16 C & D Microbiology
P5 / M4 - Explain and compare biocontainment procedures in your laboratory and other
industrial laboratories:
Biocontainment procedures are a set of precautions used to isolate dangerous
microorganisms in laboratories, so they don’t pose a risk to researchers/students/staff,
community and environment.
There are two types of biocontainment procedures:
1. Primary biocontainment/barriers:
This uses personal protective equipment like laboratory coats, gloves and goggles.
Additionally good microbiological techniques and use of biosafety cabinets.
2. Secondary biocontainment/barriers:
This involves the protection of the environment external to the laboratory from exposure to
infectious materials and is provided by a combination of facility design and operational
practice. For example, the lab is located in an entirely isolated area with specialised
ventilation and waste management systems.
The biocontainment procedures followed in the college laboratory differs to biocontainment
procedures in an industrial laboratory, as the purposes in which microorganisms are being
investigated differs. For example, in the college lab, lower risk microorganisms such as
Staphylococcus Albus are being investigated for research and experimental purposes by
students. The students are less experienced in biosafety, so there is a lower risk of
contamination to the individuals, community and environment. Whereas in industrial labs,
higher risk microorganisms like Salmonella and viruses are being investigated for industrial,
pharmaceutical and public health safety purposes. These are being investigated by qualified
individuals who are experienced at preventing higher risk microorganisms becoming a risk to
staff, community and the environment.
College labs are a biosafety level 1 area, meaning they are low risk to the community and
individuals. My college lab uses primary biocontainment procedures including washing
hands before and after practical sessions, refraining from eating and drinking, not placing
hands near mouth, wearing protective clothing, tying hair back, covering cuts with bandages
and using open and clean surfaces. Additionally, making sure that all infectious material is
appropriately decontaminated before disposal. There are no specific secondary procedures,
other than ensuring a sink is available for handwashing.
On the other hand, industrial laboratories have a biosafety level of either 2,3,or 4. For
pathology and research laboratories, their biosafety level is 1. This is because their primary
biocontainment procedures involve standard microbiological practices and general safety
procedures followed in college laboratories as well as primary procedures like splash
shields. Class 1 or 2 biosafety cabinets are also used for procedures which have a splash
risk or aerosols of infectious material. Secondary procedures are similar to the college
,procedures, such as hand washing, emergency eyewash and an autoclave for correct
decontamination.
Professionals use Bio safety Cabinets (BSC’s), to contain safely and appropriately higher
risk microorganisms which are handled in a laboratory. BSC’s are enclosed spaces which
are made of stainless steel, and have no gaps or joints, to prevent microorganisms from
collecting. They ensure that personnel are not accidentally infected and prevent accidental
release of pathogens into the environment. Laminar air flow is constantly entering the
cabinet from the outside. The air from the cabinet is filtered so no microorganisms can
escape, as they are stopped by the filter. Usually, they will also have ultraviolet lamps, to kill
the microorganisms within the cabinet. The lamp must be switched off when the cabinet is
not in use, to prevent UV exposure and prevent cancer.
There are three classes of BSC’s:
Class 1: These types of cabinets provide personnel and environmental protection, but no
product protection. They are generally used during aeration of cultures which can generate
aerosols.
Class 2: These types of cabinets provide personnel, environmental and product protection.
There is a fan located at the top of the cabinets which draws sterile air over the handed
products. The air is then filtered before leaving the cabinet.
Class 3: These types of cabinets are used when BSL -4 pathogens are being handled, in
maximum containment laboratories. The enclosure is airtight, with all material leaving
through a double door autoclave, to prevent any contamination of the microorganism. Gloves
are also attached to the cabinet at the front, to prevent any direct contact with the hazardous
microorganisms.
There are four biosafety levels, which adhere to different safety protocols depending on the
type of microorganisms which are used and their associated risks.
The table below shows lowest risk (BSL -1) to highest risk (BSL-4), and the safety
procedures which must be followed.
Biosafety Risk level: Microorganism Typical Safety procedures to follow:
level: used: laboratories:
Level 1: Lower risk to Staphylococcus Schools / Standard microbiological
communities albus, E.coli colleges practices. No special primary
and handlers or secondary barriers other
than handwashing.
