Biosafety Levels Clinical Microbiology Review 136
LEVEL RISK TYPES OF AGENTS EXAMPLES OF AGENTS PRECAUTIONS
I
II
III
IV
Standard microbiological practices.
No special equipment.
Biological safety cabinet (BSC) I or II.
Personal protective equipment (PPE).
Autoclave must be available. Limited
access. Most micro labs fall in this
category.
Same as above plus negative air flow,
sealed windows.
Requires use of class III BSC; full-body,
air-supplied positive pressure suit;
independent unit with specialized
ventilation & waste management to
prevent release into environment.
Those not known to cause
disease in healthy adults
Common human
pathogens
Those that may cause
serious or lethal disease
via inhalation. Effective
treatment available
Those that pose high risk
of life-threatening dis-
ease. May be transmitted
by aerosols. No vaccine
or therapy
Minimal
Moderate
High
Extreme
Bacillus subtilis, Mycobacterium
gordonae, soil microbes
E. coli, Salmonella, HIV, HBV, influenza
Bacillus anthracis, Francisella, Brucella,
Mycobacterium tuberculosis, Rickettsia
rickettsii, Coxiella burnetii, mold stages
of systemic fungi
Ebola virus, Lassa virus, others that
cause hemorrhagic fevers
