- Start 10-15 working days before sailing – classification and 危包证 lead times drive the whole timeline.
- DGD must be filed before the carrier DG cut-off and the MSA 48-hour window; single-document errors cause the most rejections.
- Surcharges are indicative: DG fees add an indicative USD 1,000-5,000+ per container (confirm at booking), varying by class and lane.
In this guide
This page answers a single question: how to ship dangerous goods from China by sea in 2026 – and what you must get right to avoid port rejection, customs holds, or penalty fines.
If you are a B2B buyer sourcing chemicals, lithium batteries, or new-energy vehicles from Chinese suppliers, the shipping process for dangerous goods is not optional detail. It is the difference between cargo arriving on time and cargo sitting at the terminal while you pay demurrage. The rules changed on January 1, 2026. The IMDG Code Amendment 42-24 is now mandatory. [source: imo.org] [source: imo.org] That means new UN numbers for battery-powered vehicles, updated documentation requirements, and stricter port checks across major Chinese hubs.
Here is what this guide covers: the step-by-step export workflow from classification to vessel loading, the mandatory documents you cannot ship without (MSDS, DGD, UN certification), and the most common reasons shipments get rejected at the port – plus what the additional costs actually look like in 2026.
Whether you are shipping by sea for the first time or you have been exporting dangerous goods for years, the 2026 regulatory shift affects every shipment. Do not rely on 2025 procedures. The carriers are enforcing the new rules, and the ports are checking.
This guide is built for procurement and logistics professionals who need a practical, compliance-first walkthrough. We reference the IMDG Code, Chinese customs regulations, and carrier surcharge notices – not opinions.
Let us walk through the entire export cycle, starting with the foundational question every shipper must answer before booking a single container.
Step 1: Classification – Getting the UN Number, Hazard Class, and Packing Group Right
Before you can book a vessel, before you can prepare a dangerous goods shipping declaration, you must classify your product correctly. This is the single most important step in the entire how to ship dangerous goods workflow.
Classification determines everything: which documents you need, which packaging is permitted, which vessels will accept your cargo, which ports can handle it, and what the freight rate and surcharges will be. A wrong UN number invalidates your entire dangerous goods shipping declaration and will almost certainly lead to rejection at booking or at the terminal gate.
The Classification Framework
All dangerous goods shipped by sea are classified under the International Maritime Dangerous Goods (IMDG) Code. The IMDG Code is updated every two years, and the current mandatory version is Amendment 42-24, effective January 1, 2026. [source: imo.org] [source: imo.org]
The classification process has three core outputs:
- UN Number – a four-digit identifier assigned to each hazardous substance or article (e.g., UN 1203 for gasoline, UN 3480 for lithium-ion batteries).
- Hazard Class – one of nine classes ranging from explosives (Class 1) to miscellaneous dangerous goods (Class 9).
- Packing Group – a roman numeral (I, II, or III) indicating the degree of danger. Packing Group I is the most dangerous, Packing Group III the least.
What Changed in 2026 – and Why It Matters for Your Shipment
Amendment 42-24 added 11 new dangerous goods entries and revised 58 existing entries. [source: imo.org] The most significant changes for B2B buyers sourcing from China affect:
- Lithium-ion battery-powered vehicles – previously shipped under UN 3171. From January 1, 2026, they must use new dedicated UN numbers: UN 3556 (lithium-ion battery-powered vehicles), UN 3557 (lithium metal battery-powered vehicles), and UN 3558 (sodium-ion battery-powered vehicles). Shipping documentation that still shows UN 3171 for an e-bike or electric vehicle is now incorrect and will be rejected.
- Sodium-ion batteries – now have their own UN numbers: UN 3551 (sodium-ion batteries with organic electrolyte) and UN 3552 (sodium-ion batteries contained in equipment).
- Carbon (UN 1361) – the previous exemption (SP925) has been removed. Shipments must now include the date of production, date of packing, and temperature of the material on the day of packing on the transport document.
How to Classify Your Product
For most products, classification requires a hazard classification report issued by a customs-recognised third-party laboratory. This report will specify the UN number, hazard class, packing group, and proper shipping name.
In practice, the workflow looks like this:
- Obtain the Safety Data Sheet (SDS/MSDS) from your supplier. The SDS must include Section 14 ("Transport Information") and must reference IMDG Code Amendment 42-24. [source: imo.org] [source: imo.org]
- Engage a qualified testing laboratory or classification specialist to issue a dangerous goods classification report (危险特性分类鉴别报告).
