Biosafety Levels

Biosafety Level 1 practices, safety equipment, and facilities are appropriate for work done with defined and characterized strains of viable microorganisms not known to cause disease in healthy adult humans. Bacillus subtilis and E.coli (K12) are representative of those microorganisms meeting these criteria.

Many agents not ordinarily associated with disease processes in humans are, however, opportunistic pathogens and may cause infection in the young, the aged, and in immunodeficient or immunosuppressed individuals. Vaccine strains which have undergone multiple in vivo passages should not be considered avirulent simply because they are vaccine strains.

The access to a biosafety Level 1 lab is not restricted. Work is performed on an open bench, without special primary and secondary barriers. Working staff is trained in standard microbiological practices and works under the supervision of a scientist skilled in these practices.

Working procedures, safety equipment and devices compatible with biosafety level 2.

1. Standard microbial procedures

   • Access to the lab is determined by the lab supervisor.
   • Disinfect work surfaces once a day and after every biological spill.
   • Disinfect liquid waste before disposal.
   • Dispose solid waste in closed biohazard bags in leak proof containers in the departmental waste room. Bags should be transferred inside the orange plastic bins.
   • Never use mouth pipetting.
   • No eating, drinking, smoking or applying makeup in the lab. Food should be stored in designated fridges/ cupboards outside of the lab.
   • At the end of work with a biological agent, lab animals or before leaving the lab, wash your hands with soap and water.
   • Minimize aerosol production as much as possible.
   • Employ an insect and rodents extermination program.

2. Personal protective equipment

   • Use a lab coat, gloves and closed shoes.
   • When there is a risk for splashes, use safety glasses.
   • Long hair should be tied back.  

3. Facility

   • The lab should be easy to clean.
   • Work surfaces should be resistant to water, acids, bases, organic solvents and medium level heat.
   • Lab furniture should be of stiff structure, spaced allowing access for cleaning.
   • Every lab should have a sink.
   • Windows should be equipped with nets, to prevent entry of insects.
      

Biosafety Level 2 practices, equipment, and facilities are appropriate for work with a broad spectrum of indigenous moderate-risk agents present in the community and associated with human disease of varying severity. Hepatitis B virus, salmonellae and Toxoplasma spp. are representative of microorganisms assigned to this containment level.

Biosafety Level 2 is also appropriate when work is done with any human-derived blood, body fluids, human cell line or tissues where the presence of an infectious agent may be unknown. 

Primary hazards to personnel working with these agents relate to accidental percutaneous, mucous membrane exposures or ingestion of infectious materials. 
Therefore, extreme precaution with contaminated needles or sharp instruments must be emphasized. In addition, procedures with aerosol that may increase the risk of exposure to personnel must be conducted in a BSC or using other physical barriers, such as safety centrifuge cups, face protection equipment and respirators.
Secondary barriers such as hand washing and waste decontamination facilities must be available to reduce potential environmental contamination.

Working procedures, safety equipment and devices compatible with biosafety level 2.

1. Staff and access to the lab
   • Working staff should be trained in handling pathogens and work under the supervision of qualified scientists.
   • Access to the lab is restricted and controlled by the lab supervisor. People who are more susceptible to infections are not allowed in a level 2 lab or animal facility.
   • Only people who were informed about the risks and meet specific safety requirements, such as vaccinations, are allowed.
   • A sign should be posted at the entry to the lab containing the following information: biohazard symbol, biological agent, lab supervisor name, phone number of the supervisor or manager and special entry requirements.
   • A safety manual should be prepared and followed. The staff will receive training and information about the risks and will follow all safety procedures.
2. Procedures
   • Use appropriate personal protective equipment (PPE) including a lab coat, gloves and safety glasses. 
   • Remove contaminated PPE before leaving the lab. PPE should not be worn in green areas, such as offices, library and eating areas.
   • Aerosol inducing procedures should be performed inside a biological hood or using other physical barriers, such as a respirator.
   • Never use sharps or glass unless necessary and only with strict compliance to the safety guidelines.
   • No mouth pipetting, use a designated device.
   • Wash your hands at the end of work with a biological agent, a lab animal or before leaving the lab.
3. Disinfection, waste disposal and spills
   • Work surfaces are disinfected once a day and after every biological spill.
   • All waste, Liquid and solid is disinfected before disposal. Contaminated materials to be disinfected outside the lab, should be carried in leak proof containers.
   • Accidents and spills involving exposure to a BL2 agent should be reported immediately to the lab supervisor. A medical evaluation and treatment should be conducted and records should be kept.
4. General guidelines
   • No eating, drinking, smoking or applying makeup in the lab. Food should be stored in designated fridges/ cupboards outside of the lab.
   • Employ an insect and rodents extermination program.
   • Animals are allowed only for research purpose.
5. Safety equipment
   • Work in a biological hood (class II) or use appropriate safety equipment when performing the following:
     • Aerosol inducing procedures: centrifugation, grinding, meshing, sonication, whirling, opening sealed containers, intranasal infection of animals and tissue collection from infected animals.
     • Handling high concentrations or high volumes of a biological agent.
   • Centrifuge only in sealed rotors or sealed cups opened in a biological hood.
6. Facility
   • The lab should be easy to clean.
   • Work surfaces should be resistant to water, acids, bases, organic solvents and medium level heat.
   • Lab furniture should be of stiff structure, spaced allowing access for cleaning.
   • Every lab should have a sink.
   • Windows should be equipped with nets, to prevent entry of insects.
   • An autoclave should be available.

Biosafety Level 3 practices, safety equipment, and facilities are for work with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection.

Mycobacterium tuberculosis, St. Louis encephalitis virus, and Coxiella burnetii are representative of microorganisms assigned to this level. 

At Biosafety Level 3, more emphasis is placed on primary and secondary barriers to protect personnel in contiguous areas, the community, and the environment from exposure to potentially infectious aerosols. For example, all laboratory manipulations should be performed in a BSC or other enclosed equipment, such as a gas-tight aerosol generation chamber. Secondary barriers for this level include controlled access to the laboratory and a specialized ventilation system that minimizes the release of infectious aerosols from the laboratory.

As for today, BL3 work is not allowed in WIS.

Biosafety Level 4 practices, safety equipment, and facilities are applicable for work with dangerous and exotic agents which pose high individual risks from life-threatening diseases, which may be transmitted via the aerosol route, and for which there is no available vaccine or therapy. Additionally, agents with a close or identical antigenic relationship to Biosafety Level 4 agents should also be handled at this level. Viruses such as Marburg or Congo-Crimean hemorrhagic fever are manipulated at Biosafety Level 4.

As a general principle, the biosafety level (facilities, practices, and operational requirements) recommended for working with infectious agents in vivo and in vitro are comparable. It is good to remember, however, that the animal room is not the laboratory, and can present some unique problems. In the laboratory, hazardous conditions are caused by personnel or the equipment that is being used. In the animal room the activities of the animals themselves can introduce new hazards. Animals may produce aerosols, and they may infect animal handlers by biting and scratching.

WIS biohazard section of the animal facility is physically separate from other animal activities and is designed to minimize the risk to personnel as well as the risk of cross contamination. Working in the biohazard section requires additional training by veterinary resources and by a biosafety officer.