If you ship with dry ice, your dry ice packing sign must be right—every time. For air, that means UN1845, the proper name (“Dry ice” or “Carbon dioxide, solid”), net weight in kilograms, and a Class 9 hazard label; the package must also vent CO₂ gas. Those are not optional details—they’re required by the 2025 IATA DGR and 49 CFR rules. (IATA, eCFR)
This article will help you:
Know exactly what a dry ice packing sign must show for air, ground, and sea, and where to place it. (IATA, eCFR)
Format the net weight correctly (kg) and choose the right label size so carriers accept your shipment the first time. (IATA, FedEx)
Add safety icons and warnings to your dry ice packing sign to reduce risk (asphyxiation, frostbite) in handling areas. (CDC, Iteh Standards)
What is a dry ice packing sign, and why does it matter in 2025?
A dry ice packing sign is the visible set of markings and labels that identify UN1845 dry ice on the outside of your package. For air shipments, it’s mandatory to display UN1845, the proper shipping name, a Class 9 label, and the net mass of dry ice in kilograms. The packaging itself must vent CO₂ to prevent pressure buildup. (IATA, Legal Information Institute)
Beyond compliance, a correct dry ice packing sign prevents injuries and delays. CO₂ gas displaces oxygen; 1 lb of dry ice can release ~250 liters of CO₂, creating an asphyxiation risk in confined areas. Frostbite is another hazard at –78.5 °C (–109 °F). Clear, consistent signage and handling warnings reduce both. (Harvard Environmental Health and Safety)
The quick picture
(Wikimedia Commons)
What must a dry ice packing sign include for air shipments (IATA 2025)?
For any air shipment that uses dry ice:
UN1845
Proper name: “Dry ice” or “Carbon dioxide, solid”
Net weight of dry ice in kg (per package; ≤200 kg each)
Class 9 hazard label (minimum 100 mm × 100 mm)
Shipper & consignee names/addresses (on the package)
Packaging Instruction 954 kepatuhan (package must be vented)
Overpack marking if used, and the total net weight of dry ice on the overpack
Follow State/Operator variations where they apply. (IATA)
Why this matters: Airlines and ground handlers accept or reject your box based on these exact lineitems. IATA’s 2025 Acceptance Checklist explicitly confirms all of them, including the 200 kg perpackage limit and overpack totals. (IATA)
Label size tip: Carriers echo IATA’s minimum 100 mm Class 9 diamond; don’t write inside the diamond—use the adjacent text panel for UN1845 and net kg. (FedEx)
How do I format the net weight on a dry ice packing sign?
Write the net dry ice mass in kilograms (kg). You may add pounds in parentheses if helpful for your team, but kg must be present for air. Many carrier templates show a kg blank (some even remind you that 2 lbs ≈ 1 kg). (IATA, FedEx)
| Element | What to Write | Minimum Spec | Why it matters to you |
|---|---|---|---|
| Proper shipping name | “Dry ice” or “Carbon dioxide, solid” | Exact words; legible | Matches documentation and avoids delays. (IATA) |
| UN number | UN1845 | Characters ≥ 12 mm for ID number markings; place with proper name | Ensures visibility and compliance for nonbulk packages. (eCFR) |
| Net mass | “__ kg” (per package) | Kilograms required; ≤ 200 kg per package | Airline acceptance depends on it. (IATA) |
| Hazard label | Class 9 diamond | 100 mm × 100 mm minimum; do not write inside | Avoids rejections at acceptance. (FedEx) |
| Overpack | “OVERPACK” + total kg dry ice | Visible on outer overpack | Keeps the whole consignment compliant. (IATA) |
Practical tips for your dry ice packing sign
Place marks/labels on a vertical side (not the top/bottom). Keep them visible and not obscured. Postal/DOT guidance mirrors these placement principles. (Postal Explorer)
Keep proper name, UN1845, and Class 9 together on the same face when possible; remove/cover irrelevant old labels. (IATA, Postal Explorer)
Use durable labels that adhere to cold surfaces; hazards labels must remain contrasting, legible, weatherresistant. (Postal Explorer)
Realworld example: FedEx’s job aid shows the correct Class 9 ukuran, reminds you not to write inside the diamond, and provides a readytouse Dry Ice label with a kg field. Using it prevents most acceptance issues. (FedEx)
Is a dry ice packing sign required for ground shipping in the U.S.?
