How much dry ice can I ship with FedEx?

FedEx lists a 200 kg maximum dry ice quantity per package. FedEx air shipments need UN1845 marking, the proper shipping name, net weight in kg, and a Class 9 hazard label (minimum 100mm diamond). For air shipments, the AWB must include the dry ice description.

Do I need a Class 9 label for ground shipments?

FedEx Ground dry ice is not regulated as hazardous material in the same way as air service, but FedEx still says to mark the package as dry ice. UPS says dry ice shipments to and from the U.S. 48 contiguous states are processed like standard UPS Ground. USPS surface mail needs a 'Surface Only' or 'Surface Mail Only' marking. Always verify current requirements with your carrier.

Can I ship dry ice internationally with USPS?

No. USPS does not accept international mail containing dry ice. For international dry ice shipments, you must use FedEx, UPS, or another carrier that supports international dangerous goods transport.

What is the UPS 2.5 kg threshold for dry ice?

For UPS domestic air shipments with non-medical contents, packages containing more than 2.5 kg of dry ice go through an acceptance audit path with additional verification requirements. Packages with 2.5 kg or less may follow a simplified 49 CFR handling path when properly marked with dry ice or carbon dioxide solid, the contents being cooled, and the dry ice amount.

How large must a Class 9 dry ice label be?

For air transport, use a Class 9 diamond at least 100 mm by 100 mm and verify print scale with a calibration ruler.

Is the Class 9 diamond enough by itself?

No. Dry ice packages also need UN1845, proper shipping name, and net dry ice weight markings on the package.

UN1845 Class 9 label requirements

UN1845 is the United Nations identification number for dry ice (Carbon dioxide, solid). Air shipments and carrier routes regulated as air transport need specific hazard markings and labels on the outer package. Ground-only requirements vary by carrier and lane, so verify the selected service before treating the Class 9 diamond as mandatory.

This article explains what the Class 9 label looks like, how big it needs to be, where to place it, and what other markings must accompany it on a UN1845 dry ice shipment.

What Is the Class 9 Hazard Label?

Class 9 is the IATA/DOT classification for "Miscellaneous Dangerous Goods" — substances and articles that present a danger during transport but don't fit neatly into Classes 1 through 8. Dry ice falls into Class 9 because sublimating CO2 can displace oxygen in enclosed spaces (creating an asphyxiation risk) and because the extreme cold (-78.5 C / -109.3 F) can cause cryogenic burns and packaging failures.

The Class 9 label is a diamond-shaped (rotated square) marking with the following visual elements:

Upper half: Seven vertical black stripes on a white background
Lower half: White or light background
Number "9": Displayed in the bottom corner of the diamond, underlined
Border: A solid black border around the diamond perimeter

The label does not contain the word "DRY ICE" or "UN1845" — those are separate outer package markings. The Class 9 diamond purely identifies the hazard class.

Class 9 Label Size Requirements

Air Transport (IATA Standard)

For shipments traveling by air — including FedEx Express, UPS Next Day Air / 2nd Day Air, and USPS Priority Mail — the Class 9 diamond must be at least 100mm x 100mm (approximately 4 inches x 4 inches).

This 100mm minimum is derived from IATA Dangerous Goods Regulations and is the standard enforced by all major carriers for air-transported dry ice. Printing the label smaller than 100mm is one of the most common reasons dry ice shipments get rejected.

Ground Transport

For shipments traveling exclusively by ground, carrier rules vary. FedEx says dry ice is not regulated as hazardous material in FedEx Ground, and UPS says U.S. 48-state UPS Ground dry ice shipments are processed like standard Ground. USPS surface mail has its own Surface Only marking requirement.

Recommendation: Print the Class 9 diamond at 100mm when the shipment may move by air or when the carrier asks for it. If a route is clearly ground-only, follow the carrier's ground-specific dry ice instructions.

Printing the Class 9 Label Correctly

Scale Verification

One of the most frequent problems with Class 9 labels is printing at the wrong scale. Printers often default to "Fit to Page" or "Shrink to Printable Area," which reduces the diamond below the required 100mm.

To verify your print is at 100% scale, use a calibration ruler — a printed measurement reference on the same page as the label. Measure the ruler with a physical ruler; if the printed ruler matches real-world measurements, the label is at the correct size. If it's off, adjust your printer settings to "Actual Size" or "100%" and reprint.

Label Material

The Class 9 label must be:

Durable enough to survive the shipping journey without smearing, tearing, or fading
Printed on weather-resistant material if the package will be exposed to moisture
Securely attached to the package surface (adhesive-backed labels or direct printing on the box are both acceptable)

Standard office printer paper is generally acceptable for the label if the package is a corrugated box that will be handled normally. For coolers or packages exposed to condensation from the dry ice, laminated or adhesive-backed labels are more reliable.

