IMDG Code Guide: Dangerous Goods Shipping from China

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1. What is the IMDG Code

The IMDG (International Maritime Dangerous Goods) Code is the International Maritime Organization's mandatory regulation for the safe transport of dangerous goods by sea. It applies to all parties in the maritime DG transport chain: shippers, freight forwarders, consolidators, carriers, terminal operators, and vessel crews on SOLAS-compliant ships. The Code is updated every two years. Amendment 42-24, the latest edition, became mandatory on January 1, 2026, with a 12-month transitional period during which both 41-22 and 42-24 are accepted, through December 31, 2026.

The IMDG Code is legally binding under SOLAS (Safety of Life at Sea) Chapter VII. Countries that are SOLAS signatories, including China, the EU member states, the United States, Japan, and South Korea, enforce it through national legislation. In China, the Maritime Safety Administration (MSA) is the competent authority for IMDG Code enforcement at all Chinese ports, including Qingdao, Shanghai, Ningbo, Shenzhen, and Tianjin.

The Code covers classification, packaging, marking, labeling, placarding, documentation, stowage, and segregation for every type of dangerous cargo moved by container or breakbulk vessel. If your cargo has a UN number, the IMDG Code defines how it must be shipped. For exporters sending DG cargo from China to overseas buyers, understanding the IMDG Code is not optional: failure to comply results in port rejection, fines, and in serious cases, criminal liability under Chinese maritime law. See our DG freight services page for how we handle IMDG compliance for every shipment.

2. IMDG 42-24 key changes (January 2026)

IMDG Code Amendment 42-24 introduces several changes that directly affect DG shippers from China. The most impactful changes involve sodium-ion batteries, documentation references, and segregation requirements. Shippers who miss these updates will face cargo rejection at Chinese port DG yards.

Sodium-ion batteries: new documentation requirements

Under IMDG 42-24, sodium-ion batteries assigned UN3551 (sodium-ion batteries) and UN3552 (sodium-ion batteries contained in or packed with equipment) now require a full Dangerous Goods Declaration (DGD) and SEA CERT (sea transport condition certificate). Previously, sodium-ion batteries operated under relaxed provisions. The change aligns sodium-ion documentation requirements with those for lithium-ion batteries, reflecting the growing volume of sodium-ion battery exports from Chinese manufacturers. If you export sodium-ion energy storage products from China, your MSDS and DG documentation must now reference IMDG 42-24 specifically.

MSDS Section 14 must reference IMDG Code 42-24

This is the single most common rejection reason at Chinese ports in 2026. MSDS documents that cite IMDG Code 41-22 in Section 14 (Transport Information) are rejected by MSA and port authorities. Shippers must update all MSDS documents to reference "IMDG Code Amendment 42-24" before submitting the Maritime DG Declaration. Our DG freight FAQ covers the full MSDS update checklist for Chinese exporters.

Additional 42-24 changes

• New segregation provisions for carbon materials (UN1361, UN1362). Carbon from animal or vegetable origin now requires segregation from Class 5.1 oxidizing agents.
• Revised stowage requirements for Class 4.3 (dangerous when wet substances). Certain UN entries previously allowed on-deck-only now permit under-deck stowage if mechanical ventilation is continuous.
• Updated UN numbers for battery-powered vehicles. UN3171 (battery-powered vehicles) now includes specific provisions for vehicles with sodium-ion batteries.
• New entries for polymerizing substances. Expanded list of substances requiring temperature control during sea transport to prevent polymerization.

3. DG classes 1-9 overview

The IMDG Code classifies all dangerous goods into 9 classes, some with subdivisions. Each class has distinct packaging group assignments (PG I for high danger, PG II for medium danger, PG III for low danger), stowage categories, and segregation requirements. Understanding your cargo's class is the first step in arranging compliant sea freight from China.

