- The clear difference between labels and marks in dangerous goods transport.
- The information that must appear on a package under IATA and IMDG requirements.
- Technical requirements for label size, colour and placement, to avoid refusal of carriage.
- How compliant labelling and marking protects the supply chain and a company's reputation.
Why are labelling and marking so important?
In dangerous goods (DG) transport, labelling and marking are far more than an administrative formality. They are the international language that lets warehouse staff, flight crews and emergency responders quickly recognise the hazards of a shipment. In practice, quite a few consignments are held up at airports or seaports simply because a label is faded, the wrong size or in the wrong position. Compliance is not only what gets cargo cleared quickly; it is also the shipper's legal responsibility for the safety of people and the means of transport.
Labels versus marks
Many companies confuse these two concepts, which leads to missing information on packages. VPL summarises the basic difference as follows:
- Label: Usually a diamond-shaped pictogram indicating the hazard class of the goods. For example, a flame label for flammable goods or a skull label for toxic goods. There are also handling labels, such as package orientation labels and labels for cargo-aircraft-only shipments.
- Mark: Usually text and numbers that identify the specific shipment, for example the UN number, the Proper Shipping Name, and the name and address of the shipper and consignee.
Mandatory markings on the package
Under the current IATA DGR (air) and IMDG Code (sea), every dangerous goods package presented for transport must carry the following markings:
| Information | Details |
|---|---|
| UN number | A four-digit number assigned by the United Nations, preceded by the letters "UN" (for example, UN 1263). |
| Proper Shipping Name (PSN) | The technical name of the goods as listed in the dangerous goods list. |
| Shipper and consignee details | The full name and address of the shipper and consignee must be clearly shown on the package. |
| Weight/volume | For certain types of goods, the net quantity or gross weight must be shown. |
In addition, specialised packagings must bear UN specification markings on the outer packaging, certifying that the packaging has passed testing for strength, pressure and leakproofness.
Common types of labels
Labels fall into two main types that shippers should be aware of:
1. Hazard labels
Each of the 9 classes of dangerous goods has its own characteristic label. The label must be diamond-shaped, with a standard minimum size of 100 mm x 100 mm. If the package is too small, the label may be reduced in size, but the graphics and text must remain clear. If the goods present more than one hazard (for example, both flammable and toxic), the package must carry both the primary hazard label and the subsidiary hazard label.
2. Handling labels
These labels give instructions on how to handle the package during transport:
- Orientation arrows: Two arrows pointing upward, mandatory on packages containing liquids.
- "Cargo Aircraft Only" (CAO) label: For cargo aircraft only, applied when the goods are forbidden on passenger aircraft.
- Lithium battery label: Specifically for shipments containing lithium batteries under the relevant provisions.
Correct label specifications and placement
Incorrect labelling can lead aviation security or port authorities to refuse the cargo. We recommend that companies follow these principles:
- Durability: Labels and marks must be printed or affixed securely so they do not peel off under weather (rain, sun) or the impact of handling. Text must contrast with the background colour of the package.
- Position: They must be placed on the outside of the package, on a surface of contrasting colour. Do not place labels on corners and edges or where strapping would obscure them. Hazard labels and the UN number/PSN marks should be close together on the same side of the package.
- Cleanliness: If packaging is reused, remove old labels and unrelated old marks. This is critical to avoid confusing the people handling the cargo.
Practical experience from Viet Power Logistics
At VPL, we understand that labelling rules can change and become complicated for particular goods. A small mistake, such as omitting "UN" before the number, or using a reduced-size label on a package large enough for a 100 x 100 mm label, can lead to the shipment being returned, which brings storage costs and disrupts the shipper's business plans.
Beyond transport services, VPL can help customers check and advise on labelling and marking in line with IATA DGR and the IMDG Code before cargo leaves the warehouse. We help companies optimise their packing process so that every package is ready to pass the strictest checks by airlines and shipping lines. Contact VPL for support with each specific shipment.
This article is for general information and was compiled by VPL from public sources at the time of publication. Regulations may change – please contact VPL for advice on your specific shipment.