Doh - HX Risk Assessment
Doh - HX Risk Assessment
Doh - HX Risk Assessment
Tel. # 305-0090
CLINICAL
LABORATORY
HEALTH CARE RISK
ASSESSMENT
Acceptable risk: The risk that is considered acceptable and allows work to proceed bearing
in mind the expected benefit of the planned activities.
Accident: An inadvertent occurrence that results in actual harm such as infection, illness,
injury in humans or contamination of the environment.
Aerosol: Liquid or solid particles suspended in air and of a size that may allow inhalation into
the lower respiratory tract (usually less than 10 micrometres in diameter).
Biological safety cabinet (BSC): An enclosed, ventilated working space designed to provide
protection to the operator, the laboratory environment and/or the work materials for
activities where there is an aerosol hazard. Containment is achieved by segregation of the
work from the main area of the laboratory and/or through the use of controlled, directional
airflow mechanisms. Exhaust air is passed through a high efficiency particulate air (HEPA)
filter before recirculating into the laboratory or into the building’s heating, ventilation and
air conditioning system. There are different classes (I, II and III) of BSCs that provide different
levels of containment.
Core requirements: A set of minimum requirements defined in the fourth edition of the
World Health Organization (WHO) Laboratory biosafety manual to describe a combination of
risk control measures that are both the foundation for, and an integral part of, laboratory
biosafety. These measures reflect international standards and best practice in biosafety that
are necessary to work safely with biological agents, even where the associated risks are
minimal.
Dual use items: Certain materials, information and technologies that are intended for
benefit, but which might be misapplied to do harm.
Engineering controls: Risk control measures that are built into the design of a laboratory or
laboratory equipment to contain the hazards. Biological safety cabinets (BSCs) and isolators
are forms of engineering control in order to minimize the risk of exposure to and/or
unintended release of biological agents.
Exotic disease: A disease not normally occurring in a particular region or area, often
imported from another area. It can also be referred to as non-indigenous disease.
Good microbiological practice and procedure (GMPP): A basic laboratory code of practice
applicable to all types of laboratory activities with biological agents, including general
behaviours and aseptic techniques that should always be observed in the laboratory. This
code serves to protect laboratory personnel and the community from infection, prevent
contamination of the environment, and provide protection for the work materials in use.
Hazard: An object or situation that has the potential to cause adverse effects when an
organism, system or (sub)population is exposed to it. In the case of laboratory biosafety, the
hazard is defined as biological agents which have the potential to cause adverse effects to
personnel and/or humans, animals, and the wider community and environment. A hazard
does not become a “risk” until the likelihood and consequences of that hazard causing harm
are taken into account.
Heightened control measures: A set of risk control measures as described in the WHO
Laboratory biosafety manual that may need to be applied in a laboratory facility because the
outcome of a risk assessment indicates that the biological agents being handled and/or the
activities to be performed with them are associated with a risk that cannot be brought
below an acceptable risk with the core requirements only.
Inactivation: Removal of the activity of biological agents by destroying or inhibiting
reproductive or enzyme activity.
Incident: An occurrence that has the potential to, or results in, the exposure of laboratory
personnel to biological agents and/or their release into the environment that may or may
not lead to actual harm.
Infectious dose: The amount of biological agent required to cause an infection in the host,
measured in number of organisms. Often defined as the ID50, the dose that will cause
infection in 50% of those exposed.
Infectious substances: The term applied for the purposes of transport to any material, solid
or liquid, which contains biological agents capable of causing infection in either humans,
animals or both. Infectious substances can include patient specimens, biological cultures,
medical or clinical wastes and/or biological products such as vaccines.
Initial risk: Risk associated with laboratory activities or procedures that are conducted in the
absence of risk control measures.
Good microbiological practice and procedure (GMPP): A basic laboratory code of practice
applicable to all types of laboratory activities with biological agents, including general
behaviours and aseptic techniques that should always be observed in the laboratory. This
code serves to protect laboratory personnel and the community from infection, prevent
contamination of the environment, and provide protection for the work materials in use.
Hazard: An object or situation that has the potential to cause adverse effects when an
organism, system or (sub)population is exposed to it. In the case of laboratory biosafety, the
hazard is defined as biological agents which have the potential to cause adverse effects to
personnel and/or humans, animals, and the wider community and environment. A hazard
does not become a “risk” until the likelihood and consequences of that hazard causing harm
are taken into account.
Heightened control measures: A set of risk control measures as described in the WHO
Laboratory biosafety manual that may need to be applied in a laboratory facility because the
outcome of a risk assessment indicates that the biological agents being handled and/or the
activities to be performed with them are associated with a risk that cannot be brought
below an acceptable risk with the core requirements only.
Infectious dose: The amount of biological agent required to cause an infection in the host,
measured in number of organisms. Often defined as the ID50, the dose that will cause
infection in 50% of those exposed.
