How many biosafety levels are there?

There are four biosafety levels (BSL-1 to BSL-4), each representing a graded set of protective measures based on the type of biological agents being handled and the level of risk they pose to humans and the environment.

These levels are defined by the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) in the United States and are adopted globally in laboratory safety protocols.

Each level includes specific guidelines regarding:

Laboratory design and engineering controls

Personal protective equipment (PPE)

Standard microbiological practices

Required training and access control

Waste disposal and decontamination procedures

Summary of levels:

BSL-1: Minimal risk, non-pathogenic organisms.

BSL-2: Moderate risk, known human pathogens.

BSL-3: High risk, airborne transmission, serious or lethal diseases.

BSL-4: Extreme risk, no available treatment or vaccines, highly lethal pathogens.

These levels ensure that laboratory personnel, the community, and the environment are safeguarded from potential biohazards during scientific research, diagnostics, and biotechnology operations.