- Cross-reference the classification against the IMDG Code Dangerous Goods List (Chapter 3.2) to confirm the UN number, proper shipping name, hazard class, and packing group.
- If your product is a chemical newly added to China's Catalogue of Hazardous Chemicals (as of April 2026, five new chemicals were added: 3-chloropropyne, 2-iodosylbenzoic acid, 2-diazoacetoacetic acid p-nitrobenzyl ester, mesyl azide, and 2-nitro-3-methylbenzoic acid), you must also complete the mandatory import/export inspection procedures.
The Cost of Getting It Wrong
Misclassification is not a minor paperwork issue. In 2026, major Chinese ports are conducting enhanced dangerous goods declaration compliance checks, and a significant volume of cargo is being rejected due to incorrect UN numbers, mismatched documentation, or improper packaging. Rejection at the terminal gate typically involves re-inspection fees, re-documentation costs, demurrage, and missed vessel cutoffs.
Practical takeaway: If you are sourcing products that may be classified as dangerous goods, request the SDS and classification report from your supplier before you place the purchase order. Do not wait until the cargo is ready to ship. Classification can take 5-10 business days, and you cannot book a vessel without it.
Step 2: The Export Workflow – A Step-by-Step Dangerous Goods Checklist
| Step | Action | Timeline | Key Documents |
|---|---|---|---|
| 1 | Confirm classification and obtain UN number, hazard class, packing group | Before booking | SDS/MSDS, classification report |
| 2 | Secure UN-certified packaging and obtain packaging performance test certificate | 10-15 days before shipment | Packaging performance test result (出境货物运输包装性能检验结果单) |
| 3 | Apply for the dangerous goods packaging use certificate (危包证) | After packaging is ready | Packaging use certificate (出境危险货物运输包装使用鉴定结果单) |
| 4 | Submit booking request to carrier with MSDS and classification documents | 7-10 days before shipment | Booking request, MSDS, classification report |
| 5 | Carrier approves DG space and confirms stowage and segregation requirements | 3-7 days before shipment | Booking confirmation |
| 6 | Prepare and submit the dangerous goods shipping declaration (DGD) | Before the DG booking cutoff | DGD, MSDS, packaging use certificate |
| 7 | Complete maritime declaration to the China Maritime Safety Administration | At least 48 hours before vessel departure | DG declaration, packaging use certificate, packing certificate |
| 8 | Submit export customs declaration via China's "Single Window" system | Before vessel cutoff | Commercial invoice, packing list, B/L, classification report, MSDS, DG declaration |
| 9 | Customs inspection (if selected) – high probability for DG shipments | During customs clearance | All documents must match physical cargo |
| 10 | Container stuffing, labeling, and placarding | Before terminal cut-off | Packing certificate, container packing certificate |
| 11 | Vessel loading – some DG classes require direct loading at the vessel side (船边直装) | On departure day | Final shipping documents |
Once you have confirmed the classification, the operational workflow begins. This section provides a practical dangerous goods checklist for the entire export process, from documentation preparation to vessel loading.
The timeline is tighter for dangerous goods than for general cargo. Most freight forwarders recommend starting preparations at least 10 to 15 working days before the planned vessel departure.
The Step-by-Step Workflow
Step Details: What Each Stage Actually Involves
Step 1–3: Pre-booking documentation. Before you can even ask a carrier for a rate, you need the classification report and the packaging use certificate. The packaging use certificate (危包证) is issued by the local customs authority after inspecting the packaging that will be used for your shipment. Without this certificate, you cannot complete the maritime declaration.
Step 4–5: Booking. Dangerous goods bookings are not automatic. The carrier's DG team must review the MSDS and classification documents to confirm whether they will accept the cargo and, if so, what stowage and segregation requirements apply. Some carriers restrict certain hazard classes on specific vessels or routes.
Step 6: Dangerous goods shipping declaration. The dangerous goods shipping declaration (also called the Shipper's Declaration for Dangerous Goods or DGD) is the core document for the entire shipment. It must include:
- Shipper and consignee full names and addresses
- UN number
- Hazard class and subsidiary risk (if any)
- Packing group
- Proper shipping name
- Total quantity of dangerous goods (net and gross weight)
- Number and type of packages
- Emergency contact information
- Signed and stamped certification by the shipper
The DGD must be submitted before the DG booking cutoff deadline stated in the booking confirmation. Many carriers now require final DGD submission 3 days prior to the vessel's ETD (estimated time of departure).
