For the purpose of safe transport, infectious substances are divided into 2 classes:

Biological substances - category A (UN 2814, UN 2900)
Infectious substances that can cause lasting disability or a life-threatening or fatal illness if they escape from the protective packaging and come into physical contact with human beings or animals.
- Category A substances

Biological substances - category B (UN 3373)
Infectious biological substances that do not conform with category A criteria will be classified as category B.
- Patient specimen

Non-hazardous goods
Substances that contain microorganisms which do not infect human beings or animals.
Pathogens that are neutralised in such a way as to eliminate any risk of health damage.
If the concentration of pathogens is the same as out in nature and it can be assumed that that there is no significant risk of infection.
Blood or components of blood collected for transfusions, or for the preparation of blood products for transfusions or transplants, and any tissues or organs designated for transplantation.