biosafety & biosecurity

1. SAFETYAND BIOSECURITY
Lecture 3:-Biosafety levels
Dr. Raghda Saad Mohammed

2. Biosafety Levels (BSLs)
BSL-4
BSL-3
BSL-2
BSL-1
High-risk
biological agents
Low-risk
biological
agents
Biosafety levels established worldwide by WHO
What are Biosafety Levels (BSLs)?
There are four biosafety levels. Each level has
specific controls for containment of microbes
and biological agents. The primary risks that
determine levels of containment are infectivity,
severity of disease, transmissibility, and the
nature of the work conducted. Origin of the
microbe, or the agent in question, and the route
of exposure are also important.
Each biosafety level has its own specific
containment controls that are required for the
following:
•Laboratory practices
•Safety equipment
•Facility construction

3. Biosafety Levels 1–4
BSL-1 BSL-2
Microbes that are not known to cause disease in
healthy adults
•Examples: E.coli.
•Laboratory Practices
•Standard microbiological practices
•Open bench or table permitted
•Laboratory personnel have specific training
•Laboratory supervised by scientist with appropriate
training
Safety Equipment
•Lab coat ,gloves and eye protection
Facilities construction
•Sink for washing hands
•Means for controlling access (e.g. door)
Microbes that pose moderate risk to workers and
environment
•Example: Staphylococcus aureus
Laboratory Practices
•Access to work area limited when work is
conducted
Safety Equipment
•PPE includes Lab coat ,gloves ,mask and eye
protection of face shield
•Biological safety cabinet (BSC) for procedures that
may cause exposure to aerosol or splashes
•Access to autoclave
Facilities construction
•Work area includes
self-closing doors, sink and access
to eye wash station

4. BSL-1 BSL-2
A. Bench
B. PPE
A. PPE
B. BSC

5. Biosafety Levels 1–4 (cont’d.)
BSL-3 BSL-4
Microbes that can cause serious or potentially lethal
disease
•Example: Mycobacterium tuberculosis
(tuberculosis)
Laboratory Practices
•Receive immunization for microbes used
•Access restricted at all times
Safety Equipment
•PPE and respirators might be required
•BSC (preferably Class II or III)
for all open procedures
Facilities construction
•Exhausted air cannot
be recirculated
•Two sets of self-closing locked doors for entrance
•Immediate access
to autoclave
•Hand washing sink near lab exit
•Method of decontaminating
all lab waste
Very few labs in the world
Most exotic and dangerous microbes
•Example: Ebola virus
Laboratory Practices
•Change clothing before entering.
•Shower upon exiting.
•Decontaminate all materials before exiting
Safety Equipment
•Class III BSC or full-body,
air-supplied suit, positive pressure suit
Facilities construction
•Separate building or
isolated zone
•Dedicated air supply and
processed exhaust

6. BSL-3 BSL-4
A. Respirators
B. BSC
C. Self-closing and locking
doors
A. Positive pressure suit

7. Risk assessment strategy
• A strategic risk assessment is a systematic,
continuous process for organizations to
identify its strategic risks and understand how
those risks are being managed across the
business.

9. Risk assessment strategy
• Risk assessment factors include the agent's pathogenicity
(ability to cause infection) and virulence (the severity of
disease), the infectious dose, communicability, and stability
within the environment.
• The Risk Group Comparison Table below outlines the basic
differences between each group.

10. RISK GROUP
1
RISK GROUP
2
RISK GROUP
3
RISK GROUP
4
Characteristics
Does not
cause disease
in healthy
adults.
Can cause
infection of
varying
severity. Rarely
lethal. Can be
controlled
using standard
laboratory
practices.
Agents
associated with
moderate to
severe disease
outcome. Can
be lethal.
Capable of
causing severe
disease with
lethal outcome.
Availability of
Treatment
Not applicable. Treatment may
be available or
host immune
system is
capable of
controlling the
infection.
Treatment may
not be
available.
Treatment is
generally not
available.
Experimental
treatment
regimens
possible.

11. RISK GROUP
1
RISK GROUP
2
RISK GROUP
3
RISK GROUP
4
Routes of
Transmission
Not applicable. Ingestion,
through the
skin, and via
facial mucous
membranes.
Same as Risk
Group 2 plus
inhalation.
Same as Risk
Group 3.
Disease
Severity to
Individual
None in
healthy adults.
Low to
moderate.
Moderate to
high
Higher
mortality and
morbidity.
High
Highest
mortality rates
in this
category.
Community
Risk
Low Low Low to
Moderate
High
Perception risk
also very high.
Infections
Dose
Not applicable Generally high
(variable)
Lower doses
capable of
infection
Can be as low

12. RISK GROUP 1 RISK GROUP 2 RISK GROUP
3
RISK GROUP 4
Example
Agents
Non-conjugative
strains of E.
coli,
Saccharomyces
cerevisiae.
Parasites (i.e.
Plasmodium,
Trypanosomes,
Leishmania)
GI pathogens
(Salmonella,
Shigella)
Bloodborne
Pathogens (HBV,
HCV, Borrelia).
Mycobacterium
tuberculosis,
West Nile
Virus, Yellow
Fever Virus,
Rickettsia .
Ebola virus,
Marburg virus,
Sabia virus.
Rule of
Thumb
Don’t drink it!
Never eat, drink
or smoke in the
laboratory.
Don’t touch it!
Wear gloves,
decontaminate
work surfaces,
avoid touching your
face, make sure
wounds are
covered, work in a
BSC, wear eye
protection, work
behind a shield.
Don’t breathe
it!
Because of
inhalation risk,
perform all
work inside of
a biosafety
cabinet. Wear
respiratory
protection if
needed.
Don’t do it!
(Don’t do it in
your state unless
you have a
federally
approved BSL4
laboratory!)
Risk Group 4
agents require
significant
containment.

13. Risk group, Biosafety levels, practice and equipments
Risk
group
Biosafety level Laboratory
type
Laboratory
practices
Safety
equipment
1 Basic-Biosafety
Level 1
Basic
teaching,
research
Good
microbiological
techniques
(GMT)
None; open
bench work
2 Basic-Biosafety
Level 2
Primary
health
services,
diagnostic
services,
research
GMT plus
protective
clothing,
biohazard sign
Open bench
plus biological
safety
cabinet (BSC)
for potential
aerosols

14. Risk group, Biosafety levels, practice and equipments
Risk
group
Biosafety
level
Laboratory
type
Laboratory
practices
Safety equipment
3 Containment
-Biosafety
Level 3
Special
diagnostic
services,
research
Level 2 plus
special clothing,
controlled
access,
directional
airflow
BSC and/or other
primary devices
for all activities
4 Maximum
containment-
Biosafety
Level 4
Dangerous
pathogen
units
Level 3 plus
airlock entry,
exit
showers,
special waste
disposal
Class III BSC or
positive pressure
suits with class II
BSCs, doubleended
autoclaved (through the
wall), filtered air

15. Standard practices required in Bio labs.
1-Frequent hand washing
2-Door that can be kept closed when working.
3-limits on access to the lab space when working.
4-No smoking, eating, drinking, storage of food in laboratory.
5-Care to minimize splashes and actions that may create
aerosols (tiny droplets).
6-Decontamination of work surfaces after every use after any
spills.

16. Thanks for
your
attention
12/10/2021 16