Biosafety risk groups and containment levels

Risk Groups

Those capable of causing disease are considered pathogens that pose a low risk to the health of individuals or animals, and a low risk to public health or animal populations.
A microorganism, nucleic acid, or protein that is either a) not capable of causing human or animal disease; or b) capable of causing human or animal disease, but unlikely to do so.
May be opportunistic in immunocompromised individuals.
Examples: Saccharomyces cerevisiae, Lactobacillus acidophilus

A pathogen that poses a moderate risk to the health of individuals or animals, and a low risk to public health or animal populations.
These pathogens are able to cause serious disease in a human or animal but are unlikely to do so. Effective treatment and preventative measures are available and the risk of spread of diseases caused by these pathogens is low.
It is important to remember that the definition assumes that an individual/animal is not immunocompromised (e.g., immune system is weakened by disease or treatment). For such individuals, these agents may be able to cause serious disease and even death. If your immune system is compromised by a cold or if you are pregnant, additional safety considerations may be required.
Examples: Listeria monocytogenes, Campylobacter jejuni, Hepatitis A virus, Hepatitis B virus, Norwalk virus

A pathogen that poses a high risk to the health of individuals or animals and a low risk to public health.
These pathogens are likely to cause serious disease in a human or animal. Effective treatment and preventive measures are usually available and the risk of spread of disease caused by these pathogens is low for the public. The risk of spread to the animal population, however, can range from low to high depending on the pathogen.
Examples: Yersinia pestis, Mycobacterium tuberculosis, Rabies virus, Severe acute respiratory syndrome (SARS) associated coronavirus

A pathogen that poses a high risk to the health of individuals or animals and a high risk to public health.
These pathogens are likely to cause serious disease in a human or animal, which can often lead to death. Effective treatment and preventive measures are not usually available and the risk of spread of disease caused by these pathogens is high for the public. The risk of spread of disease to the animal population, however, ranges from low to high depending on the pathogen.
Examples: Ebola virus, Marburg virus, Herpes B virus

Basic lab seen in any school
No special features required except for a well-designed and functional space with cleanable work surfaces
- Biological safety cabinets (BSCs) not required
Must have appropriate PPE available, keep the lab clean, and decontaminate work surfaces

More isolation required
- Sealed windows
- Use of a BSC for all work with open vessels
- Inward-directional airflow
- HEPA filtration of exhaust air
- Strictly controlled lab access
Requires higher-level operational practices
- PPE with designated clean and dirty change areas
- Decontamination of clothes before removing it
Most of Canada's 100 CL3 labs are research-oriented

Maximum containment
- Complete seal of facility perimeter verified by pressure decay testing
- Windows as well as plumbing and electrical conduits are sealed
- Full-coverage positive-pressure suit with dedicated breathing supply, or working with samples in isolated, sealed BSC using long-sleeved gloves
- Decontamination of effluents, including HEPA filtration of all supply and exhaust air
Full-coverage PPE must be decontaminated with a chemical shower
Only two labs in Canada, one for human pathogens and the other for animal pathogens