Office of Research Assurances

Hazardous Materials Shipping

Category B Infectious Substances


Category B Infectious Substances are materials that are infectious, but do not meet the standards for inclusion in Category A. Category B Infectious Substances are assigned to UN3373.


The basic Triple Packaging concept applies to Category B Infectious Substances. Purchase packaging that complies with IATA Packing Instruction 650. Click Here for a list of some packaging suppliers. Be sure to specify if the shipment is a refrigerated sample (e.g. Ice Packs or Dry Ice).

For Category B Infectious Substances, the maximum quantity of liquid per primary receptacle is 1L and outer packaging must not contain more than 4L or 4kg.


The outer container of a Category B Infectious Substance shipment must display the following information:

  • The sender and recipient's full name and address;
  • The words "Biological Substance, Category B";
  • UN3373 label (Figure 1);
  • The text "Person responsible: Chem-Tel-1-800-255-3924"; and
  • Class 9 label (Figure 2), if packaged with dry ice.

Figure 1 Figure 2

Pullman Campus
Office of Research Assurances, P.O. Box 643005, Albrook Rm. 205, Washington State University, Pullman WA 99164-3005
Hazardous Material and Shipping Coordinator: Phone: 509-432-3869, Fax: 509-335-6410