STO Biosafety: Required Work Practices

  • Laboratory Safety
  • Biosafety
  • STO Biosafety: Required Work Practices
Required Work Practices:

(Adopted from BMBL (Section IV) and the University of Minnesota)

BIOSAFETY LEVEL 1: Description & Work Practices
  • Suitable for work involving:
    • Well-characterized agents not known to consistently cause disease in immunocompetent adult humans, and that present minimal potential hazard to laboratory personnel and the environment.
    • Transgenic or wild-type laboratory animals (e.g., rodents) that are both:
      • Free of zoonotic diseases.
      • Not infected with, implanted with, or containing RG2 or higher agents or materials.
  • Work is typically conducted on open bench tops using standard microbiological practices.
  • Laboratory personnel must have specific training in the procedures conducted in the laboratory and must be supervised by a scientist with training in microbiology or a related science.
  • Personal health status may impact an individual’s susceptibility to infection, ability to receive immunizations or prophylactic interventions.  Individuals having these conditions should be encouraged to self-identify to the institution’s healthcare provider for appropriate counseling and guidance.
  • Standard Microbiological Practices
    • Wash hands after handling viable materials, after removing gloves, and before leaving the laboratory.
    • Wear pants (or other clothing that covers legs) and close-toed shoes.
    • Lab Coats.  Are generally not necessary.  However, wear lab coat or other protective clothing when handling viable materials; remove protective clothing before leaving lab areas.  All protective clothing must be either disposed of in the laboratory or laundered by the work unit, it should never be taken home.
    • Gloves. Wear gloves whenever contact with microorganisms could be reasonably anticipated and/or whenever skin on hands is not intact – including if a rash is present.  Change gloves when contaminated, glove integrity is compromised/suspect, or when otherwise necessary.
    • Goggles.  Wear chemical splash goggles when conducting procedures that have the potential to create splashes of microorganisms or other hazardous materials.
    • Keep laboratory doors closed; only individuals who are involved with the work are allowed in the area.
    • Mouth pipetting is prohibited; mechanical pipetting devices must be used.
    • Perform all procedures with a focus on minimizing the creation of splashes and/or aerosols.
    • Food, eating, drinking, smoking, handling contact lenses, applying cosmetics, and storing food for human consumption are not permitted in laboratory areas (you don’t even want to be chewing gum in the lab!).
    • Pay attention to hand and mouth hygiene while working in the lab (e.g., do not put a pen in you mouth, or behind your ear).
    • Plants and animals not associated with the work being performed should not be permitted in the laboratory.
    • Sharps.  Follow the policies and procedures on the Sharps Safety page, including:
      • Provide sharps containers within easy reach of work stations.
      • Laboratory supervisors should adopt improved engineering and work practice controls that reduce risk of sharps injuries.
      • Needles must not be bent, sheared, broken, recapped, removed from disposable syringes, or otherwise manipulated by hand before disposal.
      • Broken glassware must not be handled directly.  Instead, it must be removed using a brush and dustpan, tongs, or forceps.  Plastic ware should be substituted for glassware whenever possible.
    • Decontaminate: 
      • Work surfaces after completion of work and after any spill or splash of potentially infectious material with appropriate disinfectant.
      • All cultures, stocks, and other potentially infectious materials before disposal using an effective method.  Materials to be decontaminated outside of the immediate laboratory must be placed in a durable, leak proof container and secured for transport.
      • Follow the appropriate decontamination procedures.
    • A sign incorporating the universal biohazard symbol must be posted at the entrance to the laboratory when infectious agents are present.  The sign must include the name and phone number of the laboratory supervisor or other responsible personnel, and may include the name of the agent(s) in use.


BIOSAFETY LEVEL 2: Description & Work Practices

  • Suitable for work involving agents that pose moderate hazards to personnel and the environment.  It is more restrictive than BSL-1.  It includes all BSL-1 practices plus the following:
    • All persons entering the laboratory must be advised of the potential hazards and meet specific entry/exit requirements.
    • Laboratory personnel have specific training in handling pathogenic agents and are supervised by scientists competent in handling infectious agents and associated procedures.  The laboratory supervisor must ensure that laboratory personnel demonstrate proficiency in standard and special microbiological practices before working with BSL-2 agents.
    • Access to the laboratory is restricted when work is being conducted.
    • Protective Laboratory Coats, gowns, smocks, or uniforms designated for laboratory use must be worn while working with hazardous materials.  Remove protective clothing before leaving the laboratory.  Dispose of protective clothing appropriately, or deposit it for laundering by the institution.  It is recommended that laboratory clothing not be taken home.
    • Gloves must be worn to protect hands from exposure to hazardous materials.  Glove selection should be based on an appropriate risk assessment.  Gloves must not be worn outside the laboratory.  In addition, BSL-2 laboratory workers should:
      • Change gloves when contaminated, glove integrity is compromised, or when otherwise necessary.
      • Remove gloves and wash hands when work with hazardous materials has been completed and before leaving the laboratory.
      • Do not wash or reuse disposable gloves.  Dispose of used gloves with other contaminated laboratory waste.  Hand washing protocols must be rigorously followed.
    • Biosafety Cabinet.  All procedures in which infectious aerosols or splashes may be created are conducted in Biosafety Cabinets or other physical containment equipment.  These may include pipetting, centrifuging, grinding, blending, shaking, mixing, sonicating, opening containers of infectious materials, inoculating animals intranasally, and harvesting infected tissues from animals or eggs.
Additional Resources:
  • Biosafety in Microbial and Biomedical Laboratories (BMBL) 6th Edition (The BMBL is both a code of practice and an authoritative reference.  Knowledge sufficient to work safely with hazardous microorganisms requires a careful review of the entire BMBL.  This will offer the reader an understanding of the biosafety principles that serve as the basis for the concepts and recommendations included in this reference.  Reading only selected sections will not adequately prepare even an experienced laboratory worker to handle potentially infectious agents safely).