Most shippers discover their cargo is regulated late — after a booking is refused, or worse, after a container is opened at a port. The cost of finding out at that point is measured in weeks and fines rather than in the surcharge you would have paid for doing it properly.
This article covers how to establish whether you have dangerous goods at all, which classes realistically move by ocean, air and rail out of China, what documentation each mode requires, and what happens when something ships undeclared.
If your product’s safety data sheet shows a UN number in Section 14, it is regulated as dangerous goods for transport. From that point the mode determines almost everything: ocean freight under the IMDG Code accepts the widest range, air under IATA rules is the most restrictive, and rail sits in between with corridor-specific limits. Classification, packaging and documentation must be correct before booking, not after.
Open your product’s safety data sheet and go to **Section 14 — Transport Information**.
If Section 14 shows a **UN number** — a four-digit code prefixed with UN, such as UN 1263 or UN 3480 — your product is regulated as dangerous goods in transport. If Section 14 says “not regulated” or “not classified as dangerous goods,” it is not.
That is the whole test, and it takes thirty seconds. It is also the step most first-time shippers skip, usually because nobody told them the SDS contained shipping information rather than only safety information.
Two things worth knowing about it.
**Your supplier has the SDS.** Every manufacturer of a chemical product is required to produce one. If a supplier cannot provide an SDS, that is a significant signal about the supplier, not a paperwork inconvenience.
**Section 14 also gives you the class and packing group.** Alongside the UN number you will find the proper shipping name, the hazard class, and the packing group. Those four items are what a forwarder needs to tell you whether your cargo can move, how, and at what cost. Send them at enquiry stage and the first answer will be the real one.
The United Nations classifies dangerous goods into nine classes, used consistently across ocean, air, rail and road regulations worldwide.
| Class | Category | Common examples |
|---|---|---|
| 1 | Explosives | Fireworks, ammunition, airbag inflators |
| 2 | Gases | Aerosols, compressed gases, refrigerants, lighters |
| 3 | Flammable liquids | Paints, solvents, adhesives, alcohols, perfumes |
| 4 | Flammable solids | Matches, sulphur, metal powders, cargo dangerous when wet |
| 5 | Oxidising substances and organic peroxides | Bleaching agents, fertilisers, some resins |
| 6 | Toxic and infectious substances | Pesticides, dyes, biological samples |
| 7 | Radioactive material | Industrial gauges, medical isotopes |
| 8 | Corrosives | Acids, alkalis, batteries containing electrolyte |
| 9 | Miscellaneous | Lithium batteries, magnetised material, dry ice, environmentally hazardous substances |
Several classes subdivide — Class 2 into flammable, non-flammable and toxic gases, Class 4 into flammable solids, spontaneously combustible and dangerous-when-wet, Class 6 into toxic and infectious. The subdivision frequently matters more than the class number for what is accepted where.
**Class 9 catches people out most often.** It sounds like a residual category and contains lithium batteries, which are among the most heavily regulated items in freight. A product with a lithium cell in it — a power tool, a speaker, an appliance — is regulated cargo even though nothing about it feels hazardous.
Within most classes, cargo is assigned a packing group indicating degree of danger: **I** high, **II** medium, **III** low.
The packing group determines the packaging standard required and affects acceptance and cost. Two products in the same class can face very different requirements if they sit in different packing groups, which is why the class alone is never enough information to quote from.
Three different rulebooks govern the three modes, and they are not equally permissive.
**Ocean — the IMDG Code.** The International Maritime Dangerous Goods Code governs sea transport and accepts the widest range of classes and quantities. Most DG that moves from China moves this way, for that reason.
**Air — the IATA Dangerous Goods Regulations.** The most restrictive of the three. Many substances are forbidden entirely; others are permitted only on cargo aircraft, not on passenger aircraft, which sharply limits available capacity and raises cost. Quantity limits per package are far tighter than at sea.
**Rail — corridor-dependent.** The China–Europe and Central Asia corridors apply their own acceptance rules, which vary by operator and by the transit countries the train crosses. Restrictions are generally tighter than ocean and the permitted list is less predictable, because a shipment must satisfy every territory en route.
| Ocean (IMDG) | Air (IATA) | Rail | |
|---|---|---|---|
| Range accepted | Widest | Most restrictive | Varies by corridor and operator |
| Quantity limits | Most generous | Tight per-package limits | Corridor-specific |
| Cost impact | Surcharge, moderate | Substantial — and capacity-limited | Varies |
| Capacity available | Broad | Limited, especially for cargo-aircraft-only items | Limited |
| Predictability | High | High, but restrictive | Lower — confirm per booking |
**The practical consequence:** do not assume that because your cargo shipped by sea last time, it will fly this time. The reverse is more reliable — what flies will almost always sail.