Class	Name	Common Examples from China Exporters	PG
Class 1	Explosives	Fireworks, airbag inflators, detonators	N/A (compatibility groups)
Class 2.1	Flammable Gases	Aerosols, LPG, butane lighters	N/A
Class 2.2	Non-Flammable, Non-Toxic Gases	CO2 fire extinguishers, compressed nitrogen, helium	N/A
Class 2.3	Toxic Gases	Chlorine, ammonia, sulfur dioxide	N/A
Class 3	Flammable Liquids	Paints, adhesives, solvents, ethanol, acetone	PG I/II/III
Class 4.1	Flammable Solids	Sulfur, matches, naphthalene, metal powders	PG II/III
Class 4.2	Spontaneously Combustible	Activated carbon, fish meal, iron oxide (spent)	PG I/II/III
Class 4.3	Dangerous When Wet	Calcium carbide, sodium, zinc powder	PG I/II/III
Class 5.1	Oxidizing Substances	Hydrogen peroxide, ammonium nitrate fertilizer, pool chlorine	PG I/II/III
Class 5.2	Organic Peroxides	MEKP (methyl ethyl ketone peroxide), BPO	N/A
Class 6.1	Toxic Substances	Pesticides, cyanides, arsenic compounds, phenol	PG I/II/III
Class 6.2	Infectious Substances	Medical waste, biological samples, cultures	Category A/B
Class 7	Radioactive Material	Medical isotopes, industrial radiography sources	Category I/II/III
Class 8	Corrosive Substances	Sulfuric acid, sodium hydroxide (caustic soda), battery acid	PG I/II/III
Class 9	Miscellaneous DG	Lithium batteries (UN3480, UN3481, UN3536), environmentally hazardous substances, dry ice, magnetized material	PG II/III

Most common DG classes exported from China

Based on our DG booking data from Qingdao, Shanghai, and Tianjin ports (2024-2026) and statistics from the International Maritime Organization (IMO), the most frequently shipped DG classes from Chinese exporters are:

1. Class 9 (Miscellaneous): Dominated by lithium-ion battery exports -- standalone batteries (UN3480), batteries in equipment (UN3481), BESS container systems (UN3536), and sodium-ion batteries (UN3551/UN3552). Also includes environmentally hazardous substances and magnetized materials. China exported approximately 650 GWh of lithium batteries in 2025, making Class 9 the largest DG export category by volume from Chinese ports.
2. Class 3 (Flammable Liquids): Industrial solvents, paints, coatings, resins, and adhesives. Major export sectors from Shandong, Jiangsu, and Zhejiang chemical industry clusters.
3. Class 8 (Corrosives): Industrial chemicals, cleaning agents, and battery electrolytes. Heavy export volume from China's petrochemical and fine chemical sectors.
4. Class 5.1 (Oxidizers): Pool chemicals, bleaching agents, and industrial oxidizers.

For detailed DG class profiles including specific packing instructions and carrier acceptance policies per class, see our DG Classes directory. For lithium battery and Class 9 expertise, see our UN3536 Energy Storage Logistics Guide.

4. Required DG documentation for sea freight from China

Shipping dangerous goods by sea from China requires a specific set of documents. Missing any one will result in port rejection. Based on our DG freight operations at Qingdao, Shanghai, and Tianjin, here is the standard minimum documentation package for DG sea freight from China:

#	Document	Chinese Name	Issued By	Validity
1	Dangerous Goods Declaration (DGD)	危险货物申报单	Shipper or authorized freight forwarder	Per shipment
2	MSDS (Material Safety Data Sheet)	材料安全技术说明书	Manufacturer or authorized lab	Typically 3 years (must reference IMDG 42-24)
3	DG Packaging Certificate	危险货物包装使用鉴定结果单 (危包证)	Local CIQ (China Inspection & Quarantine)	Per shipment or batch
4	Maritime DG Declaration	海运危险货物申报单	Submitted by freight forwarder to MSA	Per shipment
5	Carrier DG Acceptance Letter	船公司危险品接载确认	Shipping line (MSK, HPL, COSCO, etc.)	Per booking
6	UN38.3 Test Report (lithium batteries only)	UN38.3测试报告	Certified testing lab	Typically permanent for the cell/battery model
7	SEA CERT (sodium-ion batteries, UN3551/UN3552, under 42-24)	海运安全运输条件鉴定书	Certified testing lab	Per battery model

DG Packaging Certificate (危包证): the bottleneck document

The DG Packaging Certificate, known in Chinese as 危包证, is the most frequently problematic document for DG shipments from China. Issued by local CIQ (China Inspection and Quarantine) offices, it certifies that the packaging used for the dangerous goods meets UN performance standards. The certificate is shipment-specific and must match the actual cargo, packaging, and consignee details. Typical processing time is 7-10 working days; we offer expedited service at 3-5 working days through pre-reviewed documentation. For shippers unfamiliar with the process, our DG freight team handles the full documentation chain.

