IMDG Code

What is the IMDG Code?

The IMDG Code stands for the International Maritime Dangerous Goods Code. It is the international code that sets out the rules for the safe sea transport of dangerous goods.

The IMDG Code covers matters such as classification, packaging, marking, labelling, documentation, stowage, segregation and emergency response for dangerous goods carried by sea.

For shipping lines, forwarders, NVOCCs, shippers, warehouses, CFS operators and customs brokers, the IMDG Code is a key reference when dangerous goods are moved by sea.

For overseas forwarding offices arranging cargo to Japan, the IMDG Code is especially important when checking dangerous goods booking, CFS delivery, container stuffing, LCL consolidation, labels, marks and dangerous goods declarations.

Overview

The IMDG Code provides detailed transport requirements for dangerous goods in sea transport. It helps identify how each cargo should be classified, packed, marked, labelled, documented, stowed and segregated.

Dangerous goods cannot be handled in the same way as ordinary cargo. Depending on the nature of the cargo, forwarders may need to check declaration requirements, packaging, marks, labels, segregation from other cargo, and acceptance by the shipping line, CFS or warehouse.

In practical forwarding work, the IMDG Code is used to organize key information such as UN number, proper shipping name, dangerous goods class, subsidiary risk, packing group and marine pollutant status.

Key Points for Forwarders

When handling dangerous goods for sea transport, forwarders should check the following points:

• Whether the cargo is classified as dangerous goods under the IMDG Code
• Whether the UN number is confirmed
• Whether the proper shipping name is confirmed
• Dangerous goods class and any subsidiary risk, meaning a secondary hazard in addition to the primary dangerous goods class
• Whether a packing group applies
• Whether the cargo is a marine pollutant
• Whether a dangerous goods declaration is required
• Whether package labels, marks or container placards are required
• Whether the cargo can be consolidated with other cargo
• Whether segregation requirements apply
• Whether the shipping line, CFS, warehouse and trucking company can accept the cargo

A subsidiary risk may arise, for example, where a product has one primary dangerous goods class but also has an additional hazard, such as flammability, toxicity or corrosiveness. This should be checked together with the main dangerous goods class.

Container placards are large-format hazard labels or signs affixed to the outside of containers. They are different from smaller package labels used on individual packages.

When a shipper says that the cargo is dangerous goods, the forwarder should obtain the SDS and dangerous goods declaration and check the transport classification under the IMDG Code.

This is particularly important for LCL cargo, where compatibility with other cargo and CFS acceptance can become practical bottlenecks.

UN Number and Proper Shipping Name

Under the IMDG Code, dangerous goods are organized mainly by UN number and proper shipping name.

The commercial product name shown on the invoice is not always the correct transport name. Dangerous goods must be declared using the proper shipping name required by the transport rules.

For example, an invoice may describe the cargo as “paint,” “adhesive,” “cleaning agent” or “fragrance.” However, under the IMDG Code, the cargo may need to be declared under a specific proper shipping name.

Forwarders should therefore not rely only on the invoice description. They should check the transport information section of the SDS and compare it with the dangerous goods declaration.

Relationship with SDS

The SDS is usually the first document to check when reviewing dangerous goods for sea transport.

The transport information section of the SDS may show the UN number, proper shipping name, dangerous goods class, packing group, marine pollutant status and other transport-related information.

However, the existence of an SDS does not automatically confirm whether the cargo can be shipped. The SDS may be outdated, incomplete, focused on air transport, or missing sea transport information.

If the SDS is unclear, the forwarder should ask the shipper or manufacturer for the latest SDS, dangerous goods classification document, or a statement of non-dangerous goods where applicable.

Relationship with the Dangerous Goods Declaration

For sea transport of dangerous goods, the dangerous goods declaration is an important document.

It normally includes information such as UN number, proper shipping name, dangerous goods class, subsidiary risk where applicable, packing group, quantity, package type, marine pollutant status and emergency contact details.

