Category B infectious substances are human and animal pathogens not listed as Category A infectious substances (ADR 2.2.62.1.4.1 / IATA). They don’t cause permanent disability, life-threatening or fatal diseases in otherwise healthy humans or animals.
They include:

• Cultures, patient specimens and biological material containing or consisting of:
  • - most bacteria and viruses of risk group 3,
  • - all bacteria and viruses of risk group 2,
  • - any other microorganisms (parasites, fungi etc.) causing disease in humans or animals.
• Patient specimens and biological material containing or consisting of Category A infectious substances marked with “cultures only” (ADR 2.2.62.1.4.1; only cultures of such organisms have to be transported as Category A).

Biological substance, Category B: UN 3373

Category B samples must be packed according to Packing Instruction P650 (ADR) or PI650 (IATA), respectively.

• Packing Instruction P650
• Packing Instruction PI650 (air)
   

Both packing instructions require a triple packaging.

Inner Packagings:

• leak-proof (for liquids, powders) primary receptacle(s);
• leak-proof (for liquids, powders) secondary packaging
  • - for liquids: absorbent material between primary receptacle and secondary packaging to fully absorb liquid in case of leak or breakage;
  • - when multiple fragile primary receptacles are placed in a single secondary packaging, they are either individually wrapped or separated to prevent contact between them.

Outer packaging with at least one surface having a minimum dimension of 100mm x 100mm.

Either the secondary or preferably the outer packaging has to be rigid.

Note: Substances packed and packages which are marked in accordance with packing instruction P650 are not subject to any other requirement of ADR.

Additionally for air transport:

• the primary receptacle or secondary packaging must be capable of withstanding an internal pressure of 95 kPa in the range of -40° C to 55° C, without leakage.
• for liquids: primary receptacle maximal 1 l, rigid outer packaging maximal 4 l.
• for solids: rigid outer packaging maximal 4 kg (expect body parts, organs and whole bodies).
   

• UN number and proper shipping name: UN 3373, Biological Substance, Category B (at least 6 mm high)
• Name and address of consigner and consignee
• Mark: diamond-shaped mark with minimum dimensions of 50mm by 50mm containing the UN number UN 3373 (at least 6 mm high)
• If solid carbon dioxide is used: ‘Carbon dioxide, solid’ as coolant
   

Additionally for air transport:

• Phone number of responsible person
• If solid carbon dioxide is used: ‘Carbon dioxide, solid’ as coolant’, UN 1845, net quantity, class 9

Note: A shipper's declaration for dangerous goods is not required for Category B infectious substances!

It is recommended to provide an itemized list of contents, e.g. between secondary packaging and outer packaging
Required permits, if applicable
Delivery note / (pro forma) invoice for customs

Additionally for air transport:
Air Waybill (form provided and filled out by carrier)