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The safety and security must meet the requirements of accrediting and regulatory bodies. Fire extinguishers should be readily available throughout the work area. Eyewash stations, safety showers, sprinkler systems, fire alarms, spill control kits, emergency power and lighting should be included as specified by building codes. Two means of exit should be planned. The windows should be closed and sealed. Doors should be self-closing special or maximum containment facilities requires a separate building, sealed openings into the laboratory, liquid disinfectants barriers, dressing rooms, double - door entry into the lab, bio waste treatment system , separate ventilation system and treatment system to decontaminate exhaust air. Whole laboratory should preferably be air-conditioned which minimizes the chances of contamination.
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Clinical microbiology laboratory must have any of the biosafety level depends on the nature of work.
Biosafety Levels and Practices
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A biosafety level is the level of the biocontainment precautions required to isolate dangerous biological agents in an enclosed facility. The levels of containment range from the lowest biosafety level 1 to the highest at level 4 . The Centres for Disease Control (CDC) and the National Institutes of Health (NIH) have developed standard procedures providing protection against biological hazards.
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Biosafety levels are selected to provide the end-user with a description of the minimum containment required for handling different microorganisms safely in a laboratory setting and reduce or eliminate exposure to potentially hazardous agents. These biosafety levels are applicable to facilities such as diagnostic, research, clinical, teaching, and production facilities that are working at a laboratory scale. The four biosafety levels are described as:
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BSL1 containment is suitable for work involving well-characterized agents not known to cause disease in healthy adult humans, and of minimal potential hazard to laboratory personnel and the environment. It requires no special design features beyond those suitable for a well-designed and functional laboratory. Work may be done on an open bench top, using gloves and some sort of facial protection and decontamination procedures are similar to modern precautions against everyday microorganisms (i.e., washing one's hands with anti-bacterial soap, washing all exposed surfaces of the lab with disinfectants, etc.). lab materials used for cell and/or bacteria cultures are decontaminated by autoclave . Containment is achieved through the use of practices normally employed in a basic microbiology laboratory.
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Examples of BSL1 Agents: Bacillus subtilus, Naegleria gruberi, many Escherichia coli, Infectious Canine Hepatitis virus .
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- This level is similar to Biosafety Level 1 and is suitable for work involving agents of moderate potential hazard to personnel and the environment . Laboratory personnel have specific training in handling pathogenic agents. The primary exposure hazards associated with organisms requiring BSL2 are through the ingestion, inoculation and mucous membrane route. Agents requiring BSL2 facilities are not generally transmitted by airborne routes, but care must be taken to avoid the generation of aerosols (aerosols can settle on bench tops and become an ingestion hazard through contamination of the hands) or splashes. Primary containment devices such as BSCs and centrifuges with sealed rotors or safety cups are to be used as well as appropriate personal protective equipment (i.e., gloves, laboratory coats, protective eyewear). As well, environmental contamination must be minimized by the use of hand washing sinks and decontamination facilities (autoclaves). Extreme precautions be taken in handling contaminated sharp items.
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Examples of BSL2 Agents: Bacillus anthracis, Bordetella pertussis, Brucella spp., Cryptococcus neoformans, Clostridium botulinum, Clostridium tetani, Helicobacter pylori, most Salmonella spp.,Yersinia pestis, Mycobacterium leprae, Shigella spp., Human Immunodeficiency Virus.
- In this level Laboratory personnel should have specific training in handling these pathogenic and potentially lethal agents and are supervised by scientists who are experienced in working with these agents. These agents may be transmitted by the airborne route, often have a low infectious dose to produce effects and can cause serious or life-threatening disease. BSL3 emphasizes additional primary and secondary barriers to minimize the release of infectious organisms into the immediate laboratory and the environment. Additional features to prevent transmission of BSL3 organisms are
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Use of adequate ace and respiratory protection procedures for handling agents , limited laboratory access,
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Written policies and procedures for handling spills,
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Separate area with access through two sets of self closing doors,
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Sealed floors ,walls and ceilings to facilitate decontamination,
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A waste disposal system available within area ,
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A ducted air system that draw clean air from outside,
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All the exhaust air discharged to the outside, pass through HEPA filters in the exhaust of BSCs.
