Dangerous Goods Class

A dangerous goods class is a transport classification used to identify the main hazard of dangerous goods. In international transport, dangerous goods are generally classified from Class 1 to Class 9.

The class is used together with the UN number, proper shipping name, packing group, labels, marks, dangerous goods declaration, stowage requirements, segregation requirements and carrier acceptance conditions.

In forwarding practice, the dangerous goods class is one of the basic pieces of information used by shipping lines, airlines, warehouses, CFS operators, customs brokers and trucking companies to decide whether a cargo can be accepted and under what conditions.

Overview

Dangerous goods classes help transport parties understand the nature of the hazard in a common way. Dangerous goods may involve explosion, flammability, toxicity, corrosiveness, oxidizing properties, radioactivity, environmental hazard or other risks.

By grouping these hazards into Class 1 to Class 9, the transport system can control packaging, labelling, marking, documentation, stowage, segregation and acceptance more consistently.

For sea transport, dangerous goods classes are checked under the IMDG Code. For air transport, they are checked under the IATA Dangerous Goods Regulations and airline acceptance rules.

Forwarders should not treat the dangerous goods class as just a number. It indicates the type of hazard that may affect booking, packing, storage, consolidation, loading and emergency response.

Main Dangerous Goods Classes

• Class 1: Explosives
• Class 2: Gases
• Class 3: Flammable liquids
• Class 4: Flammable solids, substances liable to spontaneous combustion, and substances which emit flammable gases in contact with water
• Class 5: Oxidizing substances and organic peroxides
• Class 6: Toxic substances and infectious substances
• Class 7: Radioactive material
• Class 8: Corrosive substances
• Class 9: Miscellaneous dangerous substances and articles

The class number does not show the degree of danger. A higher class number does not mean that the cargo is more dangerous. For example, Class 3 indicates flammable liquids, Class 8 indicates corrosive substances, and Class 9 covers miscellaneous dangerous substances and articles.

The actual transport risk must be checked by looking at the UN number, proper shipping name, packing group, subsidiary risk, quantity, packaging, transport mode and carrier conditions.

Forwarder Check Points

The dangerous goods class should be checked before quotation, booking, cargo pickup, CFS delivery or warehouse storage.

• Is the dangerous goods class shown in the SDS transport section?
• Does the class in the dangerous goods declaration match the SDS?
• Is the class consistent with the UN number, proper shipping name and packing group?
• Is there any subsidiary risk?
• Are sea transport and air transport requirements different?
• Can the shipping line or airline accept this class?
• Can the warehouse, CFS or trucking company accept this class?
• Are there any consolidation, segregation or stowage restrictions?

If the class is unknown, forwarding arrangements may stop at the booking, carrier approval, warehouse receiving, CFS receiving or document checking stage.

Relationship with UN Number

The dangerous goods class should be checked together with the UN number. A UN number is a four-digit identification number assigned to dangerous goods or articles.

For each UN number, the applicable proper shipping name, dangerous goods class, packing group, labels, packaging rules and other transport requirements are determined under the relevant rules.

Forwarders should not rely only on the UN number or only on the class. The UN number, proper shipping name, class, packing group, quantity, packaging, cargo condition and transport mode should be reviewed together before confirming acceptance with the shipping line, airline, warehouse or CFS.

Subsidiary Risk

Some dangerous goods have a subsidiary risk in addition to the main dangerous goods class. For example, a liquid may be primarily flammable but also toxic or corrosive.

Subsidiary risk may affect labels, documentation, segregation, stowage, warehouse storage and consolidation. It may also influence whether a carrier or warehouse can accept the cargo.

Forwarders should therefore check not only the main class, but also any subsidiary risk shown in the SDS, dangerous goods declaration or transport classification documents.

Sea Transport

In sea transport, dangerous goods classes affect container stowage, segregation, labels, placards, dangerous goods booking approval, CFS receiving and consolidation conditions.

Oxidizing substances, flammable substances, toxic substances and corrosive substances may require special attention because they may be incompatible with other cargo.

For LCL cargo, the forwarder should confirm whether the cargo can be consolidated with other goods in the same container or handled in the same CFS area. The same class may still be treated differently depending on the UN number, quantity, packaging, route, shipping line and destination.

Dangerous goods approval and CFS cut-off times may be earlier than ordinary cargo. The class should therefore be confirmed before cargo delivery to the CFS or CY.

Air Transport

In air transport, the dangerous goods class may affect passenger aircraft acceptance, cargo aircraft only conditions, quantity limits, packaging instructions, labels and declaration requirements.

Air transport is often more restrictive than sea transport. Cargo that can be shipped by sea may be refused by air, or may be accepted only under stricter packaging and quantity conditions.

Special care is needed for lithium batteries, aerosols, paints, adhesives, perfumes, alcohol-containing products, reagents and similar cargo. If the dangerous goods class is not checked at the quotation or booking stage, the cargo may be rejected by the airline or courier company.

Relationship with SDS and Dangerous Goods Declaration

The SDS transport section is one of the first places to check the dangerous goods class. It may also show the UN number, proper shipping name, packing group, marine pollutant status and transport precautions.

The dangerous goods declaration should be consistent with the SDS and actual cargo condition. If the class shown in the SDS and the class shown in the declaration do not match, the forwarder should ask the shipper, manufacturer or dangerous goods specialist to confirm the correct classification.

Forwarders should also check whether the outer package labels and marks match the declared class. A mismatch between documents and physical cargo may cause CFS refusal, airline rejection, carrier questions or shipment delay.

Common Problems

• The dangerous goods class differs between the SDS and the declaration.
• The UN number is known, but the class or packing group has not been confirmed.
• Subsidiary risk is overlooked.
• Sea transport and air transport requirements are confused.
• The warehouse or CFS cannot accept a particular class.
• Segregation requirements are not checked for consolidated cargo.
• Outer package labels do not match the class shown in the documents.
• The class is checked only after the cargo has arrived at the CFS or airline warehouse.

Errors in dangerous goods class may lead to cargo receiving refusal, booking cancellation, shipment delay, air loading rejection, repacking, relabeling, additional cost or liability issues after an incident.

Practical Notes for Shipments to Japan

For Japan-bound cargo, overseas shippers and origin-side forwarders should check the dangerous goods class before cargo pickup or CFS delivery. Japanese-side parties may ask for SDS, dangerous goods declaration, UN number, packing group, labels, packaging details and carrier acceptance information.

The dangerous goods class is especially important where the cargo must pass through CFS, warehouse storage, domestic delivery or airline acceptance in Japan. A cargo may be acceptable under one route or carrier but refused under another.

It is also important to distinguish transport classification from domestic storage classification. A dangerous goods class under transport rules does not automatically answer whether the cargo can be stored under Japan’s domestic fire safety or warehouse rules.

Key Takeaway

A dangerous goods class is a basic classification used to identify the type of hazard in dangerous goods transport.

For forwarders, the class should always be checked together with the UN number, proper shipping name, packing group, subsidiary risk, quantity, packaging, transport mode and carrier or warehouse conditions.

Correct confirmation of the dangerous goods class helps prevent booking delay, cargo receiving refusal, incorrect labelling, unsafe consolidation and shipment problems in sea or air transport.