Biosafety Levels PDF

University of Benghazi Faculty of Biomedical sciences Biosafety levels By : Mohamed Eldali 2023/2024 Classification of pathogenic microorganisms Risk group I A pathogen that is unlikely to cause any disease in humans or animals. Risk group II A pathogen...

University of Benghazi Faculty of Biomedical sciences Biosafety levels By : Mohamed Eldali 2023/2024 Classification of pathogenic microorganisms Risk group I A pathogen that is unlikely to cause any disease in humans or animals. Risk group II A pathogen that can cause disease in humans or animals but is unlikely to be a serious hazard. Effective treatment and preventive measures are available and the risk of spread of infection is limited. Risk group III A pathogen that can cause serious human or animal disease, but does not ordinarily spread from one infected person to another. Effective treatment and preventive measures are available. Risk group IV A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available. Biosafety is the prevention of risk to human health and safety, and the conservation of the environment and reduce exposure to pathogen. The human cell lines may contain blood borne pathogens, which can be transmitted due to improper handling. The risks associated with the laboratory activities occur either from the samples or the procedural requirements. Routes of entry for pathogens ✓ Inhalation of infectious aerosols. ✓ Contact of the agent with the skin, eyes or mucous membrane. ✓ Inoculation by contaminated sharps. ✓ contact with their body fluids. ✓ Ingestion of infectious agent or contaminated hands. through mouth pipetting Application to standard techniques and employing facilities suitable for the risk level of the pathogen helps to protect the researcher from laboratory-acquired infections The biosafety levels: The biosafety levels are thus designed to identify various protective measures that are to be taken in a laboratory setting to protect the workers and the environment. 1.Biosafety Level -1 (BSL-1) Biosafety Level 1 is the level appropriate for work involving well- characterized agents not known to consistently cause disease in immune-competent adult humans and cause a minimal potential hazard to the laboratory personnel and the environment. Biosafety level 1 is the lowest safety level, and the precautions required for the level are thus limited and not as extensive. Safety practices There are no safety specific safety practices required for BSL-1. Safety equipment ✓ Special containment devices like the Bio-safety Cabinets are not required for BSL-1. ✓ In order to prevent the contamination of personal clothing, protective laboratory coats, gowns, or uniforms are recommended. ✓ While conducting tests with a high possibility of aerosol formation, protective eyewear can be used. Uses Biosafety Level-1 is commonly used while performing tests on microbial agents that are not known to cause diseases in immune- compromised individuals. These laboratories include the laboratories used for teaching purposes in colleges and training centers. Organisms The common organisms that require Biosafety Level-1 containment include less hazardous organisms like Aspergillus niger and Escherichia coli strain K12. 2. Biosafety Level-2 (BSL-2) ✓ Biosafety level-2 laboratories are the laboratories that are used for the tasks involving microbial agents of moderate potential hazards to the laboratory personnel, the environment. ✓ However, the infectious agents or the toxins might pose a moderate danger if accidentally inhaled, swallowed, or exposed to the skin. ✓ The precautions associated with biosafety level-2 are comparatively more extensive than BSL-1, but BSL-1 and BSL-2 laboratories are generally considered as basic laboratories. Standard practices ✓ All the laboratory personnel must wash their hands after using viable microorganisms and before leaving the laboratory.  ✓ Should be avoid Eating, drinking, smoking, and handling contact lenses in the laboratory ✓ Mechanical pipetting should be done instead of mouth pipetting. ✓ All contaminated cultures, glassware, plastic ware, and biologically contaminated waste must be treated as bio-hazards and thus, autoclaved. ✓ Work surfaces must be decontaminated with disinfectant at the end of the day or after any spills or splashes. ✓ Used syringes and needles, razor blades, contaminated broken glass, and blood vials are treated as medical waste and discarded in puncture-resistant sharps disposal containers. Safety Practices ✓ People with increased risk of acquiring infections like the immune-compromised and pregnant individuals should not be allowed to enter the BSL-2 laboratories while the laboratories are at work. ✓ An annual review of the BSL-2 manual should be done to update the guidelines. ✓ Documented policies and procedures should be established that limit the entrance to individuals who know of the potential hazards and are appropriately trained. ✓ A biohazard symbol is placed where biohazardous materials are used or stored. Safety Equipment ✓ Protective coats are to be worn while entering the laboratory and then removed and kept in the laboratory post work. ✓ The laboratory design should be made such that it can be easily cleaned and decontaminated with minimum nooks and corners.  ✓ The laboratory doors should be closed whenever work with hazardous biomaterials is conducted. ✓ An autoclave must be available. Uses Biosafety level-2 laboratories are mostly used for routine analysis and culture of moderately hazardous agents. Besides, some of the laboratories used for teaching and training purposes are also BSL-2 laboratories. Organisms The organisms that require BSL-2 laboratories include the pathogenic strains of E. coli, Staphylococcus, Salmonella, Plasmodium falciparum, Toxoplasma, and Herpes Simples Viruses. 