What are dangerous goods (DG) in shipping?
The UN Recommendations on the Transport of Dangerous Goods sort them into 9 hazard classes, from explosives (class 1) to miscellaneous dangerous goods (class 9), and give each substance or article a four-digit UN number. Each mode applies its own rules on top: the IMDG Code for sea, the IATA Dangerous Goods Regulations for air and ADR for road transport in Europe. These rules govern packaging, marking, labeling, quantity limits, segregation and documents.
Dangerous goods are often equated with “hazmat”, the US regulatory term for hazardous materials; the rules overlap but are not identical. A product may be regulated in one mode and not in another, or allowed only on cargo aircraft. Everyday goods such as perfume, paints, aerosols, dry ice and devices with lithium batteries are regulated too, and undeclared dangerous goods are a known cause of fires on container ships.
The shipper is responsible for classifying, packing and labeling the goods and for signing the dangerous goods declaration, supported by a safety data sheet. Carriers must approve each DG booking in advance, may refuse certain classes or ports, and often add a surcharge and an earlier cut-off. Staff who prepare DG shipments need mode-specific training, so confirm the carrier's acceptance for the class and route before quoting.