ADR Class 2 & Cryogenic Gas Transport
ADR class 2 and cryogenic transport across Europe. Compressed and liquefied gases in cylinders, bundles and tanks, including refrigerated liquefied gases such as liquid nitrogen at around minus 196 degrees, planned around boil-off and discharge windows.
ADR class 2 covers gases in three divisions: 2.1 flammable, 2.2 non flammable and non toxic, 2.3 toxic. We arrange cylinder and bundle freight, tanker movements and cryogenic transport, with ventilation, upright securing, boil-off planning and full documentation.
Three divisions that behave nothing alike
Class 2 gets treated as one category and splits in practice into three very different jobs. Division 2.2 with nitrogen, oxygen or argon is comparatively forgiving. Division 2.1 with propane is flammable and heavily restricted in tunnels. Division 2.3 with ammonia or chlorine is toxic and drives decisions right through to route selection.
The second split is the form. Cylinder freight is packaged goods with specific securing and ventilation requirements. A cryogenic tank is a tanker movement with boil-off losses and a clock running. Both are called class 2 and share almost nothing operationally.
Common class 2 gases
These make up the majority of enquiries we handle in this class.
| Gas | UN number | Division | Form |
|---|---|---|---|
| Nitrogen, refrigerated liquid | UN 1977 | 2.2 | Cryogenic tank, around -196 C |
| Oxygen, refrigerated liquid | UN 1073 | 2.2 | Cryogenic tank, oxidising |
| Argon | UN 1006 | 2.2 | Cylinder, bundle, tank |
| Propane | UN 1978 | 2.1 | Cylinder and tank, tunnel restricted |
| Ammonia, anhydrous | UN 1005 | 2.3 | Tank, toxic and corrosive |
| Carbon dioxide | UN 1013 / 2187 | 2.2 | Cylinder and refrigerated |
Cryogenic transport and boil-off
A cryogenic tank is under constant heat ingress. The insulation is good but not perfect, the product slowly vaporises, and the resulting pressure vents through relief valves. Every hour the vehicle stands still is product leaving the tank.
With liquid nitrogen at roughly minus 196 degrees that loss is expected and priced in. It stops being routine when the vehicle waits: a receiving site not ready, a weekend driving ban in a transit country, or a queue at a gate. That is why we plan cryogenic movements against the discharge window rather than against driving time, and why we ask about the receiving site before we quote.
Ventilation, securing and tunnel codes
Cylinders travel upright and restrained, in vehicles with adequate ventilation. A closed unventilated body is not acceptable for many gases because escaping gas can accumulate rather than disperse.
For divisions 2.1 and 2.3 tunnel restrictions bite early. Flammable gases are prohibited through the Westerscheldetunnel in the Netherlands, and several Alpine tunnels are restricted, which can remove the short route from consideration entirely. We plan against the tunnel restriction code before confirming.
Where industrial gas demand concentrates in Europe
Industrial gas moves as dense repeating traffic between air separation units, filling plants and users in metals, food, medical and electronics. That makes the market plannable, and also unusually sensitive to time windows, because the product itself is on a clock.
- Cryogenic loads lose product while stationary, so weekend bans hit them harder than general freight
- Germany closes to trucks over 7.5 tonnes on Sundays and public holidays from 00:00 to 22:00
- Switzerland adds a night ban from 22:00 to 05:00 and a Sunday ban
- Medical gas carries its own acceptance and documentation requirements at the receiving site
Frequently asked questions
What is ADR class 2?
ADR class 2 covers gases in three divisions: 2.1 flammable gases such as propane UN 1978, 2.2 non flammable and non toxic gases such as nitrogen and oxygen, and 2.3 toxic gases such as ammonia UN 1005.
How is liquid nitrogen transported?
In an insulated cryogenic tank at around minus 196 degrees under UN 1977. The product vaporises continuously through heat ingress and vents via relief valves, so standing time causes real product loss and movements are planned around the discharge window.
Why do cylinders need ventilation?
Cylinders travel upright and restrained in vehicles with adequate ventilation, because a closed unventilated body allows escaping gas to accumulate rather than disperse. For many gases a closed body is not permitted.
Are there tunnel restrictions for gases?
Yes, and they apply early for divisions 2.1 and 2.3. Flammable gases are prohibited through the Westerscheldetunnel in the Netherlands and several Alpine tunnels are restricted.
Moving gas or a cryogenic load?
Send the UN number, division, form and lane. We will confirm vehicle, ventilation and tunnel routing before we price it.
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