Federal and international standard references (e.g., NIH Guidelines and the World Health Organization (WHO)) outline systems for classifying human and animal infectious agents and biotoxins. Classifications are based on the hazards these materials may pose to healthy, immunocompetent individuals in the laboratory as well as the surrounding environment. Agents and biotoxins that are not associated with disease in healthy adult humans are classified as Risk Group 1 materials. Agents that are 1) associated with a human disease that is rarely serious and for which preventive or therapeutic interventions are often available and 2) low risk biotoxins, are classified as Risk Group 2 (RG2) materials. Examples of RG2 materials may include certain natural and recombinant bacterial strain collections, human and non-human primate (NHP) cell cultures, human and animal pathogens, human and NHP materials, and biotoxins. Risk Group 3 and 4 agents, or Select Agent biotoxins, are not permitted on campus (certain exceptions based on limited quantities are allowable). The recommendations in this document primarily target the storage of RG2 agents and biotoxins.


Access and Security

RG2 material must be secured to prevent access by the general public. Samples stored in a freezer, cabinet, or other storage unit should be located in a secured location that has limited access, or the storage unit itself must have a lock. Storage units must be dedicated for research use only. All samples must be identified as the property of a current University of Illinois at Urbana-Champaign researcher, student, or other responsible party.

Hazard communication: Labels and Signs

  • A door sign with the international biohazard symbol and contact information for the researcher should be posted on doors to rooms where RG2 material is being stored. The Division of Research Safety (DRS) provides door signs. (Contact the DRS at 217-333-2755 or via e-mail for more information).
  • The international biohazard sign must be prominently posted on all RG2 storage units such as refrigerators, freezers and cabinets. (Contact the DRS at 217-333-2755 or via e-mail to request stickers).
  • All boxes, racks, or containers must be labeled or coded. Researchers should be able to explain their coding system and identify all samples.
  • RG2 materials should be segregated and stored together so that someone does not unknowingly select an incorrect tube/vial.
  • Anyone with access to RG2 materials should be informed of the potential risks associated with them.


A list of stored materials should be maintained and kept in case of an incident. The inventory should be checked and updated regularly. To prevent unnecessary handling of specimens, the location of all materials should be noted in the inventory. 

Storage Containers

Containers/tubes used for storage must be intact (no tears or cracks), leak-proof, and covered or closed to avoid spills or contamination. Avoid loose tubes; every tube/container must be able to withstand shaking and moving without falling from a rack. All containers/tubes that will be frozen should be designed for low temperature storage. Containers with gaskets and security seals are also available commercially.

Preparing Tubes/Vials for Storage

Prior to storage, use a disinfectant that is effective against the potential hazard to decontaminate the outer surfaces of all tubes/containers. Secondary containment should be used when transporting samples to and from the storage unit.

Appropriate PPE

Always wear gloves when handling tubes/vials to prevent accidental contamination resulting from inadequate decontamination of the outside of the container.

Cold Storage Failure

Establish a procedure for monitoring the storage facility and for responding to freezer failure or the release of biological material (e.g., in the event of leakage of thawed material). Include instructions, the contact information of the person who should be notified, and information on the location of alternative freezers where contents may be transferred. Ensure that appropriate PPE and a spill kit for cleaning up spills or thawed materials are available and people know where they are.

Note: If a freezer needs repair, calibration, or transport, it should be completely decontaminated prior to beginning work or removing the unit.

    Last Updated: 5/6/2015