What Is UN 1845 Marking?

UN 1845 Marking The UN identification marking for carbon dioxide, solid, commonly known as dry ice.

UN 1845 is the United Nations number assigned to solid carbon dioxide, or dry ice, for transport. The UN 1845 Marking is the set of required labels and package markings that identify a shipment as containing dry ice so carriers, handlers, emergency responders, and regulators can immediately recognize the hazard and apply the correct handling and stowage procedures.

What The Marking Looks Like

The typical marking combines the UN number and the proper shipping name. On packages you will commonly see:

• UN Identifier: The four-digit number "UN 1845" printed clearly on the outside of the package.
• Proper Shipping Name: "Carbon dioxide, solid (dry ice)" or an accepted short form such as "Dry Ice" paired with the UN number.
• Class Labeling: A Class 9 (miscellaneous) label or handling label when applicable — for air transport, handling instructions and net mass of dry ice per package are typically required.

Why The Marking Matters

Dry ice is a cryogenic solid that sublimates to carbon dioxide gas. In confined spaces this can displace oxygen and create an asphyxiation hazard; it can also cause frostbite on contact. The marking quickly communicates the presence of a non-flammable, cold, oxygen-displacing substance so that:

• Handlers: Can use insulated gloves, avoid tight enclosed spaces, and ensure ventilation.
• Carriers: Can segregate or stow packages to manage off-gassing and temperature effects on nearby cargo.
• Emergency Responders: Know to ask about enclosed-space gas displacement rather than treat the shipment as a flammable or corrosive incident.

How It Varies By Mode

Regulations for marking and information to accompany dry ice differ by transport mode and jurisdiction. Air transport authorities generally require more specific markings and documentation than surface modes because of the confined environment of aircraft cargo spaces; this typically includes the net weight of dry ice per package on the package and on the air waybill. Road and rail authorities rely on the UN number and proper shipping name plus any nationally mandated placarding, while some regional rules may exempt small quantities under limited conditions.

Who Is Responsible For Applying The Marking

The shipper is primarily responsible for correctly classifying, packaging, marking, and documenting dry ice shipments under hazardous materials regulations. Carriers will refuse or rework improperly marked packages, and regulatory enforcement can result in fines or shipment delays if markings are incorrect or missing.

Practical Example

A biotech company ships refrigerated blood samples on dry ice by air. Each carton is marked "UN 1845, Carbon dioxide, solid (dry ice)" and shows "Net weight: 5 kg" on the outside. The shipper's dangerous goods declaration, which accompanies the air waybill, repeats the UN number, proper shipping name, and the net quantity per package. Ground handling staff see the marking and store cartons in a ventilated loading area away from occupied offices; flight operations place the cartons per the carrier's dangerous goods stowage plan.

Common Mistakes And How To Avoid Them

• Omitting Net Weight: For air shipments the net mass of dry ice per package is often required — include it on the package and in the paperwork.
• Using Vague Wording: Use the prescribed proper shipping name and UN number; avoid informal labels like "Cold Pack" without the UN number.
• Poor Visibility: Place markings on multiple faces of the package and ensure they are legible after palletization and shrink-wrap.

In short, the UN 1845 Marking is the standardized way to identify packages containing dry ice so everyone in the transport chain can manage the unique cold and off-gassing hazards safely and in compliance with applicable regulations.