Microorganisms are classified into Risk Groups based on their potential impact on humans and the environment. These lists are not exhaustive, and microorganisms are generally classified as follows:
Risk Group 1 (RG1): Low individual and low community risk. These microorganisms are unlikely to cause disease.
Risk Group 2 (RG2): Moderate individual risk, limited community risk. These microorganisms are unlikely to be a significant risk to laboratory workers or the environment, but exposure may cause infection.
Risk Group 3 (RG3): High individual risk, limited/moderate community risk. These microorganisms usually cause serious disease and may present a significant risk to laboratory workers, but may only present a moderate risk of spreading amongst a community.
Risk Group 4 (RG4): High individual and high community risk. These microorganisms usually cause life-threatening disease and may be readily transmissable. Effective treatments are not usually available.
Risk Groups correlate with Physical Containment (PC) facility requirements, ie. RG2 organisms should only be used in a PC2 (or higher) facility.