Maritime DG Declaration to MSA

In China, the Maritime DG Declaration (海运危险货物申报单) is submitted electronically through the China Maritime Safety Administration system at least 24 hours before the container enters the port DG yard. For Chinese exporters, the China Single Window (单一窗口) platform integrates electronic export declarations and DG declarations into a single submission. Key deadlines by port: Qingdao requires 3 working days advance filing; Shanghai requires 7 working days; Ningbo requires 3 working days. Shanghai Yangshan terminal requires clearance before port entry; Waigaoqiao terminal allows post-arrival clearance. Customs declaration typically expires after 72 hours if not activated, so timing is critical.

5. DG packaging and marking

IMDG Code Part 4 defines packaging requirements for each dangerous goods entry. All DG packaging must be UN-approved and bear the UN specification marking. The correct packaging depends on your cargo's UN number, packaging group, and the specific packing instruction assigned in the IMDG Code Dangerous Goods List.

UN specification marking explained

Every UN-approved DG package carries a permanent marking in this format, for example:. According to the International Maritime Organization (IMO) IMDG Code Part 6, the UN packaging mark must be permanently embossed or printed and contain the packaging type code, packing group letter, and manufacturer identification.

UN 1A2/Y250/S/26/CN/C110024

This breaks down as: UN (United Nations symbol), 1A2 (steel drum with removable head), Y (PG II/III approved), 250 (maximum gross mass in kg), S (for solids), 26 (year of manufacture 2026), CN (country of manufacture), C110024 (manufacturer's certification number). Packaging intended for PG I (high danger) uses "X" instead of "Y".

Packaging group requirements by hazard level

Packaging Group	Hazard Level	UN Mark Code	Hydrostatic Test	Drop Test Height
PG I	High danger	X	250 kPa (min)	1.8 m
PG II	Medium danger	Y (or X)	100 kPa (min)	1.2 m
PG III	Low danger	Z (or X/Y)	100 kPa (min)	0.8 m

Marking and placarding requirements

• Package-level labels: Each DG package must display the hazard class label (minimum 100x100mm), the UN number, and the proper shipping name. Labels must be on a contrasting background.
• CTU/container placards: Class placards on all four sides of the container. Minimum 250x250mm. UN number on at least two opposing sides.
• Marine pollutant mark: Required if the substance is listed as a marine pollutant in the IMDG Code. The dead-fish-and-dead-tree symbol, applied adjacent to the class label.
• Orientation arrows: Required for liquid DG packages. Two arrows on opposite sides pointing upward.
• Limited quantities and excepted quantities: Use the specific LQ or EQ marks, not full class labels. These provisions simplify documentation and reduce costs, but mixing LQ/EQ cargo with full-DG cargo in the same container requires carrier approval.

6. DG segregation rules

Segregation is the practice of separating different classes of dangerous goods to prevent dangerous reactions if packages leak or are damaged. The IMDG Code segregation table (Chapter 7.2) defines which classes must be kept apart, and by how much.

IMDG segregation table: simplified reference

	1	2	3	4.1	4.2	4.3	5.1	5.2	6.1	8	9
Class 1	*	2	2	2	2	2	2	2	2	2	X
Class 2	2	X	2	1	1	1	2	2	X	1	X
Class 3	2	2	X	2	2	2	2	2	X	1	X
Class 4.1	2	1	2	X	1	1	2	2	X	1	X
Class 4.2	2	1	2	1	X	1	2	2	1	1	X
Class 4.3	2	1	2	1	1	X	2	2	2	2	X
Class 5.1	2	2	2	2	2	2	X	2	1	2	X
Class 5.2	2	2	2	2	2	2	2	X	1	2	X
Class 6.1	2	X	X	X	1	2	1	1	X	X	X
Class 8	2	1	1	1	1	2	2	2	X	X	X
Class 9	X	X	X	X	X	X	X	X	X	X	X

Key: 1 = "Away from" (min 3m horizontally, or in different compartments); 2 = "Separated from" (different compartments, or separated by fire-resistant deck, or min 6m on deck); X = No segregation required (may be stowed together). Class 1 has special compatibility group rules (not shown in this simplified table). Class 7 (Radioactive) always requires dedicated segregation analysis.

Segregation in LCL containers from China

When shipping DG cargo in LCL (less than container load) from China, segregation is critical because multiple DG consignments from different shippers may share one container. Not all DG classes can co-load in the same container. The LCL shipping service requires a DG compatibility check before consolidation. Our Qingdao CFS (container freight station) maintains a segregation matrix for every LCL booking. General rules: Class 3 and Class 8 can usually co-load; Class 4.3 cannot share a container with any other class; Class 5.2 requires temperature control and cannot co-load; Class 9 generally can co-load with compatible classes.

