Biosafety Levels 1 & 2: Lab Safety Protocols

• Biosafety is a framework to minimize risks when working with biological agents.
• These protocols protect laboratory personnel, the environment, and the public from biological hazards.
• Biosafety involves a range of practices that vary depending on the risks associated with the biological agents in use.

Biosafety Level 1 (BSL-1): Basic Lab Safety

• BSL-1 is the lowest biosafety level.
• It is suitable for work with well-characterized agents that pose minimal risk to healthy adults.
• Laboratories working with non-pathogenic strains of E. coli fall under BSL-1.
• Examples of agents include nonpathogenic E. coli and Bacillus subtilis.
• Standard microbiological practices are key safety measures.
• Regular handwashing and safe handling of sharps are required.
• You need basic PPE, like lab coats and gloves.
• No specialized containment equipment is needed.
• Use an open lab bench, with access to a handwashing sink.

Biosafety Level 2 (BSL-2): Handling Moderate Risk Agents

• BSL-2 laboratories handle agents associated with human diseases of moderate risk.
• Examples include Staphylococcus aureus and HIV.
• These agents can cause illness, but the risk of severe disease is generally low.
• Treatments or vaccines are typically available.
• Examples of agents include HIV, Salmonella, and Hepatitis B virus.
• Enhanced PPE, including face shields and gloves are required.
• All work with infectious aerosols or splashes must be conducted in biological safety cabinets (BSCs).
• Self-closing, lockable doors and biohazard signage are required.
• Laboratories should be equipped with handwashing sinks and eyewash stations.
• Access should be controlled during experiments.

Biosafety Level 3 (BSL-3): Containing Serious or Lethal Agents

• BSL-3 labs work with indigenous or exotic agents that may be transmitted through the air and can cause potentially lethal infections.
• Strict access controls and specialized containment procedures are needed due to heightened risks.
• Examples of agents include Mycobacterium tuberculosis, SARS-CoV-2, and West Nile virus.
• Lab personnel must be medically surveilled and possibly immunized.
• Use biosafety cabinets and sealed enclosures for all procedures.
• Use PPE, including solid-front gowns, gloves, and respirators.
• Containment requires directional airflow from clean to potentially contaminated areas.
• Self-closing doors and air filtration systems prevent release of airborne agents.

Biosafety Level 4 (BSL-4): Maximum Containment for Deadly Pathogens

• BSL-4 is reserved for work with dangerous and exotic agents.
• Examples include the Ebola virus, that have a high risk of aerosol transmission.
• Effective treatments or vaccines are often lacking.
• BSL-4 laboratories are rare.
• Stringent controls are needed to protect workers and the environment.
• Examples of agents include Ebola virus, Marburg virus, and Lassa fever.
• You will need full-body, air-supplied suits.
• Decontamination showers are critical upon exiting.
• Rigorous access protocols are in place.
• Use Class III biosafety cabinets (airtight glove boxes) or isolated workstations.
• These labs are located in secure, isolated zones with dedicated air supplies and exhaust systems.
• You need vacuum lines and waste decontamination systems.