- Biosafety Level 2 (BSL-2) is a classification of laboratory facility and practices designed for work involving agents that pose moderate hazards to humans and the environment. These are pathogens associated with human disease, but which are generally not transmitted through casual contact and for which preventive or therapeutic measures (such as vaccines or treatments) are usually available.
- Examples of BSL-2 organisms include Salmonella spp., Escherichia coli (pathogenic strains), Staphylococcus aureus, Herpes simplex virus, and Hepatitis A, B, and C viruses.
- A BSL-2 laboratory builds upon the requirements of BSL-1, adding additional safety features and practices to address the greater risks. Laboratory staff must receive specialized training in handling pathogenic agents and must work under the supervision of experienced personnel. Access to the lab is restricted when work is in progress, and signs indicating the presence of biohazards are displayed at all entry points. Personal protective equipment (PPE) such as lab coats, gloves, and eye protection is mandatory, with face shields or biosafety cabinets required for procedures that might generate aerosols or splashes.
- The facility design of a BSL-2 lab incorporates several containment features. While it does not require the highly sophisticated systems of BSL-3 or BSL-4, it must have handwashing sinks, eyewash stations, and doors that self-close to limit access. Work that poses a risk of aerosol exposure must be performed inside a Class II Biological Safety Cabinet (BSC). Additionally, contaminated sharps and waste materials are decontaminated (usually by autoclaving) before disposal.
- BSL-2 laboratories emphasize good microbiological practices such as minimizing splashes, careful handling of sharps, proper labeling of infectious materials, and maintaining accurate records of stored agents. Routine monitoring, disinfection, and decontamination procedures are enforced to prevent accidental exposures. In some cases, vaccination of laboratory workers may be recommended depending on the pathogens being studied.
