The definition of biosafety levels:
The term “biosafety level” pertains to the specific combinations of work practices, safety equipment, and facilities, which are designed to minimize the exposure of workers, and the environment to infectious agents.
- Biosafety level 1 applies to agents that do not ordinarily cause human disease.
- Biosafety level 2 is appropriate for agents that can cause human disease, but whose potential for transmission is limited.
- Biosafety level 3 applies to agents that may be transmitted by the respiratory route which can cause serious infection.
- Biosafety level 4 is used for the diagnosis of exotic agents that pose a high risk of life-threatening disease, which may be transmitted by the aerosol route and for which there is no vaccine or therapy.