It depends. Under U.S. DOT HMR (49 CFR), the Hazardous Materials Table entry for UN1845 indicates no label code in Column 6—so a Class 9 label is not required under HMR for ground. Namun, you still must comply with marking rules (proper shipping name + UN number) and with any carrier policies. (PHMSA, eCFR)
Markings: 49 CFR requires the proper shipping name and identification number in durable, legible text; ID number characters must be ≥ 12 mm in most cases for nonbulk packages. (eCFR)
Carrier policies: Many carriers still prefer or require the familiar Class 9 diamond even on some domestic services; always check your service guide. Using the same dry ice packing sign layout as for air minimizes confusion in mixedmode supply chains. (FedEx)
Bottom line: For ground, follow DOT marking rules and your carrier’s playbook. If your parcel might connect to air, build the sign to the IATA standard to avoid rework.
What about sea (vessel) shipments—does the dry ice packing sign change?
Ya. For transport by vessel, 49 CFR 173.217(b) requires specific warning text on containers using dry ice as a refrigerant:
On transport vehicles/freight containers: conspicuously mark two sides with “WARNING CO₂ SOLID (DRY ICE)”.
On other packagings: mark “CARBON DIOXIDE, SOLID—DO NOT STOW BELOW DECKS.” (Legal Information Institute)
These are in addition to any IMDG/IATA requirements that apply to your route and carrier.
Where should you place the dry ice packing sign on the box?
Keep everything together, visible, and durable:
Use a vertical side of the outer box for the dry ice packing sign (don’t hide it on the top/bottom). (Postal Explorer)
Put the Class 9 diamond adjacent to UN1845 and the proper shipping name. Avoid seams and straps that can obscure it. (Postal Explorer)
Do not write inside the Class 9 diamond; put weights/addresses in the adjacent panel. (FedEx)
If using an overpack, ensure all required marks are visible or reproduce them on the overpack and add OVERPACK with the total kg of dry ice. (IATA)
Dry ice packing sign safety icons (ISO 7010) and OSHA essentials
Enhance your dry ice packing sign and storagearea signage with internationally recognized safety symbols:
W010: Warning; Low temperature/Freezing conditions
W041: Warning; Asphyxiating atmosphere
M009 (common in practice): Wear protective gloves (mandatory action symbol) (Iteh Standards, Fisher Scientific)
Why use them? OSHA/NIOSH set exposure limits for CO₂ at 5,000 ppm TWA and 30,000 ppm STEL; signaling asphyxiation risk around dry ice storage helps keep personnel within safe exposure windows. (CDC, OSHA)
Handling reminders to pair with your dry ice packing sign
Ventilasi: Work and store in wellventilated areas; never in cold rooms or sealed spaces. (UW Environmental Health & Safety)
No airtight containers: Dry ice must vent. Airtight containers can burst as dry ice sublimates. (Harvard Environmental Health and Safety)
PPE: Insulated gloves and eye protection prevent frostbite and eye injuries. (CDC)
Actual case: University safety programs document that 1 lb of dry ice → ~250 L of CO₂ gas; storing in an airtight vessel can cause violent failure. Clear signage plus SOPs prevent these incidents. (Harvard Environmental Health and Safety)
Stepbystep: create a compliant dry ice packing sign (with template)
Use this 2minute checklist before you tape the box:
Write “UN1845” and the proper name “Dry ice” (or “Carbon dioxide, solid”). (IATA)
Add net mass: “__ kg” (per package). If helpful, also show lbs in parentheses. (IATA)
Affix a Class 9 diamond (≥ 100 mm × 100 mm) next to the text. Don’t write inside the diamond. (FedEx)
Include shipper & consignee addresses on the package. (IATA)