Step 7: Maritime declaration. In China, the maritime declaration is submitted to the local Maritime Safety Administration (MSA). This must be completed at least 48 hours before the vessel departs. [source: msasafety.cn] If you miss this window, your cargo will not be loaded – there is no exception for dangerous goods.
Step 8–9: Customs declaration. Export customs declaration for dangerous goods is submitted through China's "Single Window" system. In April 2026, the General Administration of Customs issued Announcement No. 40 of 2026, adding new declaration fields for "prohibited and restricted goods control identification code" and "prohibited and restricted goods control declaration elements" for dual-use items. If your product falls under dual-use item controls, you must complete these additional fields.
Step 10–11: Stuffing, labeling, and loading. Dangerous goods containers must be stuffed by a certified packer, and a container packing certificate must be issued. The container must display 25cm × 25cm dangerous goods placards and 30cm × 12cm UN numbers on all four sides. For certain hazard classes, the container must be loaded directly at the vessel side (船边直装) rather than being stored in the terminal yard.
Critical Timeline Rule
The entire process from classification to loading takes 10 to 15 working days in practice. If your supplier tells you they can ship dangerous goods in 5 days, that is almost certainly not possible unless all documentation is already prepared and approved.
Practical takeaway: Use this dangerous goods checklist as your project timeline. Start the classification and packaging certification process before you finalize the purchase order. Do not wait until the cargo is ready to begin the compliance process.
Step 3: Required Documents – MSDS, DGD, UN Certification, and More
| Document | Purpose | Who Prepares | Key Requirement |
|---|---|---|---|
| Safety Data Sheet (SDS/MSDS) | Describes the product's hazards, handling, and emergency response | Supplier or manufacturer | Must include Section 14 with IMDG Code 42-24 reference; Chinese and English versions required |
| Dangerous Goods Declaration (DGD) | Shipper's certified statement that goods are properly classified, packaged, labeled, and documented | Shipper or forwarder | Must be signed and stamped; includes UN number, class, packing group, proper shipping name, quantities |
| Classification Report | Confirms UN number, hazard class, and packing group | Customs-approved testing lab | Required for customs declaration |
| Packaging Use Certificate (危包证) | Certifies that the packaging used is approved for the specific dangerous goods | Local customs authority | Required for maritime declaration |
| Packaging Performance Test Certificate | Certifies that the packaging itself meets UN performance standards | Packaging manufacturer | Required before the packaging use certificate can be issued |
| Container Packing Certificate | Certifies that the container has been properly stuffed and secured | Certified packer | Required for vessel loading; many ports and carriers mandate this |
| Commercial Invoice & Packing List | Standard trade documents | Exporter | Must match all DG declaration details |
| Bill of Lading (B/L) | Transport contract and cargo receipt | Carrier | Must include DG notation |
Documentation failure is the single most common cause of compliance problems in dangerous goods transport. Even a small mistake – a missing detail, an incorrect sequence, an unsigned declaration – can delay an entire shipment or trigger penalties.
This section covers the mandatory documents for shipping dangerous goods by sea, plus the most common errors that cause rejection.
The Core Document Set
Deep Dive: The MSDS
The Safety Data Sheet is the foundational document for any dangerous goods shipment. Under Chinese regulations, the MSDS must be provided in both Chinese and English. It must include 16 sections covering composition, hazards, first aid, firefighting, accidental release, handling, exposure controls, physical properties, stability, toxicology, ecological information, disposal, transport, regulatory information, and other details.
For 2026 shipments, the MSDS must reference IMDG Code Amendment 42-24 in Section 14 (Transport Information). [source: imo.org] [source: imo.org] An MSDS that still references the previous version (41-22) is out of date and may cause your shipment to be rejected.
Deep Dive: The Dangerous Goods Declaration (DGD)
The dangerous goods shipping declaration is the shipper's legal certification. It is not optional, and it cannot be incomplete.