Level 2: Moderate risk Staphylococcus Pathology / Microorganisms safely
within Aureus, Research opened on a bench,
communities. Salmonella laboratories potential of splashes and
Linked to aerosols is low.
human Any splashes or aerosols
disease of must follow primary
various containment equipment like
, severity BSC’s. Safety procedures
include splash shields, face
protection, and
decontamination facilities.
Level 3: Moderate risk Chlamydia, Pathology / Greater emphasis on
to Mycobacterium Research primary and secondary
communities tuberculosis, St laboratories barriers. Procedures must be
and high risk Louis carried out in a biosafety
to handlers encephalitis cabinet or controlled access
virus space. Specialised
ventilation must be included
to minimise infection aerosol
release and prevent any
other microorganisms from
entering the enclosed space.
Level 4: High risk to Ebola virus, Public Handlers must work in a
environment Smallpox, health class three BSC wearing full
and life Herpes B virus, laboratories body air supplied positive
threatening Lassa virus / medical pressure personnel suits to
diseases research isolate aerosol infectious
transmitted to laboratories material.
communities Entirely isolated
and handlers, Zone within a complex, with
via aerosol specialised ventilation and
route, from waste management systems
which no to prevent microorganism
known cures release into the
or vaccines environment.
are available
Biocontainment methods differ from college to industry. In colleges, lower risk
microorganisms are usually handled, as the students are less experienced in microbiological
techniques and there is a greater risk of exposure to other individuals. Safety procedures like
handwashing, protective clothing, covering cuts, refraining from eating or drinking are all
used to prevent contamination of the microorganisms from causing harm to the individuals.
Failure to adhere to these safety procedures could lead to individuals becoming sick and
requiring GP attention. Failure to cover cuts can lead to bacteria; infections, later possibly
leading to sepsis, and failure to wear PPE could also lead to infection spreading.
Industry deals with higher risk microorganisms due to most professionals handling these
microorganisms for research, investigative or pharmaceutical purposes. Due to higher risk
microorganisms such as BSL -4 microorganisms being handled, it is vital that there is a
higher priority taken for safety measures, to prevent contamination of these microorganisms
to personnel, community and the environment. Therefore, it is vital to have appropriate BSC,
particularly level 3 BSC’s, to ensure the microorganism cannot contaminate the air or its
surroundings and infect individuals.
Failure to adhere to biocontainment procedures could have severe consequences on the
public and environment. Airborne viruses could travel rapidly, infecting thousands of people
, in a short time frame, and if there are no known cures or treatments, it could have disastrous
effects on communities, leading to death. Wildlife and environment could also be affected,
potentially causing extinctions of plant species or animals, and would take large amounts of
money, time and resources to handle the infections.
09/24 - Practical 1:
Part 1: Calibrating Volumetric Apparatus - Calibration of a Mass Balance
The aim of this experiment is to check the calibration of a mass balance, and ensure it
recorded the correct mass for me to weigh my media accurately.
Apparatus:
● Mass balance
● 200.02g mass
Mass balances must be calibrated, zero the balance to ensure its efficiency and measure
substances mass in micrograms, to gain maximum accuracy of my results.
Method:
1) Plug the balance in, begin the experiment with the balance switched off.
2) Press and hold the ON/ZERO button until MENU appears on the display.
3) Release the ON/ZERO button, the display should now read, C.A.L.
4) Press the ON/ZERO button once, ensure you do not hold the button. The display
should briefly flash -C-.
5) Place the appropriate calibration mass on the pan of the balance and press
ON/ZERO button. The display should show 200.00g
6) Remove the mass from the pan and your balance should be calibrated. Repeat this
experiment 3 times in total.
Instructions can be referenced back to SCALECALIBRATION.com
Risk assessment:
Risk Hazard Precaution
200.00g mass Weight can be dropped on the floor, Ensure the weight is always
possibly causing injuries if dropped placed on the table, not on the
on a person's foot. edge to avoid dropping it.