3. Biosafety Level-3 (BSL-3) ✓ Biosafety level 3 (BSL-3) is the level where work is performed with agents that may cause severe or potentially lethal disease through inhalation or aerosol formation, to the personnel, and may even contaminate the environment. ✓ The tasks performed in the BSL-3 laboratories involve indigenous or exotic agents where the potential for infection by aerosols is high, and the disease may have lethal consequences. ✓ Autoinoculation and ingestion present primary hazards to personnel working with these agents at this level. ✓ Working in such laboratories require laboratory personnel with specific training in handling pathogenic and potentially lethal agents, along with supervisors competent in handling infectious agents and associated procedures. Standard Practices  ✓ The entry to the BSL-3 laboratories is limited to individuals with appropriate training in handling BSL-3 organisms, all of whom are selected by the laboratory supervisor. ✓ Besides the general procedures and laboratory practices, the supervisor also formulates additional policies to limit the entry to the laboratory. ✓ All the procedures to be conducted in the BSL-3 must be conducted within a biosafety cabinet to prevent the exposure of the aerosols to the laboratory personnel. ✓ Personnel working in the laboratory must wear personal protective equipment before entering the laboratory and then remove them before leaving. The work surfaces and sinks should be decontaminated once every work shift or after any spills or splashes. The BSL-3 laboratories should be separated from the general traffic in a building to limit entry into the laboratories at all times. Safety Practices ✓ The doors of the BSL-3 laboratories are closed at all times along with a universal biohazard sign and emergency contact information. ✓ Laboratory personnel must have medical surveillance and offered appropriate immunizations for agents handled or potentially present in the laboratory. ✓ A laboratory-specific biosafety manual, which is available and accessible to all, must be prepared and adopted as a policy. ✓ The laboratory supervisor must check for the demonstration of proficiency in standard and special microbiological practices by all laboratory personnel before working with BSL-3 agents.  ✓ Potentially hazardous materials must be placed in a durable, leak- proof container or vial during collection, processing, storage, or transport within a facility. ✓ All laboratory equipment should be routinely decontaminated after work or after any spills or splashes. ✓ The laboratory biosafety manual must define procedures t be adopted in the case of exposure to infectious materials, and these should be treated accordingly. ✓ No work in the BSL-3 laboratories should be conducted on an open bench. All the activities involving the infectious agents must be conducted within Biosafety cabinets or other physical containment devices. Safety Equipment ✓ Biosafety cabinets are to be used for the manipulation of all infectious agents. ✓ Personal protective equipment, coats, gloves, and respiratory protection should be worn while entering the laboratories and then removed before leaving. ✓ The air flowing in the laboratory shouldn’t be recirculated to any area of the laboratory and should be HEPA-filtered prior to being discharged to the outside. ✓ The filters, manuals, equipment, vacuum pipes, autoclaves, etc. should be revised and reviewed annually. Uses ✓ BSL-3 laboratories are used for clinical, diagnostic, teaching, research  ✓ These laboratories are used for the handling and manipulation of highly infectious agents that prose direct severe effects on the health of the personnel. ✓ These are used for the studies regarding the effects of infectious agents and various toxins and their effects. Organisms The pathogens that require BSL-3 laboratories include HIV, H1N1 flu, Yersinia pestis, Mycobacterium tuberculosis, SARS, Rabies Virus, West Nile Virus, Ricketts. 4. Biosafety Level 4 (BSL-4) ✓ Biosafety level 4 is the highest level that is employed while working with dangerous infectious agents and life-threatening disease, aerosol transmission, or unknown risk of transmission. ✓ The BSL-4 laboratories are often used while handling and manipulating Risk Group 4 pathogens that are extremely dangerous, with no known vaccines or therapies, and require extreme precautions during work. ✓ all the laboratory personnel are required to wear full-body, air- supplied suits of PPEs. Standard microbiological practices ✓ No work conducted within the BSL-4 should be done on an open bench or an open vessel. ✓ The work stations, equipment, and sinks should be sterilized post work. ✓ The laboratory personnel should be in protective gear that might include full-body PPEs, gloves, masks, and coats.  ✓ The doors of the laboratories should be closed at all times with the laboratory placed away from the general traffic in the building. ✓ Activities like drinking, eating, mouth pipetting should be avoided at all costs. ✓ Only people that are trained in handling the BSL-4 organisms and the equipment in the laboratory should be allowed into the laboratory. Safety Practices A system is set up for reporting laboratory accidents, exposures, and the medical surveillance of potential laboratory-associated illnesses. Safety equipment: ✓ Double-doored autoclave is placed for decontaminating materials passing out of the facility. ✓ The exhaust air from the facility is filtered through HEPA filters before being discharged to the outside so as to prevent its entry into occupied buildings and air intakes. Uses ✓ BSL-4 laboratories are used for diagnostic and research work on easily transmitted pathogens, causing fatal diseases. ✓ These laboratories are used for new and unknown pathogenic microbes, for which no vaccines or therapies are available. Organisms The BSL-4 level pathogens include the risk group IV organisms like Ebola virus, SARS-CoV-2, Central European Encephalitis virus, Hemorrhagic viruses, etc.