Infectious substances: The term applied for the purposes of transport to any material, solid
or liquid, which contains biological agents capable of causing infection in either humans,
animals or both. Infectious substances can include patient specimens, biological cultures,
medical or clinical wastes and/or biological products such as vaccines.
Initial risk: Risk associated with laboratory activities or procedures that are conducted in the
absence of risk control measures.
Risk evaluation: Part of risk assessment where the likelihood of exposure to a hazard is
weighed against the potential severity of harm under a set of predefined circumstances,
such as a specific laboratory procedure. The goal of a risk evaluation is to determine whether
the assessed risk is acceptable, or whether further targeted risk control measures should be
implemented to prevent or reduce the risks.
Safety culture: A set of values, beliefs and patterns of behaviour instilled and facilitated in
an open and trusting atmosphere by individuals and organizations working together to
support or enhance best practice for laboratory biosafety, irrespective of whether it is
stipulated in applicable codes of practice and/or regulations.
Sharps: Any device or object that is a puncture or wound hazard because of its pointed ends
or edges. In the laboratory, sharps can include needles, syringes with attached needles,
blades, scalpels or broken glass.
Sterile: The state of having a complete absence of viable biological agents and spores.
Sterilization: A process that kills and/or removes all biological agents including spores.
Transmission: The transfer of biological agent(s) from objects to living things, or between
living things, either directly or indirectly via aerosols, droplets, body fluids, vectors,
food/water or other contaminated objects.
INTRODUCTION
Laboratory biosafety and biosecurity activities are fundamental to protecting the laboratory
workforce and the wider community against unintentional exposures or releases of
pathogenic biological agents. These activities are implemented using a risk assessment
framework and through the development of a safety culture which is needed to ensure a
safe workplace where adequate measures are applied to minimize the likelihood and
severity of any potential exposure to biological agents. Biosafety awareness and expertise
have improved greatly since previous editions of the World Health Organization’s (WHO)
Laboratory biosafety manual (1-3). New technologies, such as the use of molecular methods,
have advanced considerably and reduced the number of diagnostic activities that require
propagation of high titre biological agents.
Associated monographs have also been produced to provide more detailed information
and help implement systems and strategies on specialized topics. It is anticipated that
this core document will be read first and the associated monographs can be referred to
when more detailed information is required. The monographs include:
In the case of laboratory biosafety, the hazards are biological agents whose pathogenic
characteristics give them the potential to cause harm to humans or animals should they be exposed
to these agents. The harm caused by exposure to biological agents can vary in nature and can range
from an infection or injury to a disease or outbreak in larger populations (see Box 2.1)
For this reason, factors that contribute to the occurrence of infection, such as routes of transmission,
infectious dose and communicability, need to be considered in relation to the consequence of an
exposure or release.
It is important to note that hazards alone do not pose a risk to humans or animals. For
example, a vial of blood containing a biological agent such as Ebola virus does not pose a risk to the
laboratory personnel until they come into contact with the blood contained within the vial.
Therefore, the true risk associated with a biological agent cannot be determined by only identifying
its pathogenic characteristics. Consideration must also be given to the types of procedure(s) that will
be performed with the biological agent and the environment in which these procedures will take
place. Any facility that handles biological agents has an obligation to their personnel and the
community to perform a risk assessment on the work they will conduct and to select and apply
appropriate risk control measures to reduce those risks to an acceptable risk. The purpose of the risk
assessment is to gather information, evaluate it and use it to inform and justify the implementation
of processes, procedures and technologies to control the risks present. Analysis of this information
empowers laboratory personnel as it gives them a deeper understanding of the biological risks and
the ways in which they can affect them. It helps create shared values, patterns of behaviour and
perceptions of the importance of safety, and makes laboratory personnel more likely to conduct
their work safely and maintain a safety culture in the laboratory.
Risk assessments must always be conducted in a standardized and systematic way to ensure
they are repeatable and comparable in the same context. For this reason, many organizations offer
risk assessment templates, checklists or questionnaires that provide stepwise approaches to identify,
evaluate and determine risks associated with the hazards present, before using this information to
identify appropriate risk control measures (24,25). The various steps of the risk assessment process
collectively form a risk assessment framework (Figure 2.1)
GATHER
INFORMATION
Where Figure 2.1 illustrates the steps in the risk assessment framework, Table 2.1 provides an
overview of the key considerations that apply during each step of the cycle. It is important to note
that not all factors will affect risk in the same way, but each should be carefully considered. When
conducting a risk assessment, it must be remembered that the risk is not based on the pathogenicity
of the biological agent alone, but on the likelihood and consequence of an incident occurring – in
other words, the risk of exposure to and/or release of the biological agent during laboratory
operations.