A complete DGD must include:
- Shipper name and address
- Consignee name and address
- UN number
- Proper shipping name (must match the IMDG Code Dangerous Goods List exactly)
- Hazard class (and subsidiary risk, if applicable)
- Packing group
- Number of packages (inner and outer)
- Net weight and gross weight
- Packaging type
- Emergency contact (24-hour number for a person who can provide technical information in an emergency)
- Certified signature of the shipper
The most common DGD errors according to carrier data:
- No shipping paper at all – shipments cannot legally move without it.
- Incorrect proper shipping name – using a generic name instead of the exact IMDG Code name.
- Mixing DG and non-DG entries without clear separation – dangerous goods may be overlooked during handling.
- Wrong sequence of information – even when all details are present, the wrong order breaks compliance.
- Missing emergency response number – responders lose critical time if no contact is available.
- Missing technical name – regulators require the exact chemical or technical name.
- Missing total quantity – impossible to assess risk or verify packaging compliance.
- Missing signature or certification – unsigned declarations lead to immediate rejection.
- Missing packing group – handlers cannot apply the right safety precautions.
Deep Dive: UN Certification for Packaging
All packaging used for dangerous goods must be UN-certified. The certification is indicated by a UN marking on the packaging itself, which includes:
- The UN symbol
- The packaging code (e.g., 4G for fiberboard box, 1A1 for steel drum)
- The packing group for which the packaging is approved (X = PG I, Y = PG II, Z = PG III)
- The maximum gross mass or hydraulic pressure
- The year of manufacture
- The country of manufacture
- The manufacturer's code
If your packaging does not carry a valid UN mark, your shipment will be rejected. The packaging use certificate (危包证) is the official customs document that confirms your packaging meets these standards.
The 2026 Documentation Update
Two specific documentation changes took effect on January 1, 2026:
- Carbon (UN 1361) shipments must now include the date of production, date of packing, and temperature of the material on the day of packing on the transport document.
- Lithium and sodium-ion battery-powered vehicles must use the new UN numbers (3556, 3557, 3558) on all documentation – not UN 3171.
Practical takeaway: Before you book any shipment, run through this complete dangerous goods checklist with your supplier and forwarder:
- [ ] SDS/MSDS obtained – Chinese and English versions – Section 14 references IMDG 42-24
- [ ] Classification report issued by a customs-approved lab
- [ ] UN number, proper shipping name, hazard class, and packing group confirmed
- [ ] Packaging performance test certificate obtained
- [ ] Packaging use certificate (危包证) obtained
- [ ] DGD prepared, signed, and stamped – all fields complete and accurate
- [ ] Container packing certificate arranged with a certified packer
- [ ] Labels and placards prepared (25cm × 25cm for placards, 30cm × 12cm for UN numbers)
: Port Rejection, Dangerous Goods Surcharge, and Restricted Classes
Why do dangerous goods shipments get rejected at the port?
Port rejections for dangerous goods happen frequently – and they are almost always preventable. Based on carrier and port authority data, the top reasons are: 1. Improper packaging – packaging that does not meet UN performance standards or is damaged. 2. Incorrect labeling and marking – missing hazard labels, incorrect UN numbers, or non-compliant labels. 3. Incomplete or inaccurate documentation – missing information, incorrect UN numbers, or unsigned declarations. This is the most common cause. 4. Non-compliance with regulations – using outdated IMDG Code references or incorrect classification. 5. Incorrect quantity limits – exceeding the allowed quantity for the packaging or vessel. 6. Improper segregation – incompatible hazard classes packed together or stowed too close. 7. Expired or non-compliant training – the person signing the declaration must be trained and certified. 8. Inadequate emergency response information – missing or incomplete emergency contact details. 9. Damage to packaging – packaging that is damaged during handling or transit. 10. Terminal capacity restrictions – some ports have maximum storage limits for specific hazard classes. In 2026, a significant number of rejections are also being caused by incorrect UN numbers for battery-powered vehicles (still using UN 3171 instead of the new UN 3556/3557/3558) and MSDS documents that do not reference IMDG Amendment 42-24.
What is the dangerous goods surcharge, and how much does it cost?
