IMDG Code (International Maritime Dangerous Goods Code)
Last updated: June 14, 2026
- The IMDG Code is the IMO-mandated global standard for shipping dangerous goods by sea
- Covers 9 hazard classes with requirements for packaging, stowage, segregation, and documentation
- Updated every 2 years — compliance with the current edition is mandatory for all DG sea shipments
IMDG Code (International Maritime Dangerous Goods Code) is the IMO-mandated standard for shipping dangerous goods by sea, covering 9 hazard classes with detailed requirements for packaging, stowage, segregation, and documentation. The Code is updated every 2 years, and compliance is mandatory under the SOLAS Convention.
Chinese: 国际海运危险货物规则 (Guójì hǎiyùn wéixiǎn huòwù guīzé)
The 9 IMDG Hazard Classes
Class 1: Explosives. Class 2: Gases (2.1 Flammable, 2.2 Non-flammable, 2.3 Toxic). Class 3: Flammable Liquids. Class 4: Flammable Solids (4.1, 4.2 Spontaneously Combustible, 4.3 Dangerous When Wet). Class 5: Oxidizing Substances and Organic Peroxides. Class 6: Toxic and Infectious Substances. Class 7: Radioactive Material. Class 8: Corrosives. Class 9: Miscellaneous Dangerous Substances (includes lithium batteries and environmentally hazardous substances). Great Hensen handles Classes 2-9.
Practical Example
A Qingdao chemical exporter ships 10 drums of Class 3 flammable liquid (paint solvents) to Jebel Ali. The IMDG Code requires: Class 3 label on each drum, UN-approved packaging, segregation from Class 5.1 oxidizers on the vessel, a Maritime DG Declaration submitted to China MSA 24 hours before loading, an MSDS, and a DG Packaging Certificate. The vessel stowage plan must show the Class 3 cargo is stowed on deck (required for flammable liquids) and segregated from incompatible DG classes.
Related Terms
- IATA DGR — the equivalent standard for DG by air (stricter than IMDG)
- Maritime DG Declaration — required submission under the IMDG Code
- UN3536 — BESS shipping governed by IMDG Special Provision 389
Frequently Asked Questions
What are the 9 IMDG hazard classes?
Class 1: Explosives. Class 2: Gases (2.1, 2.2, 2.3). Class 3: Flammable Liquids. Class 4: Flammable Solids (4.1, 4.2, 4.3). Class 5: Oxidizers and Organic Peroxides. Class 6: Toxic and Infectious Substances. Class 7: Radioactive Material. Class 8: Corrosives. Class 9: Miscellaneous (lithium batteries, environmentally hazardous). See our DG class pages for detailed guides on each class.
How often is the IMDG Code updated?
Updated every 2 years by IMO's Maritime Safety Committee. Amendments are adopted in even-numbered years with a 12-month transition before mandatory compliance. Amendment 42-24 (adopted 2024) becomes mandatory in 2026. Using an outdated IMDG edition can cause cargo rejection at port — our in-house DG compliance team stays current with all amendments.
What's the difference between the IMDG Code and IATA DGR?
IMDG governs DG by sea; IATA DGR governs DG by air. IATA DGR is stricter — fewer hazard classes accepted, smaller quantity limits, more stringent packaging tests. Some IMDG-approved cargo cannot be shipped by air at all. UN3536 BESS is sea-only under IMDG. See our DG freight services for both modes.
Need Logistics Help?
We handle DG Classes 2-9 under full IMDG Code compliance. In-house DG compliance team.
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