The International Maritime Dangerous Goods (IMDG) Code is the global rulebook for transporting dangerous goods by sea. It is published by the International Maritime Organization (IMO) and tells shippers how to classify, pack, mark, label, document, and stow hazardous cargo on ocean vessels. As of January 1, 2026, the 2024 Edition incorporating Amendment 42-24 is mandatory, so any ocean shipment of dangerous goods moving through PortMiami or Port Everglades must comply with it.
What the IMDG Code covers
The Code applies to packaged dangerous goods carried on ships and is built around a few core requirements that work together.
Classification
Every dangerous good is assigned to one of the nine hazard classes, given a UN number and proper shipping name, and assigned a packing group where applicable. Correct classification drives every downstream requirement.
Packaging and marking
Goods must be packed in UN-spec packaging suited to the substance, then marked with the UN number and proper shipping name and labeled with the correct hazard class diamonds and any handling marks such as the marine pollutant mark.
Documentation
A Dangerous Goods Declaration and, for containers, a Container Packing Certificate must accompany the shipment. Safety Data Sheets, Section 14, must reference the current amendment.
Segregation and stowage
The Code specifies how incompatible substances must be separated on board and which stowage categories apply, protecting the vessel, crew, and other cargo.
What changed in Amendment 42-24
Amendment 42-24 was adopted by the IMO in May 2024 and brought more than 300 updates. It became voluntary from January 1, 2025 and mandatory from January 1, 2026. Notable changes include new UN numbers and revised handling for electric vehicles and batteries, new requirements for carbon products such as carbon blacks and charcoal that can no longer be exempt, and a new stowage code (SW31) for substances that emit flammable gases on contact with water. A practical consequence: any SDS still referencing the older Amendment 41-22 after January 1, 2026 is considered invalid for shipping.
Why compliance matters at the port
Ocean carriers and terminals reject or hold non-compliant dangerous goods, and corrections at the port often mean a missed sailing plus storage charges. Pairing IMDG expertise with on-the-ground port operations keeps your cargo moving. Go Freight combines in-house hazmat compliance with asset-based PortMiami and Port Everglades drayage and bonded warehousing, so classification, documentation, and container moves are handled by one accountable team. For related reading, see the 9 hazmat classes and what triggers a hazmat repack.
Frequently asked questions
What is the IMDG Code?
The IMDG Code is the International Maritime Dangerous Goods Code, published by the IMO, that sets mandatory rules for classifying, packing, marking, labeling, documenting, and stowing dangerous goods transported by sea.
Which IMDG amendment is mandatory in 2026?
The IMDG Code 2024 Edition incorporating Amendment 42-24 became mandatory on January 1, 2026. It was available on a voluntary basis from January 1, 2025 before becoming compulsory.
What documents are required for IMDG dangerous goods?
Ocean dangerous goods shipments require a Dangerous Goods Declaration and, for packed containers, a Container Packing Certificate, supported by a current Safety Data Sheet whose Section 14 references Amendment 42-24.
Move ocean hazmat with confidence
Go Freight is a Miami-based, asset-based, AI-powered 3PL with in-house dangerous goods expertise for IMDG and IATA shipments. Get a quote at go-freight.ai/quote or call (786) 445-0150.