If you will be sending a potentially infectious substance by land, water, or air within, from, or through the United States, use this decision tree (flow chart) provided by the DOT to determine the proper classification for the substance. The decision tree shown below can also be found in the brochure "Transporting Infectious Substances Safely."1
The decision tree is discussed in more detail on the following pages.
1. U.S. Department of Transportation. (2020). Transporting Infectious Substances Safely. https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2020-04/Transporting-Infectious-Substances-Safely.pdf. Accessed April 13, 2022.