Laboratory Biosafety Guidelines for working with SARS-CoV-2

Summary of recent changes

Updates as of December 20, 2024:

• Updated biosafety level

View previous updates

Key points

• This guidance is intended for laboratory and support staff who handle or process SARS-CoV-2 samples such as clinical specimens, cultures, and environmental samples.
  • All laboratories should perform a site-specific and activity-specific comprehensive risk assessment in collaboration with biosafety professionals, laboratory management, and other scientific and safety experts, and follow Standard Precautions when handling clinical specimens. See clinical specimen and laboratory safety guidance.
  • Research laboratories that conduct activities that may increase the biosafety risk of the work, including certain manipulations such as the generation of aerosols, genetic modifications, or working with large volumes of organisms, need to consider additional site-specific and activity-specific risk mitigation measures for their comprehensive risk assessments.
  • Research with SARS-CoV-2 remains subject to US policies and regulations regarding virus manipulations.
  • The Biosafety in Microbiological and Biomedical Laboratories—6th Edition describes control measures for work with infectious biological material
    
• Refer to List N on the Environmental Protection Agency (EPA) website for EPA-registered disinfectants qualified under EPA's emerging viral pathogens program for use against SARS-CoV-2.
• At a minimum, BSL-2 facilities, practices, and procedures are recommended for diagnostic research, anatomic pathology, environmental testing, and virus propagation utilizing SARS-CoV-2. At a minimum, ABSL-2 is recommended for work with these viruses in animal models.
• Suspected and confirmed SARS-CoV-2 positive clinical specimens or cultures should be packed and shipped as UN 3373 Biological Substance, Category B.

SARS-CoV-2 specific guidance

To determine appropriate biosafety mitigation measures, laboratories should perform an activity-specific comprehensive risk assessment that evaluates laboratory facilities, personnel and training, practices and techniques, safety equipment, engineering controls, and other risk mitigation measures. Biosafety professionals, laboratory management, and scientific and safety experts should be involved in the comprehensive risk assessment process.

At a minimum, BSL-2 facilities, practices, and procedures are recommended for diagnostic research, anatomic pathology, environmental, and virus propagation activities utilizing SARS-CoV-2. At a minimum, ABSL-2 is recommended for work with these viruses in animal models.

US government policies and regulations that guide virus manipulations and research with SARS-CoV-2, include:

• The NIH Guidelines detail safety practices and containment procedures for basic and clinical research involving recombinant or synthetic nucleic acid molecules, including the creation and use of organisms, cells, and viruses containing recombinant or synthetic nucleic acid molecules.
  • Including work involving genetic modifications or large volumes of organisms [≥10 liters]. Refer to the NIH Guidelines section II-A-3 for guidance on additional considerations to determine the appropriate biosafety mitigation measures.
• The DURC-PEPP policy addresses oversight of research on biological agents and toxins that, when enhanced, have the potential to pose risks to public health, agriculture, food security, economic security, or national security.

For more information on BSL-2 and Clinical Laboratory Biosafety see section IV and Appendix N respectively, Biosafety in Microbiological and Biomedical Laboratories—6th Edition.

General guidance

All laboratories should perform a site-specific and activity-specific comprehensive risk assessment to identify and mitigate risks. Comprehensive risk assessments and mitigation measures are dependent on:

• The procedures performed
• Identification of the hazards involved in the process and procedures
• The competency level of the personnel who perform the procedures
• The laboratory equipment and facility

Follow Standard Precautions | Section IV when handling clinical specimens, all of which may contain infectious materials. Standard Precautions include hand hygiene and the use of specific personal protective equipment (PPE) determined by the potential for exposure. PPE, such as laboratory coats or gowns, gloves, eye protection, or a disposable mask and face shield, can help protect the skin and mucous membranes of the eyes, nose, and mouth.

Find online training courses and more information on clinical specimen and laboratory safety guidance.

Specimen packing and shipping

Suspected or confirmed SARS-CoV-2 positive specimens, cultures, or isolates must be packed and shipped as UN 3373 Biological Substance, Category B, in accordance with the current edition of the International Air Transport Association Dangerous Goods Regulations and U.S. Department of Transportation's Transporting Infectious Substances Safely publication. Personnel must be trained to pack and ship according to the regulations and in a manner that corresponds to their function-specific responsibilities. See appendix C of the Biosafety in Microbiological and Biomedical Laboratories

Procedures with a high likelihood of generating droplets or aerosols

Many routine laboratory procedures can generate aerosols and droplets that are often undetectable. For example, the following laboratory procedures have been associated with the generation of infectious aerosols and droplets: pipetting, centrifuging, grinding, blending, shaking, mixing, sonicating, vortexing, opening containers of infectious materials, inoculating animals intranasally, and harvesting infected tissues from animals or eggs.