If your cargo is regulated and your deadline is tight, establish air acceptance before you plan around it. Discovering at the airport that your commodity is cargo-aircraft-only, on a lane with two freighter services a week, is a meaningful problem.
Some can, many cannot, and the distinction is not intuitive.
Air transport regulations divide dangerous goods three ways: **forbidden entirely**, **permitted on cargo aircraft only**, and **permitted on both passenger and cargo aircraft** within quantity limits.
Explosives, certain flammable liquids in bulk, corrosives such as concentrated acids, toxic substances and radioactive material are among the categories most heavily restricted or excluded from passenger aircraft. Where an item is cargo-aircraft-only, your available capacity narrows to freighter services — which on many lanes means fewer departures and a different cost base.
Quantity limits matter as much as the class. A substance permitted in small packages may be forbidden in the volume you actually want to ship.
Acceptance also varies by carrier. Airlines apply their own policies on top of the regulations, and one carrier’s acceptance does not guarantee another’s. This is why we confirm acceptance with the specific carrier before quoting rather than after booking — a rate for a shipment that will not be accepted is not a rate.
Five items, and the first one drives the rest.
**Safety data sheet.** The source document. Section 14 provides the UN number, proper shipping name, class and packing group that everything else derives from.
**Dangerous goods declaration.** The formal declaration to the carrier that the shipment contains DG, stating the classification, packaging and quantity. It is a legal document and the shipper is responsible for its accuracy, whoever physically prepares it.
**Packing certificate.** For containerised sea shipments, confirming the container has been packed in accordance with the IMDG Code — correct segregation, securing and placarding.
**UN-certified packaging evidence.** DG must travel in packaging tested and certified to the appropriate standard, marked with a code such as `UN 4G/Y30/S`. The marking identifies the packaging type, the packing group it is certified for, and the specification it was tested against.
**Labels and placards.** Hazard diamond labels on each package, and placards on the container or vehicle. These are not decorative — incorrect or missing placarding is one of the more common reasons a container is stopped.
For lithium batteries specifically, a **UN 38.3 test summary** is additionally required — the manufacturer’s evidence that the cells passed the prescribed transport safety tests.
Every stage of a DG shipment carries additional time that general cargo does not, and no published guide seems willing to say so.
**Before booking**, classification review and carrier acceptance confirmation typically add several days. On an unusual commodity or a restricted class, longer.
**At origin**, DG cargo requires segregated handling and cannot simply be received into a general warehouse alongside anything else. Stuffing is slower because segregation rules govern what may travel adjacent to what.
**At the terminal**, DG containers are subject to acceptance checks that general containers are not, and terminals impose their own cut-off times for DG that are earlier than standard cut-offs — sometimes by a full day.
**At customs**, DG declarations attract more scrutiny, and a documentation discrepancy on a DG entry is treated more seriously than the same discrepancy on general cargo.
**At destination**, the same applies in reverse, plus any import requirements specific to the receiving country.
The practical guidance: add a week to your planning for a straightforward DG shipment, more for a restricted class or an unfamiliar commodity. Shippers who treat DG as general cargo with extra paperwork are the ones who miss sailings.
Undeclared dangerous goods is the most serious documentation failure in freight, and the exposure is not limited to a fine.
**Carrier penalties.** Shipping lines and airlines impose substantial charges for misdeclared or undeclared DG, and they apply them to the shipper regardless of whether the omission was deliberate. Industry reporting has put these in the range of ten thousand dollars and upward per incident.
**Cargo consequences.** The container may be stopped, discharged at an intermediate port, or in serious cases destroyed. You pay the costs of all of it.
**Insurance.** A claim arising from undeclared DG is likely to be refused. Cargo policies require accurate declaration, and a misdeclaration voids the basis on which cover was written.
**Liability.** If undeclared cargo causes an incident — a fire in a container stack is the scenario everyone in the industry has in mind — the liability is not theoretical and it is not capped at the value of your goods.
**Regulatory record.** A misdeclaration affects your compliance standing with customs, which has consequences beyond the individual shipment.
