In BSL 4 laboratories, biological agents of risk group 4 are handled. These can cause the most serious diseases of which in turn some can lead to death in humans and animals, and for which effective prevention or treatment is not possible. A current example is the recurring Ebola pathogen.
For pathogens of risk group 4, laboratory units of protection level 4 (BSL 4) are demanded. For such laboratories, in addition to those applicable to BSL 3 areas, national and international standards stipulate, among others, further requirements as follows:
- Separate air, water and power supply
- All rooms and penetrations of supply and disposal ducts must be gas-tight and secured against backflow.
- Failure-safe operation
- Special access control systems, video monitoring and other security measures
- Special hygienic barriers, i.e. personnel and material locks with additional requirements
- The laboratories applied for fumigation must be spatially separated from other parts of the building.
- Increased tightness requirements apply, e.g. from the Canadian Directive