7. DG shipping from Chinese ports

Each major Chinese port has its own DG handling procedures, MSA filing deadlines, and terminal-level acceptance rules. The port you choose affects documentation timelines, carrier availability, and total logistics cost. Here is what shippers need to know for DG exports from China's primary container ports.

Port	MSA Filing Deadline	DG Yard	SOC Container	Overweight DG (>30t)	Best For
Qingdao	3 working days	DG yard at Qianwan Container Terminal	Accepted, no extra fees	Crane capacity verification required	Northern China manufacturers, Great Hensen's home port with fastest DG handling
Shanghai	7 working days	DG zone at Waigaoqiao and Yangshan	Accepted, terminal surcharge	Yangshan deep-water only for >30t	Widest carrier selection, highest sailing frequency
Ningbo	3 working days	DG acceptance at Chuanshan terminal	Accepted, inspection required	3-day advance notice	Zhejiang/Jiangsu manufacturers
Tianjin	3 working days	DG yard at Beijiang terminal	Case-by-case	3-day advance notice	Beijing-Tianjin-Hebei industrial region
Shenzhen (Yantian)	3 working days	DG zone at Yantian terminal 9	Case-by-case approval	3-day notice + terminal bearing test	South China, SE Asia/Americas routes

DG booking: FCL vs LCL from China

DG cargo can be shipped as FCL (full container load) or LCL (less than container load) from Chinese ports, but LCL has additional restrictions. For LCL, the DG cargo is consolidated with other compatible consignments at our CFS (container freight station) near the port. The sweet spot for DG LCL is 1-10 CBM. Above 15 CBM, a dedicated 20ft FCL container becomes more cost-effective. FCL typical costs from China to US West Coast range from $2,500-5,000 in low season and $6,000-12,000 in peak season (Aug-Oct). For DG LCL, rates from China to US West Coast run $80-160 per CBM and $100-180 per CBM to US East Coast. For rates to UK/Europe, LCL sea freight runs $70-150 per CBM. All rates are approximate for 2026 Q1-Q2; DG surcharges ($150-400 per container depending on class) are additional.

Export declaration process for DG from China

Chinese customs export declarations for DG cargo follow a specific workflow. The China Single Window (单一窗口) platform handles electronic export declarations. For DG cargo, the declaration must reference the Maritime DG Declaration approval number from MSA. Shanghai Yangshan terminal requires customs clearance before the container enters the port; Waigaoqiao terminal allows post-arrival clearance within 72 hours. Customs declarations typically expire after 72 hours if not activated. For exporters unfamiliar with Chinese export procedures, we handle all customs filing as part of our DG freight service.

8. IMDG vs IATA DGR vs ADR/RID

Dangerous goods regulations differ significantly by transport mode. The IMDG Code governs sea transport, IATA DGR governs air transport, and ADR governs European road transport (RID for rail). While all three share the same UN number system and hazard classification framework, the practical differences in packaging, documentation, quantity limits, and carrier acceptance are substantial. Choosing the wrong mode or combining modes without checking compatibility is a common cause of shipment failure.

Factor	IMDG Code (Sea)	IATA DGR (Air)	ADR/RID (Europe Road/Rail)
Governing body	IMO (International Maritime Organization)	IATA (International Air Transport Association) / ICAO	UNECE (ADR) / OTIF (RID)
Update cycle	Every 2 years (42-24 current)	Annual (2026 edition)	Every 2 years (2025 edition current)
Packaging	UN-spec packaging, PG-based; allows larger packaging than air	UN-spec packaging + stricter quantity limits per package; many PG I items prohibited	UN-spec packaging; vehicle placarding required (orange plates)
Documentation	DGD, MSDS, DG Packaging Certificate	Shipper's Declaration for Dangerous Goods (SDDG); requires IATA-trained signatory	Transport document with DG details + driver DG training certificate (ADR card)
Quantity limits	Case-by-case; generally higher limits than air	Strict per-package limits; many substances banned entirely on passenger aircraft	Per-vehicle limits apply (e.g., 1,000 points threshold for ADR exemptions)
Training	IMDG Code training (Section 1.3), valid for 2 years	IATA DGR training, valid for 24 months	ADR driver training certificate, valid for 5 years
Segregation	IMDG segregation table; space-based	No co-loading of incompatible DG in same aircraft hold; stricter than sea	ADR segregation table; similar to IMDG but with vehicle-specific rules
Typical transit	28-38 days China to US West Coast; 35-45 days to US East Coast; 30-40 days to UK/Europe	3-7 days door-to-door	3-10 days within Europe depending on distance

