“Biosafety” is the use of certain practices, safety equipment, and specially designed buildings to confirm that the workers, the community, and the environment are protected from unintentional release or accidental exposure of toxins, infectious agents, and other biological hazards. 

Biosafety levels (BSL) are used to govern the protective measures needed in a lab setting to protect the workers, the environment, and the public. At any given biosafety level, there will be severe requirements for laboratory design, personal protective equipment, and biosafety equipment to be used. The four levels of biosafety are BSL-1, BSL-2, BSL-3, and BSL-4, with BSL-4 being the maximum level of containment. 

Biosafety level 2

• Biosafety level 2 laboratories are used to study moderate-risk infectious agents or toxins that may endanger if accidentally swallowed, inhaled, or exposed to the skin. 
• The BSL-2 laboratories are equipped with hand-washing sinks, eye-washing stations and automatically closing and locking doors. 
• They also need to have access to disinfecting equipment like incinerators, an autoclave, and other sterilisation methods, depending on the risk. 
• BSL-2 is used when dealing with bodily fluids, human blood, or primary human cells where the presence of a contagious agent may be unknown. 

Biosafety level 2 viruses

•  Some examples of biosafety level 2 viruses are Mycobacterium, Streptococcus pneumonia, Hepatitis B virus, HIV, the salmonellae, and Toxoplasma spp.
• These potentially infectious viruses are a part of BSL-2 and pose a moderate level hazard to healthy adult humans. 
• The people involved with these are subject to regular medical checkups as necessary.
• A BSL-2 laboratory will have a biological safety cabinet for potentially hazardous aerosols formed during standard work procedures.

Biosafety level 2 practices

Access

• Access to the lab is restricted.
• There are biohazard warning signs at the access points as well as on the equipment that may be potentially contaminated. 
• Special authorisation is needed for access to the animal house. 
• No animals other than those involved in the work should be allowed. 

Personnel protection

• Inside the lab, special protective gear like lab coats, gloves, masks, etc., needs to be worn.
• Appropriate gloves need to be worn for every procedure, especially those that require direct contact with fluids or potentially contagious materials. After use, the gloves must be decontaminated before disposal. 
• Safety glasses and protective gear must be worn to protect the eyes and face from coming in contact with infectious materials and sources of artificial radiation.
• Wearing laboratory clothing outside the lab is strictly prohibited. 
• Eating, drinking, or any kind of non-work-related activity are prohibited inside a lab. 
• Protective gear must not be stored at the same place as street gear. 

Procedures

• Never use a mouth pipette.
• Report any spills, injuries, or exposures immediately.
• The use of hypodermic needles must be limited. 
• Sharp items must be handled with precaution and should only be used if there is no alternative. 
• A written procedure for sterilisation must be developed and followed.
• Sterilise the waste before disposing of it. 

Laboratory and working areas

• A BSL-2 laboratory needs to have a sink for washing, placed near the exit door.
• Windows are not recommended.
• The lab needs to be easily sterilised.
• Sinks in the lab should be regularly cleaned using disinfectants that contain abrasives and flushed with a suitable chemical cleaner. 
• When transporting materials outside the lab, use secondary containment and a cart. Avoid public transport.

Training 

• Before starting work at a BSL-2 laboratory, researchers must be listed on an approved IBC Inventory and Activity Registration. 
• It is the laboratory director’s responsibility that all workers associated with the laboratory receive appropriate training for the work they do, for doing exposure evaluation, and to prevent injuries and exposures. 
• Apart from annual updates, the workers are informed periodically about additional training for policy changes.
• All personnel must read and sign the lab manual and ask questions wherever they have a doubt. 
• Personnel who may be exposed to human-derived materials must undergo training for bloodborne pathogens annually. 
• Personnel may need to enter into a medical program and undergo medical clearance. 

Conclusion 

Biosafety level 2 deals with moderate-risk pathogens. They can cause hazards if inhaled, swallowed, or exposed to the skin. This article talks about all the safety precautions that are mandatory when working in a BSL-2 lab. BSL-2 deals with a medium risk level and can be contained and managed with sound lab safety practices. Practising the measures mentioned above will help in achieving biosafety level 2. 

Biosafety allows us to safely manage and study factors that may cause risk and develop antidotes. This promotes the quality and safety of life.