If overpacked, reproduce marks or add OVERPACK + total kg dry ice. (IATA)
Verify ventilation and that the packaging meets PI 954 (air) and 49 CFR 173.217(a) (venting). (IATA, Legal Information Institute)
Want a ready label? Many carriers provide free Dry Ice label templates with a kg field; these simplify acceptance. (FedEx)
Tabel perbandingan cepat: what your dry ice packing sign needs by mode
| Mode | What must be on the sign | Any special text? | Max per package | Notes |
|---|---|---|---|---|
| Air (IATA) | UN1845, “Dry ice”/“Carbon dioxide, solid”, kg net, Class 9, shipper/consignee | OVERPACK (if used) + total kg | 200 kg | Package must be vented (PI 954). (IATA) |
| Ground (US DOT) | Proper shipping name + UN1845 (marking) | — | — | No Class 9 label required under HMR (Column 6 “None”); follow carrier policy. (PHMSA, eCFR) |
| Sea (49 CFR) | Proper shipping name/UN1835 [sic UN1845] + required warnings | “WARNING CO₂ SOLID (DRY ICE)” (containers); “DO NOT STOW BELOW DECKS.” (other pkgs) | — | Additional IMDG rules may apply. (Legal Information Institute) |
Practical user tips and advice
Lab samples by air? Use the IATA format every time; put the kg in a clearly printed field to avoid handwriting errors. (IATA)
Domestic courier, ground only? Still add UN1845 + proper name; consider keeping the Class 9 diamond for consistency across multimodal networks. (eCFR)
Storing pallets? Post W010 (dingin) and W041 (asphyxiation) icons at entries and reinforce with ventilation SOPs. (Iteh Standards)
Field case: A clinical lab moved to a single, carrierapproved dry ice packing sign (UN1845 + kg + Class 9) for all shipments. Result: zero IATA rejections and fewer ground delays over 90 days. Evidencebased standardization works. (FedEx)
Do passengers need a dry ice packing sign when flying with perishables?
If you’re flying with perishables and dry ice, the rules are strict: ≤ 2.5 kg (5.5 lb) of dry ice per passenger, package must vent, and checkedbag packages must be marked “Dry ice” or “Carbon dioxide, solid” and net weight (or “≤ 2.5 kg”). Airline approval is required. (Federal Aviation Administration)
2025 trends in dry ice packing sign compliance and materials
What’s new? Itu 2025 IATA DGR (66th Edition) kept core dryice marking rules intact but refreshed the Acceptance Checklist format (misalnya, explicit checks for UN1845 on the package and AWB, PI 954 venting, and 200 kg perpackage maximum). Many carriers mirror this checklist digitally at acceptance. (IATA)
Safety emphasis continues to rise. CO₂ monitoring practices in storage and staging spaces are getting tighter, guided by OSHA/NIOSH limits and local code enforcement—stronger signage around asphyxiation risk is part of that shift. (OSHA, CDC)
Latest developments at a glance
Checklists at the counter: Airlines use the IATA 2025 dryice acceptance checklist; if your sign is missing kg, expect a rejection. (IATA)
Standardized label dimensions: Carriers keep enforcing 100 mm Class 9 diamonds and no writing inside. (FedEx)
Growing safety icon literacy: More facilities adopt ISO 7010 icons (W010, W041) on doors and pallets near dry ice staging areas. (Iteh Standards)
Market insight: Today’s shippers favor preprinted dry ice labels with kg fields to reduce errors and speed acceptance (often supplied free by carriers or label vendors). (FedEx)
Pertanyaan yang Sering Diajukan
Q1: What must appear on a dry ice packing sign for air?<br/>UN1845, “Dry ice” or “Carbon dioxide, solid,” net weight in kg, Class 9 hazard label (≥ 100 mm), and shipper/consignee. Packaging must vent CO₂. (IATA, FedEx)
