Download Microbial Risk Levels

Microbial Risk Levels
This is the official symbol for biological hazards.
Disposal of these wastes or materials possibly contaminated with these wastes is
strictly regulated. We will follow the regulations in the disposal of all wastes in this
class and each team will be responsible for waste streaming for 2 weeks of the
semester. The CDC (Centers for Disease Control and Prevention), NIH (National
Institutes of Health), and World health organization (WHO) classify microorganisms
into four biosafety levels based on their known hazards and recommended safety
precautions. The biosafety levels are defined as follows and are accompanied by
precautions which will be required in class. Please see the official CDC
classification at http://www.cdc.gov/od/ohs/biosfty/bmbl4/bmbl4s3.htm
Biosafety Safety Classification
Level
1
2
3
Precautions
Biosafety Level 1 is suitable for work involving
well-characterized agents not known to
consistently cause disease in healthy adult
humans, and of minimal potential hazard to
laboratory personnel and the environment.
The laboratory is not necessarily separated
from the general traffic patterns in the
building.
Standard equipment and standard practices. No
special precautions - barrier protection- lab
coats, gloves, lab glasses. Work is generally
conducted on open bench tops using standard
microbiological practices.
Biosafety Level 2 is similar to Biosafety Level 1
and is suitable for work involving agents of
moderate potential hazard to personnel and
the environment. It differs from BSL-1 in that
laboratory personnel have specific training in
handling pathogenic agents and are directed
by competent scientists. Access to the
laboratory is limited when work is being
conducted
Biosafety Level 3 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 as a
result of exposure by the inhalation route.
Laboratory personnel have specific training in
handling pathogenic and potentially lethal
agents, and are supervised by competent
scientists who are experienced in working with
these agents.
Standard equipment and standard practices.
Some special precautions Open bench or safety
cabinet to prevent aerosol formation; barrier
protection- lab coats, gloves, lab glasses. Extreme
precautions are taken with contaminated sharp
items; and certain procedures in which infectious
aerosols or splashes may be created are
conducted in biological safety cabinets or other
physical containment equipment.
All procedures involving the manipulation of
infectious materials are conducted within
biological safety cabinets; barrier protection- lab
coats, gloves, lab glasses; The laboratory has
special engineering and design features such as
negative pressure; contained wastes (i.e.,
double-door access zone and sealed
penetrations).
Special containment equipment or facility design
is neither required nor generally used.
Laboratory personnel have specific training in the
procedures conducted in the laboratory and are
supervised by a scientist with general training in
microbiology or a related science
4
Biosafety Level 4 is required for work with
dangerous and exotic agents that pose a high
individual risk of aerosol-transmitted
laboratory infections and life-threatening
disease. Members of the laboratory staff have
specific and thorough training in handling
extremely hazardous infectious agents and
they understand the primary and secondary
containment functions of the standard and
special practices, the containment equipment,
and the laboratory design characteristics. They
are supervised by competent scientists who
are trained and experienced in working with
these agents. Access to the laboratory is
strictly controlled by the laboratory director.
The facility is either in a separate building or in a
controlled area within a building, which is
completely isolated from all other areas of the
building. Maximum containment lab with safety
cabinets and extreme personal protection;
controlled ventilation; disinfectant buffer zone;
gasket control, extreme waste stream
precautions.
Within work areas of the facility, all activities are
confined to biological safety cabinets. The
Biosafety Level 4 laboratory has special
engineering and design features to prevent
microorganisms from being disseminated into
the environment.
*note: Immune compromised individuals are susceptible to risk even from biosafety level 1 organisms
Selected Examples of Organisms from Various Biosafety Levels
Biosafety Level 1
Biosafety Level 2
Biosafety Level 3
Biosafety Level 4
Bacillus subtilis (nonsporing)
Escherichia coli K-12
Adeno-associated
viruses 1-4
T4 Bacteriophage
Saccharomyces
cerevisiae
Rhizopus stolonifer
Candida albicans
Pseudomonas (GEM)
Infectious canine
hepatitis
Staphylococcus aureus
Mycobacterium
No bacterial agents
Bacillus anthracis
tuberculosis
No fungal agents
Bordetella pertusis
Mycobacterium bovis
No parasitic agents
Corynebacterium
Brucella abortus
Ebola virus
diphtheriae
Pasteurella multocida
Marburg virus
Other E. coli
Yersinia pestis
Lassa virus
Neisseria gonorrhoea
Hanta virus
Machupo virus
Streptococcus pyogenes
SLE virus
Herpesvirus simiae
Vibrio cholera
VEE virus
Pfisteria
Klebsiella sp
Rift Valley virus
Hemorrhagic viruses and
Proteus
Yellow fever virus
some encephalitis viruses
Serratia marcescens
HIV
Rabies
Coccidiodes immitis
Hepatitis A,B,C
Prions
Cryptococcus neoformans No parasitic agents
Most parasitic agents
The organisms found in Biosafety level 1 are often genetically unable to invade human hosts.
To some extent these classifications may be misleading. E. coli classified at level 2 causes more
nosocomial infections than any other single bacteria. It is also responsible for the death of many patients.
Candida albicans, biosafety level 1, while a part of the normal flora found on many people, is often an
agent leading to the demise of an immunocompromised patient when recovered from the blood.
Coccidiodes immitis, the etiologic agent of Valley Fever and biosafety level 3, should be dealt with under
a safety hood, yet it is prolific in the air and soil in Bakersfield. The classification is not based on their
ability to produce disease, because under the right conditions any organism can produce disease, but on
the safety concerns for a healthy individual when dealing with a known specimen. In the clinical lab we
deal with all unknown specimens as though they are biosafety level 3, unless otherwise indicated.
For more information see the CDC Biosafety level Power Point at
http://www.cdc.gov/od/ohs/pdffiles/Module%202%20-%20Biosafety.pdf