Procedures with a high likelihood of generating aerosols or droplets should be conducted using either a certified Class II Biological Safety Cabinet (BSC) or other physical containment equipment. If it is not possible to perform a procedure within a BSC or other physical containment device, a combination of appropriate personal protective equipment (PPE) and administrative controls are used, based on a risk assessment.

Decontamination

Decontaminate work surfaces and equipment with appropriate disinfectants. Use EPA-registered disinfectants with a label that claims they are effective against SARS-CoV-2. Follow manufacturer's recommendations for use, such as dilution, contact time, and safe handling. For additional information, refer to EPA Resource Conservation and Recovery Act (RCRA) Regulations. See EPA regulations, State Universal Waste Programs in the United States, and Biosafety in Microbiological and Biomedical Laboratories-appendix B—6th Edition for more information.

Laboratory waste management

All waste disposal must comply with local, regional, state, national, and international regulations. Waste disposal regulations vary at the state and local levels; see Environmental Protection Agency Regulations and State Universal Waste Programs in the United States for more information.

Resources

Clinical specimen guidance

• CDC | Biological Risk Assessment: General Considerations for Laboratories
• CDC | Core Infection Prevention and Control Practices for Safe Healthcare Delivery in All Settings
• CDC | Interim Guidelines for Collecting and Handling of Clinical Specimens for COVID-19 Testing
• OSHA | Bloodborne Pathogens Standard
• EPA | State Universal Waste Regulations
  

Laboratory trainings

• CDC | Biosafety Training

Site and activity-specific risk mitigation guidance

• NIH | Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules
• CDC & NIH | Biosafety in Microbiological and Biomedical Laboratories—6th Edition

Previous Updates

Revisions made on December 13, 2021 include:

• Updated waste management guidance

Revisions made on October 26, 2021 include:

• Added definition for aerosols and droplets
• Added pneumatic tube guidance
• Added shipping instructions

Revisions made on June 12, 2021 include:

• Added new training resource for specimen packing and shipping

Revisions made on September 19, 2020 include:

• New link under Resources to DLS Preparing and Supporting Laboratories Responding to COVID-19 page

Revisions made on August 7, 2020 include:

• Standard Precautions

Revisions made on July 16, 2020 include:

• Added DOT resources to Specimen Packing and Shipping and Resource section

Revisions made on July 13, 2020 to update:

• Language for virus isolation

Revisions made on June 3, 2020 include:

• Added anatomic pathology guidance for COVID-19
• Updated Point-of-Care testing guidance for COVID-19

Revisions made on May 11, 2020 include recommendations for:

• Point-of-Care testing guidance for COVID-19
• Added information on PPE to the "General Guidance" section
• Added Biological Risk Assessment: General Considerations for Laboratories resource to the "General Guidance" section
• Added Core Infection Prevention and Control Practices for Safe Healthcare Delivery resources to the "General Guidance" section
• Added OSHA Bloodborne Pathogens Standard resource to the "General Guidance" section
• Added EPA-approved disinfectant for SARS-CoV-2 resource to the "General Guidance section
• Added Environmental Protection Agency (EPA) regulations and State Universal Waste Programs in the United States | Hazardous Waste | US EPA resources to the "General Guidance" section
• Added information on PPE to the "Anatomic Pathology" section
• Deleted "Decentralized and Point-of-Care Testing" section and provided a link to the updated Guidance for SARS-CoV-2 Point-of-Care and Rapid Testing webpage
• Added information on N95 respirator and disposable mask to "Procedures with a High Likelihood of Generating Droplets or Aerosols" section
• Added language on avoiding cross-contamination to the "Environmental Testing" section
• Add language on Animal Biosafety Level 3 (ABSL-3) practices during inoculation of animals with infectious wild-type SARS-CoV-2 virus to the "Virus Isolation" section
• Added link for state EPA regulations to the "Laboratory Waste Management" section
• Added links to the "Additional Resources" section