Q2: Do I need a Class 9 label for U.S. ground only?<br/>Under DOT HMR, UN1845 has “None” in the label column, so Class 9 isn’t required by regulation for ground—but your carrier may still require it. (PHMSA)
Q3: Does the net weight have to be in kilograms?<br/>Yes for air; kg is required. You can add pounds in parentheses, but don’t omit kg. (IATA)
Q4: How big must the Class 9 diamond be?<br/>At least 100 mm × 100 mm; do not write inside the diamond. (FedEx)
Q5: Where do I place the dry ice packing sign?<br/>On a vertical side, near the proper shipping name/UN1845, not on edges or under straps; keep marks/labels together and legible. (Postal Explorer)
Q6: Is it okay to ship dry ice in a sealed box?<br/>TIDAK. Dry ice must be able to vent; airtight containers can explode as CO₂ builds. (Legal Information Institute)
Q7: I’m flying with a cooler and dry ice. What’s my limit?<br/>2.5 kg (5.5 lb) per passenger, package must vent, and you must mark the package accordingly; airline approval is required. (Federal Aviation Administration)
Ringkasan & recommendations
For air: Your dry ice packing sign must show UN1845, the proper name, kg net mass, and a 100 mm Class 9 label; the package must vent. (IATA)
For ground (U.S.): DOT requires marking (proper name + UN1845); Class 9 is not mandated by HMR—but carrier rules can be stricter. (PHMSA)
For sea: Use the vesselspecific warnings and avoid stowing below decks unless permitted. (Legal Information Institute)
Next steps: Standardize your dry ice packing sign across modes, keep a kgbased template, and post ISO 7010 safety icons where you stage dry ice. Run the quick checklist before sealing each box. (IATA, Iteh Standards)
Action plan (copy/paste)
Adopt a universal sign template (UN1845 + proper name + “__ kg” + Class 9; 100 mm diamond). (FedEx)
Print overpack labels with total kg dry ice when you palletize. (IATA)
Post W010/W041 icons at storage and packing stations; add a short handling SOP. (Iteh Standards)
Train packers on 49 CFR marking sizes (≥ 12 mm ID numbers) and “don’t write inside the diamond.” (eCFR, FedEx)
Tentang Huizhou
Huizhou helps coldchain teams ship with confidence. We design validated packaging, provide readytouse dry ice packing sign templates (UN1845 + kg), and offer quick training for IATA PI 954 basics. Our kits are tested for label adhesion at low temperatures and include Class 9 diamonds that meet 100 mm specs. We focus on speed, kepatuhan, and fewer surprises at acceptance. (FedEx)
Talk to us: Need a branded dry ice packing sign or a onepage SOP for your team? Get expert help today.
Key sources
IATA DGR 66th (2025) Acceptance Checklist for Dry Ice — UN1845 text, kg net, Class 9, PI 954, 200 kg/package, overpack. (IATA)
49 CFR 173.217 & Subpart D (Marking) — Venting requirement; vessel warnings; 12 mm ID number size; general marking. (Legal Information Institute, eCFR)
FedEx Dry Ice Job Aid & Label — 100 mm diamond; do not write inside; kg field on template. (FedEx)
OSHA/NIOSH — CO₂ exposure limits (5,000 ppm TWA, 30,000 ppm STEL). (OSHA, CDC)
Harvard EHS Dry Ice Safety — ~250 L CO₂ per lb sublimation; asphyxiation & overpressurization cautions. (Harvard Environmental Health and Safety)
Compliance note: Regulations and carrier rules can change. Always verify State/Operator variations and your service guide before shipping. If you need a quick preflight check, use the IATA acceptance checklist alongside this dry ice packing sign guide. (IATA)
Bonus: 15second selfcheck before tendering
UN1845 + proper name present?
Net kg shown (per package)?
Class 9 diamond (≥100 mm) affixed and clear?
Packaging vents CO₂?
Overpack total kg shown (if applicable)?
Shipper/consignee shown and labels unobscured?
If all yes, your dry ice packing sign is ready.