2. OBJECTIVE
To define barriers and procedures
used by laboratories to protect workers
and others from infection.
To provide the highest practical
protection and the lowest practical
exposure.
BIO SAFETY IN LABORATORY
3. Why is Biosafety
Important?
BIO SAFETY IN LABORATORY
Laboratorians should recognize
hazards of processing infectious
agents.
To develop Guidelines to protect
workers in microbiological and
medical labs through engineering
controls, management policies,
work practices.
7. BIO SAFETY IN LABORATORY
• Literal meaning of Inoculation is “Introduction of
material into eye”
• Introduction of Infection through Eye,
Breached/Intact skin by rubbing or touching
infected hand.
INOCULATION
• Licking, sucking or accidental swallowing of
infective materials.
• Splashing on the lips, touching mouth with
contaminated fingers, pipetting by mouth etc.
INGESTION
• Infection by breathing-in of infected aerosol,
droplet-nuclei or dust.
• Invisible aerosol are generated by any action that
breaks the continuity of the surface of a liquid.
INHALATION
8. STANDARD MICROBIOLOGICAL
PRACTICES
Restricted access
Hand washing
Prohibit eating, drinking, smoking,
applying cosmetics, nail-biting
Prohibit mouth pipetting
Safe handling of sharp equipments
Use of Personal Protective Equipment
BIO SAFETY IN LABORATORY
11. Syringe & Needle : Needlestick injury,
Splashing or Spraying, Contamination by
leakage.
Pipetting : Mouth pipetting, drips or aerosol,
skin stabbing by broken or fine tipped glass
pipette.
Inoculation : Vibration of an inoculating
wire/loop may cause splashing and aerosol
production.
BIO SAFETY IN LABORATORY
12. Shaking/Mixing : Shaking produces aerosol
even in a closed container and released on
opening.
Centrifugation : Vibration generate aerosol
within the container. Careless loading/unloading,
breakage during centrifuging can lead to gross
dissemination.
Stoppering tubes : Tube breakage by applying
tight stopper forcibly.
BIO SAFETY IN LABORATORY
13. Freeze-drying : Contamination of air from the
material being dried is inevitable and the procedure
should be done in an unoccupied room.
Microbiological safety cabinets : Improper
installation, maintainance and use can release
infection into air.
Animal procedure : Work with animals, affords
many opportunities for injury and infection. Bedding
contaminated with discharge and excreta can
liberate infected dust.
BIO SAFETY IN LABORATORY
14. Transport of specimen : Improperly closed
and packaged samples may leak. The outside of
containers may become contaminated during
sample collection.
Disposal : Contamination and injury may
occur during the collection and decontamination
of discarded cultures, specimen containers and
used equipments especially ‘sharps’.
BIO SAFETY IN LABORATORY
16. 16
GROUP 1
Organisms that are
most unlikely to
cause human
disease.
Ex : E.coli,
Lactobacillus
acidophilus etc.
GROUP 2
Organisms may
cause human
disease but are
unlikely to spread
in community.
Ex : Salmonella sp.
Staph. Aureus,
C. diphtherae,
Rabies, HIV, Measles,
Hepatitis, Herpes
virus etc.
GROUP 3
Organisms may
cause human
disease, pose a
risk to spread in
community but
effective
prophylaxis is
available.
Ex : M.
tuberculosis.
SARS, B. Anthrax.
GROUP 4
Organisms may
cause human
disease, pose a
risk to spread in
community but no
effective
prophylaxis is
available.
Ex : Ebola virus
18. BSL 1
*Normally harmless
organisms. (Hazard
group 1)
*Requirements :
Lab can be easily
cleaned and
washing facilities.
No need of
separate lab from
hospital building.
BSL 2
*Most pathogens in
hazard group 2.
*Requirements :
Easy to clean, BSC 1
adequate size,
Restricted entry,
Biohazard sign.
No need of separate
lab from hospital
building
Remove protective
equipment while
leaving the lab
BSL 3
*Most pathogens in
hazard group 3.
*Requirements : PPE
kits, BSC 2,
Biohazard sign,
Restricted entry,
Negative pressure in
lab.
Separate lab from
Hospital building
Autoclave is
necessary for
disposable waste
BSL 4
*Most pathogens in
hazard group 4.
*Requirements :
Sophisticated control
of air movement +
BSC 3, Restricted
entry. –ve pressure.
Separate lab from
Hospital building
Autoclave for
disposable waste.
Multiple shower at
entry & exit, UV in
each room
20. PRIMARY BARRIERS
Physical barriers or personal
protective equipment between
lab worker and pathogen :
Gloves, masks, special
breathing apparatues.
SECONDARY BARRIERS
Structural aspects of the
laboratory that make working
environment safer against
infection.
Sinks for hand washing, Special
containment areas, special air
ventilation patterns.
23. CLASS 1
*Normally harmless
organisms.
*Requirements : Lab
can be easily cleaned
and washing
facilities. HEPA filter
CLASS 2
*Most pathogens in
hazard group 2.
*Requirements :
Easy to clean,
adequate size and
with access limited to
the laboratory
materials. HEPA filter
CLASS 3
*Most pathogens in
hazard group 3.
*Requirements :
Foregoing
precautions + away
from general
circulation +
continuous airflow +
HEPA filter.
