Publication 52 - Hazardous, Restricted, and Perishable Mail > Appendix C > USPS Packaging Instruction 6C
Infectious substance means a material known or reasonably expected to contain a pathogen. A pathogen is a microorganism that can cause disease in humans or animals. Examples of pathogens include bacteria, viruses, fungi, and other infectious agents. An infectious substance must be assigned to one of the following two packaging categories:
All vendors shipping COVID-19-related UN3373 Category B Infectious Substances kits to end-users must obtain an authorization from the Postal Service before mailing. It is the responsibility of the shipper to ensure that they are aware of, and comply with, all other applicable requirements and regulations for the mailing of these materials; and they must be able to provide evidence of compliance before a written request is submitted to the manager of Product Classification, Postal Service Headquarters (see part 214 for address).
Under these provisions, only tests developed and performed by laboratories certified under the Clinical Laboratory Improvement Amendments (CLIA) or equivalent clinical oversight regulations, and commercial tests and home collection kits authorized by either the FDA or an Institutional Review Board, will be considered.
Note: Only cold packs or dry ice may be used as a refrigerant and must be placed outside of the secondary packaging. Interior supports must be provided to secure the secondary packaging in the original position. If a cold pack is used, the packaging must be leak-proof. If dry ice is used, the container must permit the release of carbon dioxide gas and conform to 49 CFR 173.217. The primary receptacle and secondary packaging must maintain their integrity at the temperature of the refrigerant used, as well as the temperature and pressures of transport by aircraft they could be subjected to if refrigerant were lost, and sufficient absorbent material must be provided to absorb all liquids, including melted ice.
As required by 49 CFR 173.199:
Each vendor shipping COVID-19 kits must provide clear instructions to end-users regarding the procedures to be followed for preparing the samples and packaging used to transport an Infectious Substance Category B. Shippers must instruct end-users to adhere to all applicable mail-related preparation requirements before mailing to ensure the package is properly prepared for safe transportation.
- Substances identified in IMM 135.11b must be sent only by authorized laboratories to their foreign counterparts in those countries that have indicated a willingness to accept them.
Note: Countries distinguish between infectious and noninfectious (nonregulated) biological substances and may prohibit one or the other or both. See “Prohibitions” in the Individual Country Listings.
- Laboratories of local, state, and federal government agencies.
- Laboratories of federally licensed manufacturers of biological products derived from bacteria and viruses.
- Laboratories affiliated with or operated by hospitals, universities, research facilities, and other teaching institutions.
- Private laboratories licensed, certified, recognized, or approved by a public authority.