BIOSAFETY LEVELS

ByNeha RachankarMSc-FY

Caution: biohazard

Contents

1. Biosafety concept

2. History & neccesity of biosafety

3. Types of biosafety levels a. BSL 1 b. BSL 2 c. BSL 3 d. BSL 4

4. References

What is Biosafety?

Biosafety:-

Biosafety means safety from exposure to infectious agents.

Small pox infection

History And Neccesity Of Biosafety

History: 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).

Neccesity:In order to avoid infection/biohazard to the laboratory personnel & the environment biosafety levels are very important.

Types Of Biosafety LevelsThere 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 used. 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-ehs.ucsd.edu/bio11.htm

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 are available. 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 evaluation. Biosafety cabinets should be decontaminated regularly. First aid, medications on accidental cases is must. Expose to mucous membranes must be avoided. Common example of pathogen: Hepatitis A,B,C, Herpes simplex virus, Measel virus etc

A standard lab

Working on influenza virus in safety cabinet

Class 1 cabinetBiohazard sign

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 causesevere to fatal disease in humans but for which treatments exist. 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

Bsl 4 lab showing safety measures

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 & exitVaccum 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 fever etc.

Biohazard hood(glove box)

Positive pressure suits

References

Culture of animal cells (5th edition) Author- R. Ian Freshney

Biosafety levels- Wikipediaen.wikipedia.org/wiki/Biosafety_level

Laboratory Biosafety Level criteria- Centers for Disease Controlwww.cdc.gov

Biosafety levelswww.safety.duke.edu

Thank you!!!