24. CLASS 1 MICROBIOLOGICAL
SAFETY CABINET
BIO SAFETY IN LABORATORY
Room air is drawn in through the front opening (A) at
a minimum velocity of 75 fpm
passes over the work surface and then passes
through a plenum (D)
air from the cabinet is exhausted through a HEPA
filter (C). The work can be viewed through a glass
sash (B)
The HEPA filter may be located in the exhaust plenum
of the BSC or in the building exhaust.
25. HEPA FILTER
High-efficiency particulate air filter
Common standards require that a HEPA air
filter must remove at least 99.95% (European
Standard) or 99.97% (U.S.) of particles from
the air that passes through whose diameter is
equal to 0.3 μm
HEPA filters capture pollen, dirt, dust,
moisture, bacteria (0.2-2.0 μm), virus (0.02-
0.3 μm) etc
BIO SAFETY IN LABORATORY
26. CLASS II BIOSAFETY CABINET
The Class II BSC differ from Class I BSC’s by
allowing only HEPA-filtered air (sterile) to
flow over the work surface providing both
product and personnel protection.
They are classified into four types (A, B1, B2,
B3), on the basis of construction type, airflow
velocities and patterns, and exhaust systems.
Used for working with infectious agents in
Hazard Groups 2 and 3 and with infectious
agents in Hazard Group 4 when positive-
pressure suits are used..
BIO SAFETY IN LABORATORY
27. CLASS II TYPE A BSC
BIO SAFETY IN LABORATORY
29
Air drawn from the room into the cabinet through the
front opening (A) at velocity of 75 fpm
Then 70% of air is recirculated through a plenum (D)
and a HEPA filter (E)
The remainder is exhausted through the HEPA filter
(C) to the room.
The work can be viewed through a glass sash (B) , the
blower is designated by (F)
Cannot be used for Radio-nucleotides and Toxic Chemicals
28. CLASS II TYPE B1 BSC
BIO SAFETY IN LABORATORY
30
Air enters the cabinet from the room through
the front opening at velocity of 100 fpm
Then 40% of air is recirculated through a
sump (A) and recirculating plenum (D).
Passing through HEPA filter (B & E) before
being exhausted (G) through a HEPA filter
(F) into negative pressure ducts to outside
The work space (H) can be viewed through a
glass sash (C)
Can be used for Radio-nucleotides and Toxic
Chemicals
29. CLASS II TYPE B2 BSC
BIO SAFETY IN LABORATORY
31
Air enters the cabinet from the room through the
front opening (A) at velocity of 100 fpm and drawn
into a cabinet planum (E) Before being exhausted to
the outside though a HEPA filter (C) and an negative
Duct system.
Simultaneously, room air enters the cabinet through
a second portal (F) and a HEPA filter (D)
Passes down across the work area and then joins
the outflow stream in the cabinet plenum (E)
The work can be viewed through a glass sash (B)
Can be used for Radio-nucleotides and Toxic Chemicals
30. CLASS II TYPE B3 BSC
Similar to Class II A biosafety cabinet except-
ducts and plenums are under negative pressure
cabinet air are exhausted to the outside of building
suitable for work with volatile toxic chemicals and
radionuclides
BIO SAFETY IN LABORATORY
32
31. CLASS III BSC
Totally enclosed cabinet.
Four gloves are fixed to the ports so
that the operators are separated from the
work.
BIO SAFETY IN LABORATORY
Air enters through a portal and HEPA filter (D) and
exhaust out through a HEPA filter (C) into a
negative pressure duct system and outside
environment.
The worker manipulates the samples through
sealed gloves(A) & views the work through glass
shield(B)
Samples are passed into the box through an
interlock (E) where a double ended autoclave is
attached.
32. CLASS III BSC
BIO SAFETY IN LABORATORY
The disadvantages of this
approach include the difficulty of
performing fine manipulations
through thick rubber gloves
35. Disinfectants are hazardous
Precautions : Eye & Face protection,
Gloves etc.
Proper explanation of functions and
limitations of disinfectants to all who use
them.
Skin and work surfaces can be
decontaminated with 70% ethanol.
BIO SAFETY IN LABORATORY
36. DISINFECTANTS :
Use of Sodium Hypochloride : for
general purpose but not for tubercle bacilli
BIO SAFETY IN LABORATORY
Concentration Available
Chlorine
(ppm)
USE
10% 10,000 Virology and
spilled blood
2.5% 2500 Discard Jars
1% 1000 Routine surface
disinfection.
37. DISINFECTANTS :
Soluble Phenolics : for Tuberculous
material, Non-enveloped viruses etc.
Formaldehyde : Fumigation
Glutaraldehyde : on metals
BIO SAFETY IN LABORATORY
39
39. Laboratory biosecurity incidents :
accidental laboratory-acquired infections
laboratory releases of lethal pathogens,
containment failures during transport of
lethal pathogens,
exposure of lethal pathogens to
laboratory personnel,
improper disposal of contaminated
waste,
escape of laboratory animals.
BIO SAFETY IN LABORATORY
40. BIO SAFETY IN LABORATORY
DATE PATHOGEN ORIGIN COUNTRY
2014 H1N1 influenza virus United States
2014-07-01 Smallpox United States
2014 Ebola Sierra Leone
2016 Zika virus United States
2018 Ebola Hungary
2019 SARS-COV-2 China
2022 Polio Netherlands
FEW EXAMPLES :