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Examples of BSL3 Agents: Myobacterium tuberculosis, Salmonella typhi, Vesicular Stomatitis Virus, Yellow Fever Virus, Francisella tularensis, Coxiella burnetti.
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- This level is required for work with dangerous and exotic agents that pose a high individual risk of aerosol-transmitted laboratory infections, agents which cause severe to fatal disease in humans for which vaccines or other treatments are not available. This level of containment represents an isolated unit, functionally and, sructurally independent of other areas as possible. When dealing with biological hazards at this level the use of a Hazmat suit and a self-contained oxygen supply is mandatory. The entrance and exit of a biosafety level 4 lab will contain multiple showers, a vacuum room, an ultraviolet light room, and other safety precautions designed to destroy all traces of the biohazards. Multiple airlocks are employed and are electronically secured to prevent both doors opening at the same time. All air and water service going to and coming from a biosafety level 4 lab will undergo similar decontamination procedures to eliminate the possibility of an accidental release. .
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Members of the laboratory staff have specific and thorough training in handling extremely hazardous infectious agents and understand the primary and secondary containment functions, standard and special practices, the containment equipment, and the laboratory design characteristics. They are supervised by qualified scientists who are trained and experienced in working with these agents. Access to the laboratory is strictly controlled by the laboratory director.
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Examples of BSL4 Agents: smallpox virus, Ebola virus, hemorrhagic fever viruses, Marburg virus,Lassa fever Micro organisms are grouped based an increasing hazards to human health.
Microorganisms are grouped based on an increasing hazards to human health.
Risk group 1
- Microorganisms are unlikely to cause human diseases.
Risk group 2
- A pathogen that can cause human or animal diseases but is unlikely to be a serious hazard to laboratory workers, the community, livestock, or the environment. Laboratory exposure may cause serious infection, but effective treatment and preventive measures are available and the risk of spread of infection is limited.
Risk group 3
- A pathogen that usually causes serious human or animal disease may spread in the community. Effective treatment and preventive measures are available.
Risk group 4
- 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 available.
Relationship of risk group to bio-safety level practices and equipment
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Risk group
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Bio-safety level
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Examples of laboratories
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Laboratory practice
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Safety equipment
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1.
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Basic bio-safety level-1
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Basic teaching
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GMT
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None, open bench work
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2.
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Basic bio-safety
level –2
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Primary health services, primary level hospital, diagnostic, teaching and public health
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GMT
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Open bench plus BSC for potential aerosols
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3.
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Containment
Bio-safety level 3
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Special diagnostic
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As level 2 plus special clothing, controlled access, directional air flow
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BSC and /or other primary containment for all activities
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4.
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Maximum
containment level 4
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Dangerous pathogen units
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As level 3 plus airlock entry, shower exit, special waste disposal
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Class III BSC or positive pressure suits, double ended autoclave filtered air
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- GMT :Good Microbiological Technique
- BSC :Biological safety cabinet
Standard operating procedure in microbiology laboratory (general rules and regulations)
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A rewarding laboratory demands strict adherence to prescribe rules for personal and environmental safety. Because most microbiological laboratory procedures require the use of living organisms, should be treated as potential pathogens. Thus microbiology students must develop aseptic techniques. The following basic steps should be observed in microbiology lab.
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Upon entering the laboratory, place coats, books and others in specific area locations – never on bench tops.
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Keep doors and windows closed to prevent contamination from air currents.
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Wash hands thoroughly with soap and warm water before and after work.
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At the beginning and end of the work, wipe the bench top/table with gauze pads saturated with 70% ethanol or other suitable disinfectant.
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Sterilize all contaminated materials (needles, cultures, glass wares) by proper method.
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All reagents and equipments must be properly labelled and placed.
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White lab coats are required to all persons working the lab.
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Wearing apparel should be avoided.
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Never place pencil, labels or any other material in mouth while in lab.
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If culture is spilled clean and disinfect the area immediately.
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Participants