Almost none of this arises from bad faith. It arises from shippers who did not know their product was regulated — which returns to Section 14 of the safety data sheet. Thirty seconds of checking prevents nearly all of it.
More than general cargo, and the structure is what to understand rather than any figure.
Your cost includes the base freight plus a DG surcharge that varies by class, packing group and mode. UN-certified packaging costs more than standard packaging and may need to be sourced specifically. Documentation preparation carries a fee. Segregated storage and handling attract charges that general cargo does not. And on air freight in particular, the restriction to certain services can mean a higher base rate before any surcharge is applied.
Air carries the steepest premium, because the restrictions are tightest and the capacity narrowest. Ocean is the most economical route for most DG, which is why most DG moves by sea even when the cargo would otherwise justify air.
Two things reduce the total more than negotiation does: **correct classification** — being in packing group III rather than II, where the product genuinely qualifies, changes both packaging requirements and surcharge — and **consolidating DG shipments** rather than sending small quantities repeatedly, since much of the documentation and handling cost is per shipment rather than per kilo.
Many forwarders decline DG, and the ones that accept it vary enormously in how they handle it. Five questions.
**Do you classify, or do you rely on what I tell you?** A forwarder who accepts your classification without review is transferring risk to you. One who reviews the SDS and confirms it is doing the job.
**Which classes do you actually handle, and by which modes?** A general “yes we do dangerous goods” is not an answer. Ask about your specific class and your specific mode.
**Do you prepare the DG declaration in-house?** If it is subcontracted, ask who is accountable for its accuracy.
**Do you confirm carrier acceptance before quoting?** A rate issued without acceptance confirmation is provisional, whether or not it says so.
**What is your experience with this commodity at this port?** Acceptance practice varies between ports and between terminals. Local knowledge is worth more here than on almost any other cargo type.
For reference: E-AndEx handles class 2 through class 9 across ocean, air and rail, with UN packaging certification, IMO and IATA documentation and port approvals handled in-house rather than subcontracted, filed through our own AEO-Advanced customs brokerages.
Four things, and we can tell you whether your cargo moves, how, and at what cost — usually within a working day.
**The safety data sheet**, which gives us the UN number, proper shipping name, class and packing group in one document.
**The quantity and packaging** you intend to ship, since limits are frequently quantity-dependent.
**Origin and destination**, because acceptance varies by port and by receiving country.
**Your target date**, so we can tell you honestly whether DG lead times allow it.
If your product turns out not to be regulated, we will tell you that too — it happens more often than you would expect, and it saves you a surcharge you did not need to pay.
Class 1 explosives, 2 gases, 3 flammable liquids, 4 flammable solids, 5 oxidising substances and organic peroxides, 6 toxic and infectious substances, 7 radioactive material, 8 corrosives, and 9 miscellaneous — which includes lithium batteries, magnetised material and dry ice. Several classes subdivide, and the subdivision often matters more than the class number.
You need a safety data sheet for any potentially regulated product, and Section 14 of it is the test — if it shows a UN number, your cargo is regulated for transport. Your supplier should be able to provide it; a supplier who cannot is a signal worth noting.
Some classes yes, many no. Air regulations divide goods into forbidden, cargo-aircraft-only, and permitted on both passenger and cargo aircraft within quantity limits. Acceptance also varies by carrier on top of the regulations, so confirm with the specific airline before planning around air.
IMDG is the International Maritime Dangerous Goods Code governing sea transport; IATA Dangerous Goods Regulations govern air. IMDG accepts a considerably wider range of classes and larger quantities. What can fly will almost always sail; the reverse is frequently untrue.
A formal legal document declaring to the carrier that a shipment contains dangerous goods, stating the classification, packaging and quantity. The shipper is responsible for its accuracy regardless of who physically prepares it.
A test summary demonstrating that lithium cells or batteries have passed the prescribed transport safety tests. It is required for lithium battery shipments and should come from the cell manufacturer. Without it, most carriers will not accept the cargo.
More than general cargo, through a DG surcharge varying by class and mode, UN-certified packaging, documentation fees, and segregated handling charges. Air carries the steepest premium because restrictions are tightest and capacity narrowest. Correct classification and consolidating shipments reduce the total more than rate negotiation does.
Substantial carrier penalties, potential discharge or destruction of the cargo at your cost, likely refusal of any insurance claim, and liability exposure that is not capped at the value of your goods. It also affects your compliance standing with customs. Most cases arise from shippers not knowing their product was regulated.