Color

The Class 9 label is black and white. No color printing is required. The vertical stripes must be clearly differentiated from the white background — a high-contrast black-on-white print is standard.

Other Required Markings (Beyond the Class 9 Diamond)

The Class 9 label alone is not sufficient when a dry ice shipment is regulated as UN1845. The package must also display these outer package markings:

UN Number

"UN1845" must be printed on the outer package. This identifies the specific substance. Some shippers display it as "UN 1845" (with a space) — both are generally accepted.

Proper Shipping Name

The proper shipping name must appear on the package:

"Dry Ice" or
"Carbon dioxide, solid"

Either form is acceptable. Using both is common and avoids any ambiguity.

Net Weight

The net weight of dry ice in the package must be marked, expressed in kilograms. For example: "Net Weight: 2.5 kg" or "2.5 kg dry ice."

This is the weight of the dry ice itself, not the total package weight. The net weight allows carriers and handlers to assess the total quantity of dry ice on a vehicle or aircraft.

Air Waybill Text (Air Transport Only)

For air shipments, the air waybill or shipping documentation must include:

"UN1845, Dry Ice, Class 9, [packages] x [kg per package]kg"

This is not a marking on the physical package — it's a notation on the shipping paperwork or electronic shipping record.

Where to Place Labels and Markings

When Class 9 and UN1845 markings are required, IATA and carrier guidelines specify:

The Class 9 diamond should be placed on an exterior surface of the package that is easily visible during handling and inspection
Outer markings (UN1845, proper shipping name, net weight) should be on the same surface as the Class 9 diamond or on an adjacent surface
Labels should not be placed on the bottom of the package
Labels should not be obscured by tape, strapping, or other labels
If the package has multiple sides, place markings on the side most likely to be facing outward during transport

For palletized or overpack shipments, the overpack itself must carry required markings and labels unless the inner-package markings and labels remain visible. Add the "OVERPACK" marking when required.

Common Label Mistakes That Cause Rejection

Based on the most frequent documentation failures at carrier acceptance:

Wrong size. The Class 9 diamond is printed at less than 100mm due to printer scaling. Always verify with a ruler.

Missing net weight. Shippers remember the diamond and UN number but forget to include the dry ice weight in kg.

Label obscured. Packing tape placed over the label or other shipping labels covering the markings.

Incorrect label. Using a generic "hazardous materials" placard instead of the specific Class 9 diamond, or using an outdated label design.

Missing UN1845. The UN number is sometimes omitted because shippers assume the Class 9 diamond is sufficient. It's not — the UN number is a separate, required marking.

Handwritten markings. While not strictly prohibited, handwritten markings are more likely to be illegible or questioned at acceptance. Printed markings are strongly recommended.

Overpacks: Additional Marking Requirements

If multiple packages containing dry ice are consolidated into a single overpack (e.g., multiple coolers banded together on a pallet or placed inside a larger box), the overpack must be:

Marked with the word "OVERPACK" on the exterior
Labeled with the Class 9 diamond on the exterior (unless the labels on the inner packages are visible through the overpack)
Marked with "UN1845," the proper shipping name, and the total net weight of dry ice across all inner packages

Differences Between Compliance Labels and Shipping Labels

An important distinction: the Class 9 diamond and UN1845 markings are compliance labels when required — they identify the hazardous contents and fulfill regulatory requirements. They are separate from the carrier shipping label (the FedEx, UPS, or USPS label with the barcode, tracking number, and addresses).

For regulated air shipments, both must be present on the package. The compliance labels identify what's inside; the shipping label identifies where it's going. They should be placed on the same side of the package when possible, but must not overlap.

Generate Print-Ready UN1845 Labels

Dry Ice Wizard generates UN1845 compliance labels and conservative job aids as print-ready PDFs:

Class 9 diamond at exactly 100mm, verified with an included calibration ruler
Outer package marking with UN1845, proper shipping name, and your specific dry ice net weight
AWB text card with the air waybill notation formatted for your shipment
Acceptance checklist confirming all labels and markings are in place

Enter your shipment details (carrier, mode, weight, packages) and download the complete label set.

Generate your UN1845 labels now →

Important Notes

This guide is informational and not legal advice. Verify requirements with the applicable IATA Dangerous Goods Regulations, DOT 49 CFR, and your carrier's specific guidance.
Label requirements can change. The information here was last reviewed in June 2026.
UN1845 labels apply when dry ice is used as a refrigerant for non-dangerous goods. If your dry ice is packaging other dangerous goods, additional Class 9 requirements and a full Shipper's Declaration may apply.

Last updated: June 2026 | dryicecompliance.com