3. Jens
Martensson
SAFETY
“Biosafety” means the need to protect
human and animal health and
environment from the possible
adverse effects of the products of
modern biotechnology.
Biosafety defines the containment
conditions under which infectious
agents can be safely manipulated.
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Martensson
Why we need
safety???
Lab has hazards of processing infectious
agents.
Accidental threat to workers and
environment.
To have adherence with safety
regulations while dealing with highly
infectious agents.
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Martensson
Biosafety levels (BSL) are used to identify
the protective measures needed in a
laboratory setting to protect workers, the
environment, and the public.
The levels are defined in Biosafety in
Biomedical Laboratories (the BMBL).
The four biosafety levels are:
BSL-1
BSL-2
BSL-3
BSL-4, with BSL-4 being the highest
(maximum) level of containment.
Level of Biosafety
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Microbes not known consitwntly to cause disease in healthy adults and prevent
minimal potential hazard to lab and environment.
E.g : non pathogenic strain of E.coli.
BSL - 1 practices:
Standard microbiological practices are followed:
Work can be performed on an open table or bench
PPE(Personal Protective Equipment) needed
Sink – Hand washing
Lab – doors separate
Biosafety level 1:
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Martensson
Microbes that possess moderate hazards to laboratorians.
E.g : staphylococcus aureus.
BSL - 2 practices:
Access to lab is restricted when work is being
conducted
PPE ,face shields, eye goggles
Biosafety cabinet
Autoclave/Decontamination proper
Self closing doors
Sink with eyewash apparatus readily available
Biosafety level 2:
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Martensson
Biosafety level 3:
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Serious / potentially lethal disease through respiratory transmission.
E.g : Mycobacterium tuberculosis.
BSL - 3 practices:
Laboratorians – under medical surveillance and receive immunization
Access to lab restricted &controlled
PPE with respirators
BSC
Sink with eyewash
Exhaust air – not recirculated
Self closing doors with automatic
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Martensson
Highest level of biological safety
Dangerous and exotic microbes.
E.g : Ebola, Marburg viruses.
BSL - 1 practices:
Change clothes before entering
Shower upon exiting
Decontamination all materials before exiting
Class III BSC
Separate building for lab
Vaccum lines and decontamination system
Biosafety level 4:
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Martensson
The safety measures which prevent the escaping of GEOs from the laboratory called
contamination
They help to destroy harmful GEOs within the laboratory itself.
In USA ,the National Institue of Heatlth(NIH) set up the Recombinant DNA Advisory
Committee(RAC) in 1976.
PHYSICAL CONTAMINATIONS
The physical methods being adopted inside the laboratories to prevent escaping of
GEOs to the environment are called physical contamination.
It include:
1. Air filtration 3.Sterilization lights
2. Waste disposal 4.Protective handling
CONTAINMENT:
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Martensson
1) Air filtration
The exhaust air from the laboratory is filtered
through exhaust filters.
It prevents the escaping of GEOs from the lab.
2) Sterilization lights
Flurescent tube lights which emit UV light ,are fitted
in the laboratory to sterilize the work areas and
exposed surfaces of the lab.
3) Waste disposal
All waste coming from laboratory are sterilized by
autoclaving or by incinerating them in an incinerator.
4) Protective handling
The person must wear protective clothes.
Mouth pipetting should be avoided.
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Martensson
The biological principles used in laboratories to prevent the
escape of GEOs or microbes are called containment.
Biological containment makes the organism unable to survive in
the outside environment.
It prevents the spreading of vector DNAs to the organism
outside the laboratory by usual conjugation ,transformation or
transduction.
Bacteria which cannot grow outside unless suitable nutrients
have to be supplied are used for gene manipulations.
BIOLOGICAL CONTAMINATION
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Martensson
Disinfectant selection – EPA registration number in the
label and list of infectious agents that the disinfectant
is effective.
BSC – ethanol not used as decontamination as it
evaporates – no proper contact time – ethnol can be
used as a rinsing agent.
Formaldehyde vapour sterilization to be done to kill
spores
DISCONTAMINATION
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• Sterilization
• uses a physical or chemical procedure to destroy all microbial life, including highly resistant
bacterial endospores.
• Disinfection
• uses a liquid chemical to eliminate virtually all pathogenic microorganisms, with the exception of
bacterial spores, on work surfaces and equipment.
• Antisepsis
• is the application of a liquid antimicrobial chemical to skin or living tissue to inhibit or destroy
microorganisms.
• Cleaning
• uses water, detergent, and some mechanical action such as scrubbing with a gloved hand or
brush.
• Cleaning is often a required step before sterilization or disinfection of inanimate objects.
Level of discontamination
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15. Jens
Martensson
There are 4 main categories of physical and
chemical
means of decontamination:
• Heat sterilization (wet or dry)
• Liquid disinfection
• Vapors and gases
• Radiation (ionizing or non-ionizing)
Methods
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