There are four biosafety levels (BSL) ranging from BSL-1 to BSL-4, each with increasing levels of protection.
1. BSL-1: Basic level of containment, suitable for agents not known to cause disease in healthy humans. 2. BSL-2: For agents that pose moderate hazards. Requires limited access and use of personal protective equipment (PPE). 3. BSL-3: For agents that can cause serious or potentially lethal disease. Requires controlled access and specialized ventilation systems. 4. BSL-4: Highest level of containment for agents that pose a high risk of life-threatening disease. Requires full-body, air-supplied suits and a dedicated facility.
