Clinical samples, vaccines, reagents, food trials: some shipments cannot afford a single warm hour. Dry ice is the simplest way to prevent that — it holds around −78 °C, needs no power, and leaves no meltwater behind. Which is why it travels inside most deep-frozen express consignments.
What catches people out is that dry ice is dangerous goods in transport. Not because it is cold, but because of the gas. And the shipments that get held at the airport almost never fail on the contents. They fail on a missing figure written on the box.
This guide covers the rules that apply to any dry ice shipment — and, at the end, what the process looks like when yours starts in the Munich area.
Why dry ice counts as dangerous goods
Dry ice is frozen carbon dioxide. It never melts — it sublimates straight into gas, and one kilogram becomes roughly 500 litres of it. That produces the two hazards the rules are built around:
- Pressure. Sealed inside an airtight container, the expanding gas will burst the packaging.
- Oxygen displacement. CO₂ is heavier than air and pools at floor level. In a closed hold, a lift or a small stockroom it becomes dangerous well before anyone notices a smell.
In transport law it therefore travels as UN 1845, Class 9 — miscellaneous dangerous goods. For air freight, Packing Instruction 954 of the IATA Dangerous Goods Regulations applies.
The goods themselves are usually harmless. It is the coolant that is regulated — and that is exactly what gets left off the booking.
The packaging has to breathe
This is the rule broken most often: a dry ice shipment must never be gas-tight. The carbon dioxide has to be able to escape.
In practice:
- Use an EPS or PU insulated box that lets gas pass at the seams — never a hermetically sealed container.
- Do not run tape all the way round the lid to seal it.
- Pack the dry ice on top of or around the goods, not underneath. Cold air falls.
- Make the outer carton strong enough that the insulation is not crushed in handling.
The same care applies in your own building. Pack with proper gloves, in a ventilated room. Direct skin contact with dry ice causes cold burns within seconds.
What belongs on the box and on the paperwork
Where dry ice is only cooling otherwise non-hazardous goods, the burden is manageable — but it is not nothing. Every package needs:
- the UN number 1845 and the name "Dry ice" or "Carbon dioxide, solid",
- the Class 9 hazard label,
- the net quantity of dry ice in kilograms, per package,
- clearly legible shipper and consignee details.
That quantity is not a formality. The airline adds it up to work out how much CO₂ can be released in the hold and plans the load around it. An estimated or rounded figure is one of the most common reasons a shipment is refused.
Quantity limits differ by airline and aircraft type, and they change with each edition of the regulations. Do not rely on a number you read somewhere — including in this article. Ask for the limit that applies to your actual route before you pack.
Road transport within Europe is more forgiving: where dry ice serves purely as a coolant, the full dangerous goods regime does not apply. The vehicle or container still has to warn of the asphyxiation risk, and anyone opening the door needs to know what is inside.
How much dry ice do you need?
Dry ice sublimates continuously, and how fast depends on the insulation, the quantity and the ambient temperature. Nobody can give you a single reliable number — it has to be established for your box and your transit time.
What works in practice:
- Plan against the realistic transit time, not the quoted one. A weekend, a public holiday at destination or a customs inspection all stretch it.
- Build in a buffer. Dry ice left over on arrival costs a few euros. A thawed shipment costs the goods, and usually a second attempt.
- Test the combination once before you ship it regularly. Box, quantity, duration — measure it properly a single time and you never have to guess again.
- Tell the consignee it is coming. A dry ice shipment sitting two days in a post room is lost however well you planned.
Storing dry ice on your own premises
Transport is regulated; storage at the shipper's end frequently is not — and that is where most incidents happen. Three points belong in any working instruction:
- Never store it airtight. A cool box that seals well, or a container with a screw lid, becomes a hazard as the pressure builds. Dry ice belongs in something that can give.
- Never in a small, unventilated room. Basements, walk-in chillers, store cupboards: anywhere CO₂ can collect at floor level needs ventilation or a sensor.
- Never in the cabin of a vehicle. Carry a box on the passenger seat and you are breathing what comes off it. Dry ice travels in the ventilated load space.
And the simplest rule of all: anyone handling dry ice needs gloves — proper insulated ones, not thin disposables.
Where shipments actually come unstuck
From day-to-day experience, in this order:
- The dry ice quantity is missing from the box, or disagrees with the paperwork.
- The packaging has been taped airtight.
- The Class 9 label is missing, because the contents themselves are harmless.
- The shipment leaves on a Friday afternoon and sits through the weekend.
- The consignee has no idea something time-critical is on its way.
Not one of these is about the goods. All five can be settled before anything is packed.
Dry ice shipping out of Munich
We are based in Planegg, south-west of Munich, and collect across the greater Munich area — laboratories and clinics in the city, the biotech sites in the surrounding towns, the industrial estates out to the north. For a dry ice consignment that means:
- Same-day collection is available across greater Munich when the job is placed early enough. With dry ice the early call pays twice over: the less time a box spends waiting, the less dry ice you have to put in it.
- A short run to the airport. Munich is a major international freight location. Whether your shipment travels as air freight or is better driven direct within Europe is something we settle beforehand — with dry ice, the road is the better answer more often than people expect.
- A named contact rather than a hotline. Whoever answers your dangerous goods and temperature questions is the person who then looks after the shipment.
If you send frozen consignments out of Munich regularly, it is worth setting the pattern once rather than solving it per shipment: box, quantity, route and paperwork agreed a single time, and after that it simply runs.
What to have ready when you book
To set up a dry ice shipment properly we need four things: what is being shipped, how many kilograms of dry ice go into each package, where it is going and when it has to be there. With those four, it takes minutes to say whether the route works as air freight or is better driven direct, and which paperwork you will need.
Temperature-controlled consignments and dangerous goods are handled by our specialist team — there is more on the special services page, and collections and direct drives around the city are covered on courier services Munich. If you are unsure whether your case falls under the dangerous goods rules at all, ask early. The conversation takes five minutes; a refused shipment costs a day.