3. What is Biosafety?
Biosafety means safety from exposure
to infectious agents.
4. History And Neccesity Of Biosafety
On 18 april 1955 the first biological safety conferrence took place at Camp
Detrick in Fredrick, Maryland in presence of fourteen representatives from
three Principal Laboratories of U.S Army.
Biosafety, chemical, radiological & industrial safety issues were discussed.
Later in the United States, the Centers for Disease Control (CDC) specified 4
different levels of biocontainment which ranges from Biosafety level 1 (BSL-1)
to Biosafety level 2 (BSL-4).
In order to avoid infection/biohazard to the laboratory personnel & the
environment biosafety levels are very important.
5. Types Of Biosafety Levels
There are 4 types of biosafety levels according to the risk factors involved
depending on the nature of pathogen being handled.
BSL 1 (Basic teaching, Research)
This level is suitable for work involving well characterized
agents not known to cause disease to healthy adult human
& It gives minimal protection to the operating person.
Work is done on open benches or simple cabinet without
laminar air flow or with horizontal laminar (class 1) may be
Access limited when work in progress.
Basic precaution is taken such as wearing gloves,
protective eyewear, sink for washing hands, etc.
The lab is not necessarily saparated from the building.
No eating, drinking, applying cosmetics, mouth pipetting.
Openable windows must have screen.
Regular disinfection/decontamination must be done
atleast once per day.
example non pathogenic E. coli, salmonella spp. B. subtilis.
Graphic credit: http://www-
6. BSL 2 (Primary health services, diagnostic service, research)
Use of Biological safety cabinet
Open bench work
BSL 2 is same as like BSL 1 but few modifications
are made since this level includes risk factors
more than BSL1.
Agents associated with human disease.
Effective treatment and preventive measures
Biohazard sign must be at entrance.
Restricted access, control of waste disposal,
protective clothing, no food & drinking.
Class 1 cabinets (horizontal laminar) are used.
Written report for spills, accidents , medical
Biosafety cabinets should be decontaminated
First aid, medications on accidental cases is
Expose to mucous membranes must be avoided.
Common example of pathogen: Hepatitis A,B,C,
Herpes simplex virus, Measel virus etc
8. BSL 3 (Special diagnostic service, reasearch)
This level is applicable to clinical, diagnostic, teaching,
research, or production facilities in which work is done with
indigenous or exotic agents which may cause serious or
potentially lethal disease after inhalation.
It includes various bacteria, parasites and viruses that can
severe to fatal disease in humans but for which treatments
Vertical laminar flow hood with front protection.
Strict access control to lab.
Two sets of self closing doors.
Protective clothing, gloves face shield mask, goggles, closed
shoes, automatic or elbow taps on sink.
Windows closed and sealed.
Negative pressure in labs, directional airflow & air not re-
circulated, proper decontamination of wastes before disposing.
In case of spillage trained staff deals with it.
Common example of pathogens: Yersinia pestis,
Mycobacterium tuberculosis, etc
Class 2 laminar hood
10. BSL 4 (Dangerous pathogen units)
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.
Lab is separate.
Totally enclosed system.
A completely sealed cabinet (class 3) with glove pockets to
allow manipulation of cultures.
Positive pressure personnel suite.
Life support system.
Multiple showers at entry & exit
Vaccum room, ultra violet room.
Special waste disposal.
Double ended autoclave through wall.
Supervised by qualified scientists who are trained and
experienced in working with these agents.
Example of pathogen: Ebola virus, Marburg virus, Lassa
Biohazard hood(glove box)
Positive pressure suits
Culture of animal cells (5th edition)
Author- R. Ian Freshney
Biosafety levels- Wikipedia
Laboratory Biosafety Level criteria- Centers for Disease