Dry ice (UN1845, carbon dioxide, solid) is Class 9 dangerous goods by air and ships under IATA packing instruction 954, with up to 200 kg per package on passenger or cargo aircraft. Packages must let carbon dioxide gas escape, carry the Class 9 label, UN1845, the proper shipping name and the net quantity of dry ice in kilograms, and the shipper must arrange each shipment with the airline, which sets its own limits per aircraft.
Key takeaways
- Dry ice is UN1845, Class 9, shipped under packing instruction 954 with a limit of 200 kg net per package on passenger and cargo aircraft.
- Packaging must vent carbon dioxide gas; never seal dry ice in an airtight container.
- Each package needs UN1845, "Dry ice" or "Carbon dioxide, solid", the net quantity in kg, shipper and consignee details and a Class 9 label.
- When dry ice cools non-dangerous goods, a Shipper's Declaration is usually not needed, but the air waybill must show UN1845, the number of packages and the net quantity.
- Airlines set dry ice limits per aircraft type and compartment because sublimating dry ice releases carbon dioxide into the aircraft.
Why is dry ice regulated as dangerous goods by air?
Because dry ice turns straight from solid to carbon dioxide gas, which can build pressure in sealed packaging and, in enough quantity, harm crew in an enclosed aircraft.
Dry ice is solid carbon dioxide at about -78.5 °C. The FAA's Advisory Circular 91-76A explains that excessive carbon dioxide in an aircraft can incapacitate crew, and that keeping fresh air circulating is the single most important precaution. It cites a sublimation rate of about 1% per hour for large packages of around 100 lb and an average of about 2% per hour in FAA tests on small insulated packages.
For that reason dry ice is listed as UN1845, "Carbon dioxide, solid" (or "Dry ice"), Class 9 miscellaneous dangerous goods. The rules come from the ICAO Technical Instructions and the IATA Dangerous Goods Regulations, and in the United States from 49 CFR 173.217. For the wider framework, see our guide to dangerous goods air freight basics and the nine classes.
What does packing instruction 954 require?
Packing instruction 954 requires packaging that lets carbon dioxide escape, strong enough for the journey, with no more than 200 kg of dry ice per package.
- Venting: packagings must be designed to release carbon dioxide gas and prevent pressure building up. Never use airtight containers, taped-shut liners or sealed coolers.
- Quantity: the ICAO Technical Instructions 2025-2026, as listed in the BAM dangerous goods database, allow up to 200 kg net per package on both passenger and cargo aircraft.
- Packaging type: UN specification packaging is not required (special provision A48 says packaging tests are not needed), but packaging must meet the general packing requirements, including protection against the low temperature.
- ULDs: under special provision A151, when dry ice cools non-dangerous goods in a unit load device, the per-package limit does not apply. The ULD must be identified to the airline and allow the gas to vent.
Expanded polystyrene shippers inside a fiberboard outer box are the most common setup for pharma and samples, with the lid resting rather than sealed so gas can escape.
How do you mark, label and document a dry ice shipment?
Mark each package with UN1845, the proper shipping name and the net quantity of dry ice in kilograms, apply a Class 9 label, and show the same details on the air waybill.
| Requirement | What to do |
|---|---|
| UN number and name | "UN1845" and "Dry ice" or "Carbon dioxide, solid" |
| Net quantity | Net mass of dry ice in kg on the outside of each package, and on the ULD when the ULD is the packaging |
| Addresses | Full names and addresses of shipper and consignee |
| Hazard label | Class 9 miscellaneous dangerous goods label |
| Air waybill | UN1845, Dry ice, 9, number of packages and net quantity per package in kg |
| Shipper's Declaration | Not usually required when dry ice cools non-dangerous goods; required when the cooled contents are dangerous goods that need one |
| Airline arrangement | Agree each shipment with the operator in advance |
The US rules in 49 CFR 173.217 accept this alternative documentation in place of a full shipping paper and require the shipper to make arrangements with the operator for each shipment. They also include narrower US exceptions, for example for packages with 2.5 kg or less of dry ice used as a refrigerant and for frozen medical specimens for diagnosis or treatment, but airlines may still apply IATA requirements on international flights, so do not rely on them without checking.
Many dry ice shipments also contain temperature data loggers powered by lithium batteries. Loggers that meet the DGR exceptions usually need no extra marking, but check the battery rules in our guide to shipping lithium batteries by air.
How much dry ice will an airline accept?
Each airline sets limits by aircraft type and cargo compartment, so the answer depends on the flight, not only on the DGR.
The FAA's advisory circular gives operators a method to calculate safe quantities from the aircraft's ventilation rate, and the operator is responsible for the limit. Limits can change when airlines test and approve more: according to FlyingTypers (June 16, 2025), Delta Cargo raised the dry ice limit on its Boeing 767-400s from 100 lb (45 kg) to 1,250 lb (566 kg) in the forward compartment and 2,000 lb (907 kg) for active containers, while its 767-300ERs kept the existing 100 lb limit.
Total dry ice already booked on a flight counts too, so a large shipment may need to be split across flights or moved to a freighter. Book early and give the airline the total net quantity per package and per ULD.
How is dry ice used for pharma and perishables?
Dry ice keeps products frozen around -78 °C, so it is used for frozen and ultra-cold pharmaceuticals, biological samples and some frozen foods.
| Use | Typical role of dry ice | Points to watch |
|---|---|---|
| Ultra-cold biologics and some vaccines | Main refrigerant in passive shippers | Quantity sized for transit time plus a buffer; re-icing points on long routes |
| Clinical trial samples | Keeps specimens frozen to the lab | Combined rules if samples are UN3373 or other dangerous goods |
| Frozen food and seafood | Supplementary cooling | Total kg per ULD declared to the airline |
| Chilled (2 to 8 °C) pharma | Rarely suitable on its own | Risk of freezing product; gel packs or active containers are usually preferred |
Because dry ice sublimates, the amount packed must cover the full door-to-door time, including customs holds and weekend delays. Many pharma shippers plan re-icing with their forwarder for longer routes. Our guide to pharma cold chain air freight covers temperature ranges and packaging choices, and shipping clinical trial materials by air covers samples.
How do you ship dry ice without delays?
- Size the dry ice for the full transit time, using the sublimation rate of your packaging.
- Use vented packaging and never seal the container.
- Mark UN1845, the proper shipping name and net kg on each package and apply the Class 9 label.
- Give the airline the net quantity per package and per ULD when booking.
- Confirm the airline's limits for the aircraft type on your flight.
- Make sure the person preparing the shipment is trained for dangerous goods.
Dry ice adds weight, so include it when you estimate costs with the chargeable weight calculator. For frozen and temperature-sensitive medicines, see JumboPharma.
Frequently asked questions
Is dry ice dangerous goods for air freight?
Yes. Dry ice is classified as UN1845, Class 9 miscellaneous dangerous goods, because it sublimates into carbon dioxide gas, which can displace oxygen in an enclosed space and build up pressure in sealed packaging.
How much dry ice can go in one package?
Under the ICAO Technical Instructions and IATA packing instruction 954, the limit is 200 kg net per package on both passenger and cargo aircraft. When dry ice cools non-dangerous goods in a unit load device, the per-package limit does not apply, but the ULD must be declared to the airline and allow venting.
Do I need a Shipper's Declaration for dry ice?
Not usually when dry ice is the only dangerous good and is used as a refrigerant. The air waybill must instead show UN1845, Dry ice, Class 9, the number of packages and the net quantity per package. If the dry ice cools other dangerous goods that need a declaration, it goes on that declaration.
How fast does dry ice sublimate in transit?
The FAA cites a rate of about 1% per hour for large packages of around 100 lb and an average of about 2% per hour in FAA tests on small insulated packages. Actual loss depends on insulation, temperature and pressure.
Sources
- U.S. eCFR: 49 CFR 173.217, Carbon dioxide, solid (dry ice)
- U.S. FAA: Advisory Circular 91-76A, Hazard Associated with Sublimation of Solid Carbon Dioxide (Dry Ice) Aboard Aircraft
- BAM Dangerous Goods Database: UN 1845 Carbon dioxide, solid, ICAO Technical Instructions 2025-2026
- IATA: Dangerous Goods Regulations (DGR)
- FlyingTypers: Delta Cargo Expands B767-400 On Ice (June 16, 2025)
