14 minute practical guide
Dangerous Goods by Air: Classes, Documents and Acceptance
The nine hazard classes, what a shipper's declaration must contain, lithium battery provisions, why consignments are refused at acceptance, and where trained personnel are legally required.
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Choose your role and cargo scenario to see the core and conditional paperwork for a dangerous goods air shipment, and where each document comes from.
Build a DG document checklistWho this guide is for, and what it is not
Air transport of dangerous goods is governed by the ICAO Technical Instructions, implemented commercially through the IATA Dangerous Goods Regulations. Classification, packing, marking, labelling, quantity limits, documentation and acceptance are all regulated, and the regulations are revised annually.
This guide is orientation for people who work around dangerous goods shipments — export coordinators, forwarder operations, customer service — so they understand what is being asked for and why consignments get refused. It is not training, and it is not a substitute for the current regulations.
Anyone who classifies, packs, marks, labels, documents or accepts dangerous goods must hold current training. That is a legal requirement, not best practice, and a declaration signed by an untrained person is invalid regardless of how accurate its content is.
The nine hazard classes
| Class | Hazard | Common air cargo examples |
|---|---|---|
| 1 | Explosives | Fireworks, ammunition, airbag inflators, detonators |
| 2 | Gases — flammable, non-flammable and toxic | Aerosols, compressed oxygen, refrigerant gases, lighters |
| 3 | Flammable liquids | Paints, solvents, adhesives, perfumes, alcohol-based products |
| 4 | Flammable solids, spontaneously combustible, dangerous when wet | Matches, sulphur, sodium, some metal powders |
| 5 | Oxidising substances and organic peroxides | Hydrogen peroxide, pool chemicals, some fertilisers |
| 6 | Toxic and infectious substances | Pesticides, diagnostic specimens, biological samples |
| 7 | Radioactive material | Medical isotopes, industrial gauges |
| 8 | Corrosives | Acids, alkalis, wet cell batteries, some cleaning products |
| 9 | Miscellaneous dangerous goods | Lithium batteries, dry ice, magnetised material, environmentally hazardous substances |
Many everyday commercial products are dangerous goods. Perfume, nail polish, aerosols, paint, hand sanitiser, e-cigarettes and anything containing a lithium battery all fall within the regulations.
Lithium batteries
Lithium batteries are the most common dangerous goods in air cargo and the most frequently mis-shipped. They sit in Class 9 and are subdivided by chemistry and by whether they travel alone, packed with equipment, or installed in equipment — with a different UN number and a different packing instruction for each combination.
The provisions are detailed and change regularly. State of charge limits apply to some categories, quantity limits differ between passenger and cargo aircraft, some configurations are forbidden on passenger aircraft entirely, and specific marks and labels are required on the packages.
The practical risk is that shippers do not realise they are shipping dangerous goods at all. A consignment of power tools, laptops, toys, e-bikes or medical devices is a lithium battery shipment, and treating it as general cargo is both a regulatory breach and a genuine safety hazard — undeclared lithium batteries have caused aircraft fires.
- Different UN numbers apply to lithium ion and lithium metal, and to batteries alone, with equipment, or in equipment
- Packing instructions differ by category and specify the permitted quantities and packaging
- State of charge limits apply to some categories of cells and batteries shipped alone
- Some configurations are forbidden on passenger aircraft and travel Cargo Aircraft Only
- Damaged, defective or recalled batteries have their own — much stricter — provisions
- Batteries must be protected against short circuit and against movement within the packaging
- Package marks and labels are prescribed and are not interchangeable with general hazard labels
- Check the current edition of the regulations, since lithium provisions are revised frequently
The shipper's declaration
The Shipper's Declaration for Dangerous Goods is the document that accompanies most dangerous goods air shipments. It is completed and signed by a trained shipper, and it states — for each dangerous substance or article in the consignment — exactly what is being shipped and how it is packed.
- UN or ID number and the proper shipping name, which must correspond exactly
- Class or division, and any subsidiary risk
- Packing group where the entry requires one
- Quantity and type of packing, per package
- Packing instruction number applied
- Aircraft limitation — passenger and cargo aircraft, or cargo aircraft only
- Any authorisation or approval reference where one applies
- Additional handling information, including overpack and all-packed-in-one statements
- A monitored emergency contact telephone number
- The name, title, place, date and signature of the trained person making the declaration
Why consignments are refused at acceptance
Handling agents work through a formal acceptance checklist, item by item, and they refuse consignments for a narrow and predictable set of reasons. Almost all of them are documentary or preparation failures that a careful check before dispatch would have caught.
- Declaration unsigned, or missing the signatory's name, title, place or date
- Emergency contact number missing, or one that will not be answered throughout transport
- Proper shipping name that does not correspond to the UN number given
- Subsidiary risk omitted where the entry requires it
- Packing instruction inconsistent with the quantity or the packaging actually used
- Quantity exceeding the limit for the aircraft type indicated
- Packaging not UN specification, or specification packaging assembled incorrectly
- Marks and labels missing, wrong, obscured or applied to the wrong surface
- Air waybill not annotated to reference the dangerous goods declaration
- Aircraft limitation on the declaration inconsistent with the air waybill annotation
- Overpack used without the required overpack statement and markings
- State or operator variations not accounted for on the origin, transit or destination
State and operator variations
Beyond the base regulations, individual states and individual airlines publish their own additional restrictions. A substance perfectly acceptable under the regulations can be prohibited by the state of origin, the state of transit, the state of destination or the operating carrier — and those restrictions are not all in the same place.
Variations change regularly and apply to the specific routing rather than to the shipment in general. A consignment that moved without difficulty last month on a direct flight can be refused this month on a routing that transits a different country. Checking them is part of preparing the shipment, not a formality.
Preparing a shipment without surprises
- Establish whether the goods are dangerous goods before quoting, not before booking — the answer changes the price and the routing
- Confirm the classification with someone trained, using the current regulations edition
- Confirm the packing instruction and obtain the correct UN specification packaging
- Check state and operator variations for every leg of the intended routing
- Confirm quantity limits for the aircraft type the routing actually uses
- Have the declaration completed and signed by a trained person, with a monitored emergency contact
- Confirm the air waybill will be annotated and the aircraft limitation stated consistently
- Apply marks and labels to the packages before the truck arrives, not at the counter
- Allow more lead time than for general cargo — acceptance takes longer and refusal costs a flight
Put the guide into practice
Choose your role and cargo scenario to see the core and conditional paperwork for a dangerous goods air shipment, and where each document comes from.
Build a DG document checklistFrequently asked questions
Direct answers to the questions this topic raises most often in day-to-day operations.
What are the nine classes of dangerous goods?
Class 1 explosives, 2 gases, 3 flammable liquids, 4 flammable solids and related hazards, 5 oxidising substances and organic peroxides, 6 toxic and infectious substances, 7 radioactive material, 8 corrosives, and 9 miscellaneous dangerous goods including lithium batteries and dry ice.
Are lithium batteries dangerous goods?
Yes, in Class 9. They are the most common dangerous goods in air cargo and the most frequently mis-shipped, largely because shippers do not realise a consignment of power tools, laptops, e-bikes or medical devices is a battery shipment. Different UN numbers and packing instructions apply depending on chemistry and whether batteries travel alone, with equipment or installed in it.
Do I need training to ship dangerous goods by air?
Yes, and it is a legal requirement rather than best practice. Anyone who classifies, packs, marks, labels, documents or accepts dangerous goods must hold current training appropriate to their function. A declaration signed by an untrained person is invalid regardless of whether its content is correct.
What is a Shipper's Declaration for Dangerous Goods?
The document accompanying most dangerous goods air shipments, completed and signed by a trained shipper. For each substance it states the UN number, proper shipping name, class and subsidiary risk, packing group, quantity and type of packing, packing instruction and aircraft limitation, plus a monitored emergency contact and the signatory's details.
What does 'Cargo Aircraft Only' mean?
That the consignment may not travel on an aircraft carrying passengers. Some substances and some quantities are permitted only on freighters, and the limitation must appear consistently on the declaration, the air waybill and the package labelling. It constrains the routing, so it affects transit time and cost as well as compliance.
Why was my dangerous goods shipment refused?
Most commonly a documentary or preparation failure: an unsigned declaration, a missing emergency contact, a proper shipping name that does not match the UN number, a packing instruction inconsistent with the packaging used, missing or wrong labels, or an air waybill without the required annotation. Acceptance staff work a formal checklist and any single failure stops the consignment.
What are state and operator variations?
Additional restrictions published by individual states and individual airlines beyond the base regulations. They can prohibit substances that are otherwise acceptable or impose stricter limits, and they apply to the specific routing — origin, transit and destination. They change regularly, so they must be checked for each shipment rather than assumed from a previous one.
Can I ship aerosols or perfume by air?
Often yes, under the appropriate class and packing instruction, but they are dangerous goods and must be declared, packed, marked and documented as such. Treating them as general cargo because they are ordinary consumer products is one of the most common undeclared dangerous goods scenarios and it is a serious breach.
What is an overpack?
An enclosure used by a single shipper to contain one or more packages, forming one handling unit — for example several boxes shrink-wrapped to a pallet. Overpacks require a specific statement on the declaration and specific markings on the outside, including reproduction of the hazard labels of the packages inside if they are not visible.
How much lead time do dangerous goods shipments need?
More than general cargo. Classification and packing take time, correct packaging may need ordering, acceptance takes longer at the counter, and a refusal costs a flight rather than an hour. Build the preparation into the schedule at quotation stage rather than discovering the constraint on the day of departure.
Are the rules the same for sea freight?
No. Sea transport is governed by the IMDG Code, which has its own declaration format, packing provisions, segregation rules and documentation. The classification system is broadly shared, but the specific requirements, quantity limits and paperwork are not interchangeable between the two modes.
Can software check my dangerous goods paperwork?
It can check for presence, structure and consistency — signature present, emergency contact present, UN number well-formed, the declaration and air waybill agreeing on references and aircraft limitation. It cannot determine whether a classification or packing instruction is correct, which requires the current regulations and a trained assessor. Use it as a pre-check that makes specialist review faster, not as a substitute for it.
Related tools, templates and guides
- Dangerous goods declaration parserExtract declaration evidence into a structured, reviewable record.
- DG readiness pre-checkCatch missing and contradictory evidence before acceptance.
- Air cargo document checklistAssemble the full document set for a DG shipment.
- Air waybill parserCheck that the AWB carries the required DG annotation.
Research sources and further reading
Operational terms vary by carrier, contract and jurisdiction. These sources informed the guide; verify the current governing document for a live shipment.
- IATA — Dangerous Goods Regulations
The commercial implementation of the ICAO Technical Instructions, revised annually and used by airlines worldwide.
- ICAO — Technical Instructions for the Safe Transport of Dangerous Goods by Air
The underlying international standard for dangerous goods by air.