moving air from areas clear of hazardous aerosol contamination to areas 
of higher potential for hazardous aerosol contamination. This provides for two functions:

• control of the hazardous aerosol minimises the possibility of inadvertent exposure outside of the laboratory 
  space and;
• knowledge of where the aerosol hazard exists, and the extent of the hazard allows personnel to follow 
  appropriate protocols if they are required to enter areas where aerosols may exist.

Technical details about pressure differentiation and back flow prevention.

• Pressure differentials in animal facilities are held at approximately 50 Pa lower pressure than the point of 
  personnel entry so that there is airflow into the room upon door opening.
• Backflow prevention for containment labs is necessary to prevent back siphoning of contaminated liquids and 
  air. Types of backflow solutions are dependent on the medium that is considered: water, air, gas, and steam.

Electrical system

The electrical systems of containment laboratories ensure that all of the systems cohesively work together to manage the three 
essential criteria for biocontainment:

• Protection of the staff
• Protection of scientific programs
• Protection of the environment and adjacent communities

Electrical systems can be segregated into normal power systems, emergency power systems, uninterruptible power systems 
(UPS), communication systems, data and information systems, lightning control systems, security systems, lighting systems, 
equipment monitoring systems, automation control systems, life safety systems, harmonic control systems and telemetry 
systems.

Identification

Proper identification is extremely important on all systems and equipment. The most expeditious method of handling this would 
be to consult with the end user to enter their naming convention on the design and construction drawings. This is important 
when systems are being integrated within existing facilities or where a computerised maintenance management system will be 
utilised.

Effluent treatment

• Heat treatment – 95 °C
• Chemical treatment

Redundancy

Redundancy is defined as having more than one system supporting an individual mechanical function. It would be wrong to 
assume that each and every mechanical system or device needs to have redundancy. The primary areas for redundancy need 
to focus on the three principles of bio-containment- environment protection, personnel protection and product (or scientific 
outcome) protection. Therefore, during a design process the issue of redundancy needs to be well thought out.

Waste disposal

• The safe handling of infectious wastes must be considered as part of the experimental plan.
• Urine and faecal wastes for animals infected with Level 3 and 4 agents must be decontaminated either by heat or 
  chemical treatment.
• Discarded surgery or necropsy tissues from infected animals are usually sterilised by autoclaving and carcasses by 
  rendering at high temperature, steam sterilisation, incineration or chemical decontamination such as alkaline hydrolysis.

All infectious wastes that cannot be decontaminated or autoclaved will immediately be placed in red infectious waste bags