Safety/Risk Groups

What are Risk Groups and Safety Levels?

Microorganisms are classified into four Risk Groups, and biological laboratories are classified into four corresponding Safety Levels. Risk Group 1 contains non-pathogenic organisms like yeast and E. coli K-12. The majority of iGEM teams use only Risk Group 1 organisms. Some teams use Risk Group 2 organisms. iGEM teams are not permitted to use Risk Group 3 or 4 organisms, or to work in Safety Level 3 or 4 laboratories.

  Risk Group 1 Risk Group 2 Risk Group 3 Risk Group 4
Examples E. coli K-12, S. cerevisiae (yeast), Lactobacillus, B. subtilis Streptococcus, Herpes virus, most mammalian cell lines Yersinia pestis (black plague), HIV, SARS virus Ebola virus, Marburg virus, Lassa virus
Description Risk Group 1 organisms do not cause disease in healthy adult humans. Risk Group 2 organisms can cause disease in humans, but the disease is treatable or preventable. Risk Group 3 organisms cause serious disease in humans. Treatments and vaccines for these diseases may exist. Risk Group 4 organisms cause deadly disease in humans, and they can easily travel from one person to another. No treatments or vaccines exist for these diseases.
Lab Safety Level Safety Level 1 Safety Level 2 Safety Level 3 Safety Level 4
Typical Lab Photo
Typical Work Area Open bench Biosafety cabinet / laminar flow hood Class 3 biosafety cabinet Full isolation suits
  Permitted in iGEM Not permitted in iGEM

What if we want to use a Risk Group 3 or 4 organism?

Don't do it. Find a substitute.

Risk Groups 3 and 4 include the most serious and deadly pathogens in the world. They require extremely stringent safety precautions and specialized lab facilities. There is no compelling reason for any iGEM team to choose to work with Risk Group 3 or 4 organisms, when instead you could choose from the vast array of interesting project topics that use only Risk Group 1 or 2 organisms.

Using safer substitutes for dangerous organisms is entirely appropriate for iGEM. For example, the 2013 Paris Bettencourt team studied tuberculosis. Mycobacterium tuberculosis is a Risk Group 3 organism, so for safety reasons, they substituted a related Risk Group 2 organism (Mycobacterium smegmatis) in their experiments. These experiments were a proof of principle for their project ideas.

Animals and plants have no Risk Group

The four Risk Groups only apply to microorganisms (bacteria, fungi, and viruses). For animals, plants, and other multicellular organisms, there are different safety guidelines. Please consult with your advisor or university authorities if you plan to do experiments with animals and plants.

If you are using a part from an animal or plant, you should consider the function of the part, and consider whether it might be dangerous to humans. For example, the gene for Green Fluorescent Protein (GFP) comes from the jellyfish Aequorea victoria, which does not have a Risk Group. GFP is only a fluorescent protein, absorbing and emitting light, so it is safe for humans and you can use it in a Safety Level 1 lab. But if you consider a different gene from A. victoria, such as the gene for the toxin in its stinging tentacles, you might conclude that you should only use that gene under strict safety conditions!

How can I find out the Risk Group of my organism?

1. Common iGEM Organisms

Species Risk Group
E. coli K-12 and derivatives (DH5alpha, TOP10, etc.) 1
S. cerevisiae 1
Most human and mammal cell lines 2
Lactobacillus spp. 1
Bacillus subtilis 1

2. Recommended Sources

To determine the Risk Group of an organism, we must consult reliable sources. There is no world-wide standard list of microorganisms and their Risk Groups. Some countries and some cell culture vendors have provided lists, but no single list includes all species, so you might need to check several sources. iGEM recommends three sources for Risk Group information: Canadian PSDS, NIH Guidelines, and DSMZ.

Canadian Pathogen Safety Data Sheets (PSDS)

The Public Health Agency of Canada has published safety data sheets for a wide variety of microorganisms.

To use the PSDS, find your species in the list. Click on the species name to open extensive safety information about that species. Scroll down to "SECTION VII" and look for "RISK GROUP CLASSIFICATION" or "CONTAINMENT REQUIREMENTS".

NIH Guidelines, Appendix B

The NIH Guidelines are a set of rules that govern research on recombinant/synthetic DNA in the United States. Appendix B of the guidelines gives a list of pathogens in Risk Groups 2, 3, and 4. It does not list Risk Group 1 organisms.

Click here to go directly to Appendix B.


DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen / German Collection of Microorganisms and Cell Cultures) is a large collection that includes Risk Group information for thousands of different species, strains, and cell lines. It is more difficult to use, but it includes the most species of any source that iGEM recommends.

  • Catalogue Microorganisms -- search bacteria. Enter your genus, species, and/or strain information in the "Search term" box, and click Search. You will receive a long list of results, which may include many different strains and species. Examine the list to find the correct strain, and click on its DSM number to view its catalogue page. The Risk Group is listed in the table.
  • Catalogue Human and Animal Cell Lines -- search this catalogue by the same method as for Catalogue Microorganisms.
  • Prokaryotic Nomenclature Up to Date is an alphabetical list of all bacterial and archaeal species names in the scientific literature. Find your species in the list, and click on its name to view details. In the table row "Type strain", look for a blue DSM link. If one is present, it will bring you to a DSMZ catalogue page where you can find details about that species. The Risk Group is listed in the table. (If there is no blue DSM link, it means that the DSMZ does not offer that species.)
    Note: "Prokaryotic Nomenclature Up to Date" has information about wild strains of microorganisms, not lab strains. Wild strains of E. coli can cause disease in humans (so they are Risk Group 2), but lab strain E. coli is Risk Group 1 and is safe to handle.

3. Other Reliable Sources

If you cannot find your species in any of the recommended sources, you must find another reliable source. There may be a paper in the peer-reviewed scientific literature that describes your species. Your country's government might have its own list of microorganisms and their Risk Groups.

For help finding a reliable source, you can consult your advisor, or speak to the biosafety authorities of your university. You can also contact for help.