Cryogenic

Cryogenic cargo refers to shipments maintained at extremely low temperatures, typically at or below -150°C (-238°F), using liquid nitrogen or other cryogenic substances as cooling agents. These shipments require specialized insulated containers called CryoContainers and dewars to maintain payloads at cryogenic temperatures using liquid nitrogen (LN₂) as the primary cooling medium. Liquid nitrogen dry shippers are classified under IATA DGR as Dangerous Goods — UN 1977 (Nitrogen, refrigerated liquid) or, when properly constructed to meet dry shipper criteria, may qualify as non-restricted biological substances depending on their classification and LN₂ retention method. Free liquid nitrogen is classified as a Class 2.2 non-flammable, non-toxic compressed gas under IATA regulations, assigned UN number UN1977 (Nitrogen, refrigerated liquid).

A FedEx Express shipment with AWB number 023-45678901 transports stem cell samples from Chicago O'Hare (ORD) to Frankfurt (FRA) in a dry shipper container maintaining -150°C temperatures throughout the 8-hour flight. Shipping any vessel containing free liquid nitrogen by air triggers the full dangerous goods (DG) compliance stack with 50 kg maximum on passenger aircraft, 500 kg on cargo aircraft under Packaging Instruction PI 202.

• liquid nitrogen
• LN2
• cryo cargo
• cryogenic shipment
• cryogenic freight

What UN number is used for cryogenic liquid nitrogen shipments by air?

Free liquid nitrogen is classified as a Class 2.2 non-flammable, non-toxic compressed gas under IATA regulations, assigned UN number UN1977 (Nitrogen, refrigerated liquid).

What are the weight limits for cryogenic cargo containing liquid nitrogen on passenger versus cargo aircraft?

Shipping any vessel containing free liquid nitrogen by air triggers the full dangerous goods compliance stack with 50 kg maximum on passenger aircraft, 500 kg on cargo aircraft under Packaging Instruction PI 202.