Dangerous goods shipments typically incur higher freight rates and additional surcharges compared to general cargo. The exact amount depends on the carrier, the route, the hazard class, and current market conditions. In 2026, several carriers have announced specific dangerous goods surcharges: - CMA CGM implemented a dangerous goods surcharge for Middle East and Red Sea destinations – typical USD 300–600 per container for standard DG, higher for high-risk classes – is applied on a case-by-case basis, depending on the origin and route. For shipments from Northern Europe to Jeddah and Port Sudan, the surcharge is USD 5,100 per 20-foot container and USD 5,200 per 40-foot container. For shipments from the U.S. to Jeddah, Port Sudan, and Massawa, the surcharge is USD 5,000 per container effective September 1, 2026. - Maersk applied emergency freight surcharges on Gulf routes, with dangerous cargo rates at USD 3,800 per container for special equipment (reefers, dangerous goods, out-of-gauge). - Hapag-Lloyd announced a Dangerous Goods Premium increase of USD 1,000 per container for all dangerous goods except Classes 1 and 7, effective September 1, 2026. - RCL introduced rate increases for Middle East cargo at USD 2,000 per 20GP container and USD 4,000 per 40HC container for special equipment including dangerous goods. In addition to these carrier-specific surcharges, dangerous goods shipments often incur: - DG documentation fee – for preparing and processing the DGD - DG handling fee – for special handling at the terminal - Maritime declaration fee – for the MSA declaration - DG labeling and placarding fee – for preparing compliant labels - Container packing supervision fee – if a certified packer is required
The bottom line:
Dangerous goods surcharges can add an indicative USD 1,000 to over USD 5,000 per container (confirm at booking) to your freight costs, depending on the route and carrier. Always ask your forwarder for a full breakdown of DG-related charges before booking.
Which dangerous goods classes are restricted or prohibited?
While most dangerous goods can be shipped by sea with proper documentation, some classes and specific items face restrictions: - Class 1 (Explosives) – many carriers and ports restrict or prohibit explosives. Some carriers explicitly exclude Class 1 from their dangerous goods premium policies. - Class 7 (Radioactive materials) – heavily restricted; requires specialized carriers and port approvals. Often excluded from standard dangerous goods surcharge policies. - Flammable gases in reefer containers – many carriers prohibit transporting flammable gases in temperature-controlled containers. - Certain lithium battery types – while lithium batteries are commonly shipped, specific types and configurations may be restricted depending on the state of charge, packaging, and testing documentation.Outdated laboratory test data is a common reason for terminal gate restrictions. Beyond the IMDG Code, China's customs authorities also enforce export controls on dual-use items – goods that can be used for both civilian and military purposes. As of April 2026, exporters must declare "prohibited and restricted goods control identification codes" and "control declaration elements" for certain dual-use items. If your product falls into this category, additional licenses and approvals are required.
How far in advance should I start the dangerous goods shipping process?
For shipping dangerous goods by sea from China, start the process at least 10 to 15 working days before your planned vessel departure. This allows time for: - Classification and testing (if not already completed) - Packaging certification - Carrier booking approval (which can take several days for DG shipments) - Maritime declaration (48-hour minimum) - Customs declaration and potential inspection If your supplier has not previously exported the product as dangerous goods, add extra time for the classification report and packaging certification – these can take 5-10 business days each.
Can I ship dangerous goods as LCL (less than container load)?
Yes, but with significant restrictions. LCL consolidation for dangerous goods is more complex because different hazard classes must be segregated within the same container or across containers. Not all freight forwarders accept DG LCL shipments, and those that do typically restrict which hazard classes they will consolidate. The packaging and labeling requirements are the same as for FCL shipments. Some forwarders specialize in DG LCL consolidation.
What happens if my dangerous goods shipment is rejected at the port?
If your cargo is rejected at the terminal gate or during customs inspection, the consequences typically include: - Missed vessel cutoff – your cargo will not load on the planned vessel. - Demurrage and detention charges – while the container sits at the terminal. - Re-inspection and re-documentation fees. - Storage charges – if the cargo must be moved to a DG-approved warehouse. - Potential fines – if the rejection is due to misdeclaration or non-compliance. In severe cases – such as deliberate misdeclaration of dangerous goods as general cargo – penalties can include confiscation, blacklisting, and legal liability.
Practical takeaway:
The best way to avoid rejection is to complete every item on the dangerous goods checklist before the cargo reaches the terminal. Work with a freight forwarder that specializes in dangerous goods transport services and has direct experience with your product category and destination port. For specific cargo acceptance questions, always confirm with your carrier and forwarder before booking. Carriers may have additional restrictions beyond the IMDG Code requirements.
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Sources and references
All figures verified from public sources; freight rates marked indicative are confirmed at booking.