Mode selection: sea, air, or road/rail for DG cargo from China

For Chinese exporters shipping DG cargo internationally, the mode choice depends on cargo class, urgency, and destination. According to IATA Dangerous Goods Regulations, air freight acceptance of DG cargo is significantly more restricted than sea freight, with lithium batteries subject to the most stringent limits:

• Sea freight (IMDG Code) is the default for most DG cargo from China. It handles all 9 classes, allows the largest quantities, and has the lowest per-kg cost. Transit times are longer: 28-38 days to US West Coast, 35-45 days to US East Coast, and 30-40 days to UK/Europe with 3-7 additional days for LCL consolidation at both ends. For FCL or LCL DG shipping options, see our LCL sea freight and DG freight services.
• Air freight (IATA DGR) is used when speed outweighs cost. Some DG classes are prohibited on passenger aircraft entirely (many Class 1, 4.2, 5.2 items). Cargo-only aircraft (CAO) accept a wider range but at significantly higher freight rates. Typical DG air freight cost is 5-10x sea freight cost per kg.
• China-Europe rail (CRE/中欧班列) and road (ADR) is a developing option. The Xi'an to Duisburg China-Europe Railway Express runs 4 westbound trains per week, with the fastest rail transit at 12 days and standard at 17-20 days. However, most CRE operators restrict DG acceptance because the train crosses multiple jurisdictions (China, Kazakhstan, Russia, Belarus, EU), each with different DG regulations. The Middle Corridor offers an alternative routing for DG cargo avoiding Russia. Currently, CRE-DG is available case-by-case only; sea freight remains the standard for DG cargo from China.

EU-specific DG requirements for imports from China

When DG cargo arrives at European ports (Rotterdam, Hamburg, Antwerp), additional EU regulations apply beyond the IMDG Code. According to the International Maritime Organization (IMO), EU member states may impose additional national requirements beyond the IMDG Code, and importers should verify destination port DG acceptance policies before booking:

• ENS (Entry Summary Declaration) filing is mandatory. Late filing incurs a penalty of EUR 2,500 under 2026 EU customs rules, increased from EUR 1,000 in previous years. The ENS must be lodged before the vessel departs the last non-EU port.
• CBAM (Carbon Border Adjustment Mechanism) reporting is required for steel, aluminum, and cement imports to the EU from 2026. If your DG shipment contains steel packaging (drums, IBC frames) or aluminum components, CBAM reporting may apply.
• EU CLP Regulation (EC No. 1272/2008) applies to classification, labeling, and packaging of substances once they enter the EU market. Chinese MSDS documents often need to be supplemented with EU-format SDS (16-section REACH-compliant format) for customs clearance.

9. Frequently asked questions

Sources and references

• IMDG Code Amendment 42-24: IMO International Maritime Dangerous Goods Code, mandatory from January 1, 2026. IMO IMDG Code
• Sodium-ion batteries under IMDG 42-24: UN3551, UN3552 now require DGD and SEA CERT, per IMO DSC Sub-Committee decisions incorporated into 42-24.
• SOLAS Chapter VII: International Convention for the Safety of Life at Sea, Part A, Chapter VII (Carriage of Dangerous Goods). IMO SOLAS
• China MSA Maritime DG Declaration: Maritime Safety Administration of the People's Republic of China, DG declaration procedures per port. China MSA
• China Single Window (单一窗口): National electronic platform for customs and port declarations. China Single Window
• EU ENS (Entry Summary Declaration): EU Regulation (EU) 2015/2447 and amendments. Late filing penalty increased to EUR 2,500 under 2026 provisions.
• EU CBAM (Carbon Border Adjustment Mechanism): Regulation (EU) 2023/956, reporting obligations for steel, aluminum, cement imports from 2026. EU CBAM
• UFLPA (Uyghur Forced Labor Prevention Act): US CBP enforcement, requires supply chain documentation for goods entering the US. US CBP UFLPA
• Incoterms 2020: International Chamber of Commerce (ICC) rules for the use of domestic and international trade terms. FOB is the most common Incoterm offered by Chinese suppliers. ICC Incoterms
• FCL/LCL rates and transit times: Great Hensen operational data for 2026 Q1-Q2, verified against carrier rate sheets and booking records. Transit times: China to US West Coast 28-38 days, US East Coast 35-45 days, UK/Europe 30-40 days.

Operational data from Great Hensen DG Logistics operations at Qingdao, Shanghai, and Tianjin ports 2016-2026. All regulatory references verified July 11, 2026.