Forwarders should check whether the dangerous goods declaration is consistent with the SDS, invoice, packing list, product label and outer package markings.

If the information does not match, acceptance by the shipping line, CFS or warehouse may be delayed or refused.

Stowage and Segregation

Stowage and segregation are important parts of the IMDG Code. Dangerous goods with different hazards may create additional risks if they are placed together or stored too closely.

For example, oxidizers and flammable materials, corrosive substances and metal products, or toxic substances and food-related cargo may require careful handling or separation depending on the class, quantity, packaging and applicable segregation requirements.

For LCL cargo, forwarders should confirm with the CFS, consolidator or shipping line whether the cargo can be consolidated with other cargo.

Even if a cargo can be shipped as dangerous goods, it may not be acceptable for a particular LCL consolidation plan.

Marine Pollutants

Some dangerous goods are also classified as marine pollutants. If the cargo is a marine pollutant, additional marking or declaration requirements may apply.

Forwarders should check the SDS and dangerous goods declaration to confirm whether the cargo is a marine pollutant.

If this information is missed, the shipment may be treated as having incorrect marks, labels or declaration details.

Booking Issues

Dangerous goods bookings should be checked earlier than ordinary cargo bookings. The shipping line may need time to review the dangerous goods details before accepting the booking.

At the booking stage, forwarders should prepare or confirm the following information:

• UN number
• Proper shipping name
• Dangerous goods class and subsidiary risk, where applicable
• Packing group
• Quantity and package type
• SDS
• Dangerous goods declaration
• Marine pollutant status
• Required package labels, marks and container placards
• CFS, warehouse and trucking acceptance conditions

Even if the shipping line can carry the cargo, the warehouse or CFS may not be able to accept it. Acceptance may also differ depending on the route, vessel, port of loading, port of discharge or transshipment port.

Common Problems

• The dangerous goods declaration is submitted too late for shipping line approval.
• The UN number on the SDS does not match the dangerous goods declaration.
• Package labels or container placards are missing or incorrect.
• The CFS cannot accept the relevant dangerous goods class.
• LCL consolidation is not possible because of segregation requirements.
• Marine pollutant information is omitted.
• The cargo is restricted at a transshipment port.
• The commercial invoice description is too vague to identify the transport classification.

Problems related to the IMDG Code may not be solved by a simple document correction. They can lead to CFS refusal, missed sailing, booking cancellation, repacking, relabelling, additional cost or shipment delay.

Undeclared Dangerous Goods Risk

Undeclared or incorrectly declared dangerous goods are one of the most serious risks in sea transport. They may lead not only to booking problems, but also to vessel fire, cargo damage, injury, pollution or other major accidents.

For this reason, forwarders should treat unclear chemical descriptions, missing SDS information, inconsistent labels or vague shipper explanations as warning signs. The classification should be confirmed before booking, CFS delivery or container stuffing.

Practical Notes for Shipments to Japan

For cargo moving to Japan, overseas forwarders should understand that Japanese importers, customs brokers, warehouses, CFS operators and shipping lines often require conservative document checking for dangerous goods.

Even when the classification appears clear, the practical handling may stop if the SDS, dangerous goods declaration, labels, marks or booking details are inconsistent.

Forwarders should not treat the IMDG Code as a rulebook used only by shipping lines. It affects the entire shipping process, from quotation and booking to CFS delivery, container stuffing, documentation and delivery planning.

Key Point

The IMDG Code is the core international code for dangerous goods transported by sea.

For forwarders, the important point is not to memorize every rule, but to correctly check the SDS, UN number, proper shipping name, dangerous goods class, subsidiary risk, packing group, marine pollutant status, dangerous goods declaration, stowage, segregation and acceptance conditions.

Before arranging shipment to Japan, the forwarder should confirm that the shipping line, CFS, warehouse and other operators can safely accept the cargo under the applicable sea transport requirements.