IMDG Code: pack, declare and ship dangerous goods by sea correctly

IMDG groups hazardous goods into 9 classes:

• Class 1: Explosives (1.1–1.6)
• Class 2: Gases (flammable/non-flammable/toxic)
• Class 3: Flammable liquids
• Class 4: Flammable solids / spontaneously combustible / dangerous when wet
• Class 5: Oxidising / Organic peroxides
• Class 6: Toxic / Infectious
• Class 7: Radioactive
• Class 8: Corrosive
• Class 9: Miscellaneous (incl. lithium batteries, magnetised material, environmentally hazardous)

Each item has a 4-digit UN number and an official proper shipping name that drive packaging, marking, stowage and segregation rules.

Only UN-tested packaging is allowed. The UN code (e.g. 4G/Y20/S) encodes type, material, design, density and year. Packing groups I (high), II (medium), III (low) drive drop tests and stack pressure.

Each package shows UN number, proper shipping name, hazard labels (10×10 cm), orientation arrows, marine pollutant mark where relevant, and sender/consignee. Containers carry placards (25×25 cm) and UN tablet.

Document set:

• MDGD: Shipper declaration signed by trained personnel.
• CTU Packing Certificate: Proof of correct stowage/securing.
• SDS: Manufacturer safety data sheet.
• EmS: IMDG emergency schedules (fire, spill).

Liability is layered across shipper, packer, forwarder, carrier. Fines range EUR 2,000–250,000 (EU), substantially higher in the US.

Stowage categories A–E define deck vs. under-deck, passenger ships and marine-pollutant rules. Segregation table (7.2.4) defines spacing: "away from", "separated from", "separated by a complete compartment or hold", "separated longitudinally". Strictest rule wins.

Top 5 causes of IMDG rejections:

1. Misclassified lithium batteries
2. Wrong packing for the group
3. Missing marine pollutant mark
4. Undeclared hidden DG (perfumes, aerosols, batteries in e-com)
5. MDGD signed by unauthorised person