Biohazard.
A biohazard is an agent of biological origin that could produce some types of
delirious effects on humans such as microorganisms, toxins and allergens that
are derived from those organisms; and allergens and toxins derived from
higher plants and animals.
Biosafety
Biosafety is the application of combinations of different laboratory practices,
procedures, laboratory facilities, and safety equipment while working with
potentially infectious c microorganisms. It is designed to protect human health
and prevent release of pathogens into the environment.
Biosafety levels
There are four levels of control that are appropriate for research with infections
agents with various levels of risk. This can range from little/no risk for healthy
people (bsl 1) to substantial risk for life threatening disease (bsl 4)
BSL (Biosafety Levels) level 1
This level is minimal risk to individuals and communities, some examples of
microorganisms you may find in these labs are, non-pathogenic E. coli,
saccharomyces cerevisiae and b subtilis.
This laboratory setting is usually used when research is taking place on
benches without the use of special contaminant equipment. A BSL-1 lab, is not
needed to be isolated from the surrounding facilities, things that occur in a BSL
1 lab will require only standard microbial practices, such as:
Mechanical pipetting only (no mouth pipetting allowed)
Safe sharps handling
Avoidance of splashes or aerosols
Daily decontamination for all work surfaces when the work is complete
Hand washing
Prohibition of food, drink, and smoking materials in lab setting
PPE, such as eye protection, gloves and a lab coat or gown has to be
worn
Biohazard signs
BSL-1 labs also require immediate decontamination after spills. Infectious
materials also must be decontaminated prior to disposal, usually using an
autoclave.
BSl level 2
In a bsl 2 there is a moderate risk to Individuals and a minimal risk to
communities, this biosafety level will cover laboratories that work with agents
,associated with human diseases such as pathogenic or infections organisms
that may pose a moderate health hazard. Examples of agents typically worked
with in a BSL-2 include equine encephalitis viruses and HIV (Human
Immunodeficiency Virus), as well as Staphylococcus aureus (staph infections).
BSL-2 laboratories will keep the same level of standard microbial practices as
BSL-1 labs, but they can also include some enhanced measures due to the
potential risk of the microbes used in the lab. Personnel working in BSL-2 labs
are expected to take lots of care to prevent injuries such as cuts and other
breaches of the skin, as well as ingestion and mucous membrane exposures.
In addition to the BSL 1 expectation, these practices are needed in a BSL 2 lab
setting:
The Appropriate personal protective equipment (PPE) must be worn at all
times, this includes a lab coat and gloves. Eye protection and face shields
can also be worn, if necessary.
All procedures that can cause infection from their aerosols or splashes
must be performed within a biological safety cabinet (BSC).
An autoclave or an alternative method of decontamination needs to be
available for proper disposals.
The laboratory has self-closing, lockable doors.
A sink and eyewash station should be available.
Biohazard warning signs
Access to a BSL-2 lab is much more restrictive than a BSL-1 lab. Outside
personnel, or those with an increased risk of contamination, are often
restricted from entering when work is being conducted
BSL 3
Substantial risk to individuals, and moderate risk to communities. Again,
building upon the two prior biosafety levels, a BSL-3 laboratory typically
includes work on microbes that are either indigenous or exotic and can cause
serious or potentially lethal disease through inhalation. Examples of microbes
worked with in a BSL-3 includes yellow fever, West Nile virus, and the bacteria
that causes tuberculosis.
The microbes are serious therefore the work is often strictly controlled and
must be registered with the proper government agencies. Laboratory
personnel are always also under medical surveillance and could receive
immunizations for the different microbes they work with.
Common requirements in a BSL-3 laboratory include:
Standard personal protective equipment must be worn, and respirators
might be needed
Solid-front wraparound gowns, scrub suits or coveralls are usually
needed
Any work with microbes has to be done within the appropriate BSC
There should be Access to a hands-free sink and eyewash station which
should be available near the exit
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BTEC Internal Assessment QDAM December 2017
, There should be a Sustained directional airflow which draws air into the
laboratory from the clean areas towards any contaminated areas
(Exhaust air cannot be re-circulated)
a self-closing set of locking doors with access away from general building
corridors and rooms
Access to a BSL-3 laboratory is restricted and always controlled.
BSL level 4
Elevated risk to individuals and communities, BSL-4 labs are rare. However,
some do exist in a small number of places in the US and around the world. As
the highest level of biological safety, a BSL-4 lab consists of work with highly
dangerous and exotic microbes. Infections caused by these types of microbes
are often fatal and come without treatment or vaccines. Two examples of such
microbes include Ebola and Marburg viruses.
In addition to BSL-3 considerations, BSL-4 laboratories have the following
containment requirements:
Personnel must change their clothing before entering, and then shower
upon exiting
Decontamination of all materials before exiting
Personnel are required to wear the appropriate PPE that has been stated
in the other BSL levels, as well as a full body, air-supplied, positive
pressure suit.
A Class III biological safety cabinet
A BSL-4 laboratory is extremely isolated—often found in a separate building or
in an isolated and restricted zone of the building. The laboratory also features
a dedicated supply and exhaust air, as well as vacuum lines and
decontamination systems.1
Biological Safety Cabinets are classified into three classes based upon their
containment capabilities when working with biological agents.
Class 1 Cabinets
Provides personal and environment protection.
Used when working with low to moderate risk biological agents.
Biosafety levels: 1, 2 and 3
Class 2 Cabinets
Provides personnel, environment and product protection.
Used when working with low to moderate risk biological agents.
Biosafety Levels: 1, 2 and 3
Class 3 Cabinets
A highly specialized laboratory “glovebox”. A Class 3 cabinet provides the same
protection as a Class 2 but is designed for working with Biosafety Level 4
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class notes
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BTEC Internal Assessment QDAM December 2017
