Transporting Dangerous Goods by Sea: IMDG Overview – U.S. Training Course

More than 80 percent of the world's traded goods are transported by sea. Cargo vessels routinely carry fuels, chemicals, lithium batteries, compressed gases, paints, pesticides, and other regulated materials. When properly identified, packaged, marked, documented, and handled, these materials can be transported safely. However, errors can lead to fires, explosions, toxic releases, environmental contamination, cargo loss, and serious risks to people and the marine environment.

Sea transportation presents unique challenges because shipments may remain in transit for weeks while exposed to moisture, salt air, vessel movement, vibration, weather, and stacked cargo. Once a vessel leaves port, emergency response options are limited. To help manage these risks, dangerous goods transported internationally by sea are regulated under the International Maritime Dangerous Goods Code, commonly known as the IMDG Code. The IMDG Code is published by the International Maritime Organization, or IMO, and establishes internationally recognized requirements for classifying, packaging, marking, labeling, documenting, stowing, segregating, and transporting dangerous goods in packaged form by sea.

In the United States, the Pipeline and Hazardous Materials Safety Administration, or PHMSA, administers the Hazardous Materials Regulations, commonly called the HMR. Together, the HMR and the IMDG Code establish the requirements for preparing dangerous goods shipments transported by vessel from the United States. Anyone who classifies, packages, marks, labels, documents, packs cargo transport units, loads, stows, segregates, or offers dangerous goods for transportation by sea must understand the requirements applicable to the work they perform.

Safe transportation begins with correctly identifying and classifying the material into one of nine hazard classes, from explosives to radioactive materials and miscellaneous dangerous substances. Before selecting packaging, applying labels, or preparing documents, the shipper must determine whether the material is regulated and identify its correct classification. Proper classification is the shipper's responsibility and must be completed before dangerous goods enter the transportation system.

Once dangerous goods have been properly classified, the next step is to select packaging that is authorized for the material and suitable for transportation by sea. The package must safely contain the material and withstand normal marine transportation conditions. Following this, required markings, labels, and placards help identify the shipment and communicate its hazards throughout transportation. Accurate documentation must then be prepared to communicate essential information about dangerous goods to carriers, vessel personnel, inspectors, and emergency responders. Finally, dangerous goods must be properly stowed and segregated aboard the vessel to keep incompatible dangerous goods separated so they cannot interact if packages leak, become damaged, or are involved in a transportation incident.

This program is available with English and French closed captions.