What does biosafety level 4 mean?

Biosafety Level 4 (BSL-4) represents the highest level of biocontainment precautions, designated for work with agents that pose a high risk of life-threatening disease, which may be transmitted via aerosols and for which there are no available vaccines or treatments.

BSL-4 laboratories are designed to be either cabinet laboratories, where all work is conducted within a Class III biosafety cabinet, or protective-suit laboratories, where personnel wear positive pressure suits and perform work in Class II biosafety cabinets.

Entry and exit protocols for BSL-4 labs include multiple showers, a vacuum room, an ultraviolet light room, and airlocks to prevent contamination.

All air and water services going to and coming from a BSL-4 lab undergo decontamination procedures to eliminate the possibility of an accidental release.

Examples of agents handled at BSL-4 include Ebola virus, Marburg virus, Lassa virus, and other hemorrhagic fever viruses.

BSL-4 laboratories are used for diagnostic work and research on easily transmitted pathogens which can cause fatal disease.

These facilities are subject to rigorous safety and security measures, and access is restricted to trained and authorized personnel.