The first question on any dangerous goods enquiry for Iran is always whether the cargo can move at all. The answer does not depend on the value of the goods; it depends on where they sit in the UN classification of dangerous goods. This article works through the nine transport classes, says which categories are actually moved on China–Iran lanes and which are not advisable, sets out the packing, documents and carriage position by class, and explains how ocean and rail differ in their declaration requirements.
1. Start with the nine UN transport classes
The classification of dangerous goods rests on the UN Recommendations on the Transport of Dangerous Goods, usually shortened to TDG. It sorts dangerous goods into nine classes by hazard. Knowing which class a cargo falls into is the basis for everything that follows on packing, labels and documents.
| Class | Content | How common on China–Iran lanes |
|---|---|---|
| Class 1 | Explosives | Not moved |
| Class 2 | Gases, compressed, liquefied or dissolved | Rare; a few categories are negotiable |
| Class 3 | Flammable liquids | Some categories can move |
| Class 4 | Flammable solids, self-reactive substances and substances that emit flammable gas on contact with water | Rare |
| Class 5 | Oxidising substances and organic peroxides | Rare |
| Class 6 | Toxic and infectious substances | Not moved |
| Class 7 | Radioactive material | Not moved |
| Class 8 | Corrosives | Some categories can move |
| Class 9 | Miscellaneous dangerous substances and articles | Relatively common, for example lithium batteries |
2. What is actually moved on China–Iran lanes
In practice, three groups account for most of the dangerous cargo on these lanes.
Within class 3, flammable liquids, categories with a higher flash point and compliant packing can be arranged, provided the flash point and packing group are declared truthfully. Within class 8, corrosives, categories with compliant packing that are not mixed with incompatible goods can move, with the emphasis on leak and corrosion protection inside and out. Class 9, miscellaneous, has the widest coverage, and lithium batteries are its best-known example: the class itself is relatively manageable, but the documentation and packing requirements are not reduced at all, as set out in the lithium battery and dangerous goods guide.
3. What is not advisable
A few categories are clearly not advisable. Class 1 explosives, class 7 radioactive material and class 6.2 infectious substances are generally not accepted by rail or by most carriers, and most compressed and liquefied gases in class 2 are hard to arrange because of packaging and wagon conditions. These are not a matter of operating difficulty; the carriage qualification and the route conditions are simply not in place.
4. Class, packing, documents and carriage position
The table aligns the key requirements for the classes we see most often. Whether a specific consignment is carried is confirmed by the carrier at the time of booking.
| Class | Packing requirement | Documents with the goods | Whether we carry it |
|---|---|---|---|
| Class 3 flammable liquids | Packed to the applicable packing group, sealed against leakage | Packaging certificate, MSDS, dangerous goods declaration | Some categories carried |
| Class 8 corrosives | Leak and corrosion protection inside and out, not mixed with incompatible goods | Packaging certificate, MSDS, transport condition report | Some categories carried |
| Class 9 miscellaneous, including lithium batteries | Packed to the applicable conditions, protected against short circuit and impact | UN38.3, MSDS, lithium battery declaration | Some categories carried |
| Class 1 explosives | Special permit and dedicated packaging | Explosives permit and specific documents | Not carried |
| Class 7 radioactive material | Dedicated packaging and shielding | Specific radioactive transport permit | Not carried |
This table draws the boundary first. Even a carried category still has to be confirmed consignment by consignment, because within one class the acceptance of different commodity names and different packings can differ completely.
5. How ocean and rail differ in declaration
The two modes handle dangerous goods on different logic. Ocean freight is normally declared under the International Maritime Dangerous Goods Code, where the cargo has to be declared in advance and a dangerous goods slot reserved; the shipping line decides whether to accept it, so bookings need a longer lead time than general cargo, as described under China to Iran sea freight.
Rail declares by wagon or by container, some classes are not carried at all, and a carried class still has to be reported to the railway in advance so that container conditions can be confirmed. What the two share is the requirement that the declaration be made early and that the declared information match the load. The overall rail arrangement and corridor detail sit under China to Iran rail freight (FCL).
6. A four-step decision order
Faced with a cargo of uncertain status, working through these four steps in order avoids most rework.
- Classify first. Establish which TDG class and division the goods fall into, and whether there is a UN number.
- Then check the packing. Match the packing group to the class requirement, and confirm that labels and marks are complete.
- Then check the documents. Confirm that the packaging certificate, MSDS, condition report and declaration are complete, in date and consistent.
- Confirm the booking last. Hand the class and packing information to the carrier, and confirm that the current service accepts it and that a slot or wagon can be arranged.
Get current rates and transit times
Send us the commodity, UN number and hazard class, packing method, pieces, weight and dimensions, the origin city and the destination. We will return a comparison built on the current rail and ocean dangerous goods conditions, with a validity window, and a note on which mode the consignment can move under.
7. Frequently asked questions
Which dangerous goods can essentially not move on China–Iran lanes?
Class 1 explosives, class 7 radioactive material and class 6.2 infectious substances are generally not accepted, and most compressed and liquefied gases in class 2 are also hard to arrange. These are limited by carriage qualification and route conditions, not by operating difficulty.
How do ocean and rail differ in declaring dangerous goods?
Ocean freight declares under the maritime dangerous goods code, needs an advance declaration and a reserved dangerous goods slot, and the shipping line has the final say. Rail declares by wagon or container, does not carry some classes, and requires advance reporting even for accepted ones. Both require early, consistent declarations.
Does a carried category still need confirming consignment by consignment?
Yes. Within one class, the acceptance of different commodity names and different packings can differ entirely. Before dispatch, hand the commodity, class and packing information to the carrier for a per-consignment check rather than treating the class as a blanket answer.
Related lanes
- Lithium battery and dangerous goods guide — classes, packing and document requirements
- China to Iran rail freight (FCL) — rail carriage conditions and corridors
- China to Iran sea freight — dangerous goods slot declaration and booking lead time
- China to Iran road freight (FTL) — full-truck carriage and vehicle types