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Lab Safety for Biosafety Levels One and Two (BSL-1 and BSL-2)


There are four biosafety levels. This protocol provides information for both biosafety level 1 (BSL-1) and biosafety level 2 (BSL-2). The purpose of the four levels is to distinguish between different types of hazards and to provide protective measures for each level, as each level has different safety requirements. BSL-1 is designated for those working with microbes that don’t cause disease in healthy humans, for example, non-pathogenic E. coli. BSL-2 is for labs that work with pathogens including organisms such as Staphylococcus aureus or Vibrio cholerae. BSL-2 includes all of the precautions needed in BSL-1, along with additional precautions to prevent injuries, ingestion, and exposures to hazardous materials.


Watch the video to learn more about safety in the lab.


  • Lab coat
  • Close-toed shoes
  • Gloves
  • Eye protection or face shields
  • Eye wash
  • Safety shower
  • Sharps container
  • Biohazard waste container
  • Fire blanket
  • Fire extinguisher


BSL-1 Guidelines

Before You Work

  1. Right after entering the lab, put on the proper personal protective equipment (PPE) and wear it the whole time you are working in the lab.
  2. Do not eat, drink, chew gum, or apply makeup in the laboratory.
  3. Before you start your experiment, make sure your workspace is clean and uncluttered. Disinfect your workspace with appropriate materials. For example, you may use 70% ethanol, quaternary ammonium, or bleach solutions. Ask your lab supervisor what is available and the appropriate contact times for each agent. Make sure you have enough space to work at your lab bench.
  4. It’s possible that while working, you may accidentally come into contact with hazardous materials. A sink, eyewash station, safety shower, fire blanket, and extinguisher are also required to be present in the room. Make sure that you know where these are located before you start.
    • Use the eyewash station if unwanted or biohazardous materials are splashed onto your face and/or get into your eyes.
    • Wash your hands before and after working in the lab.
  5. Ensure that a designated chemical waste accumulation site is present, and that you have received hazardous waste safety training before starting the work. Before working with chemicals, first review their material safety data sheets (MSDS).

While You Work

  1. Dispose of sharps in a designated sharps container. Sharps include anything that can pierce your skin, including, but not limited to broken glass or needles. Sharps containers must be thick walled, impenetrable by a needle, and must be able to close securely.
  2. Biohazard signs should be placed in all areas containing biohazardous materials, including biohazardous waste. Dispose of waste that may be contaminated with pathogens or chemicals that present a danger to people and the environment in biohazard containers. Biohazardous materials are decontaminated prior to disposal, commonly done with an autoclave.
  3. Only mechanical pipetting should be done in the laboratory. Don’t mouth pipette!
  4. There may be some times when you may be working with a protocol that requires shaking or mixing, which may produce aerosols or splashes. These procedures should be done underneath a hood.
  5. Clean any spills immediately, and decontaminate as necessary. For large spills that cannot be easily cleaned, evacuate and close off the area and alert the chemical hygiene officer.

BSL-2 Guidelines

Remember, the BSL-1 laboratory guidelines above are expected to be followed in addition to BSL-2 guidelines below, including PPE protocols.

  1. Working in a BSL-2 laboratory requires laboratory glasses in addition to coat and gloves. This lab coat should not be worn outside of the BSL-2 area.
  2. BSL-2 laboratories must be clearly marked as “BSL-2.” The names and contact information of the laboratory manager should be clearly visible in the room and on the door.
  3. BSL-2 centrifugation steps require an aerosol-tight lid and rotors should be loaded and unloaded in a biosafety cabinet.
  4. BSL-2 safety protocols require bloodborne pathogens training. It is strongly recommended that anyone participating in BSL-2 work receives a hepatitis B vaccination or titer prior to starting work in the laboratory.
  5. For some biohazardous waste, an autoclave or other method for decontaminating must be used for proper disposal. Liquid BSL-2 waste can be decontaminated in a final concentration of 10% bleach for 30 minutes before pouring down the drain. Solid BSL-2 waste can be collected in designated biohazardous waste containers that can be autoclaved.


Although simple, following appropriate BSL-1 and BSL-2 protocol goes a long way. It is the easiest way to ensure that you’re doing your work in the safest way possible. Protecting yourself and working smart in the lab is important!

Disclaimer: The SOP presented here has been designed by the Addgene nonprofit plasmid repository and is being shared outside of Addgene for informational purposes only. If you choose to reuse or repurpose this SOP in another location, please note that you do so at your own risk; you should ensure that any local guidance is also adhered to. None of the authors, contributors, administrators, or anyone else associated with Addgene, can be held responsible for your use of the information contained in or linked to from these web pages.