The nine UN hazard classes, packing groups and how to read a dangerous goods specification — with the rules for sea, road, rail and air.
Every dangerous substance is assigned to one class by its main hazard; many classes are split into divisions. The class decides the label on the package, which goods may travel together and which routes accept it.
Substances and articles that can explode, burn rapidly or throw fragments. The letter after the division (e.g. 1.4G) is the compatibility group, which decides what may be loaded together.
Examples: Fireworks, ammunition, signal flares, detonators
Compressed, liquefied, dissolved or refrigerated gases — in cylinders, tanks, aerosols and small cartridges.
Examples: Propane, aerosols, fire extinguishers, nitrogen, chlorine
Liquids with a flash point of 60 °C or lower. The flash point also sets the packing group, so it belongs on every booking.
Examples: Paints, solvents, adhesives, perfumes, fuels, alcohol
Solids that ignite easily, heat up and catch fire on their own, or give off flammable gas in contact with water.
Examples: Matches, sulphur, charcoal, calcium carbide, metal powders
Substances that give off oxygen and feed a fire. Many organic peroxides must also travel temperature-controlled.
Examples: Ammonium nitrate fertilisers, hydrogen peroxide, pool chlorine, hardeners for resins
Substances that can cause death or serious harm if swallowed, inhaled or absorbed through the skin, and materials that carry pathogens.
Examples: Pesticides, cyanides, some dyes, medical samples, clinical waste
Material that emits ionising radiation. It needs special packages, transport index and often permits from the authorities of every country on the route — plan extra lead time.
Examples: Medical isotopes, industrial gauges, uranium ore concentrate
Substances that destroy skin or eat through metal. Often carry a subsidiary hazard, such as flammable or toxic.
Examples: Acids, caustic soda, wet-cell batteries, some cleaning agents
Everything that is dangerous in transport but fits no other class — the most common class in everyday shipping.
Examples: Lithium batteries, dry ice, environmentally hazardous substances, vehicles and engines
Within a class, the packing group shows how dangerous the substance is — and with it the packaging strength and the quantities allowed.
Strictest packaging (marked X) and the smallest quantities per package. Often restricted or forbidden on passenger aircraft.
Packaging marked X or Y. Most paints, solvents and fuels fall here.
Packaging marked X, Y or Z. Fewer restrictions, and small inner packages can often go as limited quantity.
This is how a dangerous good is described on the declaration and the booking. Section 14 of the safety data sheet (SDS) gives each part.
UN1263, PAINT, 3, PG II, (23 °C c.c.), Marine Pollutant
UN1263PAINT3PG II(23 °C c.c.)Marine PollutantThe UN classification is the same everywhere; each mode adds its own rules on top. On multimodal routes all of them apply in turn.
| Sea | IMDG CodeIMO | International Maritime Dangerous Goods Code — packing, labelling, stowage and segregation on board. Adds the container packing certificate and EmS emergency schedules. |
| Road | ADRUNECE | European agreement for road transport — ADR-trained driver, orange plates, equipment in the cab and tunnel restriction codes. |
| Rail | RIDOTIF | Regulations for rail in Europe, aligned with ADR. On 1520 mm rail (CIS, Central Asia, China routes) SMGS Annex 2 applies instead. |
| Air | IATA DGRICAO / IATA | The strictest rules: lower quantities, many goods are cargo-aircraft only, and some are forbidden by air altogether. |
Send these with your enquiry and we will check carrier acceptance, routing and the documents for your cargo.
Dangerous Goods Declaration — what it containsA general overview, not legal advice. Classification is the shipper's responsibility and comes from the SDS; carriers, terminals and countries may add their own restrictions, and the rules are updated every two years.
We arrange dangerous goods shipments in all nine classes — by sea, road, rail and air. Send us the SDS and we'll find a carrier and route that accept your cargo.
Contact usJoin companies using Cargo 4S to manage international logistics through one connected platform and dedicated logistics experts.