Biosafety Level (BSL)
A Biosafety Level (BSL) defines a set of technical, organizational, and procedural measures implemented to ensure safe work with microorganisms and biological agents that pose varying degrees of risk to human health, animal health, and the environment.
The BSL classification specifies requirements regarding laboratory equipment, facilities, ventilation, staff training, and controlled access.
Four levels of biosafety (BSL-1 to BSL-4)
BSL-1
Applies to work with microorganisms that do not cause disease in healthy humans.
Basic laboratory safety measures are sufficient, without special technical requirements.
Example: teaching and research microbiology laboratories at universities.
BSL-2
Covers work with biological agents that can cause disease in humans but are generally not easily transmitted and for which effective treatments or preventive measures exist.
Requires restricted access to laboratories, use of personal protective equipment (PPE), and defined safety procedures.
Example: hospital and diagnostic microbiology laboratories.
BSL-3
Designed for work with pathogens that can cause serious or potentially lethal diseases, particularly via inhalation.
Laboratories are equipped with controlled ventilation, negative pressure, and specific technical and organizational safety measures. Access is strictly limited, and all procedures must be rigorously followed.
Example: research on tuberculosis, West Nile virus, coronaviruses, and other respiratory pathogens.
BSL-4
Represents the highest level of biosafety and is intended for work with highly pathogenic agents that cause severe or fatal diseases for which no effective treatments or vaccines exist.
Laboratories are completely isolated, and personnel use hermetically sealed positive-pressure suits.
Example: Ebola virus, Marburg virus.
Importance of BSL-3 laboratory
BSL-3 laboratory plays a key role in protecting people’s health by enabling the rapid detection and control of infectious diseases, and they are of great importance for public health protection.
Construction of a New Diagnostic Building with Biosafety Level 3 (BSL-3) Laboratory at the Torlak Institute of Virology, Vaccines and Sera, Belgrade
The importance of the construction of the first BSL-3 laboratory in the Republic of Serbia is reflected in the advancements in laboratory research and healthcare of the population during the identification of disease agents, as well as in the early diagnostics of newly identified or exotic viruses entering the country.