Category A&B Agents

Biological Substance Category B  (UN3373)

49 CFR 173.199, IATA Section 3.6.2

Biological Substance, Category B means an infectious substance that is not in a form generally capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. This includes Category B infectious substances transported for diagnostic or investigational purposes.

Packaging Requirements

Both regulations 49 CFR (173.199) and IATA ( require that packages containing Biological Substance, Category B are "triple-packed." Triple packaging consists of a primary receptacle, a secondary packaging, and a rigid outer packaging.

Marking Requirements

Packages containing Biological Substance, Category B must be clearly marked "Biological Substance, Category B."

The package must also be marked with the identification number "UN3373" in a square-on-point configuration.

The name, address, and telephone number of a person knowledgeable about the shipment must also be included either on a written document or on the outer packaging.


Biological Substance Category A  (Special Shipping Requirements)

49 CFR 173.199, IATA Section 3.6.2

Please contact the lab prior to shipping something that is likely to contain a Category A agent.  Biological Substance, Category A are not accepted by UPS or Postal Service (only FedEx) and require specific packaging and handling.  We would be happy to work with you to ensure safe handling and that the specimen is shipped to the appropriate lab.

Here is a list of category A agents.


Additional Resources: