Shipping Dry Ice (UN 1845): IATA, IMDG & Ground Rules for South Florida Shippers

Dry ice looks harmless – it is just frozen carbon dioxide – but it is a regulated dangerous good, and shipments that treat it casually get stopped every day. Whether you are moving temperature-sensitive pharmaceuticals out of Miami-Dade, seafood through Broward, or lab samples by air, UN 1845 comes with real rules across every mode. This guide explains why dry ice is regulated and what South Florida shippers must do to stay compliant by air, ocean, and road.

Why Dry Ice Is a Dangerous Good

Dry ice (carbon dioxide, solid) is classified as UN 1845, a Class 9 miscellaneous dangerous good. Two hazards drive the regulation. First, as it warms it sublimates – turning directly from solid to gas – which can displace oxygen in an enclosed space such as an aircraft hold, a container, or a closed van. Second, that same sublimation builds pressure, so packaging must let gas escape rather than trap it.

Those two facts explain almost every rule that follows: ventilation and pressure relief are the whole point.

Dry Ice by Air (IATA DGR)

Air is the strictest mode, because an enclosed pressurized cabin or hold is exactly the environment where CO2 buildup is dangerous.

Under the IATA Dangerous Goods Regulations, dry ice used as a refrigerant is handled under its dedicated packing instruction (PI 954). Key requirements include:

• Packaging that vents. The package must be designed and closed so carbon dioxide gas can escape and pressure cannot build up. Sealed, airtight containers are prohibited.
• Net quantity marked. The actual weight of dry ice in kilograms must be marked on the package.
• Class 9 label and UN 1845 marking. The miscellaneous dangerous goods label and the UN number and proper shipping name must appear on the outer package.
• Documentation. When dry ice is used as a refrigerant for a non-dangerous product, air waybill entries are required; when it refrigerates other dangerous goods, it is captured on the Shipper’s Declaration alongside those goods. Operator variations at the airline level can add requirements, so always check the carrier.

For exporters near Miami International, the airline’s acceptance staff will verify the marked weight, the venting packaging, and the labeling before the shipment is accepted.

Dry Ice by Ocean (IMDG Code)

By sea, dry ice is again UN 1845, Class 9. The dominant concern is the same – CO2 accumulation – but the setting is a shipping container that may sit sealed for days.

Practical IMDG considerations include:

• Ventilation and packaging that allow gas to escape, consistent with the packing provisions for UN 1845.
• Container safety awareness. A container loaded with significant quantities of dry ice can become an oxygen-deficient, CO2-rich space – a genuine confined-space hazard for anyone who opens it downstream. Warning notices and safe-handling communication matter.
• Documentation on the Dangerous Goods Declaration and correct marking and labeling of packages.

If you are consolidating refrigerated goods into an ocean container leaving Port of Miami or Port Everglades, the quantity of dry ice and the container’s ventilation deserve deliberate attention, not a guess.

Dry Ice by Road (49 CFR / DOT)

Ground shipping is where many South Florida shippers assume dry ice is unregulated – and where they are often surprised. Under the U.S. hazardous materials regulations (49 CFR), dry ice is a regulated Class 9 material, though certain highway movements benefit from exceptions depending on quantity and use as a refrigerant.

Even where formal hazmat paperwork is reduced for road transport, the physical hazard does not disappear. A closed cargo van carrying a large quantity of sublimating dry ice can accumulate dangerous CO2 levels, so ventilation during transport and safe loading practices remain essential for driver safety.

A Dry Ice Compliance Checklist

Before dry ice leaves your dock in Miami-Dade or Broward, confirm:

• UN 1845, Class 9 is the correct classification for the shipment.
• Packaging vents – never airtight – and is suitable for the mode.
• The net weight of dry ice is marked on each package (critical for air).
• The Class 9 label and UN 1845 marking are applied correctly.
• Documentation matches the mode: air waybill or Shipper’s Declaration, or Dangerous Goods Declaration for ocean.
• The receiving and handling teams are warned about CO2 accumulation, especially for large quantities in enclosed spaces.
• Carrier-specific variations have been checked, particularly for air.

Getting It Right the First Time

Dry ice shipments are common, high-volume, and deceptively easy to get wrong – a missing net-weight mark or a sealed container can stop an otherwise routine consignment. Because the rules differ by mode, shippers who move product across air, ocean, and road all in the same week benefit from a partner who works in all three regimes daily.

Go Hazmat handles dry ice shipments for South Florida with 24/7 support, and our mobile specialists can mark, label, and document UN 1845 consignments on-site across Miami-Dade, Broward, and West Palm Beach. If cold-chain deadlines are on the line, having the packaging and paperwork verified before pickup keeps your product moving and your shipment compliant.

This article is general guidance and does not replace the current IATA DGR, IMDG Code, or 49 CFR. Requirements change between editions and carriers – always verify